The Deal I launch: Explorer I in orbit!

The next day, Friday, 31 January, the ABMA and JPL launch crews assembled once again in the blockhouse and other Deal operational sites, and I again joined Roger and Marty in Hangar S. Time was running out, as the days during which the satellite could be launched were waning. In the terminology of modern space-speak, the launch window was closing.

All was ready. The rocket, shrouded by the servicing gantry and illuminated by the floodlights, as shown in Figure 9.1, looked beautiful in the early evening. As the

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countdown progressed, the gantry was moved back to reveal the complete Jupiter C launch vehicle, with its diminutive fourth stage and satellite payload on its very tip. The assembly, with much of the Redstone rocket coated in frost due to the cold liquid oxygen in its oxidizer tank, and with the upper stage tub spinning, was shown earlier in Figure 0.1, which was snapped within the last 15 minutes before liftoff.

A word about the marking on the side of the Redstone booster rocket—“UE.” It was the custom at Huntsville to number the Redstone rockets in the order that contracts were issued for their manufacture. The key for the number coding was the word HUNTSVILLE. This was Missile 29. The second and ninth unique letters in the key word are U and E. Those letters are clearly visible in both Figures 0.1 and 9.1.

Not being in an active Deal project launch facility, I had access to only the general announcements being made over the Cape-wide public address system. That did not provide detailed coverage of the countdown progress. Von Braun, however, at his location in the Pentagon operations center, was in continuous telephone contact with the launch director in the Cape Canaveral blockhouse. He later recalled several exciting moments in the countdown. At one point, someone saw something dripping from the rocket. Albert Zeiler, the firing team’s propulsion man, crawled head down into the tail to investigate. Fortunately, it was just a spill, and he wiped it up.

There was a second hold a little later to investigate an anomalous reading on one of the rudders, but that was found to be an instrumentation error, and the count quickly proceeded. Finally, at 10:45, the moment came, and launch director Kurt Debus gave the word to start the firing sequence. At 10:48:16, the rising rocket opened the switch denoting liftoff, and the flight was under way.

After 156 seconds, when the rocket was 60 miles up, the booster rocket burned the last of its fuel and shut down. The spinning stages 2, 3, and 4 (with its satellite payload) coasted on toward the desired orbital altitude. During that climb, a special control system tilted the cluster so that at the apex of its flight, it would be pointed parallel to the Earth’s surface.

At that moment, Ernst Stuhlinger sent a radio signal for stage 2 to fire. Stages 3 and 4 then fired in sequence, boosting the speed of the final stage with its satellite to the critical 18,000 miles per hour.

His account continued, telling of the initial joyful reaction of the people gathered at the Pentagon and their haste to “tell the world.” But they decided to wait until a full orbit was confirmed, so they could be absolutely certain.2

From my post with Roger Easton and Marty Votaw in Hangar S, at 9:31 PM EST, I began logging the times of the transitions between two telemetered tones, as I had for the previous countdown attempt. At the beginning of that log, the vehicle count was

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at L minus 62 minutes and counting. As von Braun related above, there was a hold, which I recorded as happening at 9:48. The count resumed at 10:03. It proceeded smoothly until about 12 minutes before ignition, when a monitoring signal in the first rocket stage indicated something erratic about one of its control vanes. Members of the firing team concluded that the indicator was erratic and quickly resumed the countdown.

My notes during the last part of that countdown read:

Start spin-up at 10:37:36.

Modulation of carrier with spin at 10:38:10

L – 5 [minutes] at 10:43:09.

L – 80 seconds at 10:46:53.

L – 30 seconds at 10:47:53.

Fire at about 10:47:56 [EST].

Lift-off about 15 seconds later.

Counting rate increased rapidly.

Injection about 10:55:06. Signal was received for about 10 minutes (620 seconds) and counting rate sounded like it held steady all this time.3

Activity in the blockhouse and other control facilities is intense throughout any countdown and launch, as thousands of pieces of apparatus must be put into play and thoroughly checked.4 The Redstone booster in the Jupiter C configuration was the largest and most impressive part of the assembly. The task of that 56 foot long, six foot diameter, five ton rocket was to lift the payload and upper stages to orbital height. There the three upper rocket stages took over to accelerate its payload to the speed required for it to remain in a stable orbit.

Those three upper stages were arrayed in a tublike assembly, consisting of a second stage of 11 JPL rockets arranged in a circle around the outside circumference of the tub, a third stage of three of those same rockets arranged in a circle inside the outer ring, and a central final rocket stage with its attached satellite payload. Each of those 15 identical rockets was 40 inches long, about six inches in diameter, and weighed about 50 pounds when loaded.

About 17 minutes before booster ignition, an electric motor and chain drive started rotating the tub containing the three upper stages. It spun up quickly to about 450 revolutions per minute. During the burning of the Redstone booster, that speed was increased to about 750 revolutions per minute. The booster burned out 156 seconds after ignition, at a height of about 45 miles and at a speed of about 3000 miles per hour. The entire assembly then coasted upward for about 240 seconds to the apex of its trajectory at about 220 miles height. During that coasting period, the control system in the booster rocket pointed the complete assembly in the correct direction. At the proper moment, a signal from the ground initiated separation and second-stage firing. The spinning of the upper stage tub stabilized its alignment, much as a bullet is stabilized by its spin.

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The problem of determining the exact moment for injection was described earlier. Ernst Stuhlinger, backed by Walter Haeussermann, monitored an array of instruments as the rocket lifted through the atmosphere. They made a running calculation based on data telemetered from the Redstone booster and set several inputs into Ernst’s apex predictor. As the rocket neared its highest point, Ernst pushed a button that was in parallel with the predictor’s contact closure. That initiated ignition of the second stage. Postanalysis revealed that his timing was impeccable. Ernst has been known by his colleagues ever since as “the man with the golden finger.”

In response to Ernst’s command, a battery in the vehicle sent a current through an igniter; the heat of the igniter touched off a chemical reaction that lit a tiny amount of photographic flash power, and then, by a chain reaction, a larger amount. In a split second, the ring of 11 rockets forming the second stage roared to life, blasting the cluster away from the Redstone booster rocket. During the burning time of only six seconds, the second stage boosted the assembly to a new high in speed. A brief instant later, an automatic timing mechanism fired the third stage of three rockets, pushing it away from the second stage. After a similar six second burn, the third stage had done its work, and a few moments later, the timer ignited the final rocket stage, with its satellite payload. That final stage propelled the assembly to the required speed of over 18,000 miles per hour.

That was my first exposure to the launching of a large rocket. The initial sound of the thundering Redstone rocket took about 10 seconds to reach me across the approxi­mately two mile distance from the launch pad. When it arrived, it was overpowering—I felt as though it was trying to pound me into the floor. I recall that the noise had an unexpected crackling sound, signifying loud mid – and high-frequency components superimposed on the low-frequency thunder. The live sound is quite different from the sound one hears over the radio and television, where both the very lowest rumble and the highest frequency components are attenuated.

It took several minutes for the sound to fade as the rocket lifted and quickly gained speed. As it did, we were left with the sound of the cosmic ray instrument’s signal coming from the loudspeaker.

As mentioned before, each 32 counts of the GM counter was marked by the switching of the tone between two audio frequencies. With great satisfaction, I noted that the counting rate increased quite rapidly at first, reached a peak value, and then decreased to an essentially constant rate. It continued at that rate until the signal faded after about 10 minutes, when the departing instrument began to drop below our visible horizon. Later, after the initial ground station tapes had been processed at Iowa, the data from the JPL Microlock station at Cape Canaveral were plotted to display the information graphically. That plot is reproduced here as Figure 9.2.5,6

CHAPTER 9 • THE BIRTH OF EXPLORER I FIGURE 9.2 Plot of the counting rate of the GM counter on Deal I (Explorer I) during the first five minutes of its ascent into space. (Courtesy of the University Archives, Papers of James A. Van Allen, Department of Special Collections, University of Iowa Libraries.)

That pattern in the counting rate during ascent was exactly as expected. When the GM counter was low in the atmosphere, it was detecting mostly showers of secondary particles produced by the collisions of high-energy cosmic rays with atoms and molecules high in the Earth’s atmosphere. As the instrument rose higher, it detected an increasing number of those secondary particles as the region of primary interaction was approached, and also began to see some of the primary cosmic ray particles before they had an opportunity to interact in the air. Even higher, and the number of secondary particles decreased as the sensible atmosphere was left behind, and soon only the primary cosmic rays were seen. The combined effect resulted in a peak in the counting rate in the neighborhood of 11 miles altitude—it was the Pfotzer-Regener maximum mentioned earlier. Above that peak, the GM counting rate remained essentially constant as the instrument rose to orbital altitude. This can be seen graphically in Figure 9.2.

The gratifying conclusion was that the instrument had remained well above 11 miles altitude until after the vehicle had passed out of receiving range. Furthermore, it was clear that the instrument and telemetry system were operating properly.

Excited verbal confirmations of post-liftoff events were announced over the Cape intercom loudspeaker. First, there were reports via range instrumentation and missile telemetry receiving stations that the ignition and burnout of all stages had been normal, that separation of each of the stages had occurred on time, and that each stage had accelerated as planned. Then there was the report of the fading of the signal from

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the Patrick Air Force Base (PAFB) Microlock station at about the same time that we lost it in the Vanguard hangar, both occurring at the expected time. About two minutes after injection, the downrange station at Antigua, British West Indies, reported that the satellite had passed overhead. Finally, there was the somewhat-delayed report from the Cape’s Doppler velocity-measuring station that the payload’s speed relative to the launch site had been within the expected range as it departed over the horizon.

The Doppler measurements, however, yielded only single-axis velocities, i. e., ve­locities along the paths connecting the rocket and the ranging stations. In the absence of cross-track information, there was no way to know whether the final rocket stage had been pointed correctly, or somewhat up, down, right, or left. Misalignment could have resulted in failure to orbit.

The information received to that point produced an immediate feeling of jubilation. However, we would not know that the payload was actually in orbit until it completed a major portion of its first orbit.

After the loss of signal by the Antigua down-range station, there was nothing fur­ther that I could do at the Vanguard receiving station, as that site was not con­nected to the internal Deal communications network. I quickly made my way to JPL’s Microlock receiving station for further news. That station had been assembled in a trailer at JPL’s Pasadena facilities, transported to Cape Canaveral, and set up in an open area. Its primary purpose was to assist in checking the instrumented payload before and during the countdown. It was also used as one of the ground receiving stations for routine reception of the satellite signal throughout the satellite’s operating lifetime.

At that time, however, it had a special value—it was connected to JPL and the rest of the ground receiving station network by high-quality telephone lines. That provided access to the information being exchanged between the myriad control centers and receiving stations. I joined a small knot of individuals clustered outside the trailer’s entry steps. We did not really expect to hear of further signals from the satellite until it approached the Microlock and Minitrack receiving stations in California near the end of its first orbit. If the orbit had been as planned, with about a 105 minute orbital period, it should approach California a little more than 96 minutes after liftoff, or at between 25 and 30 minutes past midnight EST.

During the middle of the interminable wait for its arrival at the West Coast, Al Hibbs did appear at the trailer door at about 11:25 to relay some very limited but encouraging information about the initial satellite orbit prediction, based primarily on calculations done with the Cape Canaveral and downrange radar and Doppler data.

Although it has been variously stated that a few verbal reports came in during the first orbit from a scattering of amateur radio stations, no durable record of those

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contacts has been found. In any event, there were certainly no contacts before it neared the U. S. West Coast sufficient to establish whether the satellite was or was not in orbit.

Three Microlock stations had been set up in California. They consisted of the developmental installation at the JPL central laboratory in north Pasadena, a station established with JPL assistance by the San Gabriel Amateur Radio Club at Temple City east of Pasadena, and the station that had been set up for engineering tests of the Microlock system. That station was located in Earthquake Valley, near the town of Julian, about 30 miles northeast of San Diego.

The Vanguard project also had established one of their Minitrack stations at Brown Naval Air Station at Chula Vista, California, southeast of San Diego, and that station had been modified to receive the signal from one of the transmitters in the Deal satellite.

The time of expected signal acquisition came amid growing anticipation but passed with the devastating absence of any signal. We waited with increasing apprehension, fearing that the rocket or instrument might have failed.

Finally, at about 42 minutes past midnight, about 12 minutes after it was expected, and just as my worst fears were peaking, a voice from the trailer shouted, “Gold [code name for the Earthquake Valley station] has it!”7 There quickly followed reports that other West Coast stations were receiving the signal.

There was a brief silence as the reality set in, and then an outburst of shouts as our pent-up emotions exploded. A few minutes later, at about 12:46 AM, the signal was picked up in the Cape Canaveral trailer where I was standing. The new Earth satellite had completed its first full orbit.

Those in the Pentagon experienced a similar roller coaster of emotions. Von Braun’s later account indicated that the satellite was due on the West Coast at about 12:30 AM EST. But that time came and there was no signal. Eight minutes dragged on, and there was still no signal. As he related:

We were miserable. Obviously, we’d been mistaken. The Explorer had never really gone into orbit. Then, all at once, within 30 seconds, all four California stations reported hearing the Explorer’s signals! America’s moon was definitely in orbit. There’d been just a slight error in our quick estimate of the satellite’s initial speed and period of revolution.8

It became obvious that the rocket had provided a larger than expected thrust, resulting in a higher than planned orbit and a longer orbital period. The orbit had been expected to have a perigee (lowest height above the Earth) of about 220 miles and an apogee (greatest height) of about 1000 miles. The perigee and apogee heights were actually 221 miles and, most significantly, 1583 miles, with an orbital period of 114.7 minutes rather than the 105 minutes that had been originally anticipated.

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Van Allen provided his own typically succinct account of the emotional wait at the Pentagon:

The burning of all four stages was monitored by downrange stations and judged to be nominal. The final burnout velocity of the fourth stage was somewhat higher than intended, and there was a significant uncertainty in the final direction of motion. Hence, the achievement of an orbit could not be established with confidence from the available data. The telemetry transmitter was operating properly, and the counting rate data from our radiation instrument corresponded to expectations…. The reception of the telemetry signal after the lapse of one orbit was necessary before success could be confirmed. The nominal period of the orbit was ninety-five minutes, and the first pass from west to east over northern Mexico was expected to provide the first clear opportunity for reception of the signal by stations in southern California.9

By previous arrangement, I was a member of a group in the War Room of the Pentagon, which served as a center of communications. Others present included Wernher von Braun, Secretary of the Army Wilber M. Brucker, [Department of the Army Chief of Staff] General Lyman L. Lemnitzer, [ABMA’s director] General John B. Medaris, and [JPL’s director] William H. Pickering. For about an hour following receipt of the downrange station reports, there was an exasperating absence of information. Then there began a trickle of affirmative, amateur reports from around the world, none of which withstood critical scrutiny. The clock ticked away, and we all drank coffee to allay our collective anxiety. After some ninety minutes, all conversation ceased, and an air of dazed disappointment settled over the room. Then, nearly two hours after launch, a telephone report of confirmed reception of the radio signal by two professional stations in Earthquake Valley, California, was received. The roomful of people exploded with exaltation, and everyone was pounding each other on the back with mutual congratulations.10

At the Cape, I lingered at the Microlock trailer to listen to further reports of signal acquisition. The crowd there began to thin, and I started looking for my JPL associates. But they had all disappeared! The upper-level JPL and ABMA staffs had all rushed to a press conference at PAFB. As I had not been invited, and had no vehicle, there was nothing for me to do but to hitch a ride back to my motel room and retire for the night.

In that moment of great triumph, I felt terribly isolated. I lay awake for a while, thinking of the momentous turn of events that had occurred during the nearly four months since the Sputnik 1 launch.

In spite of the late hour, a number of memorable press conferences and celebrations took place during that night. This was the news the public was seeking—the Soviets no longer reigned supreme in space. There was a great eagerness to pass out the word and to celebrate this “coming of age.” The reporters rushed from the Cocoa Beach press conference to write their stories for the morning papers.

It was also time for the Washington press corps to be briefed. The U. S. National Committee for the International Geophysical Year (IGY) had insisted that the event be viewed not simply as an achievement of rocket technology, but as an achievement

CHAPTER 9 • THE BIRTH OF EXPLORER I

FIGURE 9.3 The triumph of success! From the left, William Pickering, James Van Allen, and Wernher von Braun hold aloft a model of the Explorer I satellite at the press conference at the National Academy of Sciences immediately after they announced the successful launch. (Courtesy of the Department of Physics and Astronomy Van Allen Collection, The University of Iowa, Iowa City, Iowa.)

for science and as a step in meeting the U. S. scientific commitments for the IGY. Van Allen continued with his account of events immediately following the launch:

Pickering, von Braun, and I were whisked by an army car from the Pentagon to the National Academy of Sciences and smuggled through a back door, where we made our preliminary report to Porter and the IGY staff. We were next led into the Great Hall of the Academy (by then about 1:30 AM) to report to the press. To my astonishment, the room was nearly filled with reporters, photographers, and many other interested persons who had been waiting there since about 10:00 PM. The ensuing press conference was a spirited one. The successful launch of Explorer I was an event of major national and international interest, coming as it did after three humiliating launch failures of Vanguard.11

The photo in Figure 9.3 and others like it were seen in newspapers and magazines all over the world. Although those three pioneers were previously well known in scientific and governmental research circles, the Explorer coverage brought them to the full attention of the much broader public.

At Augusta, Georgia, another drama unfolded. On that Friday evening, President Dwight D. Eisenhower was at the Augusta National Golf Club in Augusta, Georgia, for a weekend of golf and bridge. He had arrived during Friday afternoon and was told upon arrival that the weather conditions for the Jupiter C launching at Cape Canaveral would probably not be good until the following week. After completing

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15 holes of golf and settling down for a few rubbers of bridge with friends, his press secretary, James C. Hagerty, received the first of a series of phone calls from Brigadier General Andrew J. Goodpaster in Washington. Goodpaster was the White House staff secretary and Eisenhower’s liaison man with the Pentagon. In his first call, Goodpaster reported that the weather at the Cape was clearing. At 8:30, Goodpaster informed Hagerty that the weather looked even better and that the rocket was being fueled. In another call at 9:30, Hagerty and the president learned that the launch was proceeding and almost certainly would not be held up by the weather. As the launch time approached, Goodpaster was on the phone again, repeating to Hagerty the launch countdown from Cape Canaveral. At 10:48, as the firing command was given and the rocket was on its way into space, the president got on the phone and, for the next several minutes, listened to Goodpaster relay a word picture of the rocket’s flight.12

After waiting until nearly 1:00 AM, the delighted president put out the first official announcement that the U. S. satellite was in orbit around the Earth. At a dramatic news conference, Hagerty issued the president’s official statement:

Dr. J. Wallace Joyce, head of the International Geophysical office [а/с] of the National Science Foundation, has just informed me that the United States has successfully placed a scientific earth satellite in orbit around the Earth.

The Satellite was orbited by a modified Jupiter C rocket.

This launching is part of our country’s participation in the International Geophysical Year.

All information received from this satellite promptly will be made available to the scientific community of the world.13

At Huntsville, Alabama, a wild celebration broke out somewhat prematurely. Crowds began assembling in the main town square soon after they learned that the Jupiter C had lifted off. About an hour later, but still over an hour before President Eisenhower’s announcement from Augusta, the sirens from Huntsville police cars and fire engines began to scream. That signal had been prearranged by Mayor R. B. Search and other city officials. The Huntsville Times had announced in its afternoon edition that sirens would signal the event, and it was triggered by running telephone conversations between city officials and their esteemed fellow citizens at the Cape. Before the celebration was over, the crowd’s size grew to an estimated 10,000 (out of a Huntsville population of about 56,000). Firecrackers boomed, skyrockets rose from street corners, and the police drove along the main street with their sirens blaring. That local demonstration was likened in the press to those that crossed the nation at the conclusion of World War II.14

The next morning, my Dad captured some of the excitement when he interviewed Van Allen live by telephone for his daily radio program in Iowa City. During that interview, Van Allen commented on the scene in Washington:

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Well, I was here at the Pentagon, in Washington during the launching at the so-called central control room where all the information on various aspects of the firing is sent in by teletype and telephone. We were in a small room that was knee deep with generals and other important people, including the Secretary of the Army Mr. Brucker. We followed the whole progress of the operation minute by minute as it occurred, beginning about nine o’clock and continuing, of course, until well after one o’clock here.

… The first report in which we felt certain that the satellite had actually worked was received at about 12:42 EST when it first appeared on the West Coast. The West Coast report showed that both transmitters were working properly, that good cosmic ray data were coming in, and that all apparatus was working normally.15

One of the JPL public affairs officers had promised to pick me up the next morning so I could help with packing the equipment at the Cape. Apparently, he forgot. Without transportation of my own, I was stuck at my motel most of the day. My profound feeling of isolation was eased somewhat that evening, when JPL hosted a huge celebration at the nearby Bahama Beach Club. I attended the beginning of the party but had to leave early for Orlando, so that I could catch the 6:00 AM Sunday morning flight to Iowa City.