X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
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From: "1st Lt. Henry S. Cobb" <cobbhs@afsc-ssd.af.mil>
Subject: Where is everything?
To: "space+" <space+@andrew.cmu.edu>
The Space Age is now some thirty years old, and enough has happened and been forgotten that history is becoming important. I have a historical question:
Where is everything?
Most of the stuff that humans have launched went into Earth orbit and
re-entered. It's history. A lot of the rest is still in Eart orbit, and
NORAD tracks it. Presumably the Soviets do, too. But radars can't see GEO
very well, and certainly can't see much farther out, and there's enough
stuff further out to be interesting. I'll give as an example something that
I was/am interested in.
Apollo 10 did a rehersal for the Moon landing in lunar orbit. The LEM
separated from the CSM, did a partial descent burn, came back up, and
rendezvoused. The astronauts transferred back to the CSM, undocked, and
went home. Houston then commanded the LEM to burn both its engines "to
depletion", which was too dangerous to do on anything other than a dying
vehicle. They thought the engines might explode as they ran out of fuel,
but they didn't, and the delta-V sent the LEM into a heliocentric orbit.
Houston tracked the receding LEM until its batteries died.
I was told this story by someone who was a GNC flight controller for the
LEM during that mission. According to him, the tracking folks calculated
at the time that the burnt-out LEM ascent stage would pass the Earth again
"in about twenty years." Folks, it's been twenty years.
I was working at JSC at the time, and I spent some time searching for the
tracking data. I was interested in just WHEN Apollo 10 would return. I
discovered that the data is not in any library at JSC. Public Affairs didn't
have the info, or any idea where to find it. I found a few tracking types
left from Apollo who had vague memories of the event ("Oh yeeaah ... How
about that. Hmm ...") but no data and no pointers.
I never did find the data. I suspect that there's a computer tape somewhere
at JSC with the information on it, but you'll need to find both the tape
and a 1960's tape drive to read it. Neither is a trivial exercise. I
suspect it would take something on the scale of a Congressional inquiry to
unearth this information. I'm still curious.
Apollo 10 is just one example (although, as far as I can tell, it's the only
piece of Apollo left in any orbit). Where are all the Surveyors, Rangers,
Lunar Orbiters, and Mars probes? Especially the ones that crashed. Is
anyone keeping track of this stuff?
A side note of historical interest: due to the mascons in the Moon, lunar
orbits are unstable over periods of a few months. Anything left in lunar
orbit for more than a year without stationkeeping has crashed. This includes
all the other LEM ascent stages (except 13, of course). My LEM GNC friend
indicated that the LEMs, at least, may have had some help in crashing. He
didn't come right out and say it, but he mentioned that "the flight directors
didn't want any leftovers cluttering up the orbit for the next mission."
(Not a precise quote.) If this is true, the locations of the other LEMs
may be known a bit more precisely. ;-)
Where is everything? (Enquiring minds want to know! ;-)
Stewart Cobb
COBBHS @ afsc-ssd.af.mil
------------------------------
Date: 31 May 90 04:03:47 GMT
From: unhd!rmk@uunet.uu.net (Robert M. Kenney)
Subject: Re: Soviet Missions to Mars
What ever happened to the idea of a network link to the USSR? Seems
like the scope of this group(and others) could be improved by getting
interaction with our Soviet counterparts. It'd be nice to get launch
schedules and other messages from them like we do from our friends at
JPL. Whatever happened to that slow news link somebody said he was setting
