Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!ames!ames.arc.nasa.gov!mike
From: mike@ames.arc.nasa.gov (Mike Smithwick)
Newsgroups: sci.space
Subject: Re: Apollo 8, 9, and 10
Message-ID: <28856@ames.arc.nasa.gov>
Date: 19 Jul 89 21:15:46 GMT
References: <377@dftsrv.gsfc.nasa.gov> <1989Jul19.005449.3163@utzoo.uucp> <17231@bellcore.bellcore.com>
Sender: usenet@ames.arc.nasa.gov
Organization: NASA - Ames Research Center
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In article <17231@bellcore.bellcore.com> ddavey@grits.UUCP (Doug Davey) writes:
>In article <1989Jul19.005449.3163@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>> orbit, Apollo 10 flew a dress rehearsal of the landing (including LM
>> descent to 10 miles above the Moon), and Apollo 11 was the big one.
>
>Does anybody remember whether the ascent or descent engine was used
>during Apollo 10's return from low orbit to rendezvous with the CSM?
>Either option seems difficult.  On the one hand, I would not expect
>the descent engine to be restartable.  On the other, firing the
>ascent engine and getting the ascent stage cleanly separated from the
>descent stage would be tricky since the descent stage was deigned to
>be firmly on the lunar surface during this operation.

Since the Apollo 10 was a full dress-rehersal for Apollo 11 it did
everything 11 would do, except land. This flying under the same lighting
conditions as 11 to take landing site pictures, establish landmarks, etc.

This included staging and returning to high-orbit using the ascent stage, 
much as was done on Apollo 9 two months before. So they were doing nothing
really new, just verifying the LMs capabilities in the Lunar environment.
The notable thing that happened on Apollo 10 was at the point of staging when
one of the crew accedentally switched the computer from "attitude hold", over
to a mode that told it to start hunting for the CM. Since the CM was nowhere
to be found the LM went into a wild dance. Stafford hit the abort button
(what Armstrong would've done if the 1202 and 1201 alarms were too serious
to ignore), staged and everything calmed down. They were at an altitude of
about 8 1/2 NM (at least according to the Flight Plan), and were coming up
to a mountain that was 3 miles high. Pretty dramatic stuff.



          *** mike (still looking for a publisher) smithwick ***

"Los Angeles : Where neon goes to die"
[disclaimer : nope, I don't work for NASA, I take full blame for my ideas]