Category Something New Under the Sun

There was so much material for this section that the only way to make sense of it was to put it all together into one big pot, to arrange it chronologically, and to construct a series of calendars for the years in which I was interested. I also put the dates of major importance for world events and other developments in the space program on the same calen­dars. This gave me a good feel for what was happening when, and high­lighted some nice ironies between the Telstar and Syncom programs that I would otherwise have missed.

Primary source material came from AT&T, the Hughes Aircraft Com­pany, John Rubel, Bob Roney, the NAS, NASA, and the American Her­itage Center.

Interviewees were John Pierce, Harold Rosen, Tom Hudspeth, Bob Roney, Robert Davis.

AT&T’s highly professional archive yielded masses of information about Telstar and some, though to a lesser extent, about Echo.

The НАС archives give a good sense of the work that Harold Rosen and Don Williams et al. did, as well as demonstrating the company’s internal wrangles and its lobbying of NASA and the DoD.

Bob Roney had personal papers that supplemented the more extensive records from the НАС archive.

John Rubel’s papers cover the ground from the perspective of the Office of Defense Research & Engineering. The view from this office is not always the same as that from other departments of the DoD.

NASA’s records (thanks once again to David Whalen for these) gave, not surprisingly, the agency’s side of the story

I had more material from AT&T and the НАС and John Rubel than from NASA, so the story unfolds primarily from their perspective, though I have tried to synthesize different policy and technical viewpoints.

Chapter sixteen: The Players

TAT-1 capacity (page 171) from Signals, The Science of Telecommunication, by John Pierce and Michael Noll. Scientific American Library (1990).

The Space Station (page 172), Its Radio Applications, by Arthur C. Clarke, 25 May 1945 (typed manuscript).

“Extra-Terrestrial Relays, Can Rocket Stations Give World-Wide Radio Coverage,” by Arthur C. Clarke, published in Wireless World, October 1945 (page 172) (From John Pierce).

“Orbital Radio Relays,” by J. R. Pierce, Jet Propulsion, April 1955 (pages 172-173).

Pierce’s views of Rudi Kompfner, medium-altitude satellites, and Harold Rosen (pages 174—175) from interviews with Pierce, his oral history at Caltech, memos, and his autobiography (see notes for chapter 17).

Damn, I’m going to wrangle a place on that project.

—Harold Black, Transit team member, on hearing of Guier and Weiffen – bach’s work on orbital determination and prediction at the end of 1957

n November 8, 1957, Ralph Gibson dipped into the director’s dis­cretionary fund for $20,000 to fund Project D-54—to determine a satellite orbit from Doppler data, and he assigned technical and engineer­ing support to Guier and Weiffenbach.

Shortly afterwards, Guier and Weiffenbach briefed their colleagues in the research center, some of whom would later play an important part in the development of Transit. One, Harold Black, was bowled over. Guier had explained methods and coordinate systems that were on the edge of his understanding, and Black knew that he wanted to be a part of the work. He would be, but not for a few more months. Not until the Transit program was underway.

In the closing months of 1957, Guier and Weiffenbach were tackling the problem of the ionosphere—the region of the earth’s upper atmo­sphere where solar energy separates electrons from atoms and molecules, creating layers of free electrons that reflect or refract radio waves. Reflected waves pass round the curve of the Earth and carry transmissions from, say, Voice of America, or provide medium – and high-frequency channels for voice communication. Higher frequencies pass through the ionosphere, enabling communication between the ground and a satellite.

On passage through the ionosphere, radio waves interact with the free electrons, and the frequency of a signal received on Earth from a satel­lite appears different from the frequency transmitted by the satellite. This muddies the water if you are trying to relate the Doppler shift to the satel­lite’s motion. There is a qualitative explanation that gives a rough idea of what is happening.

Radio waves are, of course, examples of electromagnetic radiation. Sputnik’s oscillator was creating an electric field (with its associated mag­
netic field), and the influence of the field extended through space. The field’s influence set the free electrons of the ionosphere oscillating with the same frequency as the field. The oscillating electrons set up their own elec­tromagnetic fields, which, in turn, extended their influence out through space. The fields from Sputnik’s oscillator and from the free electrons were of the same frequency but were not exactly in step. They overlapped. If one returns to the wave analogy of electromagnetic radiation, it as though the crests of the waves from the field generated by the free electrons occurred at a slightly different time than the crests of the waves from the satellite oscillator’s field. So a receiver on Earth detected more wave crests over a given time than it would if the ionosphere were to conveniently disappear (convenient at least for this application).

The Doppler shift (received minus transmitted frequency) is related to the range rate, that is, to the way the satellite’s position with respect to the lab was changing. So when the received frequency was altered by the presence of the ionosphere, the satellite’s path appeared to be different from what it actually was.

How could the receiver distinguish between the number of crests received in a given time as a result of ionospheric refraction as distinct from the number of crests detected because of the Doppler shift?

It couldn’t. And because Sputnik I generated only one frequency, there wasn’t much that Guier and Weiffenbach could then do by judi­ciously juggling theory and observation. Fortunately, the Soviets launched Sputnik II, and Weiffenbach started recording both frequencies. By com­paring the two signals received, and knowing, from theory, that the iono­spheric effect was roughly inversely proportional to the square of the transmitter frequency, they were able to calculate the amount by which the ionosphere altered the received frequency. They were able, therefore, to remove the effects of the ionosphere from their experimental data. Once Guier and Weiffenbach corrected for ionospheric refraction, the frequen­cies computed were those due to the satellite’s motion and not to passage through the ionosphere. Needless to say, this again sounds far simpler than it was, and considerable effort subsequently went into theoretical and experimental explorations of the ionosphere’s nature.

Fortunately, the IGY was generating new observations of the iono­sphere. Of particular importance for greater theoretical understanding were the Naval Research Laboratory’s data showing that the then existing simplified description of the ionosphere was less complete than had been thought previously. The nonuniform electron density through a cross sec­tion of the ionosphere raised concerns at APL that more than two fre­quencies would be needed to correct for ionospheric refraction with suffi­cient accuracy Guier’s and Weiffenbach’s work with Sputnik II did not settle this question.

Another potential complication was that electron density, which influences the amount of refraction, varies with the amount of energy the sun is pouring onto the earth. There are, for example, more free electrons at noon than at night, and the density varies according to the latitude, the time of year, and the stage of the solar cycle.

Thus in November 1957, the ionosphere was the first quagmire that Guier and Weiffenbach encountered as they analyzed their Doppler data. Their experience led them to conclude in the first Transit proposal, erro­neously as it turned out, that the ionosphere would be the biggest obstacle to developing a navigation system.

Once the Transit program was underway, Weiffenbach and then Guier and then others tackled the ionospheric physics in greater detail and with more sophistication than in Guier and Weiffenbach’s initial paper in April 1958, entitled Theoretical Analysis of the Doppler Radio Signals from Earth Satellites.

Weiffenbach went back to basics, studying Maxwell’s equations describing the behavior of electromagnetic waves as well as the equations that provide a theoretical and simplified description of the ionosphere. He collected much of the published data and satisfied himself that theory and experiment seemed to be in synch. Weiffenbach’s aim was to find the opti­mum frequency for Transit given the constraints that physics and current or foreseeable technology imposed. Ideally, the highest possible value should be chosen, but electronic components of the day did not work at the higher frequencies. Such juggling of theory and practicality was an essential aspect of determining the early specifications for Transit, and it focused the minds of many other satellite designers.

By the end of 1958, Weiffenbach had concluded that two frequencies should do the job. The analysis he submitted to Richard Kershner, the team leader, warned that only experiment would clarify the situation, and the first experimental Transit satellite was aimed at doing just that.

Guier’s later basic theoretical analysis, bolstered by results from early experimental satellites and discussions with Weiffenbach, showed that for Transit’s purposes, physical phenomena such as the irregularity of electron density could be ignored, and that two frequencies provided an accurate enough correction for ionospheric refraction.

Shortly after the first Transit proposal was written in April 1958, they realized that the earth’s magnetic field would also affect passage of radio waves through the ionosphere. Therefore, Weiffenbach, who became responsible for space physics and instrumentation at APL, recommended circularly polarized transmitters. Such transmitters were not unusual, but Henry Riblet, who went on to head space physics and instrumentation at the lab, had to modify existing designs so that they would be suitable for the spherical surface of Transit. Having chosen circular polarization, Tran­sit’s designers were constrained in their approach to stabilizing the satellite in orbit. Thus the physics affects the technology and each technological decision affects others.

As 1957 drew to a close, Guier, later responsible for space analysis and computation, was refining the mathematical model. Weiffenbach was gath­ering data and improving the experimental setup, and together they con­tinued to explore what the model could tell them about orbits. In the meantime they were reading madly, educating themselves in ionospheric physics and orbital mechanics.

Around this time they met someone who was to become their “good angel.” His name was John O’Keefe, and he was working with the Van­guard tracking team, was in fact at the radio tracking station near Washing­ton D. C. on the morning after the launch of Sputnik I.

O’Keefe, who was to become a pioneer of satellite geodesy, had stud­ied the moon’s motion in search of clues to the nature of the earth’s gravi­tational field and had eagerly anticipated the launch of satellites. For the previous year, in preparation for the space age, he had studied orbital mechanics every morning before going to work. He was devastated when the Soviets launched first.

O’Keefe, whose son heard Sputnik’s Doppler shift on a ham radio set, was intrigued when he learned of the quality of Guier’s and Weiffenbach’s Doppler data. He went to APL to take a look and was impressed. When Guier and Weiffenbach determined Sputnik’s orbit, O’Keefe was astounded; he didn’t think they would be able to get that much informa­tion from the data.

Yet there was actually even more in the data. Later, the same curve­fitting technique enabled them to vary values for ionospheric refraction and thus to find indices of refraction in addition to transmitter frequency and the orbital parameters.

O’Keefe tweaked Guier and Weiffenbach about their lack of knowl­edge of the ionosphere and pointed out, too, that the Earth’s gravitational field would turn out to be far more complicated than people yet realized. He brought much humor and knowledge of physics to their relationship.

As a regular attendee at IGY meetings, O’Keefe was up-to-date on emerging results. In the following year, he would analyze observations of Vanguard i, known as “the grapefruit,’’ and he recognized that for the satel­lite to be in the observed orbit, the Earth must be pear-shaped in addition to being oblate. The southern hemisphere, in effect, is larger than the northern hemisphere.

The pear-shaped term for the Earth eventually became the second brush stroke on the canvas of that very simple mathematical model that Guier had initially constructed for his and Weiffenbach’s research during the autumn of 1957. And when the gravitational consequences of the pear-shaped earth were folded into the model, the fit between theoretical and experimental curves improved yet again, reducing the error of the orbital determination and prediction.

Immediately after the launch of Sputnik I, O’Keefe had very little data to work with. Hence his fascination with Guier’s and Weiffenbach’s Doppler curves. He invited them “downtown” to Washington D. C. to meet the Vanguard’s Minitrack team. At the time the Minitrack group was inundated. Calls were coming in from many people whom they really didn’t want to talk to. Guier and Weiffenbach fell into the category of nui­sance, and to their chagrin, the Minitrack people dismissed them and their work. The rebuff rankled. Weiffenbach recalls thinking, “OK, we’ll show you; you will take notice.”

Throughout the early part of 1958, Guier and Weiffenbach focused on improving orbital determination. By early spring, they thought they had the satellite’s position to within two or three miles, and they began writing their key paper on the theoretical analysis of Doppler data. But what next?

It was their boss, Frank “Mack” McClure, head of the lab’s research center, who took the next step. McClure seems to have been a compli­cated character. Various descriptions crop up from those who knew him: smart as hell; prone to terrific rows; blunt; impatient; enormous ego (I doubt this was a unique characteristic); someone who “didn’t fool himself about himself” recalls Weiffenbach. Certainly he seems to have impressed the research center’s scientists with the breadth and depth of his knowl­edge of physics.

At this time McClure’s main interest was in solving the problem of insta­bilities in the burning of fuel in solid-fuel rockets, one of the critical technolo­gies for the Polaris missiles. Hence he was spending a lot of time at Special Pro­jects, as was the man who became the Transit team leader—Richard Kershner.

On Monday, March 17,1958, Frank McClure called Guier and Weif­fenbach to his office. He told them to close the door; a clue, they knew, that something interesting or classified would be said. McClure asked them, Can you really do what you say you can? In the manner of the best courtroom attorneys, McClure was asking a question to which he was sure he already knew the answer. Guier and Weiffenbach did not know this, but they answered yes.

In that case, McClure told them, if you can determine a satellite’s orbit by analyzing Doppler data received at a known position on the earth, it should be possible to determine position at sea by receiving Doppler data from a satellite in a known orbit. The navigation problem, in fact, would be easier, argued McClure, because only two values—latitude and longitude—would have to be determined.

McClure sketched out the concept. The satellite would transmit two continuous waves, which would allow a receiving station on a submarine to record two Doppler curves and to correct for ionospheric effects. The satellite would also broadcast its position at the time of the transmission.

The submarine’s inertial guidance system could then provide an esti­mated value of latitude and longitude. A computer program would gener­ate the Doppler curves that a submarine at that estimated location would receive from a satellite at a known position. It would then continue to generate Doppler curves that would be received at nearby values of lati­tude and longitude. When a best fit was found between the estimated and received Doppler curves, those values of latitude and longitude would be the latitude and longitude of the submarine.

Thus the method that Guier and Weiffenbach had developed would be used in two ways. First, to find a satellite’s orbit by observing it from ground stations at well-determined locations, allowing a prediction of its position. The positions for the next twelve hours would then be uploaded

From left to right:William H. Guier, FrankT McClure and George C. Weiffenbach. Drs. Guier and Weiffenbach first employed Doppler tracking to determine the orbits of satellites when tracking Sputnik. Dr McClure used this principle as a basis for inventing a worldwide navigation system. Courtesy of Applied Physics Laboratory.

twice a day. Second, the same computational and statistical techniques would provide a means of fixing latitude and longitude.

McClure asked them what they thought. They agreed that it sounded plausible. Go away, McClure told them, and do an error analysis.

They did. After the computer simulations they had been working with, simulating the errors in the navigation scheme proposed by McClure was, they say, next to trivial. They looked at the answers and didn’t believe them. They seemed too good. They wondered whether they had left something out, but they knew that they had not. So they increased the errors in the assumed depth and speeds of the submarines as well as several other parameters. Then they went back and told McClure that it would work, and work beautifully.

McClure smiled and said, “I know.”

McClure told Guier that he had had the idea the weekend before and had called Richard Kershner. The two of them, who frequently spent time together away from the lab, had fleshed out the idea over the week­end. They had concluded that the navigation method would work if Guier and Weiffenbach could do what they said they could.

On the day after his meeting with Guier and Weiffenbach, McClure sent a memo to Gibson, APL’s director. The topic was “satellite Doppler as a means of ship navigation.” McClure suggested that APL’s patent group should consider seeking protection for the idea. He pointed out that “While the possible importance of this system to the Polaris weapons sys­tem is clear… an extension of thinking in regard to peacetime use is to me quite exciting.” Other advantages did not escape him, and he added that the establishment of such a system “ … might provide a wonderful cold war opportunity…. This would put the U. S. in the position of being the first nation to offer worldwide service through its venture into outer space.” Work on a technical proposal began immediately.

Developing specifications for a complex engineering system is like plan­ning an elaborate meal without reference to recipes, knowing only what combinations are most likely to work, what fresh produce is likely to be available, and making last-minute adjustments for what is not. The occa­sion for the meal guides the process. First there is the overall plan of suit­able and compatible courses. Then comes the detail, working out all of the recipes, testing quantities, temperatures, cooking times.

McClure defined the occasion and made clear what the “diners” would swallow. He knew the technical needs of Polaris in detail, but of equal importance was his sense of the technological likes and dislikes of Special Projects. If he thought Special Projects wouldn’t like a particular technical approach, he would point that out.

Several factors, therefore, converged to ensure that the Transit pro­posal would win the backing that it did in the face of opposing schemes that were emerging for satellite-based navigation. First, APL was present­ing a good idea and had some smart people able to see it through from theoretical analysis to engineering application. Second, the lab had an acknowledged history of completing complex and difficult applied physics and engineering projects, starting with the proximity fuse. (The Naval Research Laboratory’s experience with Vanguard after the success of Vi­king, however, showed that previous success is not always a harbinger of future triumphs.) Neither factor would have been enough alone, but Tran­sit would clearly have been dead in the water without the lab’s expertise and reputation. Additionally, of the emerging ideas for satellite navigation, Transit met the needs of Special Projects and, because of the Brickbat-01 status of Polaris, was compatible with national priorities.

Of the competing schemes, one, taking angles to emitting radio waves was impossible because the antennas needed would have been far too large for submarines. Even had the antennas been usable by the surface fleet, the scheme would not have been serious competition for Transit because the surface fleet was not expressing a strong desire for improved position fixing, nor had its missions the same high priority as those of Spe­cial Projects.

Another scheme, radar ranging, might have met the needs of the U. S. Air Force, but although Air Force missions did have a high priority and the Air Force had proven in its ten years of existence to be highly success­ful at lobbying the government, the preferred scheme within the Depart­ment of Defense at that time was to develop inertial guidance for aircraft. Since aircraft are not aloft for months at a time, the errors do not have as long to accumulate as they do during a submarine’s tour of duty. (Radar ranging resurfaced as the technical basis for the GPS satellites, which have replaced Transit.)

Also operating in APL’s favor was the lab’s relationship, as the consul­tant assessing the Polaris weapons system overall, with Special Projects. The organizational relationship was bolstered by professional relationships at all levels and by McClure’s political astuteness in making his inside knowledge of Special Projects work to further the technical acceptability of the Transit proposal. In short, the people who proposed Transit were the right people, in the right place, at the right time, and with the political and scientific smarts to see it through.

There was another influential factor, and that was Richard Kershner’s reputation. Kershner’s approach to technical problems was similar to that taken by Captain Levering Smith, then technical director of Special Proj­ects. Commander “Chuck” Pollow, who assisted in the day-to-day man­agement of Transit, is convinced that the perception that Special Projects and Smith had of Kershner was critical to Transit’s initial acceptance. And the Transit team members are convinced that Kershner was critical to the success of Transit.

A flavor of the times described in this chapter comes from my interviews with William Pickering, Milton Rosen (technical director of Project Van­guard), John Townsend, and Herbert Friedman (of the Naval Research Laboratory and a member of the USNC).

When the Soviet embassy’s party began (page 21) on the evening of October 4, 1957, did Anatoli Blagonravov know that Sputnik had been launched? William Pickering thinks not. John Townsend doesn’t know, but he says that Homer Newell (scientific program coordinator for Pro­ject Vanguard), who was with them, was convinced that Blagonravov did know.

My physical description of Blagonravov comes from reports in the New York Times during the week of the conference (page 22). I’m guessing that he drank vodka.

Management of Advent (March 1961): including TAB F—Memorandum from the Acting Secretary of Defense of the Army and the Secretary of the Air Force, subject, Program Management of Advent (15 September, 1960); and TAB G—Recommended Action: Memo for Signature of Sec­retary of Defense.

The problems in the Advent program were spelled out by, among others, Harold Brown, DDR&E, on May 22, 1962, in a memo for the secretary of defense, Robert McNamara. In an appendix, Brown states categorically that the contractors management of Advent (General Electric) was poor. He also wrote, “During 1961 and until February 28, 1962, USAAMA (Army Advent Management Agency) decided to gamble on the contrac­tors to realize first a March and then a June firing date. The rate of expenditures rose to twice the amount allowable on the basis of available funds and the whole project went out of balance; training, ground equip­ment and operational control rooms were fully engineered before the spaceborne equipment was out of the breadboard stage; schedules were manipulated to a point where the completion date of the first flight arti­cle was set ahead of the engineering test model” (John Rubel’s papers).

Memorandum for John H. Rubel, Deputy Director of Defense Research & Engineering, from Ralph L. Clark, Assistant Director for Communica­tions, dated January 17, I960. A number of policy documents on commu­nication satellites are attached. These are: Briefing paper for Mr. Gates, subject: Cabinet paper CP60-112—Communication Satellite Develop­ment, December 19, 1960; Draft policy presented by ODRE to the unmanned spacecraft panel of the AACB; Summary of Cabinet Paper CP60-112/1, December 23, 1960; Briefing paper by Clark and Nadler setting out their concerns with the Cabinet Paper; draft of a policy state­ment prepared by the service secretaries summarizing the DoD’s role and interest in communication satellites (John Rubel’s papers).

Memorandum for Members of the Unmanned Spacecraft Panel: State­ment of NASA Program Philosophy on Communication Satellites. November 21, 1960 (НАС archives).

The NASA Communication Satellite Program, February 9, 1961 (John Rubels papers).

“United States Policy Toward Satellite-Based Telecommunications,” cir­culated among a small group by John Rubel in April 1961 (John Rubel’s papers).

Informal Notes of the Interim Steering Committee for Satellite-Based Telecommunications Policy, second meeting, held in the Pentagon, 11 May, 1961. Appendix В was:“DoD Position on what Technical Charac-

teristics and Capabilities DoD Desires from a Commercially Operable Satellite-Based Telecommunication System”. Appendix C: Industry – Department of Defense Cooperation in Satellite-Based Telecommunica­tions (John Rubel’s papers).

A memorandum dated September 6, 1960, records a meeting at AT&T’s headquarters on that day. The meeting discussed a request from NASA for information about Bell System’s plans for satellite communication and research. Memo gives AT&T’s policy views. The views were laid out in a letter of September 9 to T. Keith Glennan, which said that satellites should be operated by commercial companies, not government, and that enough information existed from Echo 1 for Bell to want to proceed immediately to work on active repeaters. (Box 85080203, AT&T archives).

AT&T was clearly fighting for a comprehensive role in satellite commu­nication, as numerous documents in AT&T’s and NASA’s records show. For example; on March 10, 1961, Jim Fisk, head of BTL, sent a letter to Richard S. Morse, assistant secretary of the Army, expanding on an infor­mal proposal sent by Bell to Morse on March 3. Even though the letter refers to Bell’s ideas for an experimental, not operational, program, the proposal’s completeness, with all the control that it would have ceded to AT&T, might reasonably have raised concerns in government over the extent of the control that the monopolistic AT&T would yield over something as vital as international communications.

Fisk wrote, “Bell Systems’ interest is simply stated: communication satellites promise a natural extension of the present microwave common – carrier networks and a natural supplement to present overseas radio and cable circuits.”

Specifically, Fisk proposed that Bell should design, construct, and pay for the fixed ground stations in the U. S.; arrange for foreign ground sta­tions with overseas common carrier partners; design, construct and pay for repeaters, providing frequencies for specific military uses as well as common carrier uses; accommodate the experimental requirements of the other common carriers on terms mutually agreeable; provide systems engineering assistance to the Department of Defense from the develop­ment of transportable or mobile ground terminals; provide systems engi­neering assistance to the Department of Defense to adapt the low-orbit satellite repeaters into synchronous orbit repeaters when the orbiting, ori­entation, stabilization and station keeping problems of that satellite are solved; cooperate with the Department of Defense in the initial launch operation, and share the costs of launching, as may be agreed; work with other Department of Defense contractors on portions of the program of primary military interest to insure efficient planning and to insure system compatibility.

The tensions between NASA and AT&T at both policy and technical levels are also well documented. A letter from Fred Kappel, the presi­dent of AT&T, to James Webb, the administrator of NASA, written on April 5, 1961, says, “It has come to my attention that an article that The Wall Street Journal carries… that NASA has yet to receive any firm pro­posal from any company.” Kappel goes on to write, “In view of the events which have taken place during the past few months, this state­ment… is of deep concern to me. The specific events to which I refer are as follow.” Over four pages, Kappel itemizes approaches made by AT&T to NASA (George Washington University, passed to me by David Whalen).

The Department of Justice’s concerns about the antitrust implications of AT&T’s plans for an operational communication satellite system are men­tioned in various places. One source is a memo for Alan Shapley from James Webb, NASA administrator, dated August 12, 1966. In this memo Webb also makes the point that the RCA proposal (Relay) was clearly the best for the “experimental and research requirements of NASA, although not necessarily the best for the first step toward an operational communi­cation satellite as desired by AT&T” (NASA History Office).

A memorandum for the record by Robert Nunn of December 23, 1960, describes a meeting between himself; John Johnson, NASA’s special coun­cil; and Attorney General Roberts. They were discussing a paper on com­munication policy to be submitted to the White House. December 1960 was, of course, the eve of the Kennedy administration. The policy ques­tion at stake was private or public promotion of communication satellites. All acknowledged that AT&T might be the only company capable of owning and operating an operational system of communications satellites. Roberts said, “Whatever we do, we cannot act as though NASA is putting AT&T into a preemptive position…” And he said,“. . . we cannot assume. . . that when all is said and done AT&T will emerge owning and operat­ing a system. . .Nunn explained/4 … the feeling in the White House apparently favors taking a position on principle which the succeeding administration will be obliged to overturn if it does not concur. Rogers said that this was unrealistic. Their aim was to find a way of supporting the White House’s stance in favor of the private sector without “seeking to nail down the conclusion concerning what the government will or will not do in future.”

A memorandum for the special assistant to the administrator at this time spells out AT&T’s dominance of international communication. The voice segment (cable and radio) was operated exclusively by AT&T. Some nine­teen companies competed for telegraph traffic (NASA History Office).

A number of policy documents and internal ODR&E memos point out that the solar minimum of 1964 to 1966 would reduce radio communica­tion circuits by up to two-thirds. These include a letter from Jerome Wiesner, who wrote on July 7, 1961, to Robert McNamara urging him to give his personal attention to the strengthening of the Defense Com­munications Agency.

The cooperation between NASA and the DoD with respect to which organization would develop which satellites (at least at the highest levels) is apparent in a letter from James Webb to Robert McNamara, secretary of defense. On June 1, 1961, Webb wrote, “I also wish to take this oppor­tunity again to make clear my firm intent that you are kept informed of activities concerning communication satellites and that your views and interests are kept in mind at all times.” At lower levels, and even within the separate organizations, relationships were not always so open. A memo from James Webb to Hugh Dryden, dated June 16, 1961, says, “I think it important that we not ever indicate that some of our military friends, par­ticularly those down the line in the services, may not have had full access to all the information, documents, and so forth relating to the kind of decisions that Mr. McNamara, Mr. Gilpatric, and I have made on the big program” (David Whalen from NASA History Office).

The issue being discussed at this time was NASA’s involvement in synchronous altitude, or 24-hour; communication satellites. The succeeding agreements that NASA and the DoD had, first that NASA should develop only passive satellites and then that it develop only medium-altitude satellites was explained to me by John Rubel.

Letter from James Webb, NASA administrator, to the director of the Bureau of the Budget, dated March 13, 1961. On communication satel­lites, Webb wrote, “This proposal specifically contemplates that this Administration should reverse the Eisenhower policy under which $10 million of the NASA active communication satellite program would be financed by private industry In my view this would not be in the public interest at this stage in a highly experimental research and development program” (David Whalen, NASA History Office).

A memorandum, dated April 28, 1961, for John A. Johnson, NASA gen­eral council, from James Webb, on the subject of a letter to Fred Kappel, president of AT&T, gives Webb’s view that government should not reach a hasty decision about its policy on experimental programs, such as com­munication satellites, without thoroughly considering all possible interest groups (David Whalen from the NASA History Office).

Memorandum for the associate administrator, dated May 16, 1961, con­cerning expansion of the active communication satellite program, by Robert Nunn. The memo discusses the policy issues and the public ver­sus private development of operational communication satellites.

Summary of the Comsat Bill:

Comsat stock was issued on June 2, 1964. There were ten million shares at $20 per share. The net proceeds to Comsat were $196 million. Half the capital was raised from individuals and half from 150 communications companies.

You have to give yourself a chance to get lucky.

There’s plenty of time, if we work hard enough.

—Richard Kershner, Transit project leader

f people leave a legacy in the eyes and voices of those who knew them well, then Richard Kershner should rest easy Kershner led the Tran­sit team with an authority bestowed willingly by those who worked for him.

He instituted a policy of “cradle to grave” engineering, which means that the person who designs a particular component also has responsibility for testing it. This was not (and is not) a common practice, but Transit team members perceive it as having been critical to the project’s success. Kershner eschewed line management as much as possible. If he had a ques­tion about a particular component, he would go directly to the person building that component rather than the department head. The policy was applied widely. Someone working for Guier, for example, could and would go around Guier if he thought an issue would be discussed more profitably with someone else.

There were the inevitable personality conflicts and disagreements. Yet a widely held memory among the Transit team is that the optimum technical solution determined the outcome of an argument, not an indi­vidual’s position in the hierarchy. All recall that Kershner was the final arbiter. He would tell them, “you together have n votes, and I have n plus one votes.” Yet his decisions seem to have been accepted because of his character, not because of the authority vested in his position. His most admired characteristic was his acceptance of responsibility when things went wrong, and over the years many things did go wrong in the Transit program. Kershner would say that whoever did not like what had hap­pened would have to deal with him first. More than thirty-five years after the project started and fourteen years after Richard Kershner’s death, the Transit team’s respect is still palpable.

One can look for the reasons among articles Kershner wrote about management practice. They are as dry and irrelevant as, I suspect, most for­mulas for successful management. Perhaps they could not be applied by
someone other than himself; he seems to have had a natural tact and respect for his staff that won him great loyalty.

Immediately after McClure had explained his idea for satellite navi­gation, Kershner was brought in to help put together a proposal. He was joined by Guier, Weiffenbach, and Bob Newton, a reticent, elegant An­glophile. During Transit’s development, Newton was to contribute to nearly all areas of the physics. In future years, these four would commemo­rate their early collaboration by celebrating the anniversary of the first suc­cessful Transit launch.

Their initial proposal was completed by April 4, 1958. It was marked “confidential,” a low level of classification. Submarines were mentioned only in passing, even though Polaris provided the impetus for the proposal. Informal discussions about navigation for Polaris must have been going on at high levels of APL and the Pentagon.

During the next few years, details of the proposal would change. The ionosphere, for example, deemed at this time to be the biggest problem, was soon supplanted in importance by the need to understand the earth’s gravitational field. Nevertheless, a surprising amount of the original pro­posal was to remain.

For the first draft, Guier tackled computing, Newton dealt with the satellite’s motion, and Weiffenbach took on the ionosphere and assessment of error—frequency drift, for example. Kershner worked on the overall system design. After the first draft, they all worked on all sections, cri­tiquing and revising, guided by McClure’s intimate knowledge of what Special Projects wanted and would accept.

A worldwide “satellite Doppler navigation system” for all weather was possible, argued the proposal, because of the recent developments showing that it was technically feasible to establish artificial satellites in predetermined orbits with lifetimes measured in years. A position fix with a CEP (circular error probable—a circle of radius within which there is a 50% probability of finding an object) of half a nautical mile should be pos­sible immediately. CEPs of one-tenth of a nautical mile, about six hundred feet, were likely in the near future, and such accuracies, stated the proposal, were greater than those of any known military requirements. Transit team members say that the first operational satellite launched at the end of 1963 achieved a CEP of one-tenth of a mile. Even though there were still prob­lems to be solved, this was an impressive feat.

An alternative approach to navigation, involving further develop­ment of a coastal radio ranging system called Loran, would also have been accurate, but only when the submarines were within range of its signal. Loran, says a former British liaison officer to Special Projects, would have been too limiting for Polaris.

A particular strength, the proposal pointed out, was the passive nature of the proposed navigation system, which would not betray a submarine’s position. The submarine would need only to approach the surface and to deploy its antenna at night for about eight minutes.

Various approaches to calculating latitude and longitude were out­lined. One involved our old friend “miss distance,” that is, the range at closest approach. Given the miss distance, one could plot a line on a map representing positions for which the submarine might be at the corre­sponding range from the satellite. If this process were repeated for signals from two satellites, the latitude and longitude would be the place where the lines of position intersected. Conceptually, this was an approach famil­iar to navigators.

APL, of course, was not trying to persuade anyone that relying on miss distance was a good approach, and the proposal went on to describe in general terms the computational and statistical techniques developed by Guier and Weiffenbach during their research into orbital determination and to say that these would be applied for position fixing. The greater accuracy attainable by comparing the curves of the theoretically generated and received Doppler signals at many points was pointed out. They needed to make this argument explicitly because many opponents at the time, recalls Guier, though that the method was “out in left field.”

To recap, the Transit proposal was essentially this: A satellite in a known position would broadcast two continuous waves. A comparison of the two signals would allow the submarine’s computer to eliminate the effects of ionospheric refraction. That same computer would then generate—for dif­ferent latitudes and longitudes—the Doppler curves that the submarine would receive from a satellite in that position. The inertial navigation unit would provide an initial estimate of position to the computer, which would run through a number of iterations until it found the latitude and longitude that generated the Doppler curve that best fitted that received from the satellite. These values of latitude and longitude would then be fed to the inertial navigation system to automatically correct its output.

The system, which was yet to be named Transit, was explained through the example of a satellite in a polar orbit at an altitude of four hundred miles. Such a satellite takes ninety-six minutes to complete one orbit. During these ninety-six minutes, the earth turns through about twenty-four degrees of longitude. The point immediately below the satellite—the sub­satellite point—moves westward by an equivalent number of miles, depending on the latitude. Thus, how frequently one could “see” such a satellite during the course of a day depends on latitude. Near the poles, the satellite would be visible on every orbit; near the equator, less often.

Simply seeing the satellite, as Guier and Weiffenbach had come to understand by observing Explorer I, would not be enough. The relation­ship of the orbit to receiving equipment on the ground had to fall within certain limits. If the arc of the orbit were too distant, the recorded Doppler shift would change far more gradually with time than if the satellite were nearer. The quantity of positional information would then be less per unit time, and with constant noise being received, the so-called signal-to-noise ratio would be too low for optimum accuracy. Moreover, the signal would be passing through a greater distance and would be subject to more atmo­spheric refraction, which would obscure the more gradual Doppler changes of the distant satellite. On the other hand, if the satellite were to pass nearly overhead, the computations would result in an error in longi­tude. In between, there was a wide region in which the total navigational error would be acceptably small and would be insensitive to the geometry of the satellite pass.

These limitations were pointed out, but the proposal did not recom­mend a particular number of satellites or an orbital configuration. Never­theless, one begins to see how the laws of physics and the requirements of the job to be done, for example worldwide navigation versus position fix­ing in the arctic, combine to impose limits on the configuration of orbital inclinations and altitudes.

A vital part of the system would be the oscillators producing the continuous waves for the Doppler measurements and the reference frequency in the submarines receiver. The stability of the oscillators and the error in the frequency measurement defined the system’s theoretical limit of accu­racy—the limit achievable if all other problems were solved.

The first proposal asserted that the state of the art for oscillators meant that a CEP of a thirtieth of a nautical mile (roughly two hundred feet) was theoretically possible. Although the proposal had made clear that this accuracy was dependent on a number of assumptions, including a favorable geometry between satellite and receiving station, critics thought that APL was saying that it could achieve this number regularly in practice. When the figure leaked out, McClure had to field outraged and disbeliev­ing phone calls, including one from Bill Markowitz, head of the Naval Observatory. Eventually, Transit surpassed even this accuracy, but in 1958 the proposal’s claims seemed implausible.

The situation was not helped by the fact that many of the critics either did not understand or did not want to understand the computa­tional and statistical approach APL was proposing. Guier and Weiffenbach recall one group that converted their data to miss distances, calculated, inevitably, a very poor orbit, and so dismissed their work.

Transit’s history was similar to that of many technological develop­ments. First, Guier and Weiffenbach explored something new and unex­pected, initially with no clear idea in mind. Then they found a purpose for their research—orbital determination. In March, McClure entered the stage with a way of exploiting their research for a practical application. McClure brought with him Richard Kershner, someone who today would be called a systems engineer. Kershner supervised the development of a proposal, which, because it served a military need, won funding. It encountered opposition and was not widely accepted for some time.

One could write of this last aspect of Transit’s development, that there is “nothing new under the sun,” because the satellite’s development has much in common with the pursuit of longitude, the critical navigational problem that occupied physicists of the seventeenth and eighteenth cen­turies—some of these same physicists who laid the scientific foundations for Transit.

A diversion into history is too hard to resist. Geopolitical tensions between two superpowers—Spain and Portugal—provided the initial impetus for the pursuit of longitude. The two countries had a territorial dispute that could not be resolved because they did not know the location of the meridian in the Atlantic ocean that separated their claims to sover­eignty. Before a solution was found, there were political hearings, testi­mony from distinguished scientists, competing technical solutions, pleas for public funding, and suspicion of the new technology from naval officers. Once a solution to the longitude problem was found, it became invaluable to commercial shipping interests.

In the seventeenth century, the problem of determining longitude came down to the need for a means of telling the time accurately at sea. If a clock of some kind were set according to time at a reference longitude, say Greenwich, and local noon occurred at 2 RM. Greenwich time, then you knew you were thirty degrees west of Greenwich. (The earth turns through fifteen degrees of longitude per hour).

Telling the time at sea was acknowledged to be very difficult. On land there was no problem. Pendulum clocks were accurate to within a few seconds, but they did not work well on the pitching and rolling deck of a ship. First the Portuguese, then the Spanish, the Dutch, and the French offered rewards for ideas leading to a method to tell the time at sea. Every crank in Europe responded. Overwhelmed by dubious proposals, Spanish officials returned a promising idea from an Italian named Galileo Galilei that suggested taking advantage of the times of eclipse and emergence of the moons of Jupiter. Given the difficulties of stabilizing a pendulum at sea, the idea was good. But it languished in bureaucracy.

A century after the Portuguese first tackled the problem, the English Parliament bestirred itself in an effort to placate a public scandalized when, in 1707, Admiral Sir Clowdisley Shovell led the fleet onto rocks in bad weather off the tip of Cornwall. Some two thousand men died. Every nav­igator but one had agreed that the fleet was southeast of its actual position just off the coast of Brittany.

After more losses of men and goods, a petition signed by several cap­tains of Her Majesty’s ships, merchants of London and commanders of mer­chantmen was set to the House of Commons in 1714. Though couched in florid, formal language, its message was clear: Parliament should act. The petitioners suggested that public money be offered as an incentive to any­one able to invent a method of determining longitude at sea.

Parliament sought expert advice, calling, among others, Isaac New­ton and Edmund Halley to testify before the parliamentary committee of the House of Commons on June 11, 1714. Newton was not encouraging. He spoke of “ . .. several projects, true in practice, but difficult to execute.”

Rather than celestial schemes, he favored the development of an accurate clock, telling members that of the various options for determining longi­tude, “One is by watch to keep time exactly, but by reason of the motion of the ship at sea, the variations of heat and cold, wet and dry and the dif­ference in gravity in different latitudes, such a watch has not yet been made.” He offered no engineering advice.

A few weeks after this testimony, Parliament enacted legislation offering a reward to the first inventor to develop a clock that met specifi­cations laid out in the act. The award was £20,000, which for the time was a considerable amount of money. The act also established a Board of Lon­gitude, which was given the task of awarding smaller grants for promising ideas as well as responsibility for determining when the terms of the act had been met. An unschooled but skilled cabinetmaker called John Harri­son received several of these grants and eventually developed a chronome­ter (known among the cognoscenti as “chronometer No 4”) that fulfilled the act’s specifications.

The board proved reluctant to pay the full £20,000. There were conflicts of interest, ownership disputes, and numerous sea trials. Unde­terred, the Royal Society honored Harrison, but the monetary reward was still not forthcoming. Then the board paid up in part. Unsatisfied, Harri­son appealed to the king, who offered to appear under a lesser title to argue the case before the Commons. Eventually, the board paid out the full amount.

Another time, another place: In the late spring of 1958, Kershner prepared to do battle for what would be a controversial new approach to navigation. Gibson, McClure, and Milton Eisenhower, the president of Johns Hopkins University and brother to the other president, were playing their parts too.

Kershner made several trips to the Pentagon, often taking Guier and Weiffenbach with him. At first, Guier and Weiffenbach felt apprehensive and out of their depth. Amidst these efforts, Weiffenbach was awarded his Ph. D., something of a sidebar as APL fought competing navigation proposals and criticism. The Jet Propulsion Laboratory, which had a deservedly high repu­tation, posed a particular threat when it challenged APL’s error analysis. Eventually, there came a meeting at which Guier and Weiffenbach argued for an opportunity to fly an oscillator on someone else’s satellite. This would give them a chance to prove the concept and to show that an ionospheric correction was possible. Their audience, though, had already been convinced of the validity of APL’s approach to developing a navigation satellite, and Guier and Weiffenbach left with the promise of funding for a satellite, not just an oscillator. (An oscillator was flown on the Department of Defense’s Discover satellites as part of the effort to determine the earth’s gravitational field). This happened sometime in the summer of 1958, and APL had by now developed technical plans for eight experimental satellites. Their aim was to have a prototype operational satellite aloft by the end of 1962.

Others had joined the project since April. In July, Weiffenbach sent John Hamblen the operating characteristics for the satellite’s antenna. Weif­fenbach was also designing the first oscillator and reviewing what was known about the ionosphere. Harold Black had his wish and was working for Guier and Newton on the computational effort for orbital determina­tion and prediction. Joy Hook, a skilled programmer, had joined the team and was rapidly becoming invaluable. Many subroutines were being com­pleted, including those for organizing the recorded data on magnetic tape, for applying the refraction correction, and for curve fitting. There was, says Black, a quiet desperation about much of the software effort. Very few people understood it well.

In November 1958, three of APL’s engineers visited Iowa State Uni­versity, seeking advice from George Ludwig in James Van Allen’s group about the kind of environment their satellite would encounter in space. They returned with information about how ISU built and tested its satel­lites and about temperature control. They picked up schematics for the Explorer III satellite, which had been launched on March 26, as well as information about the satellite’s radiation observations. These observa­tions, which were the first data supporting the hypothesized existence of radiation belts, had not yet been widely circulated. They were to be important to Transit because the satellites would be in orbits that took them through the newly discovered radiation belts.

As work on Transit progressed, more detailed questions emerged. How many transistors, for example, would be needed in the clock circuit or the oscillator circuit? The original proposal of April 4 had said that the satellite would be fully transistorized, so these questions were significant, especially at a time when a transistor could cost as much as ninety dollars. How much power would the circuits need? How would they be packed and into what volume? The original specifications were for 293 transistors

Researchers from the Johns Hopkins University Applied Physics Laboratory position a satellite from Iowa State University on top of the Laboratory’s Transit 4A satellite in June 1961. Courtesy of Applied Physics Laboratory.

or diodes. With an estimated packing volume of two cubic inches per tran­sistor or diode, the electronics could not be packed into a volume of less than 586 cubic inches and would weigh eighteen pounds. During the rest of 1958 and through 1959, these numbers were refined.

Another difficulty arose—how to affix the electronics to the circuit boards. After some faulty starts with soldering and some burned-out tran­sistors, the engineers decided to weld the components. But different coef­ficients of expansion between the connections and the components led to many breakdowns. Reliability did not really improve until the advent of integrated circuits in the mid 1960s.

On December 15, in the midst of these ongoing problems, the Advanced Research Projects Agency (ARPA) awarded APL full funding of $1,023,000 for the Transit project. Although ARPA awarded the contract, the work was sponsored jointly by the Special Projects Office and was administered by the Navy’s Bureau of Ordnance.

The aim was for Transit to be operational by the time the Polaris submarines were on station. This goal was not met. Two submarines were on patrol by the end of 1960, three full years before Transit was opera­tional. But the Polaris deployment had moved ahead of schedule, and the Transit development slipped by a year. Even so, Transit’s development went ahead at a breakneck pace.

The objectives initially fell under two headings: the Transit program and NAV 1—the satellite. The Transit program was defined as the devel­opment of a shipboard navigation system, work on the earth’s gravitational field, and a feasibility study of a Doppler navigation system for aircraft.

The first aim is obvious. The second became critical. The last aim, however, was curious for two reasons. First, single-satellite Doppler naviga­tion was never going to work for aircraft because they need to determine altitude as well as latitude and longitude and thus would need to record either two passes of the same satellite or one pass each of two different satellites. For aircraft moving at, say, eight miles a minute, this was not an option, and the higher echelons of the Pentagon had decided to develop inertial navigation for aircraft. However, there was a new requirement for all-weather navigation for the aircraft of the radar picket fence, which stayed airborne for eighteen hours at a stretch. The thinking was that Transit coupled with interpolation from inertial navigation units might serve these aircraft.

The second part of the contract—Nav-I—comprised three satellites, which were to be delivered to Cape Canaveral in time for a launch sched­uled for August 24, 1959. Once the first satellite was in orbit, its nomen­clature would change from Nav-1 to Transit IA. NAV-Vs objectives were to demonstrate the payload (another word for satellite instrumentation), the tracking stations and data processing, and the Doppler tracking meth­ods, as well as to collect data (from analysis of Doppler curves) about the shape of the earth and its gravitational field.

The plan at the end of the 1958 was that the NAV-1 satellites would weight 270 pounds and be launched on a Thor-Able rocket toward the end of August 1959. This was considerably heavier than the original pro­posal’s estimate of 50 pounds, but Transit IA was an experimental satellite. Kershner later insisted, in the face of considerable opposition from members of the Transit team, that the weight of the operational satellites be lessened to make them compatible with the less costly Scout rockets. Some of the Transit documents suggest that the aim had always been to make the oper-

An early tracking station for Transit satellites. The station located at the Johns Hopkins University Applied Physics Laboratory was for research. Courtesy of Applied Physics Laboratory.

ational satellites compatible with Scout. Team members remember that they wanted to stay with the heavier-lift launch vehicle. As was often the case, Kershner won the debate. But the transition proved more difficult than anticipated and held up the program for a year, delaying the launch of an operational navigation satellite until the end of 1963.

By February 1959, APL had made good progress with the satellite antenna. The following month, a year after McClure had called Guier and Weiffenbach into his office, seventy percent of the satellite’s electronics had been built and mechanical fabrication had begun. Results of analytical work suggested that by 1963 a simplified Doppler navigation with an accuracy of one mile could be performed by hand, and that with more sophisticated techniques (curve fitting), an accuracy of one-tenth of a mile would be possible.

In the spring of 1959, the first computer program (ODP-1) for determining satellite position was nearly complete. It took the Univac ПОЗА twenty-four-hours to run the program in order to predict an orbit for twenty-four-hours. A year later, when the lab installed the IBM 7090 in the summer of 1960, computation time was cut to about one hour per eight hours of prediction. The 7090 was one of the world’s first largely transistorized computers.

In April, two satellites underwent environmental tests in a thermal- vacuum chamber and vibration tests at the Naval Weapons Laboratory to see whether they would be able to withstand the temperature changes in space and the vibrations and accelerations of launch. Then the two satel­lites were placed outside on a grassy knoll while the radio frequency links and solar cells were tested.

In those early days, APL had no clean rooms to prevent contamina­tion of the spacecraft, and Commander Pollow recalls asking someone to stop flicking cigarette ash on the satellite. The clean rooms that were then creeping into industry were not clean rooms as we know them today. They were intended, say the Transit members, to provide a psychological envi­ronment that made people more careful. APL’s approach to instilling greater care relied on Kershner’s cradle-to-grave policy, which was a good way of encouraging the design engineer to satisfy the test engineer.

Besides testing, April 1959 saw work begin on three permanent and two mobile tracking stations. The spring schedule called for complete installation and checkout of ground stations by June 1; the completion of thermal, vacuum, and mechanical tests on three satellites by July 1; check­out of the entire Transit tracking communication and computing system by July 15; and delivery of three completed satellites to Cape Canaveral by July 19. The scheduled launch date for the first satellite was still August 24.

By the end of July, the timetable drawn up in spring had slipped a lit­tle, but not by many days, nor is it clear from the progress reports why. According to “Kershner’s roulette,” a term that does not appear in the pro­gram’s official progress reports but was common currency among Transit team members, any delay was supposed to be because of some other part of the complicated process of launching a satellite, never because of Tran­sit. Whether or not the Transit team won that particular spin of Kershner’s wheel, the launch date had by July been set back to September 17.

Through the summer of 1959, Guier, Newton, Black, and Hook were putting the finishing touches to the software. Kershner made infor­mal arrangements for the Physics Research Laboratory of the Army Signal Corps to participate in Transit and to evaluate the absorptivity and emis – sivity of paints in an attempt to find the best materials for controlling satel­lite temperature in orbit. He and Gibson were in constant contact with the Cape and with the Air Force, which was responsible for the launch. Kersh – ner was discussing tracking and orbital requirements, drawing up the checkout procedures for the launch site, and visiting candidate tracking sites. The sites were required to be free from interference from nearby sources of radio waves, and the surrounding topography had to provide clear lines of sight to the horizon, or at least to the lowest elevation from which the satellite could provide usable Doppler curves. Each site’s posi­tion had to be accurately surveyed.

Finally, toward the end of July, things started to come together. There were only days to go before the satellites were to be shipped to the Cape. In the year since Guier and Weiffenbach had learned that they had funding for an experimental navigation satellite, the Transit team had worked impossibly hard. They were exhausted and exhilarated.

On July 31, the satellite in which they had most confidence was undergoing a dynamic balancing test. While the satellite was spinning at one hundred revolutions per minute, a structural support member in the test equipment failed. The satellite fell and was shattered.

Kershner spoke into the silence that followed, without anger or histrionics. He asked team members to pick up the pieces and to deter­mine what was still in working order. Somehow, despite the sick feeling in the pits of their stomachs, Kershner’s demeanor inspired them to work flat out to prepare their remaining two satellites for shipping. More than thirty years later, when Weiffenbach recalled Kershner’s calmness and the team’s response, there were tears in his eyes. Sooner or later, each Transit team member tells this story. It never seems very dramatic, but it clearly symbol­izes why they respect Kershner.

On August 2, two, rather than three, NAV-1 satellites were delivered to the Cape.

Throughout August, the tracking stations at APL, in Texas, New Mexico, Washington State, Newfoundland, and England followed a rigor­ous practice schedule. APL staff went to England in the middle of the month. Negotiations were underway with AT&T to ensure that enough teletypewriter and telephone links were in place to handle communica­tions between APL, the Cape, and the tracking sites. During the launch,

Weiffenbach found himself repeatedly reassuring an English operator that the expensive transatlantic telephone line should stay open even though the operator could hear no one speaking.

At APL’s own tracking station, Henry Elliott was in place as the chief operator. During the last few weeks before the launch, Elliott encountered a number of irritants. Phase shifters arrived on September 8 but were not working. The next day, he got one working in time for a practice alert on September 10. During the day a twenty-four-hour clock arrived. On Sep­tember 14, three days before launch, there was a dry run. On September 16, there was another dry run, following a timetable mimicking the next day’s launch. One of the two frequency pairs that NAV-1 carried to inves­tigate whether one pair alone would be enough to correct for ionospheric refraction was swamped by a nearby signal. If it had been the real thing, there would have been no Doppler recording of one of the frequency pairs.

September 17, 1959, was the day of the launch. A final and complete check of the station began at six in the morning. A tracking filter failed and was replaced. News came through that the launch was being held for an hour and a half. At 9:45 a. m. APL’s test transmitter was switched off in preparation for the launch. An announcement was made over loudspeakers asking everyone in the lab to turn off anything that could generate a radio signal that might interfere with the satellite’s signal. At last, at 10:33:27 Eastern Daylight Time, the rocket lifted off.

It was eighteen months since McClure had told Guier and Weiffen­bach of his idea. In that time, the Transit team had learned how to design satellites and had designed and built facilities for mechanical, thermal, and vacuum tests, ground stations, and test equipment for their ground sta­tions. They had carried out innumerable theoretical analyses, had written an orbital determination program, and had built and tested three satellites. They had seen their best work destroyed by a last-minute accident and had shipped two satellites to the Cape. Now the Nav-1 satellite that would become Transit- і A was climbing through the atmosphere.

Information about Vanguard came mainly from my interview with Mil­ton Rosen and was bolstered by articles and papers he gave me, including one by John Pierce describing how satellites might be used for telecom­munications, one that Rosen sent on 3 March 1955 describing the utility of the Viking rocket for a satellite launch vehicle, and a memo on the same date from John Mengel and Roger Eastman outlining Minitrack.

A considerable amount of useful information about Vanguard can also be found in Green’s and Lomask’s book and in the NASA History Office (see notes for the prologue). Green and Lomask give details of the costs and of the rival merits of the Projects Orbiter and Vanguard pro­posals, including details of the miniaturization to be found in Vanguard (page 26).

Milton Rosen told me that von Braun asked for a chance to make a sec­ond presentation of Project Orbiter to the Stewart committee, and of the anxiety with which he (Rosen) watched the presentation and the disbe­lief and elation felt by the NRL team when they learned that the com­mittee had backed Project Vanguard (page 26).

My interview with William Pickering and his oral history, given to Mary Terral for the archives of the California Institute of Technology, provide details of Project Orbiter and how it evolved from von Braun’s original proposal.

Information about the long playing rocket (the euphemism by which a rocket capable of reaching orbit was known), its costs, and the costs of the satellite program, as well as their acceptance by the USNC—IGY is found in the following minutes, located at the National Academy of Sciences: third meeting of the USNC executive committee (January 7, 1955), dur­ing which the technical panel on rocketry was asked to report on the technical feasibility of satellites; first meeting of the technical panel on rocketry (January 22, 1955) during which a subcommittee comprising William Pickering, Milton Rosen, and John Townsend was formed; first meeting of the subcommittee evaluating the feasibility of a satellite launch (February 3 and 4, 1955, in Pasadena). No minutes, though William Pick­ering remembers the first meeting. Fourth meeting of the executive com­mittee of the USNC, during which members were told that the technical evaluation of a satellite was ongoing; On March 5, 1955, there was a meeting between Joseph Kaplan and Hugh Odishaw, the administrative secretary of the USNC, to discuss security procedures surrounding the work of the subcommittee of the technical panel on rocketry. They con­cluded that the report would be classified but that the committee would prepare an unclassified report for the executive committee; On March 9, 1955, the technical panel on rocketry accepted a classified report on the feasibility of launching a satellite and prepared an unclassified version for the USNC’s executive committee; On March 8 — 10, the fifth meeting of the USNC executive committee discussed the rocketry panel’s report and debated whether to back the inclusion of satellites in the IGY. Unusually, the notes from this meeting are handwritten and hard to decipher. The most vocal discussants were Merle Tuve and Athelstan Spilhaus. Tuve expressed doubt about the inclusion of a satellite in the IGY; Spilhaus was strongly in favor. What caused Tuve concern was the classified nature of the project. In the end, the meeting agreed that if the long playing rocket were still classified by January 1956, then it should be dropped from the program. The seventh meeting of the USNC took place on May 5, 1955. An agenda item on the LPR refers to an attachment that is not included in the archives. This meeting was in the period following Quarles’ approach to the IGY and prior to Eisenhower’s public announcement that there would be a satellite program. Hugh Odishaw was writing and phoning the NSF at this stage, pushing for a decision on the satellite bud­get and seemingly unaware of the higher policy decisions in which the satellite program was caught.

Odishaw’s letters and Joseph Kaplans correspondence with Alan Water­man, the director of the National Science Foundation, and Detlev Bronk, the president of the National Academy of Sciences, are in the correspon­dence files of the IGY archives at the NAS.

Details of the curtailment of the satellite program (page 30) in the year following President Eisenhower’s announcement that it would go ahead are also to be found in the archives of the NAS. The USNC discussed the Earth satellite program at its tenth meeting on 13 July 1956. The minutes, classified as administratively confidential, say, “For reasons of economy, the Earth satellite program has been curtailed from 12 attempted launching to six.” Hugh Odishaw drew the committee’s attention to the need for con­fidentiality, “lest knowledge of the curtailment of the program should lead to an international loss of prestige by the U. S.”

The interaction between the IGY and national security policy comes pri­marily from R. Cargill Hall, “The Eisenhower Administration and the Cold War, Framing American Astronautics to Serve National Security,” in Prologue, Quarterly of the National Archives, spring 1996. It seems likely that the criteria that the Stewart Committee were given in order to decide between Projects Orbiter and Vanguard were chosen to ensure that the IGY could indeed be a “stalking horse” for the launch of a reconnaissance satellite.

Information about the Stewart Committee (page 25) can be found in the oral history by Homer Joe Stewart in the archives of the California Insti­tute of Technology and in Vanguard—A History (NASA History Series SP4202), by Constance Green and Milton Lomask. Milton Rosen also gave me information about the way the Stewart Committee voted and the reasoning behind their decision.

Homer Joe Stewart was interviewed by John L. Greenberg on October 13 and 19 and November 2 and 9, 1982, for an oral history, which is in the archives of the California Institute of Technology.

Details of how the scientists learned of the launch of Sputnik come from conversations with Walter Sullivan, William Pickering, and John Townsend (page 30).

Books consulted for chapter 2, as well as for the prologue and chapter 11 are Beyond the Atmosphere, Early Years of Space Science, by Homer E. Newell (SP4211—NASA History Series); Science with a Vengeance, How the Military Created the US Space Sciences after World War If by David DeVorkin (Springer-Verlag, 1992); The Viking Rocket Story; by Milton W. Rosen (Faber, 1955).

Personal details about John Pierce (mainly pages 180—182) come from my own interviews with him.

Other details are from the next four references: oral history taken by Har­riet Lyle for the archive of the California Institute of Technology in 1979.

The Beginnings of Satellite Communications, by J. R. Pierce, with a preface by Arthur C. Clarke (San Francisco Press, 1968) (copy from John Pierce);

My Career as an Engineer, An Autobiographical Sketch, by John R. Pierce, the University of Tokyo (1988); and

“Orbital Radio Relays,” by J. R. Pierce, Jet Propulsion, April 1955 (page 183).

In Spring 1958, Pierce and Rudi Kompfner read about William O’Sulli­van’s ideas for a balloon-like satellite to measure air density and realized that by bouncing microwaves off its surface they could test many techni­cal aspects of satellite communication (page 184). Interview with John Pierce.

Brief notes describing an ARPA satellite conference on July 13—14,

1958, and John Pierce’s involvement with William Pickering in develop­ing the Echo project (page 184). The notes are in the John Pierce collec­tion (#8309 Box 5, folder-leading to Echo) at The American Heritage Center at the University of Wyoming.

At the sixth meeting of the TPESP on June 7 and 8, 1955, William J. O’Sullivan, from the National Advisory Committee for Aeronautics (NACA—a forerunner of NASA), presented his ideas for a giant alu­minized balloon that could be observed from Earth, allowing information to be deduced about the density of the upper atmosphere (page 184). Richard Porter told him the idea was interesting, and that the proposal should be sent to the working group on internal instrumentation (NAS archives).

At the seventh meeting of the TPESP, on September 5, 1956, O’Sullivan told the panel that NACA was prepared to build its air drag satellite experiment without the backing of the IGY (NAS archives).

There is a May 13, 1958, memo from Rudy Kompfner to E. I. Green, including John Pierce’s memo “Transoceanic Communication by Means of a Satellite.”

May 26, 1958: a memo by Brockway McMillan, “A Preliminary Engi­neering Study of Satellite Reflected Radio Systems.” The study is based on Pierce’s ideas. McMillan favors twenty satellites at medium altitudes to give continuous service and envisages that there would be a market for a new transatlantic service between 1970 and 1975. He writes, “It is con­cluded here also… there probably exists a potentially much larger market….”

There is a July 25, 1958 memo from E. I. Green to Mervin Kelly evaluat­ing Pierce’s proposals concludes,“In summary, the proposed system would require intensive R&D on a host of problems.. . considering other demands of Bells Systems… it would be my recommendation that we do not attempt to undertake satellite communications as a Bell System devel­opment.” Presumably, it was this memo that led to his “cease and desist order” (page 185).

A letter from John Pierce to Chaplin Cutler of October 17, 1958, gives Pierce’s views of the meeting of the Advanced Research Project Agency he had attended on October 15 and 16 (page 185). Pierce was aware from the beginning of the ideas being considered by the military for communi­cation satellites. At the ARPA meeting he was acting as a consultant to what was an ad hoc panel on 24-hour satellites. ARPA’s views would change considerably. Pierce reported the view then: “It is possible that a spinning satellite with non-directive antennas will be launched early in 1960 and a satellite with an attitude stabilized platform in 1962” (Box 840902, AT&T archives).

A memorandum for the Record from John Pierce, Rudy Kompfner, and Chaplin Cutler on Research Toward Satellite Communication, Research toward Satellite Communication. Dated January 6, 1959, the memo describes a research program directed in general at acquiring the basic knowledge for satellite communication by any means and specifically at aspects of passive Echo-type satellites. A fuller version of the research memo was written on January 9, 1959 (page 185) (AT&T archives).

In a letter to William McRae, vice president of AT&T, of January 7, 1959, Pierce outlines his proposed research program for satellite communication (AT&T archives).

A memo of 16 June 1959 describes a meeting between BTL, the Jet Propulsion Laboratory, and the Naval Research Laboratory, during which William O’Sullivan provided some technical details on the aluminized balloon and the Langley Research Center’s tests (page 186) (AT&T archives).

Information scattered through the chapter came from: Monthly Project Echo reports starting October 23 1959 (AT&T archives);

Project Echo, Monthly report No. 3, December 1959. Report on the first moon bounce test;

Rudi Kompfner’s correspondence and memos (AT&T archives 59 04 01); and from

Film reels in the AT&T archives:

1. Project Echo 1. An NBC news special sponsored by BTL 409-0213

2. The Big Bounce, BTL film 399-03727.

We were pioneers, and we knew it.

—Bill Guier

arsons auditorium was crowded. Everyone was eager to hear the news as it was relayed from the Cape. They knew about the delays that had accumulated during the final countdown, heard the announcement to switch off radio frequency generators at the lab. The moments before a launch are always tense. In the final seconds the tension was alleviated, as the voice from the Cape intoned, “twelve, eleven, ten, eight, whoops, seven, six, five, four, three, two, one.” The Thor-Able rocket lifted off, car­rying Transit 1A aloft. They knew that Air Force radars were tracking its ascent; that engineers were calculating position, cross checking their slide – rule calculations and sending course corrections to the launch vehicle as needed. They heard the satellite’s transmitters and knew that everything was going well.

Then the transmitters stopped. For a while, no one knew what was happening. Then came the news that the third stage had failed. In all prob­ability, it and the satellite burned up on reentry into the atmosphere some­where over the North Atlantic, west of Ireland. Lee DuBois, one of the mechanical engineers, looked around the room. He saw the tears of disap­pointment on his colleagues’ faces.

The progress reports that APL sent to ARPA were as emotionless as those that described the shattering of their best satellite the previous month. The launch failure, it seemed, could be ascribed to the retro rock­ets on the second stage. These rockets were supposed to slow the second stage after separation of the third, so that the second stage would not inter­fere with the third as it coasted away prior to firing its own engine. When the retrorockets failed, the second stage bumped into the third stage, dis­rupting the third stage’s ignition sequence.

Transit 1A’s flight had lasted twenty-five minutes. Its electronics had survived the launch. As soon as the nose fairing that protected the satellite on liftoff had peeled away, all four frequencies were transmitted. The lab
immediately started an analysis of the telemetry, which comprised mea­surements of variables such as the satellite’s temperatures and solar cell voltages.

APL also had some Doppler data from the short period before the signal was lost. They were incomplete; Henry Elliott’s record shows that one signal was lost intermittently. For a while, an operator had locked unwittingly onto some other unknown signal. Signals from a TV station in Baltimore interfered with reception a few minutes later, and halfway through the pass, one of the tracking filters lost its lock. Nevertheless, APL learned enough to confirm “at least partially” that the ground stations’ design and operation worked, according to the progress report.

With the data received the computing team also made a rough cor­rection for ionospheric refraction. Then they set themselves a theoretical problem, imagining that the Doppler data from Transit’s brief sojourn in space had, in fact, come from a satellite in orbit. They attempted their least squares fit. Though they clearly could not check the accuracy of their “orbital determination” against prediction of the satellite’s position during its next orbit, they could check their results against the Air Force’s radar data. They found the least squares fit was closer than it had been for the Sputniks and Explorer 1 and were encouraged. Thus, though the failed launch did not yield what they had hoped for and pointed to problems that needed to be addressed, the team did learn some things.

For a definitive analysis of ionospheric corrections and to begin investigating the earth’s gravitational field they needed a successful launch. The next attempt was set for April 13, 1960. By January of that year, Kershner was coordinating preparations for Transit IB’s launch and that ol Transit 2 A. Transit IB would be similar to the lost satellite, but Transit 2A, scheduled for a June launch, would test different aspects of the proposed navigation system.

Details piled on details. All over the United States, presumably in the USSR as well, teams of engineers and scientists were slowly coming to terms with the complexities of space exploration. Memos in English and Russian were written, which, if they were like Kershner’s, covered an array of newly recognized problems that now are familiar to those in the space business: nose fairing insulation, loads on structures, details about an epoxy bond, maximum satellite skin temperature at launch, radio frequency links, concerns about deflection and vibration characteristics of the launch vehi­cle’s second stage, and on and on.

Simultaneously, preparations were going forward for the satellites that would follow IB and 2 A in the Transit experimental series with the physics, the engineering, and computing all being developed in parallel— at a time when computing and space exploration were new.

At the ground stations, repeated preparations were made during the first three months of 1960 to track one of the Advanced Research Project Agency’s Discoverer satellites, which was carrying a Transit oscillator (ToD Soc Transit on Discoverer).Transit on Discoverer was part of a program to develop precision tracking for reconnaissance satellites, and the launch was postponed repeatedly. The postponements complicated preparations for IB, as did expansion of the Transit control center and its communication links to encompass the other agencies that were now interested in the project and its data, including NASA and the Smithsonian Astrophysical Observatory.

During the same period, Kershner lined up the Naval Ordnance Laboratory to do magnetic measurements and experiments. The Transit team was interested in fitting its satellites with magnets to stop them from spinning (de-spin, in the industry’s jargon), control their attitude, and pro­vide stabilization.

By March, B and 2A were in the final stages of fabrication or test­ing. John Hamblen (who was Harry Zinc’s and Henry Elliott’s boss) decided that some discipline was needed. He had found out that flight hardware had been released before necessary electrical and environmental tests had been run. In a casually typed note he asked that in future those fabricating the satellite proceed to incorporate a component only if an engineer had first signed the test data sheet. Verbal assurances about a par­ticular component, he wrote, would not do. Thus, casually, at APL and doubtless in many other labs, was the need for documentation recognized, documentation that now, assert many engineers and managers, has grown out of proportion to its usefulness.

The year advanced to Wednesday, April 13, 1960. That was a long day at APL. The launch was scheduled for 7:02 A. M. Eastern Standard Time. Once again Parson’s auditorium grew crowded. Probably the room looked as it does in photographs of the launch of Transit 4B. The ashtray filled to overflowing on a table crowded with papers. Gibson, Kershner, and Newton formal in dark suits, others in shirt sleeves. Gib­son standing, pipe in hand. Kershner in headphones, or telephone to one ear, hand covering the other. Newton seated, twisted slightly to view over his shoulder the clock held at eight minutes to launch, frowning, as was Kershner.

For Transit IB, the countdown proceeded. The voice over the inter­com from the Cape would have been saying things like, programmer starts … gyros uncaged… electrical umbilical ejects… lift off (at 7:03 A. M.). But it was not yet time for the champagne. The satellite still had to reach orbit, which it did, though barely Instead of the nominal 500 nautical mile circular orbit, IB went into an orbit with a perigee of 373 nautical miles and an apogee of 748 nautical miles. Such a result was very inaccurate by today’s standards, but more precise orbits had to wait until those designing launch vehicles were able to perfect inertial guidance controls.

Transit IB’s orbit was, however, sufficient to allow APL to begin work checking whether two frequencies would be adequate to correct for ionospheric refraction or whether a greater number would significantly improve the correction. The answer was that two seemed to be sufficient, though more remained to be done before this question was finally settled.

The immediate task on the first day was to determine an orbit, then to predict its position for the next twelve hours. Until midafternoon, there were computer problems. Then at 15:30 they determined their first orbit. The curves did not fit well, but they thought that this might be because the satellite was still spinning. Spinning ceased on April 19. On April 20, they determined another orbit from observations of fifteen passes at five locations. Again there was a poor fit. They decided this time that the prob­lem was noise. Like Transit 1A, Transit IB carried four frequencies for the investigation of ionospheric effects. Now they turned their attention to the second frequency pair, and the fit was better.

With the data from the second frequency pair, they determined satel­lite position to within 150 to 200 feet from observations of a single pass over a limited region of the earth. With data for half a day from the differ­ent tracking stations they could, assuming a simplistic model for the gravi­tational field and uniform air drag, determine satellite position to within one nautical mile. The longer the arc, the poorer the accuracy appeared to be. Something seemed wrong. Over and over again they looked for errors in the data and software. They could find none. It was a troubling situa­tion.

Extrapolating from a day’s observations, they then predicted the fol­lowing day’s orbit. This was what it was all about, developing a way of pre­dicting an orbit so that its coordinates could be uploaded to the Transit satellites twice a day, enabling the submarines to fix position with respect to a satellite in a known position.

The Transit team looked for the satellite at the time and location they had predicted.

And then they knew they were in trouble.

There was a discrepancy of two to three miles between prediction and observation. While this much error had been acceptable when they were first establishing Sputnik’s orbit in the fall of 1957, it was unaccept­able as the basis for a navigation system. “The satellite,” recalls Guier,“was all over the sky.” Again, they thought that it was a problem with the pro­gramming. But it wasn’t. What they had suspected but had not fully rec­ognized, and what O’Keefe had repeatedly warned Guier and Weiffen – bach about, now came to dominate the theoretical analysis of satellite motion. Earth’s gravitational field was far more complicated than anyone then knew. O’Keefe, because he knew about the perturbations in the moon’s orbit, was expecting that satellites in near-Earth orbits would show more pronounced perturbations, but even he could not have antici­pated the huge variation and the complexity of the gravitational field that was to emerge.

For the position fixing accuracies they wanted to achieve, their knowledge of the gravitational forces perturbing near-Earth orbits needed to improve considerably.

There were precedents. Others had wrestled with apparently unruly satellites. Not least of these were the men within whose paradigms early satellite geodesists were working—-Johannes Kepler and Isaac Newton. Both had struggled to understand the nature of orbits as, mystics both, they sought glimpses of fundamental truths about the universe. Kepler’s focus was on the sun’s satellite Mars; Newton’s was on the earth’s moon. In his book The Great Mathematicians, Henry Westren Turnbull writes, “The Moon, for instance, that refuses to go round the Earth in an exact ellipse, but has all sorts of fanciful little excursions of her own—the Moon was very trying to Isaac Newton.”

And very trying would be the motion of satellites in near-Earth orbits to the early satellite geodesists who, with the technology to observe satellite motion in greater detail than could Kepler or Newton, noticed a veritable plethora of fanciful excursions. The forces causing these devi­ations from elliptical motion needed to be accounted for so that their effect on satellite motion could be quantified and thus orbital prediction improved. It turned out also that because the irregularities in the gravita­tional field are due to variations in the Earth’s shape and composition, sci­entists reaped an unexpected and abundant scientific harvest from observa­tions of orbits. Satellite geodesy supplied, for example, some of the evidence for the theory of continental drift and thus for theories like plate tectonics.

APL was one of the early groups observing satellite motion. They were impelled by the unlikelihood that other geodesy programs would meet Transit’s needs by the time the system was scheduled to be opera­tional, at the end of 1962.

Like other satellite geodesists around the world, the Transit team wanted to determine the “figure” of the Earth. The Earth’s figure is not the topography that we see; rather it is a surface of equal gravitational potential (a geoid) that coincides with mean sea level as it would be if the sea could stretch under the continents. This geoid looks like a contour map. It has highs and lows that represent how the gravitation potential differs at a particular geographical location from what the potential would be at that point if the earth were a water-covered, radially symmetrical rotating spheroid (an ellipsoid of revolution), not subject to the gravita­tional pulls that cause tides. This hypothetical surface is known as the ref­erence ellipsoid.

It is the differences in gravitational potential between the figure of the Earth and the reference ellipsoid that geodesists study as they seek clues to the earth’s shape and structure. At first, only the deviations in motion caused by large irregularities, such as the pear-shaped Earth, were included in geoid models. Today’s models include the gravitational conse­quences of localized irregularities in shape or density. In the mid 1990s, the most accurate geoid maps available to civilians were of what is termed “degree and order 70.” Generally speaking, the higher a model is in degree and order, the more detailed is its description of gravitational potentials, in much the same way as a finer scaled topographical map gives greater detail about a piece of terrain. A geoid map, however, cannot be understood by analogy to an ordinary map. The gravitational potential at a given location is attributable not only to the local features, but also to the varying lengths of gravitational pull exerted by everything else. And the higher the degree and order of a geoid map, the more geologists can infer about the Earth’s structure. Geodesists aspire in the next century to satellite-based models that will be accurate to degree and order greater than 300, the goal being

to provide data that will help geophysicists to understand the earth’s geo­logical origins and history

The road to such comprehensive understanding of our Earth opened with the launch of Sputnik 1. Prior to the advent of satellites, geoid maps showed modest highs and lows that were a result of local measurements of gravity. The force of gravity exerted on a satellite’s motion, though, includes the sum of all the gravitational anomalies resulting from every irregularity of shape and density in the Earth. Disentangling these effects and relating them back to a specific aspect of the earth’s physical nature is a little like unscrambling an egg. Nevertheless, with extensive computer modeling the job can be done.

APL produced the first American satellite geodesy map in 1960, a crude affair by comparison with those of today. Guier and Newton led this effort and found that as with orbital determination and satellite navigation, they had again provoked hostility. Their early geoid maps showed far greater highs and low than appeared in maps from presatellite days, and traditional geodesists dismissed them as amateurs.

APL continued to produce geoid maps of increasing sophistication, but much of this work was classified. Civilian scientists at places like the Smithsonian Astrophysical Observatory and the Goddard Space Flight Center soon came to dominate the field, though APL’s work filtered dis­creetly and obliquely along some grapevines.

The lab’s first gravitational model contained a value for the Earth’s oblateness that was more accurate than that existing pre satellites as well as a term describing the pear-shaped Earth. Shortly afterwards Robert New­ton at APL and independently the Smithsonian Astrophysical Observatory made the next big discovery, which was that the Earth is not rotationally symmetric about its axis. Just as the northern and southern hemispheres are asymmetrical, so too were the eastern and western hemispheres. A number of scientists, most particularly the Soviets, had suspected that this might be true. Later on, APL optimized their geoid maps for Transit’s orbit; that is, they only unscrambled those aspects of the egg that affected polar orbits at Transit’s altitude.

The principle involved in extracting information about the Earth from satellite data is simple to explain in general terms, but very difficult to apply in practice: observe the satellite, note its departure from elliptical motion—its “fanciful excursions”—and try to find (in the computer model) what aspect of the Earth’s shape and structure, for example a par­

ticular dense structure or a liquid area, would give rise to the gravitational anomalies that would cause the satellite’s observed departure from an ellipse.

More detailed gravitational models and ionospheric corrections enabled the orbital determination group to improve their knowledge of satellite position from between two and three kilometers in 1959 to a little under one hundred meters by the end of 1964. With problems like iono­spheric refraction corrected for, other problems emerged. Would it be nec­essary, they wondered, to correct for refraction in the lower atmosphere? Such refraction was a source of bias in their data that could make the satel­lite appear to be about half a nautical mile away from its actual position. Helen Hopfield, whose dignified presence could reduce unruly Transit meetings to silence, tackled this problem, and APL made corrections for tropospheric refraction.

When the Transit group compensated for motion of the geographic poles from their mean position in the early 1970s, the satellite’s position was known to within twenty-seven feet. Polar motion, caused by preces­sion of the earth’s spin axis due to the earth’s nonuniform shape and struc­ture, changes the position of a ground station by about a hundred feet per year, thus introducing a small error into the orbital determination and prediction. The error was negligible for navigators but important to sur­veyors.

By the time of the first launch, APL had stopped characterizing orbits solely in terms of Kepler’s elements (as had other groups). First, because motion within a single orbit does not exactly obey Kepler’s sec­ond law—there are small deviations, and the elements are actually average values. Second, even these average values change gradually as the orbit shifts in inertial space because of the gravitational consequences of physical irregularities in the Earth. For navigation and geodesy, averages were not good enough. It was necessary to know as exact a position as possible at given times in the orbit.

So satellite position was expressed in terms of Cartesian coordinates centered on the earth’s center of mass, with one axis aligned with the earth’s spin axis and the other two lying in the Earth’s equatorial plane. The orbital prediction was made by finding the acceleration from New­ton’s second law of motion—the famous F = та that is so crucial to sci­ence and engineering, where F is force, m is mass, and a is acceleration. The value of the force acting at different parts of the orbit comes from the model of gravitation; then numerical integration of the components of acceleration, a = F/m, yields position and velocity at any desired instant of time.

If it had not been for the new generation of computers, typified by the IBM 7090, this work would not have been possible. The 7090 was one of the newest and best when it was installed in August 1960. It could per­form 42,000 additions and subtractions per second and 5000 multiplica­tions and divisions per second, and it could store 32,768 words (approxi­mately 0.03 megabytes). The 7090 was almost fully transistorized, unlike the vacuum-tube Univac.

The Univac had been badly stressed by the orbital determination program, taking eight hours for eight hours worth of prediction. The IBM 7090 could do the same job in an hour. To run the early gravitation mod­els on the Univac, which embodied only a few of the terms representing the earth’s gravitational field, Guier would set aside three or four week­ends. Had the Univac, which contained vacuum tubes with a mean time to failure of between 15 and 20 hours, been called upon to run the gravita­tional models that were to appear in the coming few years, it would undoubtedly have broken down. Even the 7090 would soon have to be updated as the gravitational model grew more intricate. Today Cray super­computers run some of the largest models; desktop machines with Pen­tium or 486 chips can run models of degree and order 50.

During 1960, Newton, Guier, Black, Hook, and others prepared for the transition to the 7090. The programs had to be rewritten in an assem­bly language compatible with the 7090’s architecture. The orbital determi­nation program occupied four or five trays of punch cards. Woe betide the person who dropped one. And drop them they did, recalls Black, with a laugh that has an edge even after thirty years.

Black and his colleagues were also learning—painfully—about soft­ware engineering, a nascent, scarcely recognized field. Black’s job was to get the orbital determination program running. He was starting with the physics developed by scientists like Newton and Guier. They generated the equations representing the physical realities, and as they understood more about what was going on they generated more equations. Black learned early to freeze the program design and fold new equations repre­senting the physicists’ deepening understanding of the situation into the orbital determination program in an orderly fashion rather than piece­meal. That, at least, was his aim; but Black’s position between the scientists

and the programmers who wrote and tested the code was at times unenvi­able. He had to force agreement out of the scientists, and he fought Guier (his immediate boss), Newton, and Kershner, telling them, “You ain’t gonna change this damn thing.”

In 1962, Lee Pryor, who retired in 1995 as the last project manager of Transit, arrived at the lab. Pryor had specialized in computing while tak­ing his degree in mathematics at Pennsylvania State University. His first three months at college were spent writing programs in anticipation of the arrival of Penn State’s first computer. Black says that Pryor was a godsend. When he arrived at APL, the lab was putting the finishing touches to the first “operational candidate” of the orbital determination program. “We just needed to get it out the door,” recalls Pryor.

In 1962, much physics and mathematics remained to occupy the Transit scientists, but the computing was moving from their purview to that of the professional programmers like Pryor who were writing code for an operational situation rather than for research. The move was neces­sary because, while the scientists could write programs for their own research needs, their programs, it seems, could be cumbersome and prone to breakdown in operation.

Once work on the gravitational model was well in hand, it became apparent that the effects of air drag and the pressure of radiation from the sun would have to be considered. These were dealt with in the 1970s pri­marily by an elegant piece of engineering invented by Daniel De Bra from Stanford University. The navigation satellites were placed inside a second satellite. The separation between their faces was tiny. Sensors on the Tran­sit satellite detected when the inner satellite moved toward the outer sur­face, and tiny rockets moved the inner satellite to compensate for these forces, before they could offset the Doppler shift. An engineering solution was necessary because the time, size, and place of the forces could not be predicted.

In the mid 1960s, the failure of solar cells threatened the reliability of the operational Transit satellites. Until this problem was solved with input from Robert Fischell, the Transit satellites tended to fail within a year of launch. Once solved, some veteran satellites exceeded twenty years in operation. The Transit team also launched the first satellite with gravity – gradient stabilization, in which an extended boom encourages the satellite to align itself with the earth’s gravitational field. APL’s first—unsuccess­ful—attempt with this technology was on a satellite known as TRAAC,

Doppler shift due to satellite pass.

which also carried instruments to explore and characterize the Van Allen radiation belts. Ironically, the satellite failed because of ionized particles created artificially by a high-altitude nuclear explosion—as did many other satellites.

TRAAC carried a poem engraved on one of the satellite’s instru­ments. It was written by Thomas Bergen, of Yale University and is reprinted at the end of this chapter. Its mixture of hubris and wistfulness captures something of the atmosphere that surrounded the early work on satellites.

In the case of APL, that work led, of course, to the Navy’s Transit Navigation Satellite System. The lab built the experimental series, the pro­totypes, and many of the early operational satellites. For a time, Navy Avionics built some operational satellites, but the job reverted to APL when these proved unreliable. Eventually, RCA won the commercial con­tract for construction. More satellites were ordered than were needed,

because a problem with the solar cells that was reducing their operational life was solved after the contract was placed.

During the 1980s, under Bob Danchik’s tenure as project manager, when GPS was nipping at Transit’s heels, these satellites were finally launched. The last Transit satellite went into orbit in 1988.

Although there was always at least one operational Transit aloft and available for the submarines from 1964 onwards, the system was not declared fully operational until 1968. At that time four satellites provided global coverage. Not the instantaneous, precise three-dimensional position fix offered by the twenty-four-satellite constellation of GPS, but still, for the first time, an all-weather, global navigation system, a system developed initially for the military, but which evolved until ninety percent of its users were civilian.

In ten years, a newly perceived consequence of the Doppler effect in the three-dimensional world grew through all the stages necessary to design and engineer a space-based navigation system. The program began at a time when vacuum technology was giving way to transistors, when programs were written laboriously in assembly language, and when no one knew how to develop large software applications. The conditions in space were unknown. The physics of the newly entered environment had to be analyzed theoretically and understood experimentally. The complex nature of the earth’s gravitational field had to be researched and a provoca­tive new understanding of the geoid developed. Launch vehicles were imprecise in their placement of satellites, if the satellites reached orbit at all. Satellite design was a new field, with stabilization, attitude control, and communication between space and Earth all unknowns.

During the early development of Transit, the launch vehicle changed, the computers changed, and programs had to be rewritten. Ground stations and satellite test facilities were built. Programs and equip­ment had to be developed for the submarines. It is hardly surprising that one or two people say that they ended up in the hospital, nor that the effort is remembered vividly and affectionately. But as Pryor noted shortly before he retired in 1995, it was time for the Transit program to end.

When the Navy switched off the last Transit satellite in early 1997, it ended the longest-running singly-focused space program to date. It sev­ered the last direct link with the opening of the space age, closing the doors on that shed on the plains of Kazakhstan and on the cold morning when Sergei Korolev thanked his exhausted and elated engineers who had launched Sputnik I, which Guier and Weiffenbach would track, providing the basis for Transit, which helped Polaris, America’s riposte against the Soviet threat of nuclear attack, firing the rockets with whose develop­ment Korolev had been so involved, because he believed that rockets were defense and science, which they became, for both sides, as did Tran­sit, which also became important to civilians. Here is one thread in the Cold War.

And one wonders.

What would have happened if McClure, say, or Pickering, Milton Rosen, or von Braun had met Sergei Korolev? If they had been in a room with chalk, blackboard, and a problem? Faintly, one hears the voices, dis­cerns in imagination the energy and the imminent verbal explosions as Korolev’s little finger lifts toward his eyebrow….

William Pickering’s state of mind and actions following Lloyd Berkner’s toast to the Soviets come from my interview with him. He described also the error in calculation they had made and the phone calls that poured into the headquarters of the IGY (pages 30 — 34).

Information about Project Moonwatch comes from my interviews with Roger Harvey, Henry Fliegel, and Florence Hazeltine.

Information on the radio tracking program comes from interviews by Green and Lomask with Daniel Mazur and Joseph Siry in the NASA His­tory Office, as well as from the following papers: John T. Mengel, “Track­ing the Earth Satellite, and Data Transmission by Radio,” Proceedings of the IRE (44), 6,June 1956;John T. Mengel and Paul Hergert, “Tracking Satellites by Radio,” Scientific American (198), 1, January 1958.

Information about the goals of the IGY satellite program and details of the optical and radio tracking systems and the technical and budgetary difficulties faced comes from minutes of the IGY committees, subcom­mittees, panels, and working groups:

Minutes of the first meeting of the Technical Panel on the Earth Satellite program (TPESP), October 20, 1955. At this meeting the panel defined the program’s goals (page 32).

10 November 1955: An ad hoc meeting of the technical panel on Earth satellites (TPESP) convened to discuss the budget for the program, which had to be ready for a presentation to Congress and the Bureau of the Budget (predecessor to the current Office of Management and Budget) by March 1956. Homer Newell said that important things to be budgeted for were radio and optical tracking and scientific instrumentation. The NRL, who were the experts at radio tracking, wanted stations distributed between latitudes of 35 degrees north and south of the equator. The TPESP wanted to add two more tracking stations to extend coverage to 45 degrees. These tracking stations eventually became known as mini­track.

The optical tracking program was discussed in greater detail at the second meeting of the TPESP, on November 21, 1955. Fred Whipple, director of the Smithsonian Astrophysical Observatory, presented a report prepared by himself and Layman Spitzer. The TPESP recommended that up to $50,000 be awarded to the SAO immediately to set up a series of observ­ing stations. At the time, Whipple’s proposal was for twelve observing sta­tions and an administrative and computer analysis center. He also called for collaboration with amateur observers.

During the third meeting of the TPESP, on January 28, 1956, the difficul­ties of tracking began to emerge. A letter from Homer Newell on the problems of visual and photographic tracking of Earth satellites was read. It was not known whether radio tracking would work (see page 36). The expectation at the time was that there was only a fifty percent likelihood of minitrack succeeding; hence the need for optical tracking.

27 June 1957: The twelfth meeting of the USNC pointed out that there were still problems with the tracking system.

At the seventh meeting of the TPESP on September 5, 1956, John Hagan and Fred Whipple respectively updated the panel on radio and optical tracking. By now, Whipple had made contact with amateurs in an attempt to improve the chances of acquiring the satellite optically. The army, for example, had four hundred binocular elbow telescopes that volunteers, like Florence Hazeltine, could use at military bases.

The twelfth meeting of the TPESP, on October 3, 1957, the eve of the launch of Sputnik, opened with a discussion about how to track a Russian satellite. Fred Whipple explained delays in development of the cameras for optical tracking. It was during this meeting that the delays in delivery of the cameras prompted Richard Porter to say, “I have a number of times threatened to go up to Stanford and beat on tables. … Fred [Whipple] has so far frankly discouraged my doing so.”

At the thirteenth meeting of the TPESP, on October 22, 1957, it was reported that delivery of optics from Perkin Elmer had been increased and brought forward.

The fifteenth meeting of the TPESP, on January 7, 1958, demonstrates the poverty of information about the Sputnik s’ orbits. Whipple said, “We’ve not had a scrap of radio information.” Richard Porter, who headed the panel, said, “We may have underestimated again the difficulty of tracking and photography.” Pickering said, “The Soviet thing caught everyone off base” (page 34).

That the Soviets were also conducting the same basic science experiments and were interested in ionospheric refraction, tracking, and propagation effects comes from Selected Translations from Soviet-Bloc International Geo­physical Year Literature. Artificial Earth Satellite Observations (New York, U. S. Joint Publication Research Services, 1959) and Selected Reports Presented by the USSR at the Fifth Meeting of the Special Committee for the International Geophysical Year (New York, U. S. Joint Publication Research Services, 1958).

Details of the optical tracking program can be found in the annual reports of the SAO for 1961 and 1963.

Green and Lomask (Vanguard—A History, NASA History series SP4202) describe John Mengel’s actions when Sputnik was launched (page 35).

Documents drawn on for the launch of Telstar:

Satellite ground tracking station, Andover, Maine, Engineering notes: Tel­star July 9, 10, and 11, 1962. The document gives details of the count­down (page 188), for example, loss of calibration by the ground tracker at 1220 UT, power supply trouble at 2317 in the upper room of the com­munication antenna, etc. … (box 85080302 – AT&T archives).

Memorandum for the Record from John Pierce, Rudy Kompfner, and Chaplin Cutler on Research Toward Satellite Communication, and Research toward Satellite Communication (page 189). Both are dated Jan­uary 6, 1959, and deal with a research program directed in general at acquiring the basic knowledge for satellite communication by any means and specifically at aspects of passive Echo-type satellites. A fuller version of the research memo was written on January 9, 1959 (AT&T archives).

In this chapter references to what NASA officials said or did (pages 191 to 198) comes from documents in the NASA History Office or George Washington University. These were shared with me by David Whalen.

They include:

Memorandum for the Record, October 31, 1960, by Robert G. Nunn, special assistant to the administrator. This summarizes a meeting between NASA officials and James Fisk, president of Bell Telephone laboratories, and George Best, vice president of AT&T The purpose was to discuss Bell’s plans for “Transoceanic Communication via satellite.” It opened with T. Keith Glennan, NASA’s administrator, saying that Bell had not considered the “facts of life” with respect to vehicle availability. The meeting discussed policy issues in some depth, including finance and whether or why public money should be spent on communication satellites.

Memorandum for program directors, February 24, 1961. Subject: Guide­lines for preparation of preliminary Fiscal Year 1963 budget. On the sub­ject of communication satellites, it said to assume no funding of opera­tional systems; adequate provision should be made for back-up vehicles; and no development of passive communication systems.

Minutes of the administrator’s staff meeting: November 30, 1960; Decem­ber 1, 1960; December 8, 1960; January 18, 1961; January 26, 1961; Feb­ruary 2, 1961; March 2, 1961; May 25, 1961; June 1, 1961; June 12, 1961; June 15, 1961;June 22, 1961;June 29, 1961.

Technical details about Telstar and the attitudes and opinions of the Bell engineers were gleaned from the following:

“Project Telstar, Preliminary report Telstar 1 July—September 1962.” (AT&T archives).

Telstar—The Management Story, by A. C. Dickieson (unpublished manu­script, July 1970). Dickieson was the project manager for Telstar (AT&T archives).

Extracts from a manuscript by D. F. Floth. Chapter on Telstar Planning: January-May 1960 (AT&T Archives 84-0902).

Each quotes extensively from memos that the writers had access to.

The discussions of technology in the chapter come from a mixture of sources, including documents in the Hughes Aircraft Company’s archives.

Helpful textbooks include:

Satellite Communication Systems Engineering, by Wilbur L. Pritchard, Henri G. Suyerhoud, and Robert A. Nelson (Prentice Hall, 1993).

The Communication Satellite, by Mark Williamson (Adam Hilger, 1990).