Date: Sun, 14 Feb 93 05:09:20 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #181 To: Space Digest Readers Precedence: bulk Space Digest Sun, 14 Feb 93 Volume 16 : Issue 181 Today's Topics: HST repair mission ideas on reviving the SSF project as well as Mir Well.. Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: Sat, 13 Feb 1993 18:16:26 GMT From: Gary Coffman Subject: HST repair mission Newsgroups: sci.space In article <1lhp7hINN3rd@access.digex.com> prb@access.digex.com (Pat) writes: > >Given that NASA owns a spare mirror, hwo much would it cost >to build a lite telescope, using the mirror, and just a Faint >object camera and maybe a spare WFPC? > >I think these were the items that really needed the big mirror. >Certainly, we don't need another 5 billion dollar project, but >how much could be done for 500 million? > >ALl the engineerings been done for a large telescope, how hard >would it be to make a stripped follow-up???? Well if you followed the existing plans, all you'd have would be the metal bending costs and the launch costs. However, with some of the instruments stripped out it's dynamics would change. Of course you could fit dummy ballast in their place. I think that resisting the urge to fix some of Hubble's faults in a follow on satellite would be almost impossible though. Then you start to get back into engineering design costs again. The critical unaddressed issue is pointing accuracy and stability. You'd certainly want non-wiggling solar panels and different, more reliable gyros. The flight avionics and software would need revising. You'd like to modify the electronics to resist SEUs in the SAA, etc. Money, money, money. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | ------------------------------ Date: Sat, 13 Feb 1993 15:45:27 GMT From: Gary Coffman Subject: ideas on reviving the SSF project as well as Mir Newsgroups: sci.space In article sas52992@uxa.cso.uiuc.edu (Sanjay Ashok Sheth) writes: >It has been suggested recently that Space Station Freedom is in serious >danger of being cut out of the US budget or at least having substantially >fewer funds made available to it. I have also noted recently in the news >that the Russian Space Agency is also running out of money and is seriously >undermanned. Russian military space has been sharply cut, but they're still managing to fund their civil program at about the same rate as pre-breakup days. Like us, budgets are tight, but they are really committed to keeping the one shining star of pride they have left. >Noting the current state of friendly relations with Russia, why not turn >Space Station Freedom project into an international effort? The Russians >already have their space station Mir in orbit. Why not use Mir as a core >for a new space station that would be built around it? This way, we could >have maybe half the job done already - the critical components of the space >station are already up there. > >The existing funds could then be used to make new modules that could be >fitted onto Mir like an research module, a industrial module and maybe even >a recreational module. > >Russia also has the rockets needed to boost all these components into space >since they have been resupplying their space stations for years now. Using >American technology and Russian man-power/components/equipment, the space >station could be built within 4-5 years instead of waiting many more with >the danger of being cut each year. Mir is old. Much of the cosmonauts' time is now devoted to keeping it working. It was not designed to be a *permanent* space station, only the latest in a series of rather simple and small workspaces that the ex-Soviets have launched. They have a replacement in the works that should begin construction in about 1995, the same time the first of Freedom's components are scheduled to be ready for launch. Mir II is truss based, just like Freedom, and is designed to be easily expandable, just like Freedom, and designed to last longer than Mir, just like Freedom. With only two years remaining until the two stations start being launched, there may not be time to design compatible interfaces. But it is worth looking into. NASA teams are already working with their Russian counterparts to facilitate a Shuttle mission to Mir. That's lots easier than making station modules compatible, but it certainly is a start in the right direction. Note that both space stations are conceptually very simple, just some cans that attach to a truss and connect up to power from truss mounted arrays. But in reality the stations are incredibly complex with many issues of module compatibility and many calculations required for dynamic stability with different masses attached at different places on the moment arms. They aren't tinkertoys that can be casually mixed and matched. If we had started working on a cooperative station ten years ago, we'd have a nice combined station starting construction in 1995, but it's probably too late in the design cycle to do that now without shoving back start of construction several years. We've waited long enough for a station, more delay is not a good idea. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | ------------------------------ Date: Sat, 13 Feb 1993 18:21:38 GMT From: Peter Walker Subject: Well.. Newsgroups: sci.space In article <7XyVyB5w165w@tradent.wimsey.com>, lord@tradent.wimsey.com (Jason Cooper) wrote: > > baumgartnerb@gtephx.UUCP (Robert A. Baumgartner) writes: > > > In article <1kl0r5INNhlo@jhunix.hcf.jhu.edu>, ko_mike@jhunix.hcf.jhu.edu (Mic > > > Well, since Warp 1 is c, the speed of light, it should take a ship travelin > > > to a planet 60 light years away 60 years. Pretty basic... > > > > > > > Theoretically (Not mine), when a ship travels at near the speed of light > > time, for people aboard this ship, would slow down to near zero. > > This is a relative effect - The time for people left on earth, for > > example would take 60 years, but the people on the ship would not > > age 60 years, actually much much less. In this same theory, one > > could travel to the edge of the universe and return in a human life span. > > The problem is that when they returned it would be quadrillion-billion- > > million years later ( a large number of years). Suffice it to say the > > solar system that we live in would not exist. > > > > This is from Carl Sagan PBS series. > > -- > > Bob Baumgartner; AG Communications Systems; Phoenix AZ > > UUCP: {ncar!noao!asuvax | uunet!zardoz!hrc | att}!gtephx!baumgartnerb > > Internet: gtephx!baumgartnerb@asuvax.eas.asu.edu > > (602) - 582-7444 > > I'm reading a book called Faster Than Light, and it's got a nifty thing > about just such a situation. Documents a NAFAL (Nearly As Fast As Light) > ship, which would travel at 1g acceleration. To those external, it would > seem that the thing never went over the speed of light. However, the > book introduces (to me at least) a concept of another scale. Once the > NAFAL ship's captain stops, he's going to look back and say "WOW, I just > went 25 light years and I'm only a year older". As he travels, using > distances calculated from earth, he will find himself to be going faster > than light as well (in fact, at 1g, after 25 years he thinks he's going > 72 billion times the speed of light by that logic). This is not some > wierd twist of figures, and I'm not saying that it doesn't involve some > strange ideas, but to THAT PERSON, when he/she stops, he's going to think > that he just went and enormous distance in very little time. > > Jason Cooper True, but the energy required to get him to that speed is a significant fration of the ship that carried him's rest mass. In the real world, a NAFAL spaceship is impractical. Peter W. Walker "Yu, shall I tell you what knowledge is? When Dept. of Space Physics you know a thing, say that you know it. When and Astronomy you do not know a thing, admit you do not know Rice University it. This is knowledge." Houston, TX - K'ung-fu Tzu ------------------------------ End of Space Digest Volume 16 : Issue 181 ------------------------------