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 ; Sun, 25 Feb 90 01:30:26 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 25 Feb 90 01:29:57 -0500 (EST) Subject: SPACE Digest V11 #80 SPACE Digest Volume 11 : Issue 80 Today's Topics: Payload Summary for 02/23/90 (Forwarded) Re: Did SEASAT See More Than It Was Supposed To? Re: Fun Space Fact #1: Launcher Development Costs Re: Fun Space Fact #1: Launcher Development Costs (long) Re: New private home satellite network Beanpole NASA technicians begin removing LDEF experiments (Forwarded) ---------------------------------------------------------------------- Date: 23 Feb 90 21:01:02 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Payload Summary for 02/23/90 (Forwarded) Payload Status Report Friday, February 23, 1990 George H. Diller Kennedy Space Center NASA PA-PIB HUBBLE SPACE TELESCOPE Prelaunch functional testing of the Hubble Space Telescope in the Vertical Processing Facility at KSC was completed on Feb. 17. The telescope is being powered up again from time to time to reverify test data. A retest of the Faint Object Camera was performed on Feb. 22. The spacecraft will also be powered up to test the flight batteries after their installation. HST closeout operations began on Feb. 15. This work includes removal of nonflight items, closeout of the solar arrays, configuration of the high gain antenna in preparation for installation into the payload canister, and installation of the flight batteries. A final cleaning of the telescope is scheduled for next week. To further assure cleanliness, the cocoon--a protective sanitary liner over the spacecraft--will be changed. Upcoming schedule milestones include the installation of flight batteries on Mar. 16, HST installation into the payload canister on Mar. 23, move to the launch pad on Mar. 26, and installation of the telescope into the payload bay of Discovery on Mar. 29. The launch of the Hubble Space Telescope is scheduled for Apr. 12, with the launch window opening at 9:21 a.m. EDT. GAMMA RAY OBSERVATORY Repairs on the insulation of the Energetic Gamma Ray Experiment Telescope (EGRET), as a result of moisture from the shipping container, was completed this week. One square foot of silvered teflon and aluminized capton was replaced. Next week, the other affected surfaces will cleaned with alcohol which will be acceptable for flight. Work has been underway this week to install two electronics boxes which are elements of the spacecraft's command processing chain. This will be completed early next week. The routine leak check of the orbit adjust thrusters has been conducted. Today, one of the thrusters is being test cycled for further leakage evaluation. Also checked this week as planned was the crystal of the Total Absorption Shower Counter which must be examined periodically for evidence of moisture. The six solar cells which were cracked during installation of the solar array cover prior to shipping have been replaced. The cover glass is being installed today. There are approximately 3,200 solar cells on each panel and there are eight panels on the spacecraft. The spacecraft is scheduled to be powered up for the first time at KSC on Monday, Feb. 26, to start the scheduled series of functional tests. DELTA ROSAT The ROSAT spacecraft arrived at Cape Canaveral Air Force Station at 3:30 p.m. on Feb. 20, shipped from Munich, West Germany, aboard a German 747 cargo plane. The spacecraft in its transporation cansiter is now in the airlock of Hangar AE for cleaning before moving it into the white room on Monday for its unpacking and placement in a test stand. The Delta II launch vehicle is on Cape Canaveral Air Force Station and will be taken to Launch Complex 17 on March 28. The solid rocket boosters will be erected during the period from March 29 to April 5. The second stage will be mated to the first stage April 6. ------------------------------ Date: 23 Feb 90 17:56:43 GMT From: zaphod.mps.ohio-state.edu!uwm.edu!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Did SEASAT See More Than It Was Supposed To? In article <2235@syma.sussex.ac.uk> nickw@syma.susx.ac.uk (Nick Watkins) writes: >1) Where can we find a picture showing these seabed features? Look at almost any good source for science coverage -- Scientific American, for example -- in 1978 or shortly thereafter. There was some small fuss about the unexpected visibility of bottom features. Sorry I can't provide a more specific reference, but remote sensing hasn't been a major interest of mine, and the three or four books I have on it are all optical-only, no radar. >2) There have been rumours (e.g. a piece by Nicholas Booth in, I think, >the British "Sunday Correspondent") saying that SEASAT did not fail but >was killed as a result of the DoD exercising its prerogative. Is this >just paranoia or is it likely to have any basis in fact? I haven't heard anything I would call evidence for this. It strikes me as implausible that it could stay secret for over a decade, especially since I don't think DoD has any "prerogative" over civilian research satellites. It *is* interesting that the Shuttle Imaging Radar experiment has flown twice (I think) but all the images that I recall seeing from it have been from land areas. One wonders who had input into the coverage planning. >3)If SEASAT worked so well, why was the Navy Clipper Bow project phased out? >Does Lacrosse do naval imaging also? And, was the resolution of SEASAT ><, >, or = to that of the Russian RORSATS? Good questions; the answers are probably classified. :-) On the last, as far as I know the Soviet radarsats are not doing synthetic-aperture radar imaging at all. Their purpose is to spot surface vessels, which is orders of magnitude easier. -- "The N in NFS stands for Not, | Henry Spencer at U of Toronto Zoology or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 23 Feb 90 11:47:29 GMT From: mcsun!ukc!icdoc!syma!nickw@uunet.uu.net (Nick Watkins) Subject: Re: Fun Space Fact #1: Launcher Development Costs In article <1990Feb22.170900.10959@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <2250@syma.sussex.ac.uk> nickw@syma.susx.ac.uk (Nick Watkins) writes: >>See a recent issue of The Scientist (22 Jan 90) for the latest on Roger >>Boisjoly, and the price he has paid. >But before you weep too hard for him, read the Rogers Commission report, >noticing what he did and didn't (mostly didn't) do at the time. He's >gotten the shaft not for trying to stop the launch -- he didn't try hard -- >but for talking too much to the investigators afterwards. I *did* read it (Vol 1 anyway, to which I assume you refer), obviously I need to read it again. However, a system in which people are penalised for honesty (even if only after the fact) does not augur well for the future of NASA or the contractors, at least in terms of achieving the goals you'd like to see them achieve. There is also the relatively benign nature of the commission, in which all but Feynman and Rogers had direct aerospace connections, if I recall correctly. If talking to these is "grassing", well ... ( I grant that the press is another story.) On a related point, Feynman's memoirs suggest that Donald Kutyna (USAF general) put him onto the trail of the solid booster problem. Is there a feeling that the USAF knew, but just needed the commision to confirm it? If so, was the report's conclusion ideal for their purposes, leaving the Shuttle as usable but no future threat. Feynman drops hints, but never makes it explicit. Nick -- Nick Watkins, Space & Plasma Physics Group, School of Mathematical & Physical Sciences, Univ. of Sussex, Brighton, E.Sussex, BN1 9QH, ENGLAND JANET: nickw@syma.sussex.ac.uk BITNET: nickw%syma.sussex.ac.uk@uk.ac ------------------------------ Date: 23 Feb 90 19:17:58 GMT From: snorkelwacker!usc!cs.utexas.edu!jarvis.csri.toronto.edu!csri.toronto.edu!hogg@bloom-beacon.mit.edu (John Hogg) Subject: Re: Fun Space Fact #1: Launcher Development Costs (long) In article <3904@oolong.la.locus.com> todd@roulette.UUCP (Todd Johnson) writes: >In article <1990Feb20.173440.7976@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >>I dimly recall a design sketch from Jordin Kare's group for a laser >>launcher costing about half a billion dollars that could launch more >>than the entire shuttle fleet, for that matter. > >Henry, what were the anticipated spacecraft loads with the laser >launcher? Very high g loads would require a greater structural >mass although this trades off against lower launch costs. At >some point it gets more expensive to use a high g launcher than >even the Shuttle. I don't know what the latest figures are (why don't you ask Kare himself?) but from the Proceedings of the SDIO/DARPA Workshop on Laser Propulsion in July '86, we have: Initial Mass: 1000 kg Final Mass: 136 kg Peak Acceleration: 5.6 g Laser Power: 100 MW Graphs of cost estimates are also given. The cases considered are a 1 GW laser launching 1-ton payloads, and a 100 MW laser launching 200 lb payloads; each is plotted assuming a dedicated laser, and use of a laser built for other purposes. The 1 GW, dedicated version is more expensive than the shuttle at shuttle payload-to-orbit-per-year rates, since the capital cost of the laser dominates. However, at higher launch rates, the cost of electricity becomes the limiting factor. A dedicated laser bottoms out at about $150/lb to LEO (all figures 1986 $US), and this falls below $100/lb if the laser can be rented from a convenient defender of the free world. At that cost, the big laser is sending up 64 000 tons/year. Reread that sentence, and think about what would (and would not) pay at that volume and price. Hint: think of it as $200 000 for *every* ton, including the lowest-value ones. The costs given in this four-year-old workshop still exceed half a billion of anybody's dollars: the estimate used was $10/W for laser and optics, which means that the smaller proposed version still runs $1G for these items alone. For the 6 kg payloads that were mentioned in an earlier note, though, I suppose that something cheaper could be worked out. And the proposal used a capital cost of 20%/year; that is, the up-front expenditure was amortized over five years. This makes the financial situation much more reasonable. Quick summary: lasers looks very good if a *lot* of small payloads need launching. Small need not mean tiny. Small numbers of large payloads are still more cost-effectively sent up by rocket. --- John Hogg hogg@csri.utoronto.ca Department of Computer Science, University of Toronto 4-P vehicle: ``Let's leave everything on the ground except (Kantrowitz, 1986) Payload, Propellant, and Photons, Period.'' ------------------------------ Date: 23 Feb 90 17:16:52 GMT From: mcsun!ukc!edcastle!bob@uunet.uu.net (Bob Gray) Subject: Re: New private home satellite network In article <8577@shlump.nac.dec.com> hughes@star.dec.com (Gary Hughes - VMS Development) writes: >In article <100390@looking.on.ca>, brad@looking.on.ca (Brad Templeton) writes... >>What if a private concern, based on some lax-law island, were to get >>together $300 million an launch one of these things? They could start >>completely uncensored, unregulated TV -- assuming they got somebody >>(the Chinese?) to launch it. >In a sense this has already happened, with Rupert Murdoch's DBS plans for the >UK. This will use Astra and is therefore not under control of the UK >broadcasting authorities. Rupert has promised to be a good boy. Nothing to do with Rupert Murdoch. Murdoch's SKY company leases some of the transponders on the Astra DBS satellite. Other European companies use other transponders to broadcast other channels to other parts of Europe. In particular, one channel carries material of a more adult and sexualy explicit nature. This sort of channel is perfectly legal in both Luxembourg where the satellite is fed and controlled from, and in the Netherlands, which is where the main audience is. When the usual "moral watchdogs" in the UK learned that ordinary SKY satellite dishes could be used to recieve this channel in the UK, they had a collective fit. The people who operate the channel can't understand what the problem is. They have however started to encrypt the signal. The Government is considering banning posession of the decoders needed to decode the cannel, and making it an offence to have any business dealings with any of the companies involved. They can't think of anything else that they can do to stop people watching. Sales of SKY satellite dishes are said to be booming. >Interestingly, Murdoch was part of the Sky Cable announcement, as was Hughes >Communication. My guess is that it will be considered a US domestic comsat, >subject to US law. But suppose a company in a south American country started broadcasting to Mexico from an International DBS satellite? No US citizens involved, no laws in either country broken, but that the broadcast could be picked up with a $200 satellite reciever dish. Further suppose that the content of the broadcast offended the self appointed guardians of morality. What could they do, apart from sending in the troops? Bob. ------------------------------ Date: 24 Feb 90 06:53:19 GMT From: mephisto!prism!gt0852c@handies.ucar.edu (Daniel Rothman) Subject: Beanpole Has anybody out there heard rumors of a beanpole [ie an earthbound structure extending to low orbits]? A friend of mine in polymers mentioned that new ceramics could possibly withstand the shearing loads on such a structure. Have there been any conferences/papers/references on the topic? Thanks all, and apologies if this is a repeat... ------------------------------ Date: 23 Feb 90 20:54:23 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA technicians begin removing LDEF experiments (Forwarded) Patricia E. Phillips Feb. 23, l990 Kennedy Space Center, FL. Jean Drummond Clough Langley Research Center, Hampton, Va. KSC Release No. 30-90 NASA TECHNICIANS BEGIN REMOVING LDEF EXPERIMENTS NASA technicians from Langley Research Center began removing experiments today from the Long Duration Exposure Facility (LDEF), the satellite retrieved from space by the STS-32 crew in January. The first experiment, the Space Exposed Experiment Developed for Students (SEEDS), was removed from the spacecraft at 12:22 p.m. EST. SEEDS, sponsored by the George W. Park Seed Company in Greenwood, S.C., will eventually go to classroom students around the country for use in school science projects. Processing plans call for the removal of three other trays today. Illustrating the international flavor of the experiments, two of these trays contain cosmic ray experiments from the Dublin Institute for Advanced Studies in Dublin, Ireland. The other tray scheduled for removal today is a Langley Research Center space debris experiment. The protocol for tray removal is painstaking in its protec- tion of scientific data. As each tray is removed from LDEF, it will be placed on a workbench where the principal investigator will perform closer inspections and take basic measurements. These measurements will include detailing the sizes of micrometeoroid and orbital debris impacts. The combined data from individual trays and the LDEF frame will provide valuable information in planning future space struc- tures, including Space Station Freedom. Removal of the 57 experi- ments, contained in 86 trays mounted on the LDEF framework, is expected to continue through March. After the measurements and first analyses are completed, the experiment hardware will be appropriately configured for transport, then packaged and shipped to the investigator's laboratory. There, additional investigation and analysis will be performed. More than 200 investigators have participated in the experiments flown on LDEF, which spent almost six years in space. Preliminary results of these individual investigations will be announced late this summer during an Investigator Working Group meeting to be held at the Langley Research Center, Hampton, Va. Langley developed and managed the LDEF project, which is unique in its opportunities for analysis of the effects of space on various materials. The date of the conference will be announced later. ------------------------------ End of SPACE Digest V11 #80 *******************