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, 24 Feb 90 01:26:44 -0500 (EST) Message-ID: <0ZtWXxi00VcJI=tk5y@andrew.cmu.edu> Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 24 Feb 90 01:26:07 -0500 (EST) Subject: SPACE Digest V11 #76 SPACE Digest Volume 11 : Issue 76 Today's Topics: Re: New private home satellite network Payload Status for 02/22/90 (Forwarded) Say Cheese! Re: Say Cheese! Re: Say Cheese! Re: Spacecraft on Venus Galileo's camera "blemishes" Giotto Update - 02/22/90 Pioneer 11 passes Neptune's orbit, leaves Solar System (Forwarded) Re: Power Sources Re: Fun Space Fact #1: Launcher Development Costs ---------------------------------------------------------------------- Date: 22 Feb 90 16:57:47 GMT From: snorkelwacker!usc!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!henry@bloom-beacon.mit.edu (Henry Spencer) Subject: Re: New private home satellite network 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. > >What would happen? Would governments let it be? Would they try to jam >it? Shoot it down? Is there any sort of space law or space treaty that >would govern something like this? The government of the country in question is responsible for what its citizens/businesses do in space. (What, you thought the citizens were responsible for their own actions? Ho ho, not in space law. :-( ) So diplomatic repercussions could be expected. The ground station would be politically vulnerable. That's the place I'd expect most trouble. Any US citizens involved could expect personal trouble as well, since the US government claims jurisdiction over the actions of its citizens everywhere, not just within US territory. Jamming microwave transmissions is almost impossible, although I suppose a sufficiently annoyed government could put a jamming satellite into the same orbital slot. There is currently no technology for shooting down Clarke-orbit satellites, although the Soviet antisatellite systems might perhaps be adapted for it if you annoyed them sufficiently. It would be nice to avoid that, since Clarke orbit is a really lousy place for the debris cloud that would result. >Of course, space in geosync orbit is limited... This is a resource >that will soon become scarce. I wonder what people will do about it? It's been scarce for quite a while in prime areas like over North America. The result is the obvious: government-regulated rationing. -- "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: 22 Feb 90 20:54:45 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Payload Status for 02/22/90 (Forwarded) Daily Status/KSC Payload Management and Operations 02-22-90 - STS-31R HST (at VPF) - VPF closeout activities were worked yesterday including access platform removals and solar array closeout. Today HST will be powered up for functional testing. - STS-32R SYNCOM/LDEF (at SAEF-2) LDEF deintegration continues. - STS-35 ASTRO-1/BBXRT (at O&C) - BBXRT clearance checks were worked yesterday and will continue today. - STS-40 SLS-1 (at O&C) - The systems test was active yesterday and will continue today. Experiment functional checks will also continue today. ASCS N2 servicing will start today. - STS-42 IML (at O&C) - Racks 3, 9, and 11 staging activities were performed yesterday. Today eddy current checks will be performed on rack 7 and staging will continue on rack 11. - STS-45 Atlas-1 (at O&C) - Pallet keel installation and orthogrid hardpoint installation operations will continue today. - STS-46 TSS-1 (at O&C) - PPCU checkout will continue today. ------------------------------ Date: 23 Feb 90 07:10:22 GMT From: pasteur!cory.Berkeley.EDU!sortland@ucbvax.Berkeley.EDU (Stefan Marcus Sortland) Subject: Say Cheese! What's the status of the family photogrphic collage Voyager I was supposed to have initiated last week? Stefan (X) nafetS ------------------------------ Date: 23 Feb 90 07:39:07 GMT From: elroy.jpl.nasa.gov!jato!mars!baalke@decwrl.dec.com (Ron Baalke) Subject: Re: Say Cheese! In article <22344@pasteur.Berkeley.EDU> sortland@cory.Berkeley.EDU.UUCP (Stefan Marcus Sortland) writes: > > What's the status of the family photogrphic collage Voyager I > was supposed to have initiated last week? > Voyager 1 has taken 64 pictures of the solar system and stored them on its tape recorder. It will slowly transmit the pictures back beginning around March 16th. Ron Baalke | baalke@mars.jpl.nasa.gov Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov 4800 Oak Grove Dr. | Pasadena, CA 91109 | ------------------------------ Date: 23 Feb 90 13:20:12 GMT From: cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!lavaca.uh.edu!uhnix1!nuchat!steve@tut.cis.ohio-state.edu (Steve Nuchia) Subject: Re: Say Cheese! In article <22344@pasteur.Berkeley.EDU> sortland@cory.Berkeley.EDU.UUCP (Stefan Marcus Sortland) writes: > What's the status of the family photogrphic collage Voyager I > was supposed to have initiated last week? Funny you should ask... Edward Stone, head scientific cheese of the voyager project, spoke at Rice last week. It was mostly show-and-tell, he showed some of the best images and animations from the grand tour. The answer to the question at hand is that the shots have been taken and are waiting for high-gain antenna time. He showed a skymap from V1's perspective with little squares outlining each exposure. Everything but Sol and Jupiter will be point sources. When he put up the relative sizes slide he quoted (?)Asimov's quip about an alien describing our solar system: You've got a star, four planets, and debris. The four planets he was refering to were _not_ the little bitty inner ones. He also mentioned that the voyagers got more of a boost from their Jupiter gravity assist than they did from the chemical booster at earth. He didn't specify whether that was heliocentric total energy, delta-v, or what. He also use farenheight consistently, when Kelvins would have been much more useful. Oh well. One theme that emerged was the way certain structures -- clouds, hurricanes, volcanos, migrating ice caps -- recurr in different temperature regimes with different chemicals. I'm not going to be able to remember all the cases, but by the time he got to Triton's liquid methane (I think) volcanos I was getting convinced. Oh well, it was 1.5 hours well spent. -- Steve Nuchia South Coast Computing Services (713) 964-2462 "You have no scars on your face, and you cannot handle pressure." - Billy Joel ------------------------------ Date: 23 Feb 90 17:26:18 GMT From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Spacecraft on Venus In article wex@sitting.pws.bull.com (Alan Wexelblat) writes: >What is the major source of the heat that the craft would be subject to? >And can we shield against it? For example, if the source of heat is the >Sun, one gets into a shadow. On Venus would it be better to, for example, >burrow into the planet itself? The problem with Venus is that the ambient surface temperature simply is very high. *Everything* there is roasting hot. Burrowing strikes me as a mistake, although on reflection I'm not sure how conduction from the soil would compare to convection in that thick atmosphere. Anyway, there is no specific heat source to shield against. -- "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: Thu, 22 Feb 90 11:23:43 +0100 From: mpirbn!u515dfi@uunet.UU.NET (Daniel Fischer) Subject: Galileo's camera "blemishes" The Venus shot by the Galileo spacecraft in Av.Week 19 Feb. p.25 shows "several ring-shaped shadows" - who knows what precisely has caused them? I recall the same phenomenon from Viking Orbiter pictures and from Voyager 2's camera. In the latter case the rings were seen only in highly enhanced images (like of Uranus' disk), but the defective Galileo frame doesn't look much processed. Will it be possible to suppress these "blemishes" (AW&ST) by use of a suitable flatfield or will they spoil every Galileo picture ? I was always a bit scared by the fact that there's just o n e camera going on this big journey, compared to the 4 cameras on the two Voyagers. Daniel Fischer, Max Planck Inst. Radioastron., Bonn, FRG ------------------------------ Date: 23 Feb 90 07:35:10 GMT From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@decwrl.dec.com (Ron Baalke) Subject: Giotto Update - 02/22/90 Giotto Mission Status February 22, 1990 Giotto reactivation support using Deep Space Network's 70 meter antenna in Madrid, Spain, continues. Downlink was turned on through the Low Gain Antenna and the tracking station locked up 2-way. Telemetry modulation was turned on and a two DB drop in the downlink was observed. The project attempted two different attitude maneuvers on the spacecraft. Midway into the second maneuver it was determined, based on observed doppler shifts, that neither manuever really took place. No High Gain Antenna maneuver was attempted. Processing of previous data by Radio Science showed no evidence of a spacecraft signal. DSP tapes are being airmailed to JPL for further processing. Further attempts will be made to reactivate Giotto and assess the status of its subsystems. Following this reactivation a checkout of the scientific payload will be made to determine how much damage was suffered during the spacecraft's 1986 encounter with Haley's Comet. If the reactivation and checkout prove to be successful, Giotto will be redirected to encounter comet Grigg-Skjellerup. This would be accomplished by using the 25.45 kg of hydrazine still left on the spacecraft and a Earth swingby in July, 1990. Giotto would then be in a orbit to encounter Grigg-Skjellerup in July, 1992. Ron Baalke | baalke@mars.jpl.nasa.gov Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov 4800 Oak Grove Dr. | Pasadena, CA 91109 | ------------------------------ Date: 23 Feb 90 17:12:58 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Pioneer 11 passes Neptune's orbit, leaves Solar System (Forwarded) Charles Redmond Headquarters, Washington, D.C. February 23, 1990 Pete Waller Ames Research Center, Moffett Field, Calif. RELEASE: 90-29 PIONEER 11 PASSES NEPTUNE'S ORBIT, LEAVES SOLAR SYSTEM Pioneer 11 today will cross the orbit of Neptune and become the fourth spacecraft to leave the solar system, providing a coda to humanity's first major planetary explorations. Pioneer 11 will join Pioneer 10 and Voyagers 1 and 2 in searching for the heliopause, the point at which the Sun's electromagnetic influence gives way to the galaxy's influence. As it crosses Neptune's orbit, Pioneer 11 will be 2.8 billion miles from the Earth. Neptune's orbit currently marks one measure of the expanse of the solar system because, for the next 12 years, Pluto's eccentric orbit carries it inside Neptune's path. Some scientists refer to the heliopause as the edge of the solar system. By that definition, all four spacecraft are still within the solar system. Launched in 1973, Pioneer 11 provided scientists with their closest view of Jupiter, passing within 26,600 miles of the cloud tops in December 1974. The close approach and the spacecraft's speed of 107,373 mph, by far the fastest speed ever reached by a man-made object, hurled Pioneer 1.5-billion miles across the solar system toward Saturn. Before reaching Saturn in 1979, Pioneer 11 reached an inclination of 17 degrees above the solar equatorial plane, high enough to illuminate the true character of the sun's magnetic field. Now 780 million miles above the ecliptic plane where most of the planets orbit the sun, the spacecraft recently showed that many of the solar cosmic rays in the heliosphere originate outside the Sun's atmosphere in the interstellar gas, the space between the stars. Pioneer 11 flew to within 13,000 miles of Saturn and took the first close-up pictures of the planet. Instruments located two previously undiscovered small moons and an additional ring, charted Saturn's magnetosphere and magnetic field and found its planet-size moon, Titan, to be too cold for life. Pioneer 11, which will traverse interstellar space in the same direction as the Sun moves, continues to return good data, but in 3 years, operating the radio transmitter and scientific instruments simultaneously will be difficult, says NASA Project Manager Richard Fimmel. Technical adjustments may extend the craft's life through 1995. Pioneer 10, with a stronger power supply, may return data through the year 2000, which would extend its original 30-month design life to 28 years. In June 1983, Pioneer 10 made history by becoming the first human artifact to leave the solar system, travelling in the direction opposite Pioneer 11's path. Today, Pioneer 10 will be 4.5 billion miles from Earth. Returning data to Earth at the speed of light requires 6 hours, 36 minutes. Pioneer 10 continues to search for the heliopause for very long-wavelength gravity waves that would further understanding of Einstein's Theory of Relativity and for evidence of a 10th planet. The Pioneers are managed by the Ames Research Center, Mountain View, Calif., for NASA's Office of Space Science and Applications. The spacecraft were built by TRW Space & Technology Group, Redondo Beach, Calif. ------------------------------ Date: 23 Feb 90 18:44:55 GMT From: rochester!dietz@pt.cs.cmu.edu (Paul Dietz) Subject: Re: Power Sources In article <1990Feb23.153950.10025@utzoo.uucp> kcarroll@utzoo.uucp (Kieran A. Carroll) writes: >Fuel cells (H2/O2) can apparently produce about 110-130 W/kg, but I >don't think that that figure includes the mass of the reactants used >(i.e. it's just the mass of the cell). There is a figure quoted for >"Energy density mission" of 400-1400 kW-hr/kg; assuming that this >includes the mass of the reactants, that would give you about 3e12 to >1e13 J from 2 tonnes of them. Reality check: 3e12 joules from 2 metric tonnes of chemicals gives a specific energy of 1.5e9 joules/kilogram, which corresponds to the kinetic energy of material traveling at 54 km/s. If hydrogen/oxygen was *that* good a rocket fuel, we'd be vacationing on Mars by now. My CRC handbook says the energy of combustion of stoichiometric hydrogen and oxygen is about 1.5e7 joules/kilogram. You shifted the decimal point two places. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 23 Feb 90 00:12:43 GMT From: texbell!nuchat!moe@bellcore.com (Norman C. Kluksdahl) Subject: Re: Fun Space Fact #1: Launcher Development Costs In article <1990Feb20.180649.20959@agate.berkeley.edu> web@garnet.berkeley.edu (William Baxter) writes: >pacifists. If only Congress gave NASA enough money everything would be >fine. .......... Go read the congressional >record around the time of the original shuttle appropriations. > >Check your facts *before* you post. How can you, in good conscience, say, in the same article, 'read the Congressional record' AND 'Check your facts'? One of the biggest lies perpetrated on the American public is that the Congressional record is an accurate accounting of the dealings of our Congress. In fact, Congresscritters have the right to edit the contents of the record AFTER THE FACT. A five-minute debate might turn into a thirty+ page thesis, and be completely contrary to what the particular critter actually said. Back to the subject, you are quite correct. While it is certain that the shuttle would be vastly different, there is no guarantee (or even credible speculation) that the shuttle would have operated according to specs with unlimited funding. ===================================================================== Norman Kluksdahl ...!nuchat!moe ------------------------------ End of SPACE Digest V11 #76 *******************