
How Apollo Astronauts Didn’t Get Lost Going to the Moon - eaguyhn
http://blogs.discovermagazine.com/vintagespace/2019/06/15/how-apollo-astronauts-didnt-get-lost-going-to-the-moon/
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ncmncm
The article doesn't actually answer the question it poses. Yes, you can find
angles to stars and horizons, but how does that help?

What it doesn't say is that measuring the angles between stars and horizons
gives you a measure that doesn't depend on which way the spacecraft is
pointing. Those angles change in predictable ways as the spacecraft moves. It
also doesn't say that what matters is not what what the angles are, and where
the spacecraft is, but how they change over the course of a series of
readings, telling which direction the spacecraft is going, and how fast.

It really would not have taken more column inches to say what I said,
especially if they struck reminding us over and over that the stars' apparent
motion is negligible.

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nutcracker46
In addition to celestial navigation, there was very precise radio based
ranging between tracking stations and the spacecraft. You could call it a
precursor to GPS, where a pseudo-random noise was transmitted in the microwave
signal to the spacecraft. The spacecraft sent back that PRN stream on its
microwave downlink to Earth.

I have forgotten how precise and accurate the tracking data was, but it was
more than enough for the missions.

NASA would take measurements and then uplink nav data to the guidance
computers as necessary. With that and periodic celestial position fixes, there
was no getting lost on the journey.

"Just don't screw up a procedure or have a burn go bad and everything will be
okay."

