Posted: Jan 21, 2022 3:29 pm
by TopCat
hackenslash wrote:Doppler shift in reception throughout the flight

Ok, I'd buy that, to get the velocity in real time. I guess you could integrate that to get the distance, or perhaps time the return trip for a signal would be simpler.

They also need to know where on the spherical sector X million meters away from the transmitter it is?

though it's mostly a matter of extremely careful planning of the entire flight from selection of launch window to orbital insertion all carefully timed, a.k.a., the brilliance of Katherine Johnson.

Not disputing the brilliance, or the extremely careful planning, but I'm not sure I buy that as a method of ensuring the required precision.

For instance, the duration of the MCC-1a burn wasn't scheduled until they knew how precisely how much was needed.

I guess the three ground stations, with an accurate distance from each, would give the location on that spherical sector.

Boggles the mind

It really does :cheers: