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Sun, 10 Mar 91 01:37:08 -0500 (EST)
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Date: Sun, 10 Mar 91 01:37:01 -0500 (EST)
Subject: SPACE Digest V13 #251
SPACE Digest Volume 13 : Issue 251
Today's Topics:
Re: NOVA and Horizon; Soviet Lunar stuff.
Re: Terraforming, sun shield
Re: Voyager Update - 02/13/91
Re: meteor
Re: Lockheed Bid on Commercial Launcher...?
Re: Thrust
Re: Space Profits
Re: Wednesday NOVA on PBS: Russian Right Stuff
Re: German conference highlights doubts about ESA's manned space plans
Galileo Update - 03/05/91
Re: German conference highlights doubts about ESA's manned space plans
Administrivia:
Submissions to the SPACE Digest/sci.space should be mailed to
space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests,
should be sent to space-request+@andrew.cmu.edu, or, if urgent, to
The Galileo spacecraft's health continues to be excellent. Today, the
planned USO (Ultra Stable Oscillator) calibration test was successfully
completed. Tomorrow, spacecraft activities will consist of:
o Cruise science memory readout for the MAG (Magnetometer),
DDS (Dust Detector) and EUV (Extreme Ultraviolet Spectrometer)
instruments
o Radio frequency receiver and command detector performance
characterization tests
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab | Is it mind over matter,
___| | | | |__) |/ | | |___ M/S 301-355 | or matter over mind?
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | Never mind.
|_____|/ |_|/ |_____|/ | It doesn't matter.
------------------------------
Date: 8 Mar 91 21:55:44 GMT
From: agate!bionet!uwm.edu!spool.mu.edu!sdd.hp.com!cs.utexas.edu!sun-barr!newstop!exodus!bovic.Eng.Sun.COM!agn@ucbvax.Berkeley.EDU (Andreas G. Nowatzyk)
Subject: Re: German conference highlights doubts about ESA's manned space plans
In article <1991Mar8.183653.16059@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>>>Experience so far says very strongly that if you plan to do in-space repairs,
>>>you had better plan to have humans ... on hand.
>>
>>Or, if you prefer not to pay the $1,000,000++/hour cost of an EVA, you
>>could make sure it works before you launch it.
>
>The Solar Max, Palapa/Westar, Syncom, Hubble, Intelsat, etc. people all
>thought they had. Not to mention Apollo 13 and Gemini 8. There is this
>peculiar myth within NASA that all possible problems can be anticipated,
>and you really can be certain that the thing will work before you launch it.
>The universe keeps trying to tell NASA that this is wrong, and NASA keeps
>not listening.
True, but I read the original argument slightly differently: It is possible
to design Solar Max, etc. for in-orbit repair by robots, which was not done.
("it works" refering to the ability to repair/replace a system remotely)
If in-orbit repair is cost effective (= cheaper than launching a replacement,
which is a big IF in the context of small, specialized micro-sats),
it may still pay of to do this via robotics.
Hardware that isn't designed for this, will require a very elaborate robot.
However if the design takes robotic service into account, things change
dramatically. For example, a lot of consumer equipment (VCRs & such) and
some computer gear (Mac's, printers, etc.) are now routinely designed for
robotic assembly. Lots of tiny details reqire attention: aviod screws,
avoid round screw-in connectors, provide guide-paths for modules,
snap-into-place things are king, locking mechanisms that require tools to
push in several places are fine, but ones that require rotary action are not,
avoid ill shaped objects like cable harnesses, ... nothing really fancy, but
it is quite a departure from the way current space probes are designed.
Furthermore, in-orbit repairs are limited to module swaps. It's hard to
imagine someone replacing a 300+ pin surface mounted chip during EVA.