Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v09_3/v9_390.txt

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Subject: SPACE Digest V9 #390

SPACE Digest                                      Volume 9 : Issue 390

Today's Topics:
   Progress 41 ejected as crew prepares to leave USSR's Mir station
              Re: Hubble Space Telescope
              Re: NASA tank reuse fiasco
            Re: Fer-de-lance by TE Bearden
             Radiation hardened chips...
             Shuttle Acceleration
----------------------------------------------------------------------

Date: Sun, 23 Apr 89 20:05:25 EDT
From: Glenn Chapman <[e-mail]>
To: [e-mail], [e-mail],
        [e-mail]
Subject: Progress 41 ejected as crew prepares to leave USSR's Mir station

     On board the Mir/Kvant space station on Apr. 23 Dr. Valrey Polyakov
became the physician with the most orbital time by exceeding 236 days,
the record set by Dr. Oleg Atkov on Soyuz 10B/Salyut 7 in Oct. 1984.
Dr. Polyakov is now the tenth most experienced cosmonaut.  Alexander
Volkov and Sergei Krikalev who arrived on Soyuz TM-7 in November, have
now been up for 147 days.  The crew is making the final preparations for
coming down on Apr. 27th and preparing to leave the station in the
unmanned mode for several months.  As part of this the Progress 41 cargo
craft's engines substantially boosted Mir's altitude by about 40 Km (25
mi) to form a 400 x 372 km (250 x 232 mi) orbit.  Thus the station can
go for several months now without requiring Mir's own engines or
reboost.  On Apr. 20th Radio Moscow announced Progress 41 had been
ejected and entered the atmosphere, hence leaving the rear docking port
free for the next crew or other craft to service the station.  (Also
AW&ST Apr. 17)
     There is some controversy concerning the reason for the leaving Mir
unmanned.  The conflict in the media, both western and eastern, is
between the closing down of the station for because of high program
costs, as compared to a short term suspension due to technical problems.
Confirmation of the report on Soviet TV about the power loss (see my
Apr. 13th posting) was given in an Aviation Week article on Apr. 17th.
All reports agree that there has been a progressive decline in the
station power, which will require a mission to repair the station in
about August.  On the short wave they have stated that the next mission
will go up and then two expansion modules (about 20 Tonnes each - the
mass of Mir's core section) will be launched nearly simultaneously.
This will allow them to dock one section, transfer it to the side port,
then rapidly dock the second section.  The will allow them to minimize
the problems with asymmetry that will occur when Mir has only one module
docked to the side.  The problems with the gyroscopic momentum wheel
system have probably forced easy of maintaining stability to become a
very important issue for them.
    On the other hand many press reports have tended to focus on
statements like that of Boris Yeltsins during the Moscow election
campaign of "Bread not Sputniks."  The New York Times (Apr. 19) ran an
article that quoted Viktor Blagov as stating that the close down was to
save money rather than for technical reasons.  On Soviet television
there was a news interview with another official which stated that yes
the station was unmanned to save money until the new modules were ready
in the fall.  However, when asked about the power problems the answer
was that Mir was three years old and previous stations had run into
problems that required repairs at about that age [especially Salyut 7 in
June 1985].  Hence some repair needs should be expected.  Also the new
modules would add solar panels which will add more power to the station.
Meanwhile on the short wave on Apr. 18th the Soviets listed the number
of paying customers that will be sending people to Mir in the future.
These are the Japanese in May 1991, British in 1991/92 for a 14 day
mission, the French in 1991/92 for a two month flight, and an Austrian
in 1992 for an 8-10 day visit.  The Japanese visit is especially
interesting as the Tokyo Broadcasting System is paying for a journalist
to fly, the first to do so (the NASA Journalist in Space program was
cancelled).  Indeed there is an interesting rivalry in this launch as
NASDA, the main Japanese space agency, is scheduled to fly an astronaut
on the shuttle the summer of the same year. (New Scientist Apr. 1).
    All of this suggests that there are technical problems with Mir.
but does not answer the question as to whether the Russian manned space
program is being significantly scaled back for economic reasons.
Historically the soviets have said that they are reducing some activity
because of economic reason, when really the difficulties were technical
(eg. the Tu-144 supersonic transport).  They have been very reluctant to
admit problems with their equipment.  My personal feeling is this is a
case of the station having some power problems which reduces the
experiments the cosmonauts can do while possibly putting them at risk if
things get much worse (the life support system takes a considerable
fraction of the power).  Meanwhile delays in the modules mean the new
experiments the crew were to perform are not yet ready.  Hence, the risk
of maintaining the crew up there under these circumstances is not
balanced by a gain of more scientific information.  Thus, in some ways
both views are correct, both economics and technical problems are saying
bring the crew down.  To put this in perspective consider that this
hiatus is rather a short period between long duration space station
crews by historical standards.  Outside of Mir's 26 month continuous
occupation there are only two times since 1978 when the period between
extensive visits was 3 months or less.  Indeed such delays are common in
all the world's space programs; the NASA Discovery launch, scheduled for
Aug. 10th has just been set back until Nov. while the next ESA's Ariane
4 flight is now delayed due for technical reasons.
     Thus it is with some amusement that I have watched a number of
people post notices, based on the western media economic statements, of
how this indicates the Russian program is going to fall apart, just as
one would expect from a Communist run system.  Until I see more
evidence, such as a failure of the mission to go up in Aug./Sept., there
little proof to back up this belief.  Only time will tell whether the
USSR has dropped out of the race toward being the first human space
faring nation, or just has stumbled and will rise again.
     Unfortunately, I will be away giving some lectures for the next two
weeks so it will not be possible for me to post the events of the Soyuz
TM-7 landing.  If someone else out there in netland follows the program
would they please do so to keep the others informed.  Thank you in
advance.

                                           Glenn Chapman
                                           MIT Lincoln Lab

------------------------------

Date: 7 Apr 89 22:05:25 GMT
From: stsci![e-mail]  (Jim Berry)
Subject: Re: Hubble Space Telescope

From article <[e-mail]>, by [e-mail] (Greg Hennessy):
> In article <[e-mail]> (Philip Verdieck) writes:
> #
> #What are the capabilities for rotating this baby and using it for
> #spying purposes???

> Not much, since the detectors are sensitive enough to burn out. A
> KH-11 or KH-12 will do the job for you though.

Funny how we seem to go through this every six months or so.

In general, the instruments on board will not 'burn out' if they get
pointed at the Earth, although I don't think that either the Faint Object
Camera or the Faint Object Spectrograph would fare very well...

In fact, the current method for flat-fielding the Wide Field/Planetary
Camera is to take several 'smears' of the cloud covered Earth at different
angles as it goes by under the telescope, trying to get a flat gray.

A couple people have toyed around with linear deblurring algorithms, but
just for fun, though.  HST simply isn't equipped to take pretty pictures
of Grandma's House.

Put the right gadgets onto an HST frame and you get a KH-12.  They use us
to test all of the equipment before they use it on the KH-12 - I think
that's why nobody ever got upset about us sitting around at Lockheed taking
up space - people were getting experience handling a "KH-12".

- Jim

--
------------------------------------------------------------------------------
Jim Berry                         | UUCP:{arizona,decvax,hao}!noao!stsci!berry
Space Telescope Science Institute | ARPA:   [e-mail]
Baltimore, Md. 21218              | SPAM:   SCIVAX::BERRY, KEPLER::BERRY

------------------------------

Date: 19 Apr 89 14:42:08 GMT
From: mcvax!ukc!reading!cf-cm!cybaswan![e-mail]  (Steve Hosgood)
Subject: Re: NASA tank reuse fiasco

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (andrew) writes:
>>I was horrified to read that more than $8B has already been junked by
>>discarded fuel tanks; about $300M per tank...
>>Wouldn't it be so nice just to attach a parasitic mini-thruster and
>>control system to all tanks, just to go that last ten yards?
>
>As has been mentioned a number of times in the past (sigh), it is not
>that simple.  Tanks left to themselves in orbit will not stay there for
>long -- they are too big and too light, air drag will bring them down.
>Keeping them up is not a trivial problem, especially if you insist on
>using only fully-proven technology (which is considered a requirement
>when the risks include dropping many tons of metal on a city somewhere).
>If you *do* manage to get them to stay up, the insulation on them
>will "popcorn" in vacuum, adding considerably to the space-debris problem.

I used to wonder if it would be possible to redesign the ET so that:

1) They could be taken to orbit
2) The end caps could be removed
3) The internal pressure vessels could be removed.

This would leave you with quite a few long tubular tank skins. Now, assuming
that spacewalkers could handle the job, you take up some adaptors and join
the tanks end-to-end - eventually forming a ring. Some of the discarded end-caps
and pressure vessels could be stuck on at trendy angles, the rest carefully
chucked into Earth atmosphere to burn up (better get that bit right :-)).

Even if the ring you've built couldn't be used as a space-station, it
might be a semi-cheap way of testing the technology needed to build a *real*
space station.

I assume that the ET is carefully redesigned to allow this re-use. I don't
propose that this is viable with the present ET design.

Comments appreciated - flames to /dev/null please!
Steve

------------------------------

Date: 21 Apr 89 22:38:26 GMT
From: thorin!alanine![e-mail]  (Jonathan Leech)
Subject: Re: Fer-de-lance by TE Bearden

In article <[e-mail]> [e-mail] (John Karabaic) writes:
>Full book info is:  Fer-del-lance, A Briefing on Soviet Scalar...
>Anybody on either physics or space hear about this before?

    Just to give you an idea, when the local New-Agers opened a shop,
this was on the shelves next to the UFO and Antigravity books.
    This topic isn't relevant to sci.space, so followups are
redirected to misc.misc.
--
    Jon Leech ([e-mail])    __@/
    "I met a wonderful new man. He's fictional, but you can't have everything."
    - Cecelia, _The Purple Rose of Cairo_

------------------------------

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Date:     Fri, 21 Apr 89 17:11:31 -0900
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From: ROBERT J HALE                    <[e-mail]>
Subject:  Radiation hardened chips...

   Was wondering if anyone out there can tell me how the manufactures
make or harden chips for use in orbit...    Please Email it to me.

------------------------------

Date: Sat, 22 Apr 89 01:54 EDT
From: John Taylor <[e-mail]>
Subject: Shuttle Acceleration

>Date: 17 Apr 89 16:47:46 GMT
>From: jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
>Subject: Re: Unmanned shuttle advantages (was: Re: alien contact)

>There are tradeoffs here.  Higher acceleration is generally more efficient,
>as you spend less time fighting gravity.

    Less time fighting gravity? I can't see what time has to do with it.
If you disregard friction momentarily (read as non-conservative forces),
then you simply must supply an energy to the shuttle of (Potential +
Kenetic)=(mgh + .5mv**2); this has nothing to do with how fast the shuttle
accelerates.
    Now, bring back in friction (air resistance, for example). If you
accelerate faster, you develop more speed at a lower altitude; this means
that you have to do more work (i.e. waste energy) because the air is denser
closer to the earth.
    I can't see how larger accelerations would be more efficent; I can
see how it would *less* efficent...


-------------
John Taylor -- SUNY at Buffalo
Bitnet  : v131q5cg@ubvmsc
Internet: [e-mail]

------------------------------

End of SPACE Digest V9 #390
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