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From: prb@access.digex.net (Pat)
Newsgroups: sci.space
Subject: Re: Space Manuevering Tug (was HST servicing mission_)
Date: 1 May 1993 15:25:38 -0400
Organization: Express Access Online Communications USA
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In article <C6BBow.IH9@news.cso.uiuc.edu> jbh55289@uxa.cso.uiuc.edu (Josh Hopkins) writes:
>prb@access.digex.net (Pat) writes:
|
|>Given that what i described for the HST  seemed to be the SMT,   and given
|>the mass amrgins on the discovery mission  is tight enough that  spacewalking
|>has to be carefully constrained.....  No EDO pallets,  no spare Suits,
|>no extra MMU's.   
|
|Has someone actually verified that mass is the predominant constraint on this
|mission?  You seem to be assuming it without giving supporting evidence.  
|

Someone from NASA posted that there were very significant mass margins
on the HST re-boost mission.  A while back i had asked why not carry
the EDO pallet up,  and the answer was the mass margins were tight enough, they weren't even carrying extra suits.

|>WHy not do this?
|
|>	Quick Test  Goldins philosophjy  of faster cheaper, better.
|
|>Build a real fast Space TUg,  to handle the re-boost  of the HST  using
|>clean Cryo fuels,  and get it ready before the  HST mission.
|
|Pat, this would be slower, more expensive and worse.  
|
|Slower:  The shuttle mission is scheduled to go up in December.  That's less
|than eight months away.  There is no way you could build new hardware, retrain
|and reschedule the EVA's in that time.
|

Where's wingo when you need him:-)

COme on.   Knock that S**T off.

YOu forget,  that during skylab,  they did  overnight mission planning
for the repair EVA's.   Also during theøÄ   
Intelsat Mission,   they did overnight  WETF simulations.
I somehow think they could train up a new  EVA in  8 months.

And as for building hardware,  anything can  be built if you want it
bad enough.

YOu forget,  the  BUS 1  is already built.  all they'd ahve to do
is soup it up, even test it  on a delta mission.

Don't get into this mode of  negativism.   besides,  at the rate
missions slip,   the Discovery won't launch on this mission until
March.  that's almost a year.

|More Expensive:  Your proposal still requires the shuttle to do everything it
|was going to do execpt fire the OMS.  In addition, you've added significant
|extra cost for a new piece of complex hardware.
|

Ah,  but how much more expensive is the Second HST servicing mission.

YOu forget,  there is a bum FGS,  the Solar array electronics, are
getting hinky  and there is still 8 months until the servicing mission.

The time for the space walks are growing rapidly.  THis was orignally
planned out as 3 spacewalks,  now they are at 5 EVA's  with 3 reserve
walks.

If the SMT can avoid a second servicing mission that's $500 million
saved.  If the Weight savings,  means they  can sit on orbit  for 30 Days.
and  handle any contingency  problems,  that's quite a savings.

|
|According to a GAO report on the OMV I have before me, there are
|only two currently planned missions that could use such a vehicle -- HST and
|AXAF.  Since AXAF has since been scaled back and HST can rely on the shuttle,
|there doesn't seem to be any need for your vehicle.


Of course,  there wasn't any need for the Saturn  V  after apollo too.

as for the problems with the aperture door,  I am sure they can
work out some way to handle  that.  Maybe a Plug  made from
Frozen ice.?   it'll keep out any contamination,
yet sublime away  after teh boost.

pat