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 ; Wed, 1 Nov 89 04:23:04 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 1 Nov 89 04:22:40 -0500 (EST) Subject: SPACE Digest V10 #183 SPACE Digest Volume 10 : Issue 183 Today's Topics: Re: Space Shuttle SRB exhaust gas makeup. NASA Headline News for 10/26/89 (Forwarded) Re: "Terraforming", so-called... Re: Wood in space Re: Galileo Schedule Re: Computer Re: PowerSat Options INMARSAT / GLONASS Study Re: "Terraforming", so-called... Re: Mach - what does it really mean? Spacecraft made of wood. ---------------------------------------------------------------------- Date: 26 Oct 89 05:28:01 GMT From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Space Shuttle SRB exhaust gas makeup. In article <1989Oct26.025442.17842@agate.berkeley.edu> gwh@typhoon.Berkeley.EDU (George William Herbert) writes: >>And don't sneer at the idea of doing without the aluminum, because the >>rubber is also a fuel; similar combinations without aluminum have almost >>as high a specific impulse... > >... As for the 'no aluminum' bit, it really was described as making >most of the difference. There's a whole lot more energy in Al than rubber... I confess I was a bit surprised myself, but Sutton lists a PVC/AP combination as having only about 10% less exhaust velocity than PVC/AP/Al. Aluminum is a lot more energetic, but it also exacts a price: aluminum oxide has a very high molecular weight, and it tends to condense out to complicate things further. I'm not up enough on the fine points of solids to really assess the tradeoffs. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 26 Oct 89 14:29:38 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 10/26/89 (Forwarded) ----------------------------------------------------------------- Thursday, Oct. 26, 1989 Audio: 202/755-1788 ----------------------------------------------------------------- This is NASA Headline News for Thursday, October 26th...... The House yesterday, by voice vote, approved a compromise spending bill which includes the NASA budget for FY '90-- $12.4 billion. The measure now goes to the Senate for final action. Stormy weather at the Kennedy Space Center this morning again forced postponment of the space shuttle Discovery's rollout to the launch pad. It has been re-scheduled to begin at 12:01 A.M. tomorrow...weather permitting. Officials say the delay...so far...will not impact the launch date, now planned for around Nov. 20. The STS-33 crew is scheduled to arrive at KSC on Saturday to participate in the final hours of a dress-rehearsal countdown. NASA yesterday awarded a $64 million contract to General Dynamics Corporation to launch a government satellite. The satellite, which is a joint venture of NASA and the Air Force, is scheduled to be launched in June 1990. It will mark the first commercial launch by General Dynamics and will use an Atlas 1 launch vehicle. Aerospace Daily reports that House and Senate conferees have approved a measure that would give the President more latitude in approving export licenses for U.S.-built satellites destined to be launched on Soviet or Chinese boosters. Revised language permits launches on Chinese boosters if the President submits a report to Congress indicating that China has "made progress" on a program of political reform. A second stipulation, which applies to both Soviet and Chinese launch requests, would require the President to report that approval of an export license is in "the national interest of the United States." ********** ----------------------------------------------------------------- Here's the broadcast schedule for public affairs events on NASA Select television. All times are Eastern. Friday, Oct. 27........ 7:00 A.M. Rollout of the orbiter discovery to launch pad 39-B. Wednesday, Nov. 1...... 2:00 P.M. STS-34 astronaut crew news conference to discuss the recent mission to deploy the Galileo spacecraft. 2:30 P.M. The quarterly "Aeronautics & Space Report" will be transmitted. It contains four reports: "Combating Malaria", "Voyager's Last Encounter", "Better Airplane Wings" and "Sights and Sounds of Space" All events and times are subject to change without notice. ----------------------------------------------------------------- These reports are filed daily, Monday through Friday, at 12 noon, Eastern time. ----------------------------------------------------------------- A service of the Internal Communications Branch (LPC), NASA Headquarters, Washington, D.C. ------------------------------ Date: 26 Oct 89 14:50:12 GMT From: philmtl!philabs!briar.philips.com!rfc@uunet.uu.net (Robert Casey;6282;3.57;$0201) Subject: Re: "Terraforming", so-called... In article gnb@bby.oz (Gregory N. Bond) writes: > >Can anyone explain why Venus, which is smaller and with weaker gravity >than Earth, has an atmosphere 100x more dense? Why didn't it just >escape? (Conversly, why is Earth's atmosphere so thin?) > I asked this question in a letter to _The Planetary Report_ and it got answered and published. They said that most of the Earth's CO2 was absorbed by the oceans and made into limestone (or some such mineral). (guess that we should avoid adding too much air pollution to the atmosphere, or we'll eventually get 1% air and 99% pollution :-) Anyone know if the atmospheric pressure has been constant over millions and billions of years? Maybe those flying terradyctals of the dinosaur years had a thicker atmosphere to fly in. ------------------------------ Date: 27 Oct 89 01:56:22 GMT From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Wood in space In article <1989Oct26.102551.16546@jarvis.csri.toronto.edu> hogg@db.toronto.edu (John Hogg) writes: >... I believe that >the Saturn V also used some cork insulation as well. Not that I know of. There *was* serious discussion of using balsawood as tank insulation on one of the stages. Turned out that when you added up the quality requirements, the narrow physical specs, and the particular type of balsa they wanted, to run the Saturn V production line at the originally-planned capacity they would have had to pick through most of the world's balsa production for suitable logs. This was considered impractical, so they opted for the closest synthetic equivalent they could find. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 28 Oct 89 01:41:22 GMT From: gem.mps.ohio-state.edu!wuarchive!mailrus!jarvis.csri.toronto.edu!utgpu!watmath!mks.com!alex@apple.com (Alex White) Subject: Re: Galileo Schedule In article <5221@uhccux.uhcc.hawaii.edu> goldader@uhccux.UUCP (Jeff Goldader) writes: >Galileo will store the Venus data on its tape recorder, which has a capacity >of 900 Mbytes. The amount of data it can gather at Venus is limited by this >capacity. Does anybody know anything about this tape recorder? From personal experience with normal tape units of many varying types for computers, I know I would never want to leave a tape unit unattended for more than about say 10 minutes, or they screw up badly. What would happen with the dramatic temperature variations I'd hate to think. Voyager also apparently had a tape recorder -- this lasted for many years, many many replays -- and I never heard that they had any problems at all. ------------------------------ Date: 27 Oct 89 18:25:08 GMT From: crash!orbit!pnet51!schaper@nosc.mil (S Schaper) Subject: Re: Computer I'd opt for 80860's that are rad-hardened, or 88k's in parallel, I have a friend in Mass, programming AI for a company already producing a machine with 508 88k's in parallel. And Laser Ram Disks to record data during those times when there is too much gathered to radio back real-time. Disclaimer: on this message AI means expert system type software, not Boar Power :-) Steve Schaper UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper ARPA: crash!orbit!pnet51!schaper@nosc.mil INET: schaper@pnet51.cts.com ------------------------------ Date: 26 Oct 89 07:13:19 GMT From: zephyr.ens.tek.com!tektronix!psueea!parsely!bucket!leonard@uunet.uu.net (Leonard Erickson) Subject: Re: PowerSat Options dietz@cs.rochester.edu (Paul Dietz) writes: >In article <1335@orbit.UUCP> schaper@pnet51.orb.mn.org (S Schaper) writes: >>The CPSU would take a dim view of a 15 megawatt laser in orbit. So would the >>UN. Actually a maser would be better, as it should penetrate cloud cover, I >>think, but it too, has that weapons potential >A powersat's aperture would be small, so it could not form an intense >beam at the earth's surface. The power density would be far lower >than in BMD applications. This weapons application stuff is a canard. I'd expect the beam to be more like 15 *giga*watts! And one thing you'd have to worry about if powersats were "common" is what happens if your friendly neighborhood military types get the beam redirected to power a space based weapon of some sort? What kind of FEL (Free Electron Laser) could you drive with a 15 GW power input? An FEL is the first thing that comes to mind that can convert "raw electric power" to something that might be a nuisance on the ground, but I'm sure there are other possibilities. Is it possible to use a maser to "pump" a laser directly? -- Leonard Erickson ...!tektronix!reed!percival!bucket!leonard CIS: [70465,203] "I'm all in favor of keeping dangerous weapons out of the hands of fools. Let's start with typewriters." -- Solomon Short ------------------------------ Date: Sat, 28 Oct 89 14:40:30 ADT To: "Space Digest" From: LANG@UNB.CA Subject: INMARSAT / GLONASS Study INMARSAT and Morsviazsputnik sign satellite navigation consultancy agreement INMARSAT (England) and Morsviazsputnik, the Soviet satellite communications organization, have signed an agreement under which the USSR will provide technical consultancy services to INMARSAT on the design of a geostationary international civil complement to GLONASS, the Soviet global navigation satellite system. The study, to last four months, will be performed by expert representatives from Glavkosmos, the Soviet agency responsible for GLONASS developments, and Morsviazsputnik. Two specific subjects will be addressed: Firstly, the compatibility between signals of both the INMARSAT and GLONASS systems. And secondly, the formatting of integrity messages of health status of GLONASS satellites. INMARSAT's efforts, in cooperation with the European Space Agency and others in developing an international satellite navigation capability are focused on the geostationary augmentation of GPS and GLONASS navigation satellite constellations. GPS is the US satellite navigation system under deployment. This augmentation is intended to increase in a cost-effective manner the reliability and dependability of GPS and GLONASS for international civil users. (Source: INMARSAT via Geodetical Info Magazine, September 1989) Richard B. Langley BITnet: LANG@UNB.CA or SE@UNB.CA Assoc. Prof. Phone: (506) 453-5142 Geodetic Research Laboratory Telex: 014-46202 Dept. of Surveying Engineering FAX: (506) 453-4943 University of New Brunswick Fredericton, N.B., Canada E3B 5A3 ------------------------------ Date: 29 Oct 89 22:12:38 GMT From: uc!nic.MR.NET!thor.acc.stolaf.edu!larsonjs@tut.cis.ohio-state.edu (James S. Larson @ St. Olaf College) Subject: Re: "Terraforming", so-called... In article <66527@philabs.Philips.Com> rfc@briar.philips.com.UUCP (Robert Casey) writes: >In article gnb@bby.oz (Gregory N. Bond) writes: >> >>Can anyone explain why Venus, which is smaller and with weaker gravity >>than Earth, has an atmosphere 100x more dense? Why didn't it just >>escape? (Conversly, why is Earth's atmosphere so thin?) >> >I asked this question in a letter to _The Planetary Report_ and it got >answered and published. They said that most of the Earth's CO2 was absorbed >by the oceans and made into limestone (or some such mineral). > (guess that we should avoid adding too much air pollution to the atmosphere, > or we'll eventually get 1% air and 99% pollution :-) >Anyone know if the atmospheric pressure has been constant over millions and >billions of years? Maybe those flying terradyctals of the dinosaur years had >a thicker atmosphere to fly in. Probably not. James Lovelock in his Gaia books says that the pressure, temperature, and chemical composition of the atmosphere has been almost constant over the history of life on earth, even though the power output from the sun has increased by as much as 30%. This, he claims, is evidence for his theory that life actively regulates the atmosphere and the seas. Without life, the earth would have a different atmosphere. The nitrogen would gradualy be absorbed in the seas and the carbon dioxide would not be removed, resulting in a runaway feedback that would leave the earth looking like a cooler Venus. Or in other scenarios an ice age might turn the Earth into a warmer Mars. Read Lovelock's "Gaia: A New Look at Life on Earth" for the exciting details. -- ------------------------------------------------------------------------------- | Jim Larson | "What? You mean behind the rabbit?" | | larsonjs@thor.acc.stolaf.edu | -Monty Python and the Holy Grail | ------------------------------------------------------------------------------- ------------------------------ Date: 26 Oct 89 14:02:37 GMT From: milton!maven!games@beaver.cs.washington.edu (Games Wizard) Subject: Re: Mach - what does it really mean? In article <4656@fy.sei.cmu.edu>, krvw@sei.cmu.edu (Kenneth Van Wyk) writes: > In article Mach - what does it really mean? of 25 Oct 89 19:49:22 GMT > clj@ksr.com (Chris Jones) writes: > > sound at Standard Atmospheric Conditions. In other words, if the > speed of sound is 700 mph at standard atmosphere, and the shuttle is > doing 7000 mph, then they might (incorrectly) refer to this as "Mach > 7". Of course, this wouldn't be as accurate as saying N m/sec or some Seems to me that 700 x 10 = 7000 not 700 x 7 = 7000 or is mach not a scalar multiple ? ------------------------------------------------------------------------------- Trendy footer by: John Stevens-Schlick Internet?: JOHN@tranya.cpac.washington.edu 7720 35'th Ave S.W. Seattle, Wa. 98126 (206) 935 - 4384 ------------------------------------------------------------------------------- My boss dosen't know what I do. ------------------------------ Date: 26 Oct 89 21:33:22 GMT From: wrksys.dec.com!klaes@decwrl.dec.com (N = R*fgfpneflfifaL 26-Oct-1989 1730) Subject: Spacecraft made of wood. The early 1960s United States RANGER unmanned probes to Earth's Moon, specifically RANGERs 3 through 5, carried hard-landing capsules which had their instruments protected by a thick shell of balsa wood. Unfortunately, none of the probes were successful: RANGER 3 and 5 had technical problems enroute and missed the Moon, while RANGER 4 - though becoming the first U.S. probe to hit the lunar surface (the lunar farside, another first) - also suffered mechanical failure and returned no data. Larry Klaes klaes@wrksys.dec.com or - ...!decwrl!wrksys.dec.com!klaes or - klaes%wrksys.dec@decwrl.dec.com or - klaes@wrksys.enet.dec.com N = R*fgfpneflfifaL ------------------------------ End of SPACE Digest V10 #183 *******************