Saturday Space — Reviving the Apollo Communications System
After nine months of effort, the incredible team of Curious Marc, Ken Shirriff and Mike Stewart have revived my 50+year-old Apollo S-Band communications system, using my ground support equipment and the vintage Apollo CSM transponder. In the most recent episode, they powered it up and got the Apollo transponder to lock bidirectionally, with the original NASA test transmitter and receiver, which we both restored to their original Apollo frequencies: https://youtu.be/hBKHNADtNPs (aka Ground Control to Major Tom)
The original “USB” (Unified S-Band) was the sole deep space communication channel used during the Apollo missions. With just 20 Watts, they could communicate with Houston from the moon (across 239,000 miles). And a single antenna combined voice, television, command, tracking and ranging. They even used it to study the lunar surface, with the aid of the Stanford Dish.
You can see the black art of microwave RF design as they disassemble my Apollo CSM transponder, travelling wave tube amplifier and the various ground panels used for communications. They even had to have a custom crystal made, to undo modifications made post-Apollo to adjust the ground test equipment for a mystery application (deduced to be the GEOS-3 satellite in 1975).
I will be loaning these panels to SETI to decorate their new HQ with the heroes of our deep space communications systems. In addition to the Apollo S-Band suite, I will be loaning the panels for Viking (the first Mars landers, which failed to find the signatures of alien life), the docking adapter for the Apollo-Soyuz Test Project (the symbolic end of the last space race), and various Saturn V rocket engine monitoring and communications systems.
Here is the complete video playlist, with 13 episodes so far: https://www.youtube.com/playlist?list=PL-_93BVApb58SXL-BCv4rVHL-8GuC2WGb and more items in the FV space collection: http://tinyurl.com/FVspace
Leave a Reply