HQM%MIT-OZ@MIT-MC.ARPA (Henry Minsky) (10/16/85)
I am confused as to how NASA is going to win with the space telescope's orbit: If they orbit it at the same height as the shuttle, won't it drag the atmosphere and burn up like skylab in a few years? And if they boost it to a higher orbit, how can anyone get to it to make repairs when it breaks?
eder@ssc-vax.UUCP (Dani Eder) (10/18/85)
> > I am confused as to how NASA is going to win with the > space telescope's orbit: > > If they orbit it at the same height as the shuttle, won't it drag the > atmosphere and burn up like skylab in a few years? > > And if they boost it to a higher orbit, how can anyone get to it to make > repairs when it breaks? The Shuttle normally flies to 160 Nautical miles. At that altitude the payload capability is about 65,000 pounds. In order to reach higher altitudes, the Orbiter must carry more propellant, and hence less payload. The Hubble Space Telescope is currently scheduled to be deployed at 320 Nautical miles (on 8 August 1986, flight 61-J). The Orbiter Atlantis is capable of carrying about 40,000 pounds to that height. The Space Telescope, including carrying cradle in the Orbiter cargo bay, weighs 27,700 pounds. As for drag, at 160 miles, drag lowers your orbit about 0.5 miles per day. At 320 miles, it is about 100 times less. Over the 3 years until the next scheduled Shuttle visit, the Telescope should fall about 5 miles. The Telescope may be brought down at that time not because the equipment has broken down, but because the incredibly thin layer of aluminum on the mirror surface may evaporate off. If not, they will replace instruments, make any needed repairs, and drag it back up five miles. Then they will leave it in orbit for another three years. Dani Eder/Boeing Aerospace/ssc-vax!eder
andrew@alberta.UUCP (Andrew Folkins) (10/18/85)
In article <8510161537.AA16848@s1-b.ARPA> HQM%MIT-OZ@MIT-MC.ARPA (Henry Minsky) writes: > >I am confused as to how NASA is going to win with the >space telescope's orbit: > >If they orbit it at the same height as the shuttle, won't it drag the >atmosphere and burn up like skylab in a few years? > >And if they boost it to a higher orbit, how can anyone get to it to make >repairs when it breaks? My guess is a fairly high low earth orbit, somewhere around 300 nautical miles (Anyone out there know the maximum operational altitude of the shuttle?). As the ST will be visited fairly often, there will be ample opportunities to haul it up a few more miles. I don't think they'll let it get down to the 150-180 miles that Skylab was at. -- Andrew Folkins ...ihnp4!alberta!andrew "Any statements to the effect that this parrot is still a going concern are hereby considered inoperative!"
ray@rochester.UUCP (Ray Frank) (10/20/85)
> In article <8510161537.AA16848@s1-b.ARPA> HQM%MIT-OZ@MIT-MC.ARPA (Henry Minsky) writes: > > > >I am confused as to how NASA is going to win with the > >space telescope's orbit: > > > >If they orbit it at the same height as the shuttle, won't it drag the > >atmosphere and burn up like skylab in a few years? > > > >And if they boost it to a higher orbit, how can anyone get to it to make > >repairs when it breaks? > > My guess is a fairly high low earth orbit, somewhere around 300 nautical > miles (Anyone out there know the maximum operational altitude of the shuttle?). > As the ST will be visited fairly often, there will be ample opportunities > to haul it up a few more miles. I don't think they'll let it get down > to the 150-180 miles that Skylab was at. > > -- I believe the space telescope is designed to last about 13 years. How high would it have to be to stay aloft that long?
garym@telesoft.UUCP (Gary Morris @shine) (10/21/85)
In article <694@alberta.UUCP> andrew@pembina.UUCP (Andrew Folkins) writes: >In article <8510161537.AA16848@s1-b.ARPA> HQM%MIT-OZ@MIT-MC.ARPA (Henry Minsky) writes: >> >>If they orbit it at the same height as the shuttle, won't it drag the >>atmosphere and burn up like skylab in a few years? >> >>And if they boost it to a higher orbit, how can anyone get to it to make >>repairs when it breaks? > >My guess is a fairly high low earth orbit, somewhere around 300 nautical >miles (Anyone out there know the maximum operational altitude of the shuttle?). According to the "Space Shuttle Operators Manual" the space telescope will be deployed in orbit at 500 miles (800 km). It also states the maximum orbit for the Shuttle is 690 miles (1100 km). -- Gary A. Morris -- USENET : ...{decvax,ucbvax}!sdcsvax!telesoft!garym CompuServ: 76317,520 TeleMail : GMorris/TeleSoft "Always listen to experts. They'll tell you what can't be done and why. Then do it." -- Lazarus Long
al@ames.UUCP (Al Globus) (10/22/85)
> In article <8510161537.AA16848@s1-b.ARPA> HQM%MIT-OZ@MIT-MC.ARPA (Henry Minsky) writes: > > > >I am confused as to how NASA is going to win with the > >space telescope's orbit: > > > >If they orbit it at the same height as the shuttle, won't it drag the > >atmosphere and burn up like skylab in a few years? > > > >And if they boost it to a higher orbit, how can anyone get to it to make > >repairs when it breaks? > As the ST will be visited fairly often, there will be ample opportunities > to haul it up a few more miles. I don't think they'll let it get down > to the 150-180 miles that Skylab was at. > > -- > Andrew Folkins ...ihnp4!alberta!andrew > > "Any statements to the effect that this parrot is still a going concern > are hereby considered inoperative!" I don't remember the numbers, but according to Aviation Week the Space Telescope mission will set an shuttle altitude record. Furthermore, the shuttle can nominally go about twice as high as it usually does.
DINGMAN@RADC-TOPS20.ARPA (11/07/85)
The operational altitude of the orbiter is 115 miles to 600 miles. I would imagine at the upper limits maneuverability is limited due to fuel requirements to get back down. The shuttle will remain with the ST for the duration of the mission (about a week) to check out its systems and directional (pointing) stability. Also, the computer components of the ST are modular, designed to be popped in and out for repair. The expected life of ST is 15 years. --- jd -------
dhp@ihnp3.UUCP (Douglas H. Price) (11/09/85)
There was a notation in Aviation (sic) Leak that the telescope would be placed at the maximum orbital height that the shuttle could reach with that weight of cargo (~325mi?) -- Douglas H. Price Analysts International Corp. @ AT&T Bell Laboratories ..!ihnp4!ihnp3!dhp