Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Fri, 8 Jun 1990 01:45:23 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 8 Jun 1990 01:44:51 -0400 (EDT) Subject: SPACE Digest V11 #505 SPACE Digest Volume 11 : Issue 505 Today's Topics: Termination of Lunar/Mars intiative Re: DSN Reliability and Resources Question Ulysses risks I: Design of RTG Re: "CCD imagers in HST" from EE Times Re: ROSAT IN ORBIT!!!! Re: ROSAT IN ORBIT!!!! Jonathan's Space Report, Jun 6 Re: "CCD imagers in HST" from EE Times Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 6 Jun 90 22:48:12 GMT From: ptolemy!fineman@ames.arc.nasa.gov (Charles Fineman) Subject: Termination of Lunar/Mars intiative The following is from a letter from Charlie Walker, former shuttle astronaut, and President of the National Space Society: Congress is ready to terminate the Lunar/Mars (aka Space Exploration) initiative. *** ZERO FUNDING *** [emphasis added by poster] The decision to cut this program has already been made behind the scenes. Congress is only waiting to return from the Mermorial Day recess to vote this important program out of existence. Termination would be catastrophic. No program is of more importance to [the US (both government AND comercial) space program]. Without this program there will be ... *NO* manned activity in space beyond low earth orbit for the foreseeable future. This is what YOU need to do, if the Lunar/Mars [aka: Space Exploration] initiative is to survive. Telephone or write (preferably telephone): Senator Barbara Mikulski (D-MD) and Congressman Bob Traxler (D-MI) 320 Hart Senate Office Building 2364 Rayburn Building Washington, DC 20510 Washington, DC 20515 (202) 224-4654 (202) 225-2806 Your call or letter MUST arrive during the week of June 4 to be fully effective. The earlier, the better. Updated information reguarding timing can be obtained by call the Space Hotline (202) 543-1995. [An important side effect of this issue is presidential embarrassment]. If President Bush fails in this effort - an effort he began - an effort for which he has expressed strong personal support, then other space initiatives will [fail to get] the attention that they [need]. In fact, it is unlikely that there will be any new space initiatives [by Bush or any other presidents] for a long time. The space program is in jeopardy. Let your opinion count in this vital vote on America's future. Call or write. America's space program needs your support today! Thanks you, Charlie Walker, former shuttle astronaut and pres. NSS PS: Your support makes a difference! According to former NASA administrator, James Fletcher, "Without your letters and phone calls, there is a [very high probablity] that the space station program would have been canceled last year." ====== Also, the following senators and congresspersons should be contacted: Senators: Frank Lautenberg (D-NJ) Robert Kerrey (D-MA) J Bennett Johnson (D-LA) Wyche Fowler (D-GA) Patrick Leahy (D-VT) Don Nickels (R-OK) Charles Grassley (R-IA) Phill Gramm (R-TX) Congresspersons: Louis Stokes (D-OH) Alan Mollohan (D-WV) Jim Chapman (D-TX) Chester Atkins (D-MA) Lawrence Coughlin (R-PA) Bill Green (R-NY) Jerry Lewis (R-CA) All members of Congress ca be contacted by calling 202-224-3121 and asking for the member in question Mail to: Senator (name) Congressperson (name) Washington, DC 20510 Washington, DC 20515 Get those calls going in. Thanks from Space Cause. ------------------------------ Date: 6 Jun 90 19:28:28 GMT From: att!watmath!maytag!watdragon!watyew!jdnicoll@ucbvax.Berkeley.EDU (Brian or James) Subject: Re: DSN Reliability and Resources Question This is probably a very stupid question, but are there safeguards to prevent unauthorised types from successfully sending the HST spurious commands? JDN ------------------------------ Date: Wed, 6 Jun 90 21:35 CDT From: William Higgins Subject: Ulysses risks I: Design of RTG Original_To: SPACE I've summarized what I know about the Ulysses RTG's and the risks posed by its plutonium dioxide fuel. Because of its length, I'm breaking my discussion up into several separate postings. DESIGN OF ULYSSES RTG Ulysses is powered by a particular model of radioisotope thermoelectric generator (RTG) known as a General Purpose Heat Source (GPHS). Galileo had two of these, Ulysses has only one. It is a 55.5-kg device which produces 285 watts of electrical power when its fuel is fresh. The fuel is plutonium-238 (not 239, the fissionable isotope used in bombs) in the form of plutonium dioxide, a ceramic. This isotope decays exclusively by giving off 5.5 MeV alpha particles, and no other radiation. Alpha particles are the easiest kind of radiation to stop. A thin sheet of paper will stop most alphas. The iridium cladding on the plutonium-oxide fuel slugs is more than enough shielding to prevent radiation from escaping. It is also malleable enough to deform under stress without releasing the oxide inside. The fuel pellets are in cylinders, 2.75 cm in diameter by 2.75 cm long. Each pellet yields thermal power of 62.5 watts; the 72 pellets loaded into Ulysses have a total thermal loading of about 4410 watts. Therefore specific power for the GPHS is 5.1 watts/kg, and electrical conversion efficiency is 6.8%. Two cladded pellets go into a cylindrical graphite-epoxy impact shell; this is wrapped in a carbon-bonded carbon fiber insulator. Two impact shells go into a block-shaped graphite-epoxy enclosure called an aeroshell. The aeroshell, measuring 9.7 x 9.3 x 5.3 cm, is the primary re-entry protection for the fuel. The insulators should protect the fuel from the high temperatures of re-entry, while the impact shells protect it from mechanical impact. Eighteen aeroshell modules are stacked into the aluminum housing of the GPHS, which also contains 576 silicon-germanium thermocouples. In the case of an accidental reentry, the GPHS is designed to separate into separate modules. Between $20 million and $30 million have been spent on a testing program to insure its safety, exposing RTG components to heating, projectile impact, explosions, immersion in water, and fires. ______meson Bill Higgins _-~ ____________-~______neutrino Fermi National Accelerator Laboratory - - ~-_ / \ ~----- proton Bitnet: HIGGINS@FNALB.BITNET | | \ / SPAN/Hepnet/Physnet: 43011::HIGGINS - - ~ Internet: HIGGINS@FNALB.FNAL.GOV ------------------------------ Date: 7 Jun 90 03:39:46 GMT From: usc!cs.utexas.edu!news-server.csri.toronto.edu!qucdn!gilla@ucsd.edu (Arnold G. Gill) Subject: Re: "CCD imagers in HST" from EE Times In article <7568@ncar.ucar.edu>, dlb@hao.hao.ucar.edu (Derek Buzasi) says: > >I hate to rain on anyone's parade, but the CCDs used on the HST are not >even close to being state of the art by modern standards, although they >may qualify based on 1982 standards. These chips have low quantum >efficiency (around 32% at best), high noise levels (~15 electrons), >and relatively low dynamic range by modern standards. My question is, why weren't the CCDs exchanged and updated while Hubble was sitting on the ground in its expensive clean room? Putting in a better CCD sounds like a very trivial thing to do, with only minor changes in the other hardware around it, especially since the signal will so markedly improve. ------- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- | Arnold Gill | | | Queen's University at Kingston | If I hadn't wanted it heard, | | BITNET : gilla@qucdn | I wouldn't have said it. | | X-400 : Arnold.Gill@QueensU.CA | | | INTERNET : gilla@qucdn.queensu.ca | | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- ------------------------------ Date: 6 Jun 90 13:46:55 GMT From: mcsun!unido!mpirbn!p515dfi@uunet.uu.net (Daniel Fischer) Subject: Re: ROSAT IN ORBIT!!!! In article <1926@cfa237.cfa250.harvard.edu> mcdowell@cfa250.harvard.edu (Jonathan McDowell) writes (message shortened) : >The ROSAT x-ray astronomy satellite was launched from LC17B at Cape >Canaveral at 2148UT today (Jun 1). Launch was delayed several minutes ... >... The Harvard-Smithsonian ROSAT team >rented a satellite dish to watch NASA Select, and celebrated with beer >and pretzels... > | Jonathan McDowell | phone : (617)495-7144 | > | Center for Astrophysics | uucp: husc6!harvard!cfa200!mcdowell | > | 60 Garden Street | bitnet : mcdowell@cfa.bitnet | > | Cambridge MA 02138 | inter : mcdowell@cfa.harvard.edu | > | USA | span : cfa::mcdowell (6699::) | At the German Space Operations Center (GSOC) at the DLR in Oberpfaffenhofen, Bavaria, W.Germany, there was a 'lauch party' at this time, with approx. 600 guests, bands playing (folk [i.e.: Blasmusik] and jazz), light shows, lots of good things to eat, and, of course, NASA Select on a big projection screen. The final seconds of the CountDown were awesome: people first became very silent, but from about t-5sec on they started to count louder and louder, and at ignition the NASA soundtrack was drowned in a tremendous cheer. This repeated at the first booster separation (NASA's TV coverage was of oustanding beauty) and again at the second one. It was *big* fun to watch NASA Select from Europe (not usually available here), and the party was just perfect. P.S.: During the celebrations I've learned from a key DLR manager involved in German-Soviet space activities that the Soviet MARS'94 spacecraft will almost certainly be launched in 1996 not 1994 - they do not want to repeat the PHOBOS errors. Most likely a very complicated German camera will be on board: with German unification on the horizon, the Eastern and Western German space agencies have decided to cooperate in its development. ------------------------------ Date: 7 Jun 90 01:04:24 GMT From: dftsrv!dftnic.gsfc.nasa.gov!lev@ames.arc.nasa.gov (Brian S. Lev) Subject: Re: ROSAT IN ORBIT!!!! In article <1926@cfa237.cfa250.harvard.edu>, mcdowell@cfa250.harvard.edu (Jonathan McDowell) writes... >The ROSAT x-ray astronomy satellite was launched from LC17B at Cape >Canaveral at 2148UT today (Jun 1). Launch was delayed several minutes >when an airliner strayed into the launch area. Orbit insertion occurred >at 2159UT and the orbit was circularized at 2226UT. The spacecraft was >due to separate from the Delta second stage at 2230, but loss of data at >the Indian Ocean ground station prevented confirmation of the event at >the time I am writing this (2250UT). The Harvard-Smithsonian ROSAT team >rented a satellite dish to watch NASA Select, and celebrated with beer >and pretzels... I LOVE IT! Seems like the SAO crew and the GSFC crew were on the same wave- length! Someone from the group here convinced the management of a nearby Mexican eatery (one of the big chains) to cut part of their music video system over to the local cable TV company, which also carries NASA Select TV. We enjoyed a happy hour sitting in front of a projection TV, watching that beautiful bird fly and toasting the fact that we all still had jobs! It was especially nice to see the bartended *cut off* the music videos during the actual launch so that we -- and a number of patrons -- had a clearer view. >ROSAT observations will begin in a few weeks with the X-ray all sky >survey. Next year, observatory-type pointed observations will be made. Yep -- and (as part of the team doing Level 1 & 2 data processing and keeping the project-dedicated network links "alive") I can't wait... lots of neat stuff out there to "see" in the X-ray spectrum, and the whole dumb world don't seem to care... +----------------------------------------------------------------------------+ | Brian Lev/STX (301)286-9514 (FTS)888-9514 | | NASA Goddard Space Flight Center DECnet: SDCDCL::LEV (6153::LEV) | | Advanced Data Flow Technology Office TCP/IP: lev@dftnic.gsfc.nasa.gov | | Code 930.4 BITNET: LEV@DFTBIT | | Greenbelt, MD 20771 TELENET: [BLEV/GSFCMAIL] | | X.400 Address: (C:USA,ADMD:TELEMAIL,PRMD:GSFC,O:GSFCMAIL,UN:BLEV) | +----------------------------------------------------------------------------+ | "The ability of a network to knit together the members of a sprawling | | community has proved to be the most powerful way of fostering scienti- | | fic advancement yet discovered." -- Peter Denning | +----------------------------------------------------------------------------+ | DISCLAIMER: THESE STATEMENTS ARE MY OWN AND *NOT* NASA'S OR STX'S! | +----------------------------------------------------------------------------+ ------------------------------ Date: 6 Jun 90 19:58:47 GMT From: frooz!cfa250!mcdowell@husc6.harvard.edu (Jonathan McDowell) Subject: Jonathan's Space Report, Jun 6 Jonathan's Space Report Jun 6 1990 (no.41) ---------------------------------------------------- Launch of STS-38/Atlantis is due for early July. Atlantis will be transferred from the Orbiter Processing Facility to the Vehicle Assembly Building this week, where it will be mated with the ET and SRBs. Launch of STS-35/Columbia has been rescheduled for August 9. A fuelling test revealed a leak in the seal between the orbiter and the External Tank; repairs will require destacking of the Shuttle in the Vehicle Assembly Building. The delay means that Spacelab Life Sciences 1 will also slip. The ROSAT (Rontgensatellit) x-ray astronomy satellite was launched on a Delta 6920 on Jun 1. The satellite, which is in a 600 km orbit, is similar to the Einstein Observatory (1978-81) but with more sensitive detectors. ROSAT is a joint project between the German DLR space agency and NASA, with British collaboration. The main X-ray telescope focusses radiation onto the PSPC (Position Sensitive Proportional Counter) which will make the best survey yet of the X-ray sky. Another detector, the HRI (High Resolution Imager) has higher spatial resolution and can be rotated into the focus of the telescope. ROSAT also carries a piggyback British telescope, the Wide Field Camera which will observe the sky in the extreme ultraviolet. The Hubble Space Telescope is in its Orbital Verification Phase 1. All the instruments have been turned on for electronics checks; acquisition of guide stars has improved greatly. Focussing of the telescope continues. Anatoli Solov'yov (Komandir) and Aleksandr Balandin (Bortinzhener) continue in orbit aboard the Mir complex. The Soyuz TM-9 transport is currently at the station. The Kristall module was launched on May 31, and is due to dock today at the forward port. It will be transferred to a side port soon after. Progress-42 undocked from the rear port on May 27, and Soyuz TM-9 made a 24-min flight from the front port to the rear port on May 28, leaving the front port open for Kristall. Solov'yov and Balandin have been in space for 114 days. The 6th Resurs-F remote sensing satellite was launched on May 29 by Soyuz from Plesetsk. (c) 1990 Jonathan McDowell ------------------------------ Date: 7 Jun 90 14:46:29 GMT From: frooz!cfa250!wyatt@husc6.harvard.edu (Bill Wyatt) Subject: Re: "CCD imagers in HST" from EE Times > From _EE Times_, 4 June 1990, pg 33 (reproduced w/o permission) [...] > The first image returned from the Hubble Space Telescope > was matched with a similar image from a telescope in Chile, > and proved to be distinctly clearer. It better be, at 1.5 gigabucks! Actually, NASA PR really blew it by overstating the expectations this early in the mission. Every instrument, ground-based or not, has an extensive check-out and calibration period. It always takes more time that you expect to optiimize an instrument, sometimes weeks, more likely years. > Texas Instruments supplied the thermoelectrically-cooled > CCD imager arrays on the Hubble; they are set up in four > tiled, 2048x2048 pixel imagers. Wrong. Remember, these chips were state-of-the-art 10 years ago. Each chip is 800x800, and there are mosaics up to 2x2, for a total of 1600x1600. The 2048x2048 size has only become common in the last year or two. TI no longer makes CCD chips, btw. Bill Wyatt, Smithsonian Astrophysical Observatory (Cambridge, MA, USA) UUCP : {husc6,cmcl2,mit-eddie}!harvard!cfa!wyatt Internet: wyatt@cfa.harvard.edu SPAN: cfa::wyatt BITNET: wyatt@cfa -- Bill Wyatt, Smithsonian Astrophysical Observatory (Cambridge, MA, USA) UUCP : {husc6,cmcl2,mit-eddie}!harvard!cfa!wyatt Internet: wyatt@cfa.harvard.edu SPAN: cfa::wyatt BITNET: wyatt@cfa ------------------------------ End of SPACE Digest V11 #505 *******************