nasa (04/01/83)
Does anyone out there know what frequency NASA is using for radio transmission between the Challenger and Houston during the STS-6 mission? I know that they were using 146.475 Mhz a few missions ago, but was unable to pick up anything during STS-5. Thanks in advance. foxvax1!nasa Bob McNally
karn (04/02/83)
The frequency you specified is in the amateur 2-meter band; I doubt very seriously that NASA uses it directly for air-to-ground transmissions. This may have been the frequency used by one of the amateur repeaters authorized during the last mission to rebroadcast shuttle communications that were picked off the NASA circuit (NASCOM) for the benefit of local amateurs listening in. As far as I know, only the Johnson Space Center and the Jet Propulsion Laboratory amateur radio clubs did this last time. The actual frequencies used for shuttle communications are as follows. Source is the Rockwell Space Shuttle Transportation System Press Information kit. Uplinks (ground to shuttle, all are phase modulated:) S-band NASA Space Tracking and Data Acquisition Network: 2106.4 mhz (primary) 2041.9 mhz (secondary) Department of Defense Air Force Satellite Control Facility: 1831.8 mhz (primary) 1775.7 mhz (secondary) Downlinks (orbiter to ground), PM: 2287.5 mhz (primary) 2217.5 mhz (secondary) FM Downlinks: 2250.0 mhz (FM operational transmitter) 2205.0 mhz (DFI transmitter) These S-band links can be used for wideband data, digitized voice and FM video. Receiving (and decoding) them directly would be a VERY challenging job, but the information to do so is probably available in the tons of shuttle project reports available from NTIS. There is also a UHF (actually high VHF) conventional analog voice-only system, used over smaller ground stations. Frequencies are 296.8 mhz primary and 259.7 mhz secondary. The military emergency frequency of 243.0 mhz is also available. This system is much more reasonable to intercept, requiring only a scanner covering the correct frequency range. However, the shuttle in its low, typically 28 degree inclination orbit makes only very brief, quick, low elevation passes over most northern US locations, and any direct reception would be quite limited. Unless you live near one of the tracking stations, you would also hear only one side of the conversation. If you want to see and hear just about everything, your best bet is to ignore all the information I've just given you and get yourself a domestic TV satellite receiver. Point it either at Satcom 1, transponder 9 or Satcom 2, transponder 13. I'm not sure which, as Johnson Space Center gave me the first answer and Goddard Space Flight Center gave me the second; not having a receiver (yet) I am unable to verify which is correct. In any case, the transponder in question is used during missions to carry NASCOM, the relatively "clean" audio and video feed provided to the TV networks for subsequent butchering. Lacking a backyard satellite receiver, call 900-410-6272 and hear the audio (as your quarters tick away...) Phil Karn
kevenb (04/03/83)
If anyone does know the HAM frequencies which repeat the NASA comms, please post them. My scanner programming finger is ready. Keven