On 1/9/17, Robert Bruninga bruninga@usna.edu wrote:
After seeing the great movie “hidden figures” last night, I had lots of questions from my faded memory of the time (it was the same year I got my ham license and was 14 years old). This Wiki page has a lot… but the questions lingering in my mind were:
https://en.wikipedia.org/wiki/Project_Mercury
Was his mission planned at 3 orbits? (I thought it was more andthen cut to three).
The comment by the capcom was that he was "good for 7 orbits", but the plan was for only 3.
If #1, then they must have had to have recovery ships at adifferent spot for every potential orbit since he could not maneuver anything other than when to fire the retros. If it was 7 cut to three, then I guess they only needed two ship areas…
There were several potential landing sites during a mission in case something went wrong.
Gemini VIII, with Neil Armstrong and Dave Scott, had to be cut short after a few orbits because of the problem with one of the spacecraft's manoeuvring thrusters. It splashed down in one of the auxiliary recovery zones in the South China Sea and they were picked up by a USN destroyer.
That didn't always work as NASA found out during the next Mercury mission, Aurora 7. Carpenter apparently fired his retro thrusters a bit late and landed some 400 km away from he was supposed to.
What frequency was CAPCOM? Was it the 108 MHz? I think thetracking stations all relayed the voice via HF?
I don't believe so. I think the ground stations might have connected by telephone lines to Mission Control. The only signal fading would be when the spacecraft was out of range of a tracking station.
Also related to #1, if something happened to the pilot, I assumeground control could fire the retros.
If I remember correctly, the spacecraft was entirely under control of the pilot. During Shepard's mission, Freedom 7, the retros didn't fire automatically so he had to light them manually.
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73s
Bernhard VA6BMJ @ DO33FL