The Very First Light by John Boslough

Author:John Boslough
Language: eng
Format: epub
Publisher: Basic Books

THE SPACE RACE, PART II

During the period the COBE team was designing and beginning to build its instruments, Ned Wright attended an International Astronomical Union meeting in Greece, and brought back word that the Soviets were building a DMR type of instrument. My colleagues and I were dismayed to learn that the instrument was scheduled for launch in 1983. As we studied details of the Soviet plans, we were comforted slightly: We believed our design was superior and felt the 8-millimeter wavelength the Soviet scientists contemplated studying was too long. On the other hand, if the cosmic signals did turn out to be large enough for the Soviet equipment to detect, the race would be over and we would have finished in second place.

The mission, called the Relikt, eventually was flown successfully. When the data were analyzed, curious sky features appeared that one could interpret as the first faint images of anisotropy in the cosmic background radiation. Looked at more carefully, the data revealed their secret: The instrument’s antennas had been overly sensitive to the Moon. After eliminating the suspicious lunar anisotropies, the Soviet scientists still claimed their sky maps contained the earliest hints of cosmic anisotropy. Their map differed significantly from the ones we obtained later, and was never confirmed.ao The Soviet scare demonstrated to us how nearly impossible it would be to make the measurements we were planning for COBE.

We received new word, meanwhile, that the IRAS project was in danger of cancellation because of technical failures, cost overruns, and schedule slips. We were deeply worried: IRAS was developing the cryostat technology we would use, it was developing infrared detectors we needed, and it was in front of us in the queue. Worse, testing of the IRAS dewar was not going well. If it could not maintain a low temperature, COBE’s might not either. At last it was discovered that glue had come loose on one of the IRAS vent lines, and, at great expense, the cryostat was opened up and repaired.

Even the finest engineers found cryogenically cooled equipment difficult to work with, primarily because the properties of ordinary materials change as they get cold: Plastics become hard and brittle, certain stainless steel alloys disintegrate as their crystal structures change, glue pops off as it loses its adhesive abilities. You could not simply take a screwdriver and open up a dewar containing cold helium, look inside, and fix a broken wire. The dewar had to be warmed up slowly over a period as long as a month to avoid stress on the many individual parts, all made of different materials expanding at varying rates.

Most, but not all, of IRAS’s technical problems were solved by late 1982, and it was readied for a dusk launch on January 25, 1983. Nancy Boggess and Mike Hauser flew out to Vandenberg to watch. Enough problems still persisted on the spacecraft, which had been built in the Netherlands, that Hans Mark, NASA’s deputy administrator, believed some parts would fail under the stress of launch.

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