:>do you need to boost the orbit on this mission anyway? ...
:You don't *need* to, but it's desirable. HST, like all satellites in
:low Earth orbit, is gradually losing altitude due to air drag. It was
:deployed in the highest orbit the shuttle could reach, for that reason.
:It needs occasional reboosting or it will eventually reenter. (It has
:no propulsion system of its own.)
Has any thought been given as to how they are going to boost the HST yet?
Give it a push? I can see the push start cartoons now :-).
--
Kenneth Ng
Please reply to ken@blue.njit.edu for now.
"All this might be an elaborate simulation running in a little device sitting
on someone's table" -- J.L. Picard: ST:TNG
------------------------------
Date: Sun, 2 May 1993 15:56:08 GMT
From: Frank Crary <fcrary@ucsu.Colorado.EDU>
Subject: Human Habitale Planets?
Newsgroups: sci.space
In article <1993May1.042810.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes:
>Habital planets are also dependent on what kind of plant life can be grown..
>and such.. Length of growing season (that is if you want something more than
>VAT food, argh, Id ratehr eat an MRE for along period of time).
Using greenhouses to extend the growing season shouldn't be a problem.
I'm supprised they don't do so in Alaska (cheaper to import, perhaps?)
>Incans and Sherpa and other low pressure atmosphere and such are a limit in
>human adaptability(someone mentioend that Incan woman must come to lower
>elevations to have babies brought to term? true?)
No, the Incas had no problems with this, but the Spanish did.
Frank Crary
CU Boulder
------------------------------
Date: Sun, 2 May 1993 18:03:04 GMT
From: Walter Wohlmuth <wohlmuth@cehpx10>
Subject: large accelerations revisited
Newsgroups: sci.space
Why can't an aircraft be designed so that the pilot can always be
maintained in a upright position, perpendicular to the plane of
acceleration? With the visual helmets now being used that display
some of the flight parameters and with a keyboard and manuvering
equipment moving with the pilot, a pilot may be able to function at
accelerations in excess of 12G. Is anyone currently pursuing this
area or is there a reason why this is impossible at the present time?
--
Walter A. Wohlmuth walter@capone.ccsm.uiuc.edu
U. of Illinois @ Urbana-Champaign
------------------------------
Date: Sun, 2 May 1993 12:27:56 GMT
From: Marcus Lindroos INF <MLINDROOS@FINABO.ABO.FI>
Subject: Mothership for Flybys and cutting costs..
Newsgroups: sci.space
In <1993May1.051312.1@aurora.alaska.edu> nsmca@aurora.alaska.edu writes:
> Getting wierd again?
>
> Okay what about launching one probe with multiple parts.. Kind of liek the old
> MIRV principle of old Cold War Days.
> Basically what I mean is design a mother ship that has piggy backed probes for
> different missions,namely different planets. Each probe would be tied in with
> the mother ship (or earth as the case may be).. This is good when and if we go
> for Mars (the MArs mission can act as either Mother ship or relay point for the
> probes.
I can't see the need for a single (big? expensive? heavy?) "mothership" except
for Voyager style flyby missions. A few years ago, I did some calculations on a
"Grand Tour" space probe launched by a Saturn V in 1975-76. At the time,I felt
that
the idea of a big "mother ship" had some merit - the Voyagers had to be rather
small, lightweight craft due to the limitations imposed by using weak Titan
III/Centaur launchers. The concept I examined (and Michael's?) had a lot in
common with the British Interplanetary Society's Daedalus project for sending a
probe to Barnard's Star - i.e. a large "bus" spacecraft carrying several
smaller probes to be dispatched when the ship arrives at its destination.
The Saturn V supposedly would have been able to launch a 10-ton payload towards
Jupiter and beyond. The "bus" could have included far more powerful
cameras/telescopes/scientific equipment and a heavier/more powerful power
source than the Voyagers as there would be no limitations on weight anymore.
Extremely important as the Voyagers had to perform most of their measurements
within a couple of weeks before and after planetary encounter, and usually at a
relatively great distance.
---
The smaller probes carried aboard might have been based on the "real" Voyagers,
and an even smaller version like the one scheduled for launch towards Pluto in
the early 21st century, and would have been released at various points during
the mission. The advantages are obvious: the bus would have carried out the
same basic Jupiter-Saturn-Uranus-Neptune mission than Voyager 2 did, but in
addition two "sub-probes" could have been relased at Saturn, examining
that planet's south polar regions before moving on to Pluto. This would have
enabled NASA to map both hemispheres of Pluto/Charon by 1986...and several
other probes could have examined parts of the Jupiter/Saturn/Uranus/Neptune
systems that weren't examined in great detail by the Voyagers due to
trajectory-related factors. A small "swarm" of camera-equipped miniature space
probes released a month before encounter would have been too costly for a
small Voyager-type mission but entirely feasible if launched from a heavy,
well-equipped spacecraft. And would we have learned a lot more about the outer
planets! The reason why the Grand Tour was cancelled was lack of money, of
course.
MARCU$
> ==
> Michael Adams, nsmca@acad3.alaska.edu -- I'm not high, just jacked
>
------------------------------
Date: 2 May 1993 17:52:05 GMT
From: Jeff Foust <jafoust@cco.caltech.edu>
Subject: Mothership for Flybys and cutting costs..
Newsgroups: sci.space
In a recent article nsmca@aurora.alaska.edu writes:
>Okay we have figure out that a mission specifically to Pluto is to large
>and to expensive..
I'd hardly call the current Pluto Fast Flyby proposal "too large" (if the
new technology insertion currently taking place succeeds, the S/C mass will
drop to 110-120 kg) or "too expensive" ($400 million [FY92 $] for two S/C),
especially when compared to other NASA planetary missions.
>Basically what I mean is design a mother ship that has piggy backed probes for
>different missions,namely different planets. Each probe would be tied in with
>the mother ship (or earth as the case may be).. This is good when and if we go
>for Mars (the MArs mission can act as either Mother ship or relay point for
>the probes.
This proposal would work only if your various targets are relaively nearby and
the require minimal delta-v from the mother ship. A mission to the main belt
might be one possibility for such a mission -- I recall a paper being presented
at an AIAA deisgn conference in Irvine in February where such a proposed
spacecraft was designed by some grad students at UT Austin (I think). Four
mini-spacecraft would detatch from the main S/C, each visiting a seperate
asteroid and then returning to the main S/C. After analysis, the main S/C
would then be targeted for the most "interesting" object for further study.
Now, if I could only *find* that paper... =)
--
Jeff Foust [40 days!] "Historical analogy is the last refuge
Senior, Planetary Science, Caltech of people who can't grasp the current
jafoust@cco.caltech.edu situation." -- from _Red_Mars_ by
jeff@scn1.jpl.nasa.gov Kim Stanley Robinson
------------------------------
Date: 2 May 1993 14:40:11 -0400
From: Pat <prb@access.digex.net>
Subject: Report on redesign team
Newsgroups: sci.space
In article <Cohen-270493073219@q5022531.mdc.com> Cohen@ssdgwy.mdc.com (Andy Cohen) writes:
>The following is what they feed to us..... most has been posted already,
>but there are a number of items not seen here yet.....
>
>
>The Design Teams then presented the three options under study:
>
> Option A - Modular Buildup -- Pete Priest presented the A option. Priest
>
I don't think this will work. Still the same in space
integration problems, small modules, especially the Bus-1 modules.
the MOL would be bigger.
Also, budget problems may end up stalling developemnt.
A small undersized station wont have the science community support.
> Option B - Freedom Derived -- Mike Griffin presented the status of Option
>
Program effeciencies may cut costs, but the basic problems
with freedom remain. in space integration, too many flights
too build. not enough science retrurn.
> Option C - Singe Launch Core Station -- Chet Vaughn presented Option C,
>the Single Launch Core Station concept. A Shuttle external tank and solid
>
Essentialy $5 billion to build MIR.
I think had NASA locked onto this design, back in 1984, with
scarring to support a TRUSS for real expandability, we'd be looking
at a flying space station.
This looks the most realistic, to me, IMHO, but, i dont know if
there is enough will power to toss the CDR'd existing hardware
and then take a 1/3rd power cut and do it this way.
the core launch station has a lot of positive ideas. You could stick
in more hatches for experimental concept modules. Like the ET
derived workshops. Or inflatable modules.
pat
>(Oct. 31-cancellation .....just my opinion...AC)
Sad but true.
epitaph. Killed by mis-management.
pat
------------------------------
Date: Sun, 2 May 1993 05:05:05 GMT
From: Josh Hopkins <jbh55289@uxa.cso.uiuc.edu>
Subject: Space Manuevering Tug (was HST servicing mission_)
Newsgroups: sci.space
prb@access.digex.net (Pat) writes:
>I wrote:
>>prb@access.digex.net (Pat) writes:
>|
>|>Given that what i described for the HST seemed to be the SMT,
>|
>|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.
So how much mass is saved by not burning the OMS? That's the critical question.
My data shows that the OMS engines hold 10,900 kg of propellant. Of that, a
substantial fraction is going to be used for the first OMS burn, the reentry
burn and the reserve. So Pat, tell us how much fuel the altitude change is
going to take, and how much the EDO pallet, BUS-1 and extra parts are going
mass. If you can make the numbers work out, _then_ I'll be interested. After
you show us that it can be done, then tell us how much the EDO pallet, BUS-1
and extra equipment is going to cost.
>|>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.
>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 thexD
>Intelsat Mission, they did overnight WETF simulations.
>I somehow think they could train up a new EVA in 8 months.
First, while astronauts certainly have done EVAs with minimal planning, that was
because they _had_ to. They don't like to do that as a general rule.
Second, remember why they had to improvise during Intelsat 6? They were trying
to attach a motor to a piece of hardware that wasn't designed to do that.
Trying to shortcut the training is only going to make a repeat more likely.
Third, they don't have eight months. They have however much time is left
after someone comes up with a plan, shows it can work and gets it approved.
You may think I have a pessimistic attitude. I think it's realistic. I'm not
saying that the engineering task is impossible (few engineering tasks are).
What I'm saying is that this is neither cost effective nor feasible under NASA
management.
>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.
"All they have to do is soup it up?" Just what does that mean?
>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.
The second servicing mission is a contingency. You have neither shown that it
would be necessary without your plan nor that it would be unnecessary with your
plan.
>YOu forget, there is a bum FGS, the Solar array electronics, are
>getting hinky and there is still 8 months until the servicing mission.
No, Pat, I haven't forgotten.
>If the SMT can avoid a second servicing mission that's $500 million
>saved.
No Pat. That's $500 million minus the cost of the new hardware, minus the cost
of the extra struff you want to bring along, minus development and mangement
costs, minus extra operating costs. TANSTAAFL.
>|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.
I'm sure that if you reread this you'll see that your argument is falacious.
>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, not only is this messy and less reliable than a device that's _made_ to
perform this task, it also ignores the point. There is a desire to have
astronauts available so that if the door fails to open, something can be done
about it. Unless you can provide a very reliable way of reopening the door,
you haven't solved the problem.
--
Josh Hopkins jbh55289@uxa.cso.uiuc.edu
"Find a way or make one."
-attributed to Hannibal
------------------------------
Date: 2 May 1993 15:00:54 -0400
From: Pat <prb@access.digex.net>
Subject: Space Manuevering Tug (was HST servicing mission_)
Newsgroups: sci.space
In article <C6DvGH.ApH@news.cso.uiuc.edu> jbh55289@uxa.cso.uiuc.edu (Josh Hopkins) writes:
>prb@access.digex.net (Pat) writes:
>
>>I wrote:
>>>prb@access.digex.net (Pat) writes:
>
>My data shows that the OMS engines hold 10,900 kg of propellant. Of that, a
>substantial fraction is going to be used for the first OMS burn, the reentry
>burn and the reserve. So Pat, tell us how much fuel the altitude change is
>going to take, and how much the EDO pallet, BUS-1 and extra parts are going
>mass. If you can make the numbers work out, _then_ I'll be interested. After
>you show us that it can be done, then tell us how much the EDO pallet, BUS-1
>and extra equipment is going to cost.
>
I don't know. Does anyone in NASA land know how much fuel is
budgeted for the altitude change?
Henry, any figures on the mass (full) for the EDO pallet plus
it's dry weight? How about for the dry mass of Bus-1? it was
being de-classified as i checked last.
Also, I need.
1) current orbital parameters of HST
2) projected orbital parameters after re-boost.
3) Discovery's DRY weight
4) HST's Dry weight.
>>I somehow think they could train up a new EVA in 8 months.
>
>First, while astronauts certainly have done EVAs with minimal planning, that was
>because they _had_ to. They don't like to do that as a general rule.
>
So how long do they need to train? a year? 2 years? somehow
I think 2-3 moths should be adequate.
>Second, remember why they had to improvise during Intelsat 6? They were trying
>to attach a motor to a piece of hardware that wasn't designed to do that.
>Trying to shortcut the training is only going to make a repeat more likely.
>
Also because they significantly lacked on-orbit EVA experience.
The HST is designed for on-orbit servicing. it should be a lot easier.
>Third, they don't have eight months. They have however much time is left
>after someone comes up with a plan, shows it can work and gets it approved.
>You may think I have a pessimistic attitude. I think it's realistic. I'm not
>saying that the engineering task is impossible (few engineering tasks are).
>What I'm saying is that this is neither cost effective nor feasible under NASA
>management.
>
There comes a time in every project, to kill the management.
They can if neccessary, re-schedule the HST mission. December is
not a drop dead date, unlike say the LDEF retrieval mission.
>
>"All they have to do is soup it up?" Just what does that mean?
>
I suspect, the BUS-1, may not have enough basic thrust for the HST
re-boost. it mayu need bigger tanks, or bigger thrusters.
My understanding is the Second HST servicing mission is not
a contingency. My understanding is the mission needs both
a new FOC and work on the electrical system, plus
another re-boost.
>
>>If the SMT can avoid a second servicing mission that's $500 million
>>saved.
>
>No Pat. That's $500 million minus the cost of the new hardware, minus the cost
>of the extra struff you want to bring along, minus development and mangement
>costs, minus extra operating costs. TANSTAAFL.
>
Somehow, i think the cost of an expendable SMT will be less then
$500 million.
and the extra stuff is real cheap. NASA has lots of suits, MMU's,
and the EDO pallets are re-usable. Oh, one double magnum of champagne,
now there's a couple hundred bucks.
>
>
>Pat, not only is this messy and less reliable than a device that's _made_ to
>perform this task, it also ignores the point. There is a desire to have
>astronauts available so that if the door fails to open, something can be done
>about it. Unless you can provide a very reliable way of reopening the door,
>you haven't solved the problem.
That door has cycled, X times already. Once after massive G loading.
I somehow think they can work ou;reliability methods to ensure the
door works.
Also, please tell me how some sort of sublimated material like
CO2, or H2O would manage to contaminate the mirror, anything
that goes to vapor state, shouldn't adhere to the mirror.
somehow, the door, problem can be worked. maybe they can put a one
time spring on it.
what do they do now, if the door hangs up. that door is part
of a intrument safing mechanism. if it hangs up tomorrow, it'll
be 8 months until someone gets up there witha crowbar to fix it.
pat
------------------------------
Date: 2 May 1993 10:40:42 -0400
From: Pat <prb@access.digex.net>
Subject: U.S. Government and Technolgy Investment
Newsgroups: sci.space,talk.politics.space
In article <1993Apr30.151033.13776@aio.jsc.nasa.gov> kjenks@gothamcity.jsc.nasa.gov writes:
>It's interesting to note that some of our best tools for cost control
>available in industry today were derived from Government projects.
>GANTT charts, CP/M, and most of the modern scheduling software comes
>from DoD projects and their contractors. The construction industry
Of course,
How many government projects after Using PERT, GANT, C.P.M.s
Process flow diagrams, Level 5 software projects.... actually
come in on schedule and under Cost. I know the GAO determined
that 80% of all NASA projects miss their budgets due to failing
to adequately measure engineering developement costs.
Me, I am allin favor of Government R&D. I thought Bell Labs was one of the best
to do research. I don't think the government should pour money
into any one sector, but should engage in projects which naturally
push the state of the art.
THings like High tech construction projects, apollo was worth it for the doing. Running hte national labs. The SSC is grossly overweight, but
is a reasonable project at a lower cost.
Unfortunately support for solo investigators is direly neglected.
Maybe what they should do, is throw out much of the process and just tell
new PH'ds, you get a 1 time grant of $50,000.00 If you produce, you
can qualify for other grants. If you don't you never get in again.
THis way young people get a shot at reserach, and older stale
scientists don't dominate the process.
pat
------------------------------
Date: 2 May 1993 10:25:54 -0400
From: Robert Bunge <rbunge@access.digex.net>
Subject: Vandalizing the sky.
Newsgroups: sci.astro,sci.space
In article <C6BDIo.K7C@news.cso.uiuc.edu> jbh55289@uxa.cso.uiuc.edu (Josh Hopkins) writes:
>rbunge@access.digex.net (Robert Bunge) writes:
>
>It's vandalism because many people -- power companies -- do maliciously waste light.
>
>"maliciously" implies evil intent. The lighting companies aren't going out
>of their way to spoil the sky. They just don't care.
>
>>If they can sell you
>>or your city or your state an unshielded light that wastes 30 to 50 percent
>>of its light, they make more _money_. Never mind that your money is wasted.
>
>It is the responsibility of the customer to choose the most efficient hardware.
>If that's what your city will buy, that's what the lighting company will sell.
>Write a letter to city hall.
That's fine idea, but it only works if the lighting/power company even bothers to supply good light fixtures. For instance, a power company in Virginia
recently asked a state commission for permission to sell more lights of various
type. Yet, all of the different fixture that they sold and wanted to sell
were bad designs - one that wasted the light. Thus, you couldn't even buy
a good light from them. In most places, to get a good light, you have to
either order it special at high cost or call a store in Arizona. At some
point, society starts to make rules. Cars have to pass safety tests.
Companies have to meet pollution standards, etc.. There are two ways to achieve this: educate the public so that they demand good lighting or force code
down the lighting companies backs. History seems to suggest that the latter
is more likely to work.
>
>Please note that I'm not defending light pollution. The orignial focus of
>this thread was space based light sources.
>
Agreed, so I won't respond again. It's important for all you spacers out
there to realize that some people will object to various wild ideas that
have been presented. Just like Congress, it would be best to consult
the astronomers/lovers of the night sky before you try some PR stunt
