Date: Fri, 19 Feb 93 05:00:05 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #198 To: Space Digest Readers Precedence: bulk Space Digest Fri, 19 Feb 93 Volume 16 : Issue 198 Today's Topics: *advocate* anonymous postings Antimatter/Atomic Booms for Jettison! (2 msgs) Are Landsat Satellites receivable? FGS Info (RE: HST repair mission) Henry Spencer stamps Mars flyby + asteroid rendezvous (was Re: Mir mission to Mars?) NF-104 (was Re: kerosene/peroxide SSTO) (2 msgs) NOAA, METEOR satellites Nobody cares about Fred? (2 msgs) Pressure fuel delivery, ideas regarding (2 msgs) Sabatier Reactors. SETI and Virtual Reality SPACE DAILY VR, Mars Pix 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: 17 Feb 93 22:22:57 GMT From: Jay Maynard Subject: *advocate* anonymous postings Newsgroups: news.admin.policy,comp.org.eff.talk,alt.privacy,sci.space,sci.astro,sci.crypt In article <1993Feb16.191517.12896@fuug.fi> an8785@anon.penet.fi (8 February 1993) writes: >Now that we've seen that pseudonymous postings are not an >unmitigated evil "What you mean we, white man?" (Misattrubuted to Tonto...) You may think you've proven that, but the tide of opinion is against you. >by demonstrating their accountability and >responsibility What accountability and responsibility? You haven't been held accountable yet for disrupting sci.space, etcetera... >True, a lot of sludge will be channeled by Anonymous. But >of far more importance will the occasional Copernican theory >(still censored in some areas until the early 19th C.) be able >to surface without intimidation or retribution. Good grief. This a lot of self-righteous hooey from someone defeinding his right to repost from the Weekly World News to a scientific newsgroup, and to do so with patently false and offensive material. If that's your idea of a Copernican theory, what do you call relativity?? -- Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can jmaynard@oac.hsc.uth.tmc.edu | adequately be explained by stupidity. "Support your local medical examiner - die strangely." -- Blake Bowers ------------------------------ Date: 17 Feb 93 22:56:45 GMT From: "David M. Palmer" Subject: Antimatter/Atomic Booms for Jettison! Newsgroups: sci.space kjenks@gothamcity.jsc.nasa.gov writes: >In my Introduction to Nuclear Engineering class, I was taught that >there are four ways of limiting exposure to radiation: > 1) Increase the distance between yourself and the source > 2) Decrease your exposure time > 3) Increase your shielding > 4) Reduce the intensity of the source >If somebody has come up with a new way, please advise. Let your grad student do it. -- David M. Palmer palmer@alumni.caltech.edu palmer@tgrs.gsfc.nasa.gov ------------------------------ Date: Wed, 17 Feb 1993 22:57:07 GMT From: Michael Robert Williams Subject: Antimatter/Atomic Booms for Jettison! Newsgroups: sci.space In article <1993Feb17.172632.4350@aio.jsc.nasa.gov> kjenks@gothamcity.jsc.nasa.gov writes: >Andrew Haveland-Robinson (andy@osea.demon.co.uk) wrote: > >: In article <1993Feb9.145038.1@fnalf.fnal.gov> higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey) writes: > >In my Introduction to Nuclear Engineering class, I was taught that >there are four ways of limiting exposure to radiation: > 1) Increase the distance between yourself and the source > 2) Decrease your exposure time > 3) Increase your shielding > 4) Reduce the intensity of the source > >If somebody has come up with a new way, please advise. > How about ... 5) Hire a graduate student to do the job In Real Life:Mike Williams | Perpetual Grad Student e-mail :mrw9e@virginia.edu| - It's not just a job, it's an indenture --------------------------------------------------------------------------- "If you ever have a world of your own, plan ahead- don't eat it." ST:TNG ------------------------------ Date: Wed, 17 Feb 1993 23:36:06 GMT From: Henry Spencer Subject: Are Landsat Satellites receivable? Newsgroups: sci.space In article nickh@CS.CMU.EDU (Nick Haines) writes: >The ways to beat the diffraction limit are basically means of >simulating a larger aperture... Actually, it is possible to *really* beat the diffraction limit, rather than cheating by simulating larger apertures... but it's not something that can be applied to satellite observations. (Hint: what are the assumptions behind the diffraction limit?) I overlooked optical interferometry because it's cheating -- you really do need that larger aperture, you just don't have to fill it in completely or all at once. Astronomers are just starting to experiment with it. I'm sure the NRO has thought about it, but heaven knows whether they're doing it. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Wed, 17 Feb 1993 23:52:31 GMT From: gawne@stsci.edu Subject: FGS Info (RE: HST repair mission) Newsgroups: sci.space In article <1ltbl9INNet@access.digex.com>, prb@access.digex.com (Pat) wrote: >> Guidance comes from the Fine guidance system. A series of three banana >> shaped ccd, which tap light off the WF/PC? My understanding is the >> FGS is considered almost a separate science instrument on it's own. and Kent Reinhard wrote a nice explanation of what the FGS system really does in article <1993Feb17.131520.1@stsci.edu> > The Fine Guidance Sensors (FGS) are located in the focal plane structure and > placed at right angles to the optical path of the telescope. They have > "pick-off" mirrors that deflect the incoming light into the apertures. [remainder of Kent's posting deleted for brevity.] To correct another misconception that Kent did not address, the FGS's are not CCD's. Each FGS uses four photomultiplier tubes to measure the signal directed to them by the star selector mirrors. The pointing and guidance system is independent of the WFPC, and vice verse. -Bill Gawne, Space Telescope Science Institute "Forgive him, he is a barbarian, who thinks the customs of his tribe are the laws of the universe." - G. J. Caesar ------------------------------ Date: 17 Feb 93 21:39:01 GMT From: James Thomas Green Subject: Henry Spencer stamps Newsgroups: sci.space In article 18084TM@msu.edu (Tom) writes: > >To be honest, I have no idea what Henry actually looks like, so if he was >on those stamps, I wouldn't know anyway :-) > He probably looks like Elvis. /~~~(-: James T. Green :-)~~~~(-: jgreen@eros.calpoly.edu :-)~~~\ |I didn't do it! Nobody saw me do it! You can't prove anything! | | | ------------------------------ Date: Wed, 17 Feb 1993 21:34:02 GMT From: James Thomas Green Subject: Mars flyby + asteroid rendezvous (was Re: Mir mission to Mars?) Newsgroups: sci.space,alt.sci.planetary In article henry@zoo.toronto.edu (Henry Spencer) writes: >In article szabo@techbook.com (Nick Szabo) writes: >>>(Upon reading your message I went looking for Mars Trojans in the >>>*Boys' Big Book of Asteroids* but found nothing. >> >>I seem to recall a Mars Trojan being discovered a while back. > >There is, indeed, one known. There may be some more, although it's not >likely that there are great swarms of them. They're not easy to spot, >because they are "Trojans" only in a loose sense -- they wander a long >way from the actual Trojan points. > >There actually isn't much about the Mars Trojan(s) that makes it/them >particularly useful for future space activities, compared to other >non-main-belt asteroids like the Earth-approachers. What's the latest news about the Jupiter Trojans. I understand that there are quite a few known (I know that there's at least one with a name: Hektor at the leading trojan). I've often thought that the potential concentration of asteroids at these points might one day lead to those points being the most densely populated points in the solar system off the Earth (in say 500 years or so...). /~~~(-: James T. Green :-)~~~~~(-: jgreen@eros.calpoly.edu :-)~~~\ | "Once you can accept the universe as being something expanding | | into an infinite nothing which is something, wearing stripes | | with plaid is easy." | | | ------------------------------ Date: Wed, 17 Feb 1993 23:07:38 GMT From: Mary Shafer Subject: NF-104 (was Re: kerosene/peroxide SSTO) Newsgroups: sci.space On Sat, 6 Feb 1993 02:56:20 GMT, gawne@stsci.edu said: BG> In article , henry@zoo.toronto.edu BG> (Henry Spencer) writes: > Also of note were the peroxide monopropellant rocket engines used in the > NF-104 rocket-boosted aircraft flown by NASA and the USAF, which worked > quite well and were serviced and fuelled by ordinary USAF technicians. BG> Isn't that the one Chuck Yeager almost killed himself in? Seems I recall BG> somebody saying its flight envelope had more holes in it than a BG> Tiajuana .... [nevermind]. That's the one immortalized in "The Right Stuff". Supposedly, that incident (Chuck taking off because he felt like it) is the reason that Edwards AFB uses the system of ops numbers and CONFORM. One gets one's flight put on the flight schedule and an ops number is assigned. One then relays this ops number to CONFORM _before_ taxiing. Although I'm at a loss to explain how this will keep the determined from an illicit flight. Maybe it gives the ground crews a little longer to block the plane's path with a tug? BG> I guess what I'm asking is did the engines work well, or the plane as BG> a whole, or both, or neither? Maybe Mary can provide some light on this BG> if nobody else can. There's some confusion here--NASA didn't fly the NF-104 rocket-boosted aircraft. We were flying F-104Ns at that time; these were regular F-104s without the weapons suite and radar. I don't really know anything about the NF-104 project except that it went pretty much as planned. (Well, the accident wasn't _planned_ but it wasn't totally unexpected either; in flight test one frequently assumes that one will lose the vehicle, which is why we do so much flying over uninhabited areas.) One of the NF-104s is on a plinth beside the Test Pilot School down at the other end of the flightline here and one of the F-104Ns is parked in the desert at the museum site. Now, to get back to the original subject, which is H2O2; we've used it as a propellant in a variety of RCSs (reaction control systems), including the X-15, various lifting bodies, and (I think) the RCS YF-104A (see, there's another F-104--we had 11 different aircraft, 6 different models, so they keep appearing). It's certainly no worse that hydrazine, better if the amount of training required to walk through the hangar with it around can be used as a gauge. -- Mary Shafer DoD #0362 KotFR NASA Dryden Flight Research Facility, Edwards, CA shafer@rigel.dfrf.nasa.gov Of course I don't speak for NASA "A MiG at your six is better than no MiG at all." Unknown US fighter pilot ------------------------------ Date: Thu, 18 Feb 1993 00:22:24 GMT From: Henry Spencer Subject: NF-104 (was Re: kerosene/peroxide SSTO) Newsgroups: sci.space In article shafer@rigel.dfrf.nasa.gov (Mary Shafer) writes: >> NF-104 rocket-boosted aircraft flown by NASA and the USAF... >BG> Isn't that the one Chuck Yeager almost killed himself in? ... > >That's the one immortalized in "The Right Stuff". >Supposedly, that incident (Chuck taking off because he felt like it) >is the reason that Edwards AFB uses the system of ops numbers and >CONFORM... Actually, the subject came up when Mitch Burnside Clapp was talking about NF-104 peroxide experience at Making Orbit 93, and Mitch said (as best I recall) that the movie had exaggerated the unauthorized nature of Yeager's flight. (I don't know details myself, but given how many other things the movie exaggerated, I can well believe it...) >BG> I guess what I'm asking is did the engines work well, or the plane as >BG> a whole, or both, or neither? Maybe Mary can provide some light... > >There's some confusion here--NASA didn't fly the NF-104 rocket-boosted >aircraft... Wups, my fault. I knew that, too -- don't know why I mentioned NASA in the original posting. My understanding is that there were never any serious problems with the peroxide hardware, and the aircraft systems gave no more trouble than usual. However, the F-104 was a notoriously unforgiving aircraft, and flying a ballistic trajectory using rocket boost wouldn't be exactly an easy mission even in a better-behaved aircraft. It worked fairly well but called for good pilots who never let their guard down even briefly. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Wed, 17 Feb 1993 15:23:53 EST From: Ron McCarty Subject: NOAA, METEOR satellites Newsgroups: sci.space We have set up a satellite receiving station and are receiving images from NOAA and Meteor (Russian) satellites. We would like to correspond with others who are doing this or who are interested in doing this. We are a branch college of Penn State, located in in Erie PA. We hope to get some programs going with local elementary and high schools to get students interested in science at an early age. We also hope to get our own students involved in some undergraduate research projects. We have faculty involved from computer science, physics, biology and geoscience. As I said, we would like to correspond with others who have like interests so we can pool our knowledge/resources/experiences. Please respond by e-mail or followup, whichever you feel most appropriate. Ron McCarty Division of Science (Computer Science) Penn State Erie, Behrend College ------------------------------ Date: 17 Feb 1993 20:30:10 GMT From: Doug Mohney Subject: Nobody cares about Fred? Newsgroups: sci.space In article <1993Feb17.003421.28116@iti.org>, aws@iti.org (Allen W. Sherzer) writes: >too little too late. Recent EVA's seem to have found it is a lot harder >than first thought and what the tank tests say. If there are major problems, >it is too late now to fix them. >Wouldn't it have been nice if NASA where engaged in a regular program >of EVA years ago? >That NASA hasn't engaged in this work is nothing short of incompetance. >Now before Doug whines about Intelsat, if NASA had engaged in such a >program of practice he would have a point. They didn't and he doesn't. First you whine about the Intelsat rescue. "No value," he says, "Cheaper to send up a new satellite." NASA (as one of their STATED objectives), conducts the rescue to gain more EVA experience, based in part on the concern to keep said skills fresh for the Hubble repair mission this November. During the course of the mission, they find there ARE some differences between ground simulations and The Real Thing. So, NASA adds EVA time whenever it can on future Shuttle missions. Which, if I might quote you again: >It would have been very cheap to add an evperimental >spacewalk to gain skills and we would have FAR more confidence in our >ability to assemble Freedom. NASA realizes it has some shortcomings. It now does EVAs and people such as yourself start bitching about how useless it is to have two astronauts haul each other around in the Shuttle cargo bay. So tell me, Mr. Sherzer, what is the REAL reason why you don't like NASA? Were you denied a job there? Astronaut slot? It is obvious you have an axe to grind, beause they're incapable of meeting your standards of perfection. I have talked to Ehud, and lived. -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: Wed, 17 Feb 1993 23:49:02 GMT From: Henry Spencer Subject: Nobody cares about Fred? Newsgroups: sci.space In article <1lu78iINNkcv@mojo.eng.umd.edu> sysmgr@king.eng.umd.edu writes: >>Wouldn't it have been nice if NASA where engaged in a regular program >>of EVA years ago? ... >>Now before Doug whines about Intelsat, if NASA had engaged in such a >>program of practice he would have a point. They didn't and he doesn't. > >First you whine about the Intelsat rescue... >NASA (as one of their STATED objectives), conducts the rescue to gain more EVA >experience, based in part on the concern to keep said skills fresh for the >Hubble repair mission this November. This is why it was one of a bare handful of EVA missions scheduled between 1985 and start of Fred assembly? That wasn't a stated objective; that was a stated excuse. They were doing it for PR value, even if a lot of people (including some at NASA) thought that getting more EVA experience was a damn good idea. Before the Intelsat rescue, NASA was deliberately minimizing EVA activity, on the grounds that there wasn't much to be learned and it was too risky. Only now, with the Intelsat experience throwing a good scare into everybody, have *experimental* EVAs, in substantial numbers, gone back into the plans. >During the course of the mission, they find there ARE some differences >between ground simulations and The Real Thing. >So, NASA adds EVA time whenever it can on future Shuttle missions. I believe Allen's point was that differences between simulations and the real thing were absolutely predictable, but NASA was ignoring the issue. The addition of EVA time wasn't a small change to existing plans based on unexpected minor problems; it was a 180-degree reversal of policy, based on getting a big nasty surprise on what was supposed to be a showpiece mission. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 17 Feb 93 20:00:07 GMT From: Craig Meyer <01crmeyer@leo.bsuvc.bsu.edu> Subject: Pressure fuel delivery, ideas regarding Newsgroups: sci.space Is it agreed upon that pressure-feeding fuel to engines is very advantageous in terms of complexity (no pumps), but disadvantageous in terms of wieght (thicker tanks to contain pressure)? If so, I'd like to suggest a couple ways to possibly make pressure-feed lighter, and see if you think they hold any water: 1 Use a high-pressure gas to deliver the fuel in the same manner as a perfume atomizer. 2 a. Transfer fuel from thin-walled main tank to theoretical smaller, thick-walled secondary tanks by *light* pressure-feeding. b. Close valve between main tank and secondary pressure tanks. c. Pressure-feed fuel from secondary pressure tanks. d. Depressurize pressure tanks, refill, and return to step a. ----------------------------------------------- about standard pressure-feed systems: I've read of a aluminum natural gas tank (for a bus) being wrapped with carbon-fiber to hold a great deal more pressure. I suppose the same technique could be applied to non-cryogenic propellant tanks (Or is it common practice already)? How formiddable is the weight of the pressure-gas system itself, which no scheme can reduce? Thank you for your time, CM -- Craig Meyer 01CRMEYER@LEO.BSUVC.BSU.EDU Indiana Academy for Science, Mathematics, and Humaities. Muncie, IN 47306 317-285-7433 Opinions expressed are mine alone, and not necessarily shared by the Indiana Academy. ------------------------------ Date: Thu, 18 Feb 1993 00:01:19 GMT From: Henry Spencer Subject: Pressure fuel delivery, ideas regarding Newsgroups: sci.space In article <1993Feb17.150008.15241@bsu-ucs> 01crmeyer@leo.bsuvc.bsu.edu (Craig Meyer) writes: >...I'd like to suggest a couple ways to possibly make pressure-feed >lighter, and see if you think they hold any water: > >Use a high-pressure gas to deliver the fuel in the same manner as >a perfume atomizer. This is a pump, of a type known as an ejector. The problem is that you need vast amounts of gas. >a. Transfer fuel from thin-walled main tank to theoretical smaller, thick-walled > secondary tanks by *light* pressure-feeding. >b. Close valve between main tank and secondary pressure tanks. >c. Pressure-feed fuel from secondary pressure tanks... This is a reciprocating pump of a slightly unusual type. Gas consumption should not be significantly higher than for a straight pressure-fed system, but it's not clear to me why it has much of an advantage over a reciprocating pump powered by a turbine or something on that order. You've got much of the same complexity (valves etc.), and all the weight of large amounts of pressurization gas. >about standard pressure-feed systems: >I've read of a aluminum natural gas tank (for a bus) being wrapped with >carbon-fiber to hold a great deal more pressure. I suppose the same technique >could be applied to non-cryogenic propellant tanks (Or is it common practice >already)? Filament-wound pressure tanks are routine practice in modern space hardware. >How formiddable is the weight of the pressure-gas system itself, which >no scheme can reduce? Substantial, unfortunately. You just plain need large amounts of *gas*, which amounts to a fair bit of weight in itself, and storage is also a headache. The lightest gases, hydrogen and helium, are particularly painful to store. -- C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology effect since OS/360. | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Wed, 17 Feb 1993 21:12:55 GMT From: "Phil G. Fraering" Subject: Sabatier Reactors. Newsgroups: sci.space matthew@phantom.gatech.edu (Matthew DeLuca) writes: >(Do note, however, that "modest unknowns" is Spencer-speak for "we're >clueless"; it's not just a matter of hooking up a pump and pumping away. >We should learn to do it, though...we have to sooner or later.) Hmm... in my copy of the Oxford Spencer-Speak Dictionary, "modest unknowns" doesn't totally equate to "clueless." It means we don't know how to do it now, but we do have lots and lots of ideas on how to do it, many of which might work, we just haven't bothered to try any of them. It's a fascinating book, BTW; apparently !attcan!utzoo!henry originated in the transliteration into English of the battle cry of a branch of an African nomadic tribe from British Guyana that was living in the swamps south of New Orleans... >Matthew DeLuca >Georgia Institute of Technology, Atlanta Georgia, 30332 >uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!matthew >Internet: matthew@phantom.gatech.edu -- Phil Fraering |"...drag them, kicking and screaming, pgf@srl02.cacs.usl.edu|into the Century of the Fruitbat." - Terry Pratchett, _Reaper Man_ ------------------------------ Date: Wed, 17 Feb 93 20:09:22 GMT From: Ata Etemadi Subject: SETI and Virtual Reality Newsgroups: sci.space In article <1lttroINNhsu@elroy.jpl.nasa.gov>, tjt@Jpl.Nasa.Gov (Tim Thompson) writes: |> In response to an earlier query, I am quite confident that the NASA SETI |> program has nothing to do with virtual reality. Remember, communication with |> any possible aliens is definitely NOT part of the NASA SETI project. It is |> strictly a radio search for extraterrestrial signals of an intelligent nature. |> Detection of such a signal is the project's sole purpose, responding to any |> such signal has never been considered as part of the NASA SETI project. Of course, |> I suspect that if such a signal is detected, someone will become interested in |> the communication aspects. I remember about 10-15 years ago some organisation (I though it was SETI) gathered together teams of top graduates and set them a puzzle to do with communication. Basically the teams were given some hundreds of pages of computer printout with 1's and 0's. This represented a "signal" from an alien. The teams were given the job of decoding it. The idea was to use the methodology they developed to "listen" for aliens. Hence why I mentioned it. Sounds like a fun thing to try on the net.. regards Ata <(|)>. ------------------------------ Date: 18 Feb 1993 00:20:49 GMT From: CLAUDIO OLIVEIRA EGALON Subject: SPACE DAILY Newsgroups: sci.space I am aware of a publication entitled Space Daily which is published daily (as the name says) and I was wondering if this thing is available in the NET. Does anyone know anything about that? ------------------------------ Date: Thu, 18 Feb 93 13:40:46 EET From: flb@flb.optiplan.fi (F.Baube x554) Subject: VR, Mars Pix Richard Ottolini > Subject: Virtual Reality research at NASA > VPL also coined the current term of virtual reality. They copyrighted it, too. That's why you see an alternative term "Virtuality". Ed McCreary > Subject: Pictures of Mars wanted > >>>>> On Sun, 14 Feb 1993 17:40:57 GMT, chenina@rhrk.uni-kl.de (Robert Chenina [Chemie]) said: > RC[> I'm looking for some pictures from the Viking mission. The pictures > RC[> are details obout the region called _Cydonia Mensae_ (approx. 40.9N, > RC[> 9.45W) and referenced as: > RC[> 35A72, 70A13, 673B56, 753A33. > 35A72 and 70A13 can be found at: > cs.ubc.ca under pub/local/image/mars > phoenix.oulu.fi under pub/ufo_and_space_pics Is this the reference for the "Face" ? -- * Fred Baube GU/MSFS * "Leave aside the brush, because the * Optiplan O.Y. * government has supplied the sprayguns." * baube@optiplan.fi * -- Hoxha-era Albanian saying * #include * > Where is the PGP follow-on found ? < * Nymphs vex, beg quick fjord waltz (27 letters) ------------------------------ Date: Thu, 18 Feb 93 17:22:20 EST From: MAILRP%ESA.BITNET@vm.gmd.de Press Release Nr.05.93 Paris, 17 February 1993 HUBBLE SPACE TELESCOPE SERVICING MISSION JOINT ESA/BAE UK TECHNICAL PRESS BRIEFING Wednesday 10 March 1993 On Wednesday 10 March 1993 astronauts from ESA and NASA will be at British Aerospace Space Systems Limited, Filton, Bristol, UK, training on the replacement set of solar arrays which they are scheduled to fit to the Hubble Space Telescope at year end. You are invited to attend a technical briefing on that day, which will be given by senior representatives of the European Space Agency and British Aerospace. The briefing will include details of the design modifications and status of the solar arrays, together with a brief overview of the scientific results already achieved by the teams of astronomers using the telescope. There will be an opportunity for interviews with the mission specialists in the crew of NASA's Space Shuttle flight STS-61, who will be carrying out the servicing mission for the Hubble Space Telescope in a series of "Extra-Vehicular Activities - EVA' (space-walks). Five astronauts are expected : Story Musgrave, Colonel Tom Akers, Jeffrey A. Hoffman, Kathryn C. Thornton from NASA and Claude Nicollier from ESA. There will also be a chance to view the solar arrays in the British Aerospace clean room area where the astronauts are working on their familiarisation programme. The briefing will take place on Wednesday 10 March 1993 at British Aerospace Space Systems, Filton, Bristol, UK (on the northern outskirts of the city of Bristol). The event will begin at 10h30 a.m. and end with a buffet lunch running from approximately 01h30 p.m. to 02h30 p.m. In order to assists with arrangements for travel to and from bristol, British Aerospace proposes to run a free coach from and to London Victoria Coach Station - if there proves to be sufficient press interest. This coach would depart from London at approximately 07h50 a.m. and arrive back at around 05h30 p.m. Further details will be available on request when numbers are known. In order to gain access to the site and the briefing it is essential that all attendees are expected and their names are provided in advance. Please let us know by returning the attached fax form as soon as possible and by Friday 26 February at the latest if you or a colleague will be attending this briefing.  ------------------------------ End of Space Digest Volume 16 : Issue 198 ------------------------------