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 ; Sat, 30 Jun 1990 02:07:57 -0400 (EDT) Message-ID: <4aX46Qe00VcJQ1Ok50@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 30 Jun 1990 02:07:25 -0400 (EDT) Subject: SPACE Digest V11 #587 SPACE Digest Volume 11 : Issue 587 Today's Topics: Re: Is there a backup HST mirror ??? (see sci.astro) Re: Magnetic solar sail? Re: More on NASA 91 Appropriation Vote Trying to locate Donald K. (Deke) Slayton HST focus problem Re: What Spherical Aberration is Re: ESA-brief summary of activity Re: Anyone Know What MOL Is/Was? Re: Is there a backup HST mirror ??? RE: public image of HST Re: 10 psi overpressure Re: NASA announces next steps in Space Exploration Outreach Program (F Re: Anyone Know What MOL Is/Was? Hubble Space Telescope Update - 06/27/90 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: 29 Jun 90 00:21:32 GMT From: zaphod.mps.ohio-state.edu!swrinde!emory!mephisto!prism!ccoprmd@tut.cis.ohio-state.edu (Matthew DeLuca) Subject: Re: Is there a backup HST mirror ??? (see sci.astro) In article dlbres10@pc.usl.edu (Fraering Philip) writes: > >_Maybe_, with the shuttle backlog being the way it is, a >Buran could be used... I don't know about you, but I wouldn't want *my* billion-dollar space toy brought home on something that has (a) only flown once, (b) won't fly again until 1991, and (c) has had its pilots refuse to fly it, due to instrumentation and redundancy problems. I think I'd like to see it fly a few times first. -- Matthew DeLuca Georgia Institute of Technology Do not meddle in the affairs of wizards, Office of Computing Services for they are subtle, and quick to anger. ARPA: ccoprmd@prism.gatech.edu ------------------------------ Date: 28 Jun 90 05:14:51 GMT From: swrinde!zaphod.mps.ohio-state.edu!sunybcs!ubvms.cc.buffalo.edu!collie@ucsd.edu (collie) Subject: Re: Magnetic solar sail? In article <9006280328.AA04504@quake.LCS.MIT.EDU>, kfl@QUAKE.LCS.MIT.EDU (Keith F. Lynch) writes... >> A magnetic sail uses the fact that the solar system has a magnetic >> field. You take a superconducter ring, and start a current in it, >> it now has a magnetic field, and the one for the solar system >> pushes against it. >This doesn't sound right. A magnet in space will tend to orient >itself in the direction of the field lines. But magnetic *attraction* >is due to the *difference* in magnetic flux from one side of the >magnet to the other. This is why magnets on earth have little >tendency to hurtle northward (or southward). The magnetic domain >of space is even flatter. >[ I just heard on the radio that the HST mirror is seriously warped. ] > ...Keith **************************** This is horrible news for NASA as the public would start crying even more about the 1.5 bill. price tag,and will further loose fate in any NASA plans for the future.I can now see the space station Freedom size getting even smaller,as the purse string draws even tighter.Where I stand,this is not a good sign. 1) What cause the mirror to become warped ? 2) What is the prognosis for the H.S.T now ? ****************************** ******************************************************************************** Can there be order in Chaos ? ******************************************************************************* ------------------------------ Date: 27 Jun 90 23:51:33 GMT From: usc!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!David.Anderman@ucsd.edu (David Anderman) Subject: Re: More on NASA 91 Appropriation Vote I'm curious to know the mechanics of how Andy Cutler gets to determine the final mission architecture of the SEI? Or, for that matter, how you or I could participate in the definition of the project. If no funds are voted this year for the project does this mean that we get to participate in the project next year (assuming it is funded next year)? --- Opus-CBCS 1.13 * Origin: Universal Electronics, Inc. (1:103/302.0) -- uucp: David Anderman Internet: David.Anderman@ofa123.fidonet.org BBS: 714 544-0934 2400/1200/300 ------------------------------ Date: 28 Jun 90 14:42:34 GMT From: uc!shamash!timbuk!lfa@tut.cis.ohio-state.edu (Lou Adornato) Subject: Trying to locate Donald K. (Deke) Slayton Dear fellow netters - I _desperately_ need to get in touch with former astronaut office head (and former astronaut) Donald K. (Deke) Slayton. The last I heard he was at American Rocket (AMROC), but I don't know if he's still there or not, or where thier headquarters might be. If anyone has _any_ information that might help (especially the location of AMROC headquarters), _please_ email to me at lfa@cray.com BEFORE July 10. Thanks in advance. Lou Adornato | Statements herein do not represent the opinions or Cray Research | attitudes of Cray Research, Inc. or its subsidiaries. lfa@cray.com | (...yet) ------------------------------ Date: 28 Jun 90 14:50:59 GMT From: usc!cs.utexas.edu!asuvax!hrc!gtx!al@ucsd.edu (Alan Filipski) Subject: HST focus problem Couldn't this be corrected by digitally post-processing the image? By looking at stars you can evaluate the point spread function at each point of the field. The distortion of non-point objects could be modeled as a linear combination of these point spreads. As long as this function is invertible (which seems likely) you could reconstruct the image you want from the distorted image. This is a standard image-processing technique. Could it be used here? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ( Alan Filipski, GTX Corp, 8836 N. 23rd Avenue, Phoenix, Arizona 85021, USA ) ( {decvax,hplabs,uunet!amdahl,nsc}!sun!sunburn!gtx!al (602)870-1696 ) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ------------------------------ Date: 28 Jun 90 18:17:15 GMT From: cscs!csmith@uunet.uu.net (Craig E. Smith) Subject: Re: What Spherical Aberration is In <1990Jun28.025200.14616@murdoch.acc.Virginia.EDU> gsh7w@astsun7.astro.Virginia.EDU (Greg S. Hennessy) writes: >Once more with feeling. >Since HST is apparently suffering from Spherical aberration, and >seeing how lousy the news reports were tonight, I thought I would give >the readers a brief summary of what spherical aberration is. > ... Does anyone know if it is possible to correct for spherical aberration, or at least reduce its effects significantly, by the use of advanced computer image analysis techniques. -- The truly proud man knows neither superiors | Internet: csmith@cscs.UUCP nor inferiors. The first he does not admit | UUCP: ... uunet!cscs!csmith of - the last he does not concern himself | about. - William Hazlitt | ------------------------------ Date: 26 Jun 90 16:56:23 GMT From: zephyr.ens.tek.com!tekfdi!videovax!dmc@beaver.cs.washington.edu (Donald M. Craig) Subject: Re: ESA-brief summary of activity In <1990Jun25.175946.20917@cc.ic.ac.uk> seds@cc.ic.ac.uk (M.sean Bennett) writes: "Beginning on 19 February, a series of telecommands was transmitted to Giotto via the Madrid tracking station, using a 70m antenna and a 100000 W transmitter, many thousand times the power of a TV broadcasting station." Reaching for my trusty Television and Cable Factbook, which lists in gory detail facts about all US television stations, I extracted the following: KNLC, Channel 24 (530 - 536 MHz), St. Louis, MO, Authorized power: 3090-kw max. visual, 309-kw max.aural. WTZA, Channel 62 (758 - 764 Mhz), Poughkeepsie, NY, Authorized power: 5000-kw max. visual, 500-kw max. aural. KICU, Channel 36 (602 - 608 MHz), San Jose, CA, Authorized power: 4098-kw max. visual, 410-kw max. aural. That's 3 million watts, 5 million watts, and 4 million watts. Perhaps the 100000 W number was a typo? cheers, Don Craig Tektronix Television Division, dmc@tv.tv.tek.com ------------------------------ Date: 28 Jun 90 15:35:49 GMT From: orc!inews!td2cad!yoyodyne!jreece@decwrl.dec.com (john reece) Subject: Re: Anyone Know What MOL Is/Was? In article <1990Jun28.022641.1230@cbnewsj.att.com>, rcraig@cbnewsj.att.com (r.craig.montero) writes: > Actually, there was a test of a Gemini vehicle with a circular hatch cut > through the heat shield. The Gemini vehicle had actually flown one of the > manned missions and was refurbished (and given a new heatshield) enough > to fly on a short (one orbit?) mission. Where was the hatch located with respect to the astronauts seats, and how were they supposed to move around inside the capsule to get to it? I remember reading about how the Gemini astronauts had to practically be shoehorned into their seats, and how it was so cramped astronauts had difficulty after EVAs getting back into the vehicle on their own. John Reece Not an Intel spokesman jreece@yoyodyne.intel.com ------------------------------ Date: 28 Jun 90 16:22:25 GMT From: clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Is there a backup HST mirror ??? In article <29487@eerie.acsu.Buffalo.EDU> collie@ubvmsd.cc.buffalo.edu writes: >>>Now that the HST is safely in orbit, what happens to the backup mirror... >>Providing that one does actually exist, it may be sent up to fix the >>"spherical aberration" mentioned in another article. ;) > No.The cost would be too high for NASA,and the G.A.O also > would kick up a big fuss.(The purse is closed.) The HST purse is not closed, since there has been work underway for quite some time on upgraded instruments and the like for HST. The schedule as it was until a few days ago called, as I recall, for a shuttle visit in 1993-4 with an improved WideField/PlanetaryCamera and replacements for the solar arrays and batteries, and another in 1997-8 to replace the two spectrometers with a newer general-purpose spectrometer and an infrared instrument (combination imager and spectrometer, I think). There is some small likelihood of changes to this plan now. :-) However... although HST was designed for various forms of maintenance in orbit, I don't think replacing the main mirror was among them! It just might be possible to replace the secondary mirror. There was a backup main mirror, built by Kodak, but I don't think launching it is a realistic possibility. (I'm not sure how far it went towards completion, also.) There is talk of a mission in 1991 -- one had been pencilled in as a contingency in case something went badly wrong -- but I suspect that's a little too soon for something as drastic as mirror replacement. If a replacement WFPC with aberration compensation can be built in haste, that might perhaps be done. -- "Either NFS must be scrapped or NFS | Henry Spencer at U of Toronto Zoology must be changed." -John Osterhout | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 28 Jun 90 23:17:14 GMT From: zaphod.mps.ohio-state.edu!uwm.edu!bionet!hayes.fai.alaska.edu!acad3.fai.alaska.edu!ftdjt@tut.cis.ohio-state.edu (THOMAS DAVID J) Subject: RE: public image of HST In <1232@berlioz.nsc.com>, Andrew Palfreyman writes: >If I try to put myself into the mind of Joe Public (not difficult), I would >feel very angry (about my $1.5B) and also very amazed about defective >mirrors. After all, there was a whole lot of wingeing from the scientific >community, via the media, as Hubble rose into the limelight around its >launch date, about how long it had languished in storage. Since the >mid-80's, wasn't it? >So I would say the reaction would be amazement that mirror testing of >some sort was not done in the 6-ish *YEARS* available to ground crews. I must agree that the general public will probably react to the current events in the manner Mr. Palfreyman describes. However, as Ron Baalke at JPL has pointed out, the mechanisms of the HST are too sensitive to be tested in Earth-normal gravity. Our space program, as old as it is, is still quite experimental. With investments (scientific and financial) as large as the HST, there are bound to be risks. However, I believe that the potential benefits are well worth the risks. ------------------------------ Date: 27 Jun 90 16:15:03 GMT From: mojo!SYSMGR%KING.ENG.UMD.EDU@mimsy.umd.edu (Doug Mohney) Subject: Re: 10 psi overpressure In article <1990Jun26.162847.28348@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: >>>NASA point-blank refuses to put destruct charges aboard the orbiter. >> >>I seem to recall that the charges went in by the SSMEs ... > >References, please? The Rogers Commission report, among other sources, >is quite explicit that there are no destruct charges on the orbiter and >never have been. This was a post-Rogers, post-Challenger launch. Other than that, I'll have to dig through AvWeek to find the reference. ------------------------------ Date: 28 Jun 90 00:51:23 GMT From: thorin!algol!leech@mcnc.org (Jonathan Leech) Subject: Re: NASA announces next steps in Space Exploration Outreach Program (F In article <2687a7d7-4cb.3sci.space-1@vpnet.chi.il.us> akcs.gregc@vpnet.chi.il.us (*Greg*) writes: >Getting idea's from proper scientwits is the best way to obtain lowcost ^ This gets my vote for best neologism on sci.space. -- Jon Leech (leech@cs.unc.edu) __@/ "Student Activism 1968-69 Oct 23: 15 students picket the Circus Room to protest the poor quality of UNC sandwiches." _The Daily Tar Heel_, 11/15/89 ------------------------------ Date: 28 Jun 90 02:26:41 GMT From: att!cbnewsj!rcraig@ucbvax.Berkeley.EDU (r.craig.montero) Subject: Re: Anyone Know What MOL Is/Was? In article <1990Jun26.144855.8694@terminator.cc.umich.edu> Gavin_Eadie@um.cc.umich.edu (Gavin Eadie) writes: >The best part was that access to the tank was through a hatch cut in the >heatshield of the Gemini. I always wondered if that could actually work >without excessive risk ... we'll never know! Actually, there was a test of a Gemini vehicle with a circular hatch cut through the heat shield. The Gemini vehicle had actually flown one of the manned missions and was refurbished (and given a new heatshield) enough to fly on a short (one orbit?) mission. Thus, Columbia was not truly the first spacecraft to be re-used (certainly manned re-use of course). The test was rated a success, but did not help save the MOL concept. This information was retrieved from memory, but is from one of the many texts written shortly after the Apollo 11 mission about how we got to the moon. The title and author escape me, although I do know it was not Collins' book. Hope this helps. Craig Montero rcm@att.mtuxo insert STANDARD DISCLAIMER here ------------------------------ Date: 28 Jun 90 16:44:57 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Hubble Space Telescope Update - 06/27/90 Hubble Space Telescope Update June 27, 1990 Dr. Lew Allen, director at the Jet Propulsion Lab, has been selected to lead the inquiry board to investigate the spherical aberrations in the telescope's mirror system. The two mirrors on HST are components of the Optical Telescope Assembly (OTA). The optical system is a variation of a Cassegrain design, called Ritchey-Chretien, which uses a folded design to enable a long focal length of 189 feet to be packaged into a small telescope length of 21 feet. Both mirrors are hyperboloidal in shape, meaning they have a slightly deeper curvature than a parabolic mirror. This shape was to correct all coma and spherical aberations everywhere in the field of view. The OTA takes incoming light down its tubular baffle. The light is reflected off the 94.5 inch primary mirror to the 12.2 inch secondary mirror. The light is then reflected by the secondary mirror through a hole in the primary mirror to the focal plane. From the focal plane, the Scientific Instruments (SI) and the Fine Guidance Sensors (FGS) recieve the light. The OTA was designed and built by the Perkin-Elmer Corporation. The telecope was designed such that 90% of the equipment and instrumentation has a backup or identical unit. Components on the telecope which were critcial subsystems and might possibly degrade over time were packaged into what are called Oribital Replaceable Units (ORU), which could be easily replaced in orbit in one piece. There are 70 ORUs on HST ranging from small fuse plugs to the telephone-booth size FOC. The telecope's two mirrors are not in an ORU package. Very little has happened in orbit during the past 24 hours, but the next 24 hours should see an OTA test, Faint Object Spectrograph (FOS) High Voltage (HV) turned on and tests of the High Speed Photometer (HSP) Photomultiplier Tube (PMT) detector. On the Pointing Control Subsystem (PCS) instabilities, it may be possible to remove most of the disturbances seen in the HST pointing to reduce the amplitude of the disturbance by at least a factor of 10 and maybe by as much as a factor of 100, and do this ahead of schedule (late July instead of early August). The Fixed Head Star Tracker (FHST) produced two large updates yesterday, these precipitated a few failed acquisitions. The Fine Guidance Sensor (FGS) S-Curve calibration is in progress. The Faint Object Camera (FOC) is in hold. FOC diagnostic images in support of focus efforts may start on July 1. The Goddard High Resolution Spectrograph (GHRS) is in hold. The HV electronic dark count test apparently went well, the data is being analyzed at this time. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ End of SPACE Digest V11 #587 *******************