INFRARED TELESCOPE

The payload was composed by a gallium-doped germanium bolometer fed by a conical light-pipe situated at the focus of a Newtonian telescope with an f/8 primary mirror 20 cm in diameter. The field of view of the detector was 0º 56. The bolometer and light-pipe were cooled to 1.8° K by liquid helium at ambient atmospheric pressure

Balloon launched on: 1/21/1970 at 18:48 cst
Launch site: Hobbs, New Mexico, US  
Balloon launched by: National Center for Atmospheric Research (NCAR)
Balloon manufacturer/size/composition: Zero Pressure Balloon Winzen - 750.000 cuft (1.0 Mil. Stratofilm)
Balloon serial number: SF 120.55-100-NS-02 SN:5
Flight identification number: 522H
End of flight (L for landing time, W for last contact, otherwise termination time): 1/22/1970 at 9:00 cst
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): F 12 h 20 m
Landing site: In Center, Texas, US
Payload weight: 801 lbs.

The balloon was launched at 18:48 CST on January 21, 1970 from Hobbs, New Mexico. It reached a float altitude of 28 km at 20:30 CST and remained there, drifting almost due east about 2° in longitude every 3 hours, until cutdown at 09:00 CST on January 22. The artificial source was seen when actuated about every 2 hours, and all of the equipment appears to have operated properly throughout the flight. About 10 percent of the sky was observed during the 12.5 hours at ceiling.

During the earlier (nighttime) part of the flight, were recorded six signals with good signal-to-noise ratios, whose characteristics are those of point sources. Two of the signals were definitely observations of the Moon, one occurring shortly before the balloon had reached float altitude and while the telescope's azimuthal rotation period was about 3 min; the other lunar sighting was much later, at 0513 CST January 22. The four events were unique in the flight record of the instrument. They satisfied the requirements for attribution as point sources, in terms of signal shape and polarity, and were larger by far than any other events with the exception of the lunar sightings. Several other possible sources may have been observed, but their signal amplitudes were so much closer to the background noise level that they have not been included in post-flight analysis.

• Detection of Celestial Sources at Far-Infrared Wavelengths Astrophysical Journal, vol. 162, p.L87
• NCAR Scientific Balloon Facility Annual Report, 1970 National Center for Atmospheric Research, February 1971