pv04+@andrew.cmu.edu (Philip Verdieck) (04/07/89)
This maybe the stupidest question, especially if its allready been asked and answered since the point where I saw an article here mentioning it (early march/late feb). So if its been discussed, ignore this cause I'll catch up, but..... What are the capabilities for rotating this baby and using it for spying purposes???
ccoprmd@pyr.gatech.EDU (Matthew T. DeLuca) (04/07/89)
In article <wYCugSy00Ui0E0kWMI@andrew.cmu.edu>, pv04+@andrew.cmu.edu (Philip Verdieck) writes: > > What are the capabilities for rotating this baby and using it for > spying purposes??? According to the NASA material I have, the HST is a low-light telescope, meaning that it cannot view bright objects like the sun, moon, or the Earth. However, the KH-12 reconaissance satellite (wasn't this launched recently?) is a close cousin of the HST, except it can view the earth. -- --------------------------------------------------------------------------------Matthew DeLuca : Georgia Institute of Technology : Remember, wherever you go, there you are. ARPA: ccoprmd@pyr.gatech.edu : --------------------------------------------------------------------------------
gsh7w@astsun1.acc.Virginia.EDU (Greg Hennessy) (04/07/89)
In article <wYCugSy00Ui0E0kWMI@andrew.cmu.edu> (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.
-Greg Hennessy, University of Virginia
USPS Mail: Astronomy Department, Charlottesville, VA 22903-2475 USA
Internet: gsh7w@virginia.edu
UUCP: ...!uunet!virginia!gsh7wmbkennel@phoenix.Princeton.EDU (Matthew B. Kennel) (04/08/89)
In article <1343@hudson.acc.virginia.edu> gsh7w@astsun1.acc.Virginia.EDU (Greg Hennessy) writes: >In article <wYCugSy00Ui0E0kWMI@andrew.cmu.edu> (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. > >-Greg Hennessy, University of Virginia > USPS Mail: Astronomy Department, Charlottesville, VA 22903-2475 USA > Internet: gsh7w@virginia.edu > UUCP: ...!uunet!virginia!gsh7w My father, who is on various NASA committees, claims that a KH-11/12 is essentially a Hubble Telescope pointing down. 2-3 meter primary, >2 gigadollars, many tons. I suspect that it's not the optics on the space telescope that make it unsuitable for spying, but the lack of encryption for the beamed-down data. Does the space telescope have cryostats? By "burn out" do you mean boil away? (i.e. does do IR?) Or are CCD's damaged permanently from high fluxes? What happens if a 10 GeV proton decides to deposit its energy in the CCD chip? Matt Kennel mbkennel@phoenix.princeton.edu
berry@stsci.EDU (Jim Berry) (04/08/89)
From article <1343@hudson.acc.virginia.edu>, by gsh7w@astsun1.acc.Virginia.EDU (Greg Hennessy): > In article <wYCugSy00Ui0E0kWMI@andrew.cmu.edu> (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: berry@stsci.edu Baltimore, Md. 21218 | SPAM: SCIVAX::BERRY, KEPLER::BERRY
sims@stsci.EDU (Jim Sims) (04/12/89)
HST will OFTEN be pointed at the Earth (the HSP even has an EARTH-CALIB mode)
You won't 'burn-up the sensors' unless you point it at the sun...
(of course the data probably won't be worth much since it won't focus at
-only- 200 miles & the target is REAL bright compared to most of what it was
designed to look at)
--
Jim Sims Space Telescope Science Institute Baltimore, MD
UUCP: {arizona,decvax,hao,ihnp4}!noao!stsci!sims
ARPA: sims@stsci.edu SPAM: SCIVAX::SIMSrogers@falcon.SRC.Honeywell.COM (Brynn Rogers) (05/09/89)
I have heard that the HST should see some thing like 10 Billion light years
out, past the edge of the Big Bang. This should give lots of data to
support or deny the Big Bang. (At least thats what I understand)
How good will it be at looking at Planets?
I don't think anyone has ever got a picture of pluto and it's moon (charron??)
[ Pluto is really a twin planet, right? ]
Will it take good pictures of Mars,Jupiter,...??? (better than viking,voyager?)
How about the surface of mercury?
TV newscasters should be lined up with the laywers and shot.
Brynn Rogers Honeywell S&RC rogers@src.honeywell.com
nic.MR.net!srcsip!rogerssw@cbnewsl.ATT.COM (Stuart Warmink) (05/10/89)
In article <21551@srcsip.UUCP>, rogers@falcon.SRC.Honeywell.COM (Brynn Rogers) writes: > I have heard that the HST should see some thing like 10 Billion light years > out, The"distance" it can see out to rather depends on what it is looking at! > past the edge of the Big Bang. This should give lots of data to > support or deny the Big Bang. (At least thats what I understand) The "edge of the Big Bang"? Is that related to "The Restaurant at the End of the Universe"? :-) > How good will it be at looking at Planets? Pretty good. > I don't think anyone has ever got a picture of pluto and it's moon (charron?) Yes, pictures have been taken of the two bodies - using very sensitive CCD devices if I am not mistaken; that is how Charon was discovered. In fact, after the discovery, some "old" negatives which include Pluto have also shown the characteristic "bulge" caused by Charon. At the time, no-one noticed this small distortion as it was thought to be caused by turbulence, grains in the negative, etc. By an amazing stroke of luck, Pluto and Charon are going through a series of mutual eclipses just about now, allowing much more accurate measurements of Pluto's and Charon's surface reflectivities to be made. If Charon had been discovered a few years later, it would have been a *long* time before those measurements could be made, as the eclipses occur only twice in Pluto's orbit around the Sun. > [ Pluto is really a twin planet, right? ] Perhaps "twin moon" is a better way of looking at it, according to the latest estimates (rocky core, water ice mantle and methane/water ice crust). > Will it take good pictures of Mars,Jupiter,...? (better than viking,voyager?) Not even close! (no pun intended) HST's resolution is about 5 times that of the best Earth based instruments. > How about the surface of mercury? It is convex, unlike water, which is concave (with glass). ;-) Hey, wouldn't this stuff be great for sci.astro? -- ------------------------------------------------------------------------------ "Captain, I see no reason to stand here | Stuart Warmink, Whippany, NJ, USA and be insulted" - Spock | sw@cbnewsl.ATT.COM (att!cbnewsl!sw) -------------------------> My opinions are just that <------------------------
rjg@sialis.mn.org (Robert J. Granvin) (05/10/89)
> > How good will it be at looking at Planets? > >Pretty good. There was an article buried long ago in the bowels of Air and Space, or Scientific American that was discussing the HST. It was focusing more on the technologies used, and therefore the technological problems in bringing it about. However, it pointed out that the operations of the telescope must be done very very carefully, since if they accidentally pointed the telescope towards the Earth or Moon, the reflected light would burn out all or most of the sensors. It continued to note that therefore it could not be used for planetary surveys within our own solar system. Whether the other planets in our own solar system would reflect enough back to actually cause damage, it wasn't specifically noted. -- ________Robert J. Granvin________ INTERNET: rjg@sialis.mn.org ____National Computer Systems____ CONFUSED: rjg%sialis.mn.org@shamash.cdc.com __National Information Services__ UUCP: ...uunet!rosevax!sialis!rjg
kevin@gtisqr.UUCP (Kevin Bagley) (05/18/89)
In article <21551@srcsip.UUCP> rogers@falcon.UUCP (Brynn Rogers) writes: >I have heard that the HST should see some thing like 10 Billion light years >out, past the edge of the Big Bang. This should give lots of data to ^^^^^^^^^^^^^ This is like 'somewhere over the Rainbow':-). If the Big Bang theory holds up, this is no such critter as 'past the edge' as the theory is that space itself, not the matter contained in space, but all of space, was entirely confined inside the Big Bang. Even that statement is confusing since there isn't any 'outside'. The Big Bang was all of space beginning it's expansion. Whether or not there was a contraction prior will not be discovered by looking 'past' the Big Bang, but may be discovered obtusely through use of the HST by discovering 'hidden' mass in the universe sufficient to cause the universe to re-contract through gravitational forces. Which leads to the Big Question... If the Universe contracted prior to the Big Bang, what should we call that contraction? The Big Squeeze? Mother Nature's Labor? The Fuse? >support or deny the Big Bang. (At least thats what I understand) [stuff deleted] Either way, the HST will very likely lead to some amazing discoveries. Will it be able to resolve a Jupiter sized planet orbiting in a nearby solar system? If so, how near (or far)? > Brynn Rogers Honeywell S&RC rogers@src.honeywell.com > nic.MR.net!srcsip!rogers I heard this morning that the HST is being pushed into 1990 2nd quarter. This means it will actually launch around New Years eve 1991! :-) -- _____ Kevin Bagley Global Tech. Int'l Inc., Mukilteo WA 98275 206-742-9111 )___) __ _ _ UUCP:uw-beaver!uw-nsr!uw-warp!gtisqr!kevin _/___) (__(__(_)_/_)_ ARPA:uw-nsr!uw-warp!gtisqr!kevin@beaver.cs.washington.edu _______________/ Disclaimer... "I did not say this. I am not here."
tneale@aeras.UUCP (Tom Neale) (05/19/89)
In article <678@gtisqr.UUCP> kevin@hindmost.UUCP (Kevin Bagley) writes: > > I heard this morning that the HST is being pushed into 1990 2nd quarter. I noticed a short article in the San Jose Mercury News the other morning that said the HST had ben bumped out about 3 months. Can anyone shed a little more light on why this happened (again) ? I'm still trying to get in to see the thing before it leaves Lockheed in Sunnyvale. Looks like I might have a little more time now. I'll post a full report if successful. -- Blue skies, | ...sun!aeras!tneale | | in flight: N2103Q | The hurrieder I go Tom Neale | in freefall: D8049 | the behinder I get. | via the ether: WA1YUB |
tneale@aeras.UUCP (Tom Neale) (07/07/89)
Well, I got lucky. I actually got to see the Hubble Space Telescope while it is still here on Earth. I won't bore you all with the details of how I managed to get in...it's a secret anyway. It is in a high bay at Lockheed in Sunnyvale, CA. The bay is a clean room and was described to me as a Class 10,000 room (not all that clean). It is easily the largest clean room I have ever seen as it is about 4 stories tall and then about 50'x150'. They change the air in there every 90 seconds! The entire west wall is filters (yes, 4 stories tall). Since a test was in progress on the vehicle I couldn't get into the bay and touch it :-(, I could only look through the observation window about half way up. There was only one technician in the whole bay and he was reading a book half the time. The HST is mounted in a gantry/scaffold structure vertically with the instrument packages at the bottom. Several of the instrument bay doors were open with power and cooling lines running in and out so they can test various pieces of the vehicle. There is a dummy cover over the light gathering end. The real cover is wrapped up and sitting on the floor at the other end of the bay. The vehicle will be moved out of the gantry in about October (this week's version of the schedule) and laid down horizontally for some finish work. The movement is accomplished by a crane which runs on rails for the length of the bay at the ceiling. Once it is horizontal they will insert another scaffold like structure into the telescope to epoxy some nuts in place. I guess there is a concern that they will vibrate loose and damage/destroy the optics. The solar wings are in place again. Currently they are folded up and look quite yellow. HST is really quite large. The published specs are: Length 43 feet Diameter 14 feet Weight 25,000 pounds Primary Mirror 94 inches Never having seen a shuttle in person I now have a better appreciation of the size of the cargo bay since HST will take up most of it. On the way up the stairs to the observation area there are several drawings of early HST concepts. They start off quite different from the final design but gradually evolve into the real vehicle. There are also pictures of several of the mockups undergoing various phases of testing (shock/vibration, heat, astronaut training). All in all a very interesting visit. I wish I could have gotten a closer look from inside the bay. I guess I shouldn't complain, though, at least I got to see it before it gets launched! -- Blue skies, | ...sun!aeras!tneale | | in flight: N2103Q | The hurrieder I go Tom Neale | in freefall: D8049 | the behinder I get. | via the ether: WA1YUB |
envbvs@epb2.lbl.gov (Brian V. Smith) (07/12/89)
In article <351@aeras.UUCP>, tneale@aeras.UUCP (Tom Neale) writes:
< Well, I got lucky. I actually got to see the Hubble Space Telescope
< while it is still here on Earth. I won't bore you all with the details
< of how I managed to get in...it's a secret anyway.
<
[ some deleted ]
< Once it is horizontal they will insert another scaffold like structure
< into the telescope to epoxy some nuts in place. I guess there is a
< concern that they will vibrate loose and damage/destroy the optics.
<
There is an interesting article in Discover Magazine (July) about the
mirror for the HST, which was made by Perkin Elmer. The story tells of how long and how many precautions they were required to take before they could
move the mirror after casting.
Several years back (1966) some engineers at Perkin Elmer dropped a
$1 million mirror destined for some satellite. NASA is trying to be very
careful this time.
_____________________________________
Brian V. Smith (bvsmith@lbl.gov)
Lawrence Berkeley Laboratory
We don't need no signatures!gordon@prls.UUCP (Gordon Vickers) (07/13/89)
>In article <351@aeras.UUCP>, tneale@aeras.UUCP (Tom Neale) writes:
->
-< Well, I got lucky. I actually got to see the Hubble Space Telescope
-< while it is still here on Earth. I won't bore you all with the details
-< of how I managed to get in...it's a secret anyway.
-[ remainder deleted ]
To no one in particular:
I've heard that there will be an "open house" sometime after
the scope is rotated to the horizonal. I've been told that I
will be invited so I assume it will be a private open house. Is
this true or will it be public ? Any idea when ?jwp@larry.sal.wisc.edu (Jeffrey W Percival) (07/13/89)
In article <23692@prls.UUCP> gordon@prls.UUCP (Gordon Vickers) writes: > I've heard that there will be an "open house" sometime after > the scope is rotated to the horizonal. The HST has been lowered into the horizontal position at least once before, for the thermal vacuum test. At the beginning of the lowering process, a clean room technician was asked how long it would take. He is rumored to have responded something like "Oh, 4 hours or 3 seconds." -- Jeff Percival (jwp@larry.sal.wisc.edu)
tneale@aeras.UUCP (Tom Neale) (07/13/89)
In article <2983@helios.ee.lbl.gov> envbvs@epb2.lbl.gov (Brian V. Smith) writes: >Several years back (1966) some engineers at Perkin Elmer dropped a >$1 million mirror destined for some satellite. NASA is trying to be very >careful this time. I'm not sure but I think that the mirror in the HST is actually the backup mirror. I believe that the first one was destroyed during the polishing operation when the diamond polishing tool broke and the automatic machine kept lowering the supporting arm until it gouged the surface of the mirror. Now, this could be one of those myths that gets propagated by word of mouth despite its lack of factual basis. Anyone know for sure? -- Blue skies, | ...sun!aeras!tneale | | in flight: N2103Q | The hurrieder I go Tom Neale | in freefall: D8049 | the behinder I get. | via the ether: WA1YUB |
envbvs@epb2.lbl.gov (Brian V. Smith) (07/13/89)
According to several sources, the cost of storing the HST until it can be launched is around $10 million PER MONTH. It has been waiting since about 1985 or so to go up, so this amounts to several hundred million dollars! Can anyone enlighten me as to why it costs so much just to STORE it? _____________________________________ Brian V. Smith (bvsmith@lbl.gov) Lawrence Berkeley Laboratory We don't need no signatures!
envbvs@epb2.lbl.gov (Brian V. Smith) (07/13/89)
In article <355@aeras.UUCP> tneale@aeras.UUCP (Tom Neale) writes:
< I'm not sure but I think that the mirror in the HST is actually the
< backup mirror. I believe that the first one was destroyed during the
< polishing operation when the diamond polishing tool broke and the
< automatic machine kept lowering the supporting arm until it gouged the
< surface of the mirror.
<
< Now, this could be one of those myths that gets propagated by word
< of mouth despite its lack of factual basis. Anyone know for sure?
This isn't mentioned in the article in Discover magazine... but, of course
that doesn't mean it isn't true.
_____________________________________
Brian V. Smith (bvsmith@lbl.gov)
Lawrence Berkeley Laboratory
We don't need no signatures!ccoprmd@prism.gatech.EDU (Matthew DeLuca) (07/13/89)
In article <355@aeras.UUCP> tneale@aeras.UUCP (Tom Neale) writes: > >I'm not sure but I think that the mirror in the HST is actually the >backup mirror. I believe that the first one was destroyed during the >polishing operation when the diamond polishing tool broke and the >automatic machine kept lowering the supporting arm until it gouged the >surface of the mirror. > Well, the Discover article mentioned that there were *two* main mirrors commissioned for Hubble. One (the one that is to fly) from Perkins-Elmer, and another (fate not mentioned) from Kodak. The article gave a very in-depth chronology of the mirror, so I'm led to believe that the mirror flying is in fact the original. Anyone know what became of the Kodak mirror? -- --------------------------------------------------------------------------------Matthew DeLuca : Georgia Institute of Technology : [This space for rent] ARPA: ccoprmd@hydra.gatech.edu : --------------------------------------------------------------------------------
gordon@prls.UUCP (Gordon Vickers) (07/13/89)
In article <2998@helios.ee.lbl.gov> envbvs@epb2 (Brian V. Smith) writes:
->According to several sources, the cost of storing the HST until
->it can be launched is around $10 million PER MONTH. It has been
->waiting since about 1985 or so to go up, so this amounts to
->several hundred million dollars!
->
->Can anyone enlighten me as to why it costs so much just to STORE it?
Prehaps this includes the cost of the many, many employees who
are out here on per-deim. I know one gentalmen who has been out
here from Colorado on per-deim for nearly four years! Since he is
a manager, he must also fly back once in a while. I would suppose
all this gets changed against the HST project, and prehaps considered
as storage cost.
Another wild speculation from:
Gordon Vickers 408/991-5370 (Sunnyvale,Ca); {mips|pyramid|philabs}!prls!gordon
------------------------------------------------------------------------------
Every extinction, whether animal, mineral, or vegetable, hastens our own demise.
clyde@ut-emx.UUCP (Clyde W. Hoover) (07/14/89)
The Kodak-figured backup HST mirror is in storage waiting to be used for some other project, along with a smaller mirror to test fabrication and figuring technology. This comes from a long story in this month's Sky and Telescope by someone who has been involved in the Space Telescope project for a long time. Shouter-To-Dead-Parrots @ Univ. of Texas Computation Center; Austin, Texas clyde@emx.utexas.edu; ...!cs.utexas.edu!ut-emx!clyde Tip #268: Don't feel insecure or inferior! Remember, you're ORGANIC!! You could win an argument with almost any rock!
wendt@segovia.CS.ColoState.Edu (alan l wendt) (07/19/89)
I've heard that the telescope will be launched with defective charge- coupled device arrays and that the plans are to replace them in a later service visit. Anybody know anything about this? Alan Wendt
philhowr@unix.cie.rpi.edu (Bob Philhower) (07/22/89)
In article <7310@bunny.GTE.COM> s914@GTE.COM (Lawrence Bilker) writes: > >I read somewhere that it is a class 10,000 clean room. Which is even more >expensive than a class 100 clean room! > In case this wasn't a joke, the "class" of a clean room refers to the amount of particles in the air inside. The number is the nominal count of particles 1 micron and larger in a 1 cubic-meter of space. Thus a class 100 clean room is 100 times CLEANER than a class 10,000 clean room. (Normal air is somewhere around class 1 million or so.) Given the size of HST, I would be surprised if they can actually maintain better than class 10,000 around it. -- Robert Philhower Rensselaer Center for Integrated Electronics E-Mail: philhowr@unix.cie.rpi.edu USMail: CII 6111 / Rensselaer Polytechnic Institute / Troy, NY 12180 / USA
groves@noao.edu (Lee Groves) (07/22/89)
From article <2217@ccncsu.ColoState.EDU>, by wendt@segovia.CS.ColoState.Edu (alan l wendt): > > I've heard that the telescope will be launched with defective charge- > coupled device arrays and that the plans are to replace them in a > later service visit. Anybody know anything about this? > > Alan Wendt Here at NOAO, we have a contract to evaluate "next generation" CCDs. What I hear is 5 years until they fly. I hope that means they go up on a "service" flight.... Believe it or not, I have seen a chip with < 10 photon per ADU sensitivity! (ADU = Analog to Digital Unit.) (I do the CCD camera system software here.) Lee -- Lee J. Groves, National Optical Astronomy Observatories, Tucson, AZ Usenet: {arizona,decvax,ncar}!noao!lgroves or uunet!noao.edu!lgroves Internet: lgroves@noao.edu SPAN/HEPNET: draco::lgroves Phonenet: 602-325-9357
johnson@ncrcce.StPaul.NCR.COM (Wayne D. T. Johnson) (07/26/89)
In article <1136@noao.UUCP> groves@noao.edu (Lee Groves) writes: >Believe it or not, I have seen a chip with < 10 photon per ADU sensitivity! >(ADU = Analog to Digital Unit.) > But how do you mesure < 10 photons? -- Wayne Johnson (Voice) 612-638-7665 NCR Comten, Inc. (E-MAIL) W.Johnson@StPaul.NCR.COM or Roseville MN 55113 johnson@c10sd1.StPaul.NCR.COM These opinions (or spelling) do not necessarily reflect those of NCR Comten.
jpainter@tjp.East.Sun.COM (John Painter - Sun BOS Hardware) (07/27/89)
In article <1405@ncrcce.StPaul.NCR.COM> johnson@ncrcce.StPaul.NCR.COM (Wayne D. T. Johnson) writes: >In article <1136@noao.UUCP> groves@noao.edu (Lee Groves) writes: >>Believe it or not, I have seen a chip with < 10 photon per ADU sensitivity! >>(ADU = Analog to Digital Unit.) >> >But how do you mesure < 10 photons? >-- If a cascade photo-multiplier tube can register ONE photon, I imagine a solid state equivalent could be had. (but then you didn`t ask for a solid state solution) /Tjp - signature withheld pend investigation
pat@grebyn.com (Pat Bahn) (12/11/89)
Hi, I hate to ask a stupid question, but I was flipping through the channels and saw some partial report on the 11 year solar flare cycle. It said that if predictions on flares are off 20%, it could cut 5 years off the orbital life of HST. Now are there any plans or capabilities to reboost HST? She does not have thrusters to nudge her about as far as I know. There was some talk at one time of reboosting solar max and skylab but we all knew what happened. I'd hate to see a project that has been going since 1975, go down due to a sunspot. WOuld it be better to delay (I can hear the screams from baltimore) HST one year till after the peak? Of course we may lose atlantis by then and boy would they be screwed. -- ============================================================================= Pat @ grebyn.com | If the human mind was simple enough to understand, 301-948-8142 | We'd be too simple to understand it. =============================================================================
jbayer@ispi.UUCP (Jonathan Bayer) (12/11/89)
pat@grebyn.com (Pat Bahn) writes: > Hi, I hate to ask a stupid question, but I was flipping through >the channels and saw some partial report on the 11 year solar flare >cycle. It said that if predictions on flares are off 20%, it could cut >5 years off the orbital life of HST. Now are there any plans or >capabilities to reboost HST? She does not have thrusters to nudge her The HST is designed to be serviced in orbit. If necessary it can be taken aboard the shuttle and reboosted into a higher orbit, or brought back to earth for repairs. JB -- Jonathan Bayer Intelligent Software Products, Inc. (201) 245-5922 500 Oakwood Ave. jbayer@ispi.COM Roselle Park, NJ 07204
henry@utzoo.uucp (Henry Spencer) (12/12/89)
In article <14089@grebyn.com> pat@grebyn.UUCP (Pat Bahn) writes: >... Now are there any plans or >capabilities to reboost HST? She does not have thrusters to nudge her >about as far as I know... HST is definitely scheduled for a shuttle visit a few years from now, to change instruments and reboost. There was some concern that this might have to be moved up with abnormally high solar activity. > WOuld it be better to delay (I can hear the screams from >baltimore) HST one year till after the peak? ... There was talk of doing this, but the astronomers were understandably upset, and I believe the final conclusion was that it wasn't necessary if major efforts were made to get the telescope into the highest possible orbit to start with. -- 1755 EST, Dec 14, 1972: human | Henry Spencer at U of Toronto Zoology exploration of space terminates| uunet!attcan!utzoo!henry henry@zoo.toronto.edu
dsmith@hplabsb.HP.COM (David Smith) (12/13/89)
In article <1254@ispi.UUCP> jbayer@ispi.UUCP (Jonathan Bayer) writes: >>cycle. It said that if predictions on flares are off 20%, it could cut >>5 years off the orbital life of HST. Now are there any plans or >>capabilities to reboost HST? She does not have thrusters to nudge her > >The HST is designed to be serviced in orbit. If necessary it can be >taken aboard the shuttle and reboosted into a higher orbit, or brought >back to earth for repairs. That's right, just like Solar Max. David R. Smith, HP Labs dsmith@hplabs.hp.com (415) 857-7898 ------------------------------------------------------------------------- |"Meanwhile Newton became as mad as a hatter: by 1692 he was suffering | |from depression, paranoia, insomnia and forgetfulness, and his hands | |shook. Poor Newton's scientific work was impaired but in that state | |he was judged fit for public office and went on to become Master of | |the Mint and a Member of Parliament." -- Nigel Calder | -------------------------------------------------------------------------
ken@argus.UUCP (Kenneth Ng) (12/13/89)
In article <1254@ispi.UUCP>, jbayer@ispi.UUCP (Jonathan Bayer) writes:
: The HST is designed to be serviced in orbit. If necessary it can be
: taken aboard the shuttle and reboosted into a higher orbit, or brought
: back to earth for repairs.
I'm just curious, does anyone know how HST will be lifted into a
higher orbit? Will it be put into the shuttle and the shuttle
takes it higher? Will an arm grab onto it and tow it? Will
the shuttle get in back and push? :-) Perhaps the shuttle will
refuel it and the HST station keeping rockets will raise it?
How about put the HST on a long tether and as the shuttle descends
the HST will orbit faster until the cable is released and the HST
is propelled into a higher orbit? Am I making sense?henry@utzoo.uucp (Henry Spencer) (12/15/89)
In article <1387@argus.UUCP> ken@argus.UUCP (Kenneth Ng) writes: >I'm just curious, does anyone know how HST will be lifted into a >higher orbit? The nominal plan is to have the Orbital Maneuvering Vehicle grab on and push. What happens if HST needs reboost before the OMV is ready to fly, I'm not sure. >Will it be put into the shuttle and the shuttle >takes it higher? This is theoretically possible -- HST's solar arrays are designed to re-fold (well, re-roll actually), unlike those of most satellites -- but it would be wasteful. The shuttle orbiter weighs lots more than HST, and one would prefer not to haul all that extra weight along. >... Perhaps the shuttle will >refuel it and the HST station keeping rockets will raise it? HST has no propulsion system of its own. It uses momentum wheels for attitude control and magnetotorquers (electromagnets interacting with Earth's magnetic field) to desaturate the momentum wheels when needed. >How about put the HST on a long tether and as the shuttle descends >the HST will orbit faster until the cable is released and the HST >is propelled into a higher orbit? Am I making sense? This would make some sense, and similar ideas have been talked about in other connections, but tether technology is still mostly on paper. -- 1755 EST, Dec 14, 1972: human | Henry Spencer at U of Toronto Zoology exploration of space terminates| uunet!attcan!utzoo!henry henry@zoo.toronto.edu
doug@herbert.uucp (Doug Phillipson 5-0134) (12/16/89)
While were on the subject of things dropping out of the sky. Why don't the people that are responsible for orbit predictions use worst case solar flare activity as the norm? Wouldn't this alone have saved Skylab? Douglas Phillipson (EG&G)