Data tape logistics

Ground receiving stations would be recording tapes at locations around the world. Considerable coordination was necessary to arrange for shipping the expected large numbers of tapes within and across the national boundaries and to ensure that all three parties involved, NRL, JPL, and us experimenters, would be able to read the tapes reliably once they were received.

It had been arranged from early in the Vanguard planning that the Minitrack tapes would be sent from the ground stations to the NRL Computing Center in Washington, D. C., for cataloging, quality checking, and duplication. On 18 December 1957, soon after the Deal project was approved, Henry Richter at JPL called Jack Mengel at NRL to arrange for JPL to receive the Deal I telemetry tapes directly from the Minitrack ground stations, so that JPL could analyze the payload engineering data.27

OPENING SPACE RESEARCH

By early January, it was time to nail down the detailed assignment of responsibilities and to ensure that all arrangements and procedures were in place.

It was then, too, that I heard of a suggestion by one of the JPL scientists that they be allowed to reduce and analyze the SUI cosmic ray data. I became alarmed that, with the immensely larger resources at JPL, they would be able to analyze the data and announce significant findings before we would be able to do so at Iowa. We had always assumed that the principal investigator and his staff (Van Allen and I) would have first rights to the data and that all information about the performance of the cosmic ray instrument and scientific results would come from us.

I alerted Van Allen to that development during the first week in January. Fortunately, he was attending a meeting of the TPESP on Tuesday, 7 January, where he had an opportunity for an extended private discussion with Pickering. That evening, Van penned a note to me that conveyed some of the results of their conversation:

(a) He [Pickering] agrees on having a meeting in the near future (during next week) on the problem of sorting out raw data from the two Juno flights [Deal I and II] among: SUI, AFCRC, and JPL. He will arrange a meeting in Pasadena with Cormier, Manring, an NRL representative, JPL persons concerned, and you (representing SUI, i. e., getting the C. R. data to SUI as promptly and as completely as possible).

(b) Pickering says to forget the Snyder proposal for reducing and analyzing our C. R. data at JPL. This proposal got “out of hand” and has no status whatever. All C. R. data will be handled as the exclusive property of SUI.28

Upon his return to JPL, Pickering took immediate follow-up action. First, he arranged a meeting to work out the details for handling the data for the entire Deal project (Deals I and II). That meeting, with Albert (Al) Hibbs as chairman, took place on Thursday, 16 January. Attending the meeting were John F. Bedinger and Frank Dearborn (Geophysics Research Directorate, AFCRC); L. N. Cormier (National Academy of Sciences); Whitney Mathews (Vanguard, NRL); JPL participants Phyllis Buwalda, Al Hibbs, B. D. Martin, Marcia Neugebauer, John C. Porter, and Henry Richter; and me.29

The agreements reached at that meeting called for JPL to serve as the central collecting agency for all low – and high-power data tapes, including those from their own Microlock receiving stations, the Vanguard Minitrack stations, and recordings made by amateur radio operators. The one exception was that, for reasons described below, the Deal II high-power recordings would be sent directly from the Minitrack stations to NRL’s Vanguard Processing Center in Washington.

At that time, we also received a status report on the readiness of all ground stations. The following stations were reported as ready to support the Deal I launch: [9]

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• JPL Microlock stations at PAFB, Florida; Earthquake Valley, near San Diego, California; Singapore; and Ibadan, Nigeria

• San Gabriel Valley Microlock amateur radio station at Temple City, California (other amateur radio stations were anticipated)

Additional stations were activated before the Deal I launch actually took place. Those were at JPL (Microlock); San Diego (Minitrack); Antigua, British West Indies (Mini­track); Blossom Point, Maryland (Minitrack); Lima, Peru (Minitrack); and Tokyo, Japan (conventional). That made a total complement of 17 stations for recording the Explorer I data.

Amateur radio operators were to notify JPL and NRL by postcard of the amount and quality of their recorded data. Science coordinators would distribute a listing of available amateur radio tapes, and tapes desired by the engineers and scientists would then be requested of the amateur radio operators. As it turned out, although radio amateurs provided highly useful tracking data, they provided very few recordings of telemetry, other than those of the San Gabriel Valley club.

As tapes arrived at JPL, their first task was to play them to produce long paper charts on Sanborn strip-chart recorders. Those multiple-pen chart recordings displayed all channels of the telemetered information, plus time information that had been recorded with the data at the receiving stations. The strip-charts were used by the staff at JPL (with oversight by Conway Snyder and major support from Phyllis Buwalda) to assess the overall performance of the satellites, including the general quality of the cosmic ray and micrometeorite data, and to obtain readings of the internal temperatures of the instruments.30 Copies of those strip-charts were sent to the experimenters. We used ours to quickly assess the quality and content of the scientific data. The copies sent to AFCRC gave them their micrometeorite data.

The second task at JPL was to copy selected tracks from the original station tapes onto magnetic tapes for the two sets of experimenters. Those for Iowa were produced on one-quarter inch, two-track magnetic tapes.

The Deal II onboard tape recorder could be interrogated only by the Vanguard Mini­track stations. It was agreed that the University of Iowa would be the central agency for handling all data from the Deal II high-power transmitter, since only our cosmic ray data were conveyed by that system.

The recordings of those high-power signals were sent from the Minitrack stations directly to the Vanguard Computing Center, on Washington’s Pennsylvania Avenue. There paper strip-chart recordings were produced, so that the NRL engineers could monitor and control system operations. They also made duplicate recordings of se­lected tracks, again on one-quarter inch, two-track magnetic tapes. Both the one-half

OPENING SPACE RESEARCH

inch originals and the one-quarter inch duplicate recordings were sent to SUI, along with copies of their strip-charts.

In summary, for all Deal I and II continuously transmitted data, we at SUI were to re­ceive from JPL (1) one-quarter inch, two-tracktape recordings containing the detected output from the GM counter channel, plus a time reference and voice announcements; (2) reproductions of the JPL strip-charts; (3) reduced internal temperature data; and (4) copies of the payload calibration books. From the Deal II high-power system, we were to receive the recordings and strip-charts from NRL.

The AFCRC experimenters were to receive, for all Deal I and II continuously transmitted data, half-inch, four-track tape recordings containing the outputs from the high-power transmitters, the low-power transmitters, and timing and voice informa­tion, plus copies of the same JPL strip-charts, reduced internal temperature data, and payload calibration books that we would be receiving.

The January meeting produced other miscellaneous agreements, including specific procedures and standards. As an example, it was agreed that all times would be recorded in Greenwich Mean Time (GMT) to avoid confusion.

A time delay of four days between satellite passage and receipt of the strip – chart records and tapes at Iowa was projected before launch. That delay lengthened considerably after launch as the immensity and complexity of the data-handling task became apparent. In fact, many of the recordings did not reach us until several weeks after they were recorded.

Some of the above arrangements were modified after we, collectively, had gained experience in handling the Explorer I data. At a meeting at JPL on 11 and 12 March, Van Allen requested funds for SUI to procure a one-half inch, seven-track recorder with characteristics matching those at the receiving stations, so that we could work directly with the original recordings and eliminate JPL’s tape-duplicating step. After we acquired the seven-track tape deck, a change in procedures was made that included circulating the original ground station magnetic tapes between JPL, AFCRC, and SUI. That reduced the workload at JPL and speeded the delivery of data to the two experimenter sites. Similarly, after that improved tape deck was placed in operation, we were able to work directly from the recordings of Explorer III data dumps produced by the Minitrack stations.

The initial plan was to permanently archive the original continuously transmitted data tapes at JPL. After the change in the tape-handling procedures mentioned above, SUI became the permanent archive site for all of the Explorer I, III, and other follow-on SUI experiments. Those original tapes still exist (in 2010) in the former Van de Graff

CHAPTER 11 • OPERATIONS AND DATA HANDLING particle accelerator vault located under the front lawn of the old Physics, Astronomy, and Mathematics Building on the University of Iowa Campus. Arrangements are being made by the University of Iowa Libraries, Department of Special Collections to digitize those tapes and maintain them in long-term storage.

Pickering’s second action upon his return to JPL after his January discussion with Van Allen clarified any lingering question about the analysis of the experimental data. On his instructions, a memo was issued that stated, simply:

It has been decided that no data analysis of cosmic ray counts or meteorite impacts obtained from Project Deal will be done by the Lab. Data reduction will be done in accordance with agreements made by you [Al Hibbs] and the experimenters, Van Allen and Dubin. The Data Reduction Lab may scan the data for obvious inconsistencies, but no analysis of this will be performed.31