Date: Sat, 27 Mar 93 05:10:36 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #373 To: Space Digest Readers Precedence: bulk Space Digest Sat, 27 Mar 93 Volume 16 : Issue 373 Today's Topics: Galileo Update - 03/25/93 Gaubatz talk on the DC program help In what craft did Glenn orbit the E (2 msgs) JPL's Public Access Site Looting in Baikonur & Ukrainian Space Program Magellan Update - 03/22/93 NASA's Future Retraining at NASA SR-71 Maiden Science Flight The courage of anonymity Timid Terraformers (was Re: How to cool Venus) Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: Fri, 26 Mar 1993 15:38:37 GMT From: fisher@skylab.enet.dec.com Subject: Galileo Update - 03/25/93 Newsgroups: sci.space I have not seen any posted results from the analysis of the HGA receive pattern test. Has the analysis been completed? Thanks, Burns ------------------------------ Date: Fri, 26 Mar 1993 16:44:31 GMT From: Bruce Dunn Subject: Gaubatz talk on the DC program Newsgroups: sci.space In response to several requests for more information on the DC program, I repeat this posting that I made in late January. Apologies in advance if the formatting of this posting is poor - the preview capability of my posting software indicates that it should be ok, but it has lied to me before. I recently attended the "Orbit 93" conference in Berkeley. The following are notes I made at the presentation "Delta Clipper" by Bill Gaubatz, head of the SSRT program at McDonnell Douglas. The presentation was given using professionally prepared view-graphs from MacDonnell Douglas, many of which were marked "competition sensitive" (presumably reflecting the preparation of the view-graphs before MacDonnell Douglas won the contract for the DC-X test vehicle). Delta Clipper vehicle: The following comments refer to the "Delta Clipper" (name used during the talk) or DC-1 (name used on the net), the eventual product of a development program involving a DC-X technology demonstrator and a DC-Y prototype. Planned capability is 16,000 lbs to a 220 nautical mile orbit, 25,000 lbs to an unspecified LEO (low earth orbit). Vehicle is roughly three times as long as it is broad. The upper end is bullet like, becoming wider towards the base. The cross section is circular, except at the base where the four main engines give the shape of a round edged square. In addition to the four main engines, there are four smaller engines. Engine type was not specified in the view-graphs. The vehicle burns hydrogen and LOX, and has a cargo bay at mid-vehicle. The cargo bay is 15x15x30 feet, and has a door to the side of the vehicle. The cargo is supposed to be put into a standard container, and loaded into the cargo bay using a simple ground-based scissors jack. The standard container will have power, coolant, and data transfer connections for maintaining the health of the payload. Gaubatz says the vehicle is "people capable", a term which he prefers to "man rated" which he implies is a term which should be used only for older style launchers. The vehicle has large design margins based on current aircraft practice, so that the vehicle will have a long lifetime. The vehicle will have "reliability centered maintenance", a buzz term which was not particularly clearly defined by Gaubatz. Gaubatz says that for design work, MacDonnell Douglas has brought together people with rocket skills (from their Delta commercial vehicle group) and airplane skills (from their aircraft group). In reply to a question from the audience, he stated that the group was about 60% rocket people, and about 40% aircraft people. The total launch crew in the "flight operations center" (he points out that "blockhouse" is not appropriate) is 3 people; a "flight operations manager" and deputy, and a ground operations controller. Drawings show something like a control tower for operations, with no provision for protection against explosions. Ascent to orbit will involve a burn of 369 seconds, with a maximum G loading of 3.0 The vehicle will have engine out capability at any time in flight. On ascent, once past 60,000 feet (about 9 miles downrange) the vehicle will pass out of FAA control - prior to this FAA clearance will be used. The vehicle enters nose first. The re-entry aerodynamics of the vehicle are derived from the very large body of data which is available on missile warhead re-entry aerodynamics. The angle of attack of the vehicle is controlled to minimize thermal loading. The vehicle has a 1200 to 1500 nautical mile cross range. Deacceleration is 1.1 g maximum during descent. On descent, the vehicle goes subsonic at 60,000 feet altitude, and the engines are then started and idled. At 5000 to 10,000 feet altitude, the vehicle is rotated base down. 2 engines are powered up to deaccelerate and land the vehicle (note that the other two main engines are idling, and can be powered up if needed). The vehicle will land on a pad using retractable landing gear. Wheels will be attached to the landing gear, and the vehicle rolled over to a "flight stand". After placement on the flight stand (which takes the weight of a fueled vehicle), the vehicle will be given a new payload, fueled, and reflown. Gaubatz notes that the noise footprint for a vertical takeoff and landing is more restricted than the noise footprint for a horizontal takeoff vehicle. Most maintenance is projected to take place on the flight stand - in normal circumstances a 12 hour turnaround is expected. Minor maintenance with "line replaceable units" will take less than 24 hours, while major maintenance involving interior components such as fuel cells will take place in less than 1 week at an adjacent hanger. Once a year, the vehicle will undergo a 30 day maintenance and certification. Gaubatz notes that the launch organization for the existing commercial Delta expendable launcher involves 320 people, who can send off 12 flights per year. He claims that this is the most efficient launch organization in the US. He claims that the same number of people will be able to support 4 to 5 Delta Clipper vehicles, each flying 40 times per year. He further notes that for expendable launchers, two thirds of the cost of a launch is for the cost of the expended hardware. DC-X vehicle: The following comments refer to the DC-X experimental vehicle, currently being built by MacDonnell Douglas for proof of concept testing: The DC-X program is a 2 year program, costing about $60 million. Gaubatz states that were the program handled in the "usual NASA manner" it would have been a $ 1000 million program, taking 5 to 8 years. The DC-X is similar in shape to the final Delta Clipper, but one third scale. The hydrogen tank is on the bottom of the vehicle, while the oxygen tank is on the top. The nosecone and tail of the vehicle is being built of composite material by Burt Rutan, of Scaled Composites. The interior of the hydrogen tank is lined with balsa wood bonded to the metal (no- this is not a typo). All avionics are off-the-shelf from current aircraft instrument manufacturers. The vehicle is not designed to go above about 30,000 feet and does not carry enough fuel to get to orbit. MacDonnell Douglas however seems to be thinking about using the DC-X as a reusable sounding rocket after testing is finished ("SOAR" = Sub Orbital Applications Rocket"). The vehicle is unmanned, and is flown by computer with links to ground control. The major objective of the flight testing is to verify the design tools and assumptions used, in order to demonstrate the feasibility of the McDonnell approach to building an SSTO. Vehicle engines are an RL-10 derivative with a reduced expansion ratio for atmospheric flight. Isp at ground level is 337, and the engine can be idled at about 10% power, and run at any setting between 30% to 100 % power (3700 to 13500 lbs force). Only 30% power is required for landing. The first engine tested already has "a couple of hours" of run time (impressive for an engine originally designed as a throw-away item which only had to run for a few minutes). Considerable testing has been done to demonstrate "snap throttling", or very rapid changes in engine power. There are probably 4 engines (the viewgraph was confusing so I am not certain on this point). The RCS (Reaction Control System) runs on gaseous hydrogen and gaseous oxygen, and is in a replaceable module in the base of the vehicle between the engines. The top of the vehicle has a compartment for a parachute, for a "belt and suspenders" approach to getting the vehicle back in one piece. The top of the vehicle also has GPS receivers. The vehicle is launched by a 3 person crew in a trailer (flight operations manager, deputy, and ground operations controller). Total testing crew will be 35 people. Testing will be from WSSH, or "White Sands Space Harbor", starting in late May of this year at the White Sands Missile Range in New Mexico. Some provision will be made for the public to watch the testing - arrangements are not yet firmed up but will be publicized when available. Gaubatz notes that the White Sands people have been very co-operative. Gaubatz wants to test at White Sands to "get away from the current launch culture" (presumably represented by NASA). The vehicle will not carry a destruct package - something that Gaubatz regards as a victory over the existing launch culture and a demonstration of the reasonableness of the White Sands range safety people. Landing gear of the vehicle is retractable, and made by MBB (Deutsche Aerospace, in Germany). The landing gear is designed for up to a 7 G landing, and rough field capability is designed in. The landing gear is retracted during takeoff, and only deployed in the terminal phase of landing. Flight software is designed as much as possible to be the same software that would be used in controlling the final Delta Clipper vehicle. The software is being written in ADA, and is ahead of schedule and under cost. Gaubatz says "If I could build the whole vehicle out of software, I would". The flight operations control screens are designed to look like a "glass cockpit" in a modern airliner. Items displayed on the screen can be "clicked on" (presumably with a mouse) to display further information. Gaubatz is "fully anticipating overall success". Burt Rutan figures that the simplest approach to flight control is to put a pilot on board the vehicle. One of the flight controllers (operating a computer console on the ground) will be Pete Conrad. Gaubatz states that Conrad has been eyeing the parachute compartment in the DC-X, and hinting that if the parachute were removed, there would be room for a pilot! -- Bruce Dunn Vancouver, Canada Bruce_Dunn@mindlink.bc.ca ------------------------------ Date: 26 Mar 93 11:42:00 GMT From: Espen Kristensen Subject: help Newsgroups: sci.space TO: archive-server@ames.arc.nasa.gov help send space FAQ/index send space FAQ/faq1 send space FAQ/manifest --- > OLX 2.1 TD > Press "+" to see another tagline. ---- +-----------------------------------------------------------------------+ | Thunderball Cave BBS 47 22 29 94 41 / 47 22 29 94 42 (HST DS V.32bis) | | -- thcave.no -- Oslo Norway -- | +-----------------------------------------------------------------------+ ------------------------------ Date: Fri, 26 Mar 1993 15:51:21 GMT From: Doug Loss Subject: In what craft did Glenn orbit the E Newsgroups: sci.space In article <1469100030@igc.apc.org> tom@igc.apc.org writes: > >it wasn't a ship it was a mercury CAPSULE. i believe it was called >freedom 7. >also he wasn't the first man to orbit the earth in a u.s. >spacecraft. >answer tomorrow. Sorry, Tom, Glenn's capsule was called Friendship 7. That was an official NASA name; they stopped using names for spacecraft with Gemini. The names for all the Apollo command and lunar modules were in fact radio call signs, non-official designations to make communications easier. Doug Loss Bloomsburg University loss@husky.bloomu.edu ------------------------------ Date: 26 Mar 93 11:53:23 EST From: Chris Jones Subject: In what craft did Glenn orbit the E Newsgroups: sci.space In article , loss@fs7 (Doug Loss) writes: >In article <1469100030@igc.apc.org> tom@igc.apc.org writes: >> >>it wasn't a ship it was a mercury CAPSULE. i believe it was called >>freedom 7. >>also he wasn't the first man to orbit the earth in a u.s. >>spacecraft. >>answer tomorrow. > >Sorry, Tom, Glenn's capsule was called Friendship 7. Freedom 7 was the capsule Alan Shepard rode on a 15 minute suborbital flight. Shepard thereby became the first US astronaut (5 May 1961, following Yuri Gagarin's 1 orbit flight on 12 April 1961). Glenn, whose 3 orbit flight took place on 20 February 1962, was, in fact, the first American to orbit the earth (and the third human -- another Soviet citizen, Gherman Titov, had made a 16 orbit flight in August 1961). -- Chris Jones clj@ksr.com ------------------------------ Date: 26 Mar 1993 17:12 UT From: Ron Baalke Subject: JPL's Public Access Site Newsgroups: sci.space,sci.astro,alt.sci.planetary From the "JPL Universe" March 26, 1993 Public access computer site spurs worldwide interest in Lab activities While Pasadena sleeps through the wee hours of the morning, a college student in Australia brings up a Voyager picture of Jupiter's Great Red Spot on her desktop computer. Across the world, a hobbyist in Germany calls up an artist's rendering of the Cassini spacecraft on his computer screen. Meanwhile a few miles from JPL in the San Gabriel Valley, a night owl amateur scientist scrolls through an update on the Mars Observer mission. All of them are tapping into the wealth of text material and imagery that flow from JPL's space missions, thanks to a new public access computer site established by JPL's Public Information Office. Called JPL Info, the public access site has had a total of nearly 5,000 logons by electronic visitors from most U.S. states and 28 countries during its first month of operation, according to Frank O'Donnell, deputy manager of public information. The site includes a selection of public affairs materials on JPL projects, including news releases, fact sheets, mission status reports and technical information such as orbital elements and spacecraft position tables. Also at the site are educator materials from JPL's Public Education Office and back issues of the Universe in the form of plain text files. Soon to be added are electronic copies of spacecraft project newsletters. "By far, though, the most popular materials are the images," said O'Donnell, who spent the fall configuring the system before opening it in January. "The pictures from JPL missions are stunning, and they are always what the public has been most enthusiastic about." The images at the computer site are stored as electronic files in what is called GIF format (for Graphic Interchange Format). These files can be seen with viewing software available for most types of computers. The JPL Info site itself stocks a variety of "shareware" graphics programs for PC, Windows, Macintosh, Unix, NeXT, Amiga and Atari, which allow viewing the pictures. Many of the images, such as launch pictures and artists renderings, are scanned in from photo prints in the Public Information Office. A few are converted directly from original digital data sent by spacecraft such as Voyager and Magellan. Currently the site has a total of about 50 images, "but we hope to add to that quickly to bring it up to at least 200 to 300 before too long," said O'Donnell. "Ideally we would like to have, for every JPL mission, a launch picture, spacecraft picture and a handful of the best pictures returned by the spacecraft." The site also stocks non-mission pictures, such as an aerial photo of the Lab's Oak Grove site. JPLers and their families and friends are invited to log on to the JPL Info site. Access is possible in several ways: -- Those with a computer and a modem may call 354-1333, setting parameters to 8 bits, no parity, 1 stop bit (N-8-1). Modem speeds of up to 9600 bits per second are accommodated on two phone lines. -- JPLers and others who have access to the Internet network can use file transfer protocol, or ftp, to the address pubinfo.jpl.nasa.gov (128.149.6.2), then log on as user name "anonymous." Internet is an international network that ties together JPL and many government agencies, universities, institutions and companies. -- JPL PC and Mac users who are on the institutional Ethernet can log on to the Public Information Office's file server as a guest. Mac users can go into Chooser, click on AppleShare, go to zone 180-2-Enet and click on server JPL-PIO, logging on as a guest. PC users must have Novell software loaded, then execute the command "login jpl-pio/guest" to connect to the site. Visitors logging on any of the three ways see the same set of files. All users are encouraged to download and read a file called README, which explains how the site operates and how to use its materials. For more information or help with logging on, call O'Donnell at ext. 4-7170. ### ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't ever take a fence /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | down until you know the |_____|/ |_|/ |_____|/ | reason it was put up. ------------------------------ Date: 26 Mar 93 10:18:18 EST From: Chris Jones Subject: Looting in Baikonur & Ukrainian Space Program Newsgroups: sci.space In article , pgf@srl03 (Phil G. Fraering) writes: >fcrary@ucsu.Colorado.EDU (Frank Crary) writes: > >>In article yamauchi@ces.cwru.edu (Brian Yamauchi) writes: >>>Does anyone have more details [...] >>> about the >>>extent of the Ukrainian space program? > >>The Ukrainian program can't be too extensive: The only launch complex >>they have access to is Kapustin Yar. While it is quite equitorial >>for a ex-Soviet site, it is currently only capable of launching >>sounding rockets and very small orbital launchers like the SL-8 >>(1.25 tonnes to Low Earth Orbit.) > >In the past, Kapustin Yar did see more use than that... I don't >think un-mothballing the pads would be that much of a problem According to one of the VSA reports published early last year ((c) Sergey A. Voevodin, and often posted to sci.space.news): "Soviet Kapustin Yar cosmodrome is closed. Boris Yeltsin gave this place for Soviet Germans settlements." So, I think un-mothballing the pads WOULD be a problem. Why all the talk about Kapustin Yar in relation to the Ukrainians? It's in Russia (on the Volga, a little north of Volgograd, and closer to Kazakhstan than to Ukraine). -- Chris Jones clj@ksr.com ------------------------------ Date: 26 Mar 1993 16:56:42 GMT From: Steve Derry Subject: Magellan Update - 03/22/93 Newsgroups: sci.space,sci.astro,alt.sci.planetary Eric H Seale (seale@possum.den.mmc.com) wrote: : To be fussy, the radar is doing fine -- Magellan can map all it wants : with the radar. Problem is, both transmitters are pretty much shot when : it comes to sending back science data (one's gone entirely, the other : can only transmit high-rate data when you get it REALLY, REALLY hot -- : say, 60 deg C). One option that I heard being talked about is called (I : think) bistatic radar -- Magellan transmits the radar which bounces off : the surface and is then received at Arecibo. Even with a low circular : orbit, I'm not sure that this buys you much, tho' ... Another alternative would be to map small selected areas of high interest and play the data back at the current 1200bps rate. By the time that TEX and cycle 5 gravity mapping is complete, the target areas could be selected. If they were small enough, and spaced far enough apart, then the data could be stored onboard during mapping orbits (only mapping over a small latitude range), and played back at slow rate after the target area has been covered. Alternatively, portions of the data could be played back between mapping passes, but this would make operations a bit more complex. -- Steve Derry ------------------------------ Date: 26 Mar 1993 17:19 UT From: Ron Baalke Subject: NASA's Future Newsgroups: sci.space,sci.astro,alt.sci.planetary From the "JPL Universe" March 26, 1993 O'Toole discusses NASA's future By Karre Marino In an address on NASA's history and its future in a changing American economy March 16, Dr. Richard O'Toole, JPL's manager of legislative affairs, began with some humor, telling the audience that "economists are people who are good with numbers, but don't have the personality to be accountants." The light mood, however, certainly belied the serious road ahead, as in the struggle for federal dollars, NASA will have to undertake a variety of steps to ensure it receives about $14 to $15 billion annually. O'Toole told a near-capacity crowd in von Karman Auditorium that the economically unrestrained days of the '60s are gone. "Those Apollo days are over. We have to get on with it." The late 1980s -- the era of the Space Shuttle Challenger accident -- he said, signaled that NASA was in trouble. "NASA misperceived the funding increases it received after Challenger. It took them to be a long-term commitment that would continue indefinitely." The space agency was wrong. "Congress never bought into an Apollo-scale program," he explained. Indeed, he said, unless NASA can demonstrate that its projects have substantial societal value, they will be threatened in the future. Looking ahead, O'Toole indicated that the structural changes in the economy --fewer high-paying manufacturing jobs, less domestic gross product devoted to public investment, tax revenues of 19 percent that attempt to pay for expenditures of 25 percent, a lower-wage base, and a staggering federal deficit -- would call for a restructuring of NASA's own approach and the way it justifies its program. He explained that while the Clinton/Gore plan would call for sacrifice from all sectors of society, it encourages the very thing that NASA and labs like JPL do best -- create technologies that can stimulate growth in the decades ahead. The trick, he said, is to redefine NASA's role, "to be consistent with the President's plan. It is about strengthening the link between NASA projects and competitiveness via technology, as well as fostering technological developments that lead to industrial competitiveness. The emphasis must be on a transfer of technology from the lab setting to private industry. NASA must push advances in space technology to help make U.S. technology more competitive." O'Toole also delineated the challenge that faces NASA Administrator Daniel Goldin. "He must redefine NASA's mission to meet this new environment. There is no entitlement for NASA; the space race is over. Projects now must stand on their own merit to meet society's needs." That includes shifting resources to support more important programs -- technology, human exploration, Mission to Planet Earth and space science. But the bottom line, O'Toole indicated, is that Goldin doesn't expect an influx of money for NASA, so he must ensure that the agency can do more by conducting more frequent, less costly missions. The NASA administrator is also attempting to encourage risk taking via smaller projects. "Cheaper projects are often more visible, the results more apparent," according to O'Toole. That means Congress and the public place more value on NASA's role. JPL is not lost in this new view. O'Toole said that "we must bring our strategy in line with the new external reality." Concepts like the Mars Rover/Sample Return that approached the $10 billion mark are no longer viable, he explained. Innovative ideas like the Mars Network -- with a $1 billion price tag -- are those that should be developed, he said. JPL Director Dr. Edward Stone's moves to cut the Lab's work force, for instance -- before it was mandated by others -- was an excellent idea, he added. "We get credit for such action. Our credibility goes up when people perceive that we're doing what is necessary -- and inevitable -- before we're forced to." In the end, O'Toole said, NASA will have to prove its value in contributing to solving real problems -- and its relation to all of America -- as it seeks funding. "The space program must show its relevance to all segments of society. We have to reach out to women and the minority community, more than we have in the past." ### ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't ever take a fence /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | down until you know the |_____|/ |_|/ |_____|/ | reason it was put up. ------------------------------ Date: Fri, 26 Mar 1993 16:27:49 GMT From: Dan Vento Subject: Retraining at NASA Newsgroups: sci.space In article <1o8g2rINNfas@access.digex.com>, prb@access.digex.com (Pat) wrote: > > Yes, but their 'focused' domain seems to be doing more basic engineering > work then your 'big picture'. All three of the above are engineering > missions to qualify and develope hardware with numerous other applications. > > NASA needs to have a basic annual flight program just to test new pieces > of gear out there. DO you know, that as of 1989, no LED's were > space-qualified? Even though LED's have lifetimes 10 times greater then > light bulbs. Light bulbs were still shelf spec for space gear. > This is bunk. I have worked on several Shuttle experiments (such as the SSCE which recently flew for the sixth time) which are made entirely out of commercial parts including LED's and chips in plastic housings. So do many other microgravity payloads. You only worry about "flight qualified" i.e. type S components for the really high stake high cost stuff such as SSME avionics or expensive spcacraft such as TDRS. There is no regulation anywhere in NASA which says we must always use "flight qualified" parts. A little testing will can usually allow engineers to use just about anything including unmodified Apple Macintoshes or HP 41 calculators. Dan Vento vento@mars.lerc.nasa.gov NASA Lewis Research Center Launch Vehicles Project Office ------------------------------ Date: Fri, 26 Mar 93 02:43:49 GMT From: Bob Combs Subject: SR-71 Maiden Science Flight Newsgroups: sci.space In article <1993Mar25.104802.1@fnalf.fnal.gov> higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey) writes: >In article <1993Mar24.020725.5283@sed.stel.com>, bobc@sed.stel.com (Bob Combs) writes: > >And nobody will *ever* offer you a ride on an SR-71... I guess I'll have to wait for the NASP! [=> -- ----------------------------------------------- Traditions are the living faith of dead people. bobc@sed.stel.com Bob Combs ------------------------------ Date: 25 Mar 93 10:36:55 MST From: James Friesen Subject: The courage of anonymity Newsgroups: news.admin.policy,alt.privacy,comp.org.eff.talk,sci.space In article <2237@frackit.UUCP> dave@frackit.UUCP (Dave Ratcliffe) writes: >In article <1993Mar7.004339.4397@fuug.fi>, an8785@anon.penet.fi (8 February 1993) writes: >> > [ some babble deleted ] > >[ a lot of babble deleted ] > >> Sci.space and sci.astro need many more blunt posts centered >> on the human theme, even if strong medicine to many readers. > GET IT OFF THOSE GROUPS!!!! What has this got to do with science. If the person who originally thought the post was an attack on there senses they shouln't be reading the USENET chaosium:-/ > [ and tons of useless babble deleted ] Can we get on with this folks, this is really tiresome to read all this trash AND FOR IT TO BE CROSSPOSTED TO HELL!!!! It is just plain rude. Not that this isn't a good debate (well it was, but now it has degenerated into something we see in daycare parks) this crossposting is a major piss off and _what_ has it got to do with sci.space.* -- _____ James Friesen (403)720-0140 / _ I think.... therefore I own an Amiga ___/ /\ |\/| |= _/ I gotta dingadingdang my dangalonglinglong - Ministry FidoNet 1:134/27 Internet James@Lucretia.cuc.ab.ca ------------------------------ Date: 26 Mar 93 11:31:29 EST From: "John F. Woods" Subject: Timid Terraformers (was Re: How to cool Venus) Newsgroups: sci.space dietz@cs.rochester.edu (Paul Dietz) writes: >In article <93085.002514GRV101@psuvm.psu.edu> Callec Dradja writes: >> Bill, I am afraid that you did not quote all of what I said. The reason >> that I do not like the idea of using nuclear weapons to blast the >> atmosphere into space is because I feel that this would be a waste of >> Oxygen. >Good grief. Oxygen is one of the most common elements beyond helium. >The earth's crust is 46% oxygen by mass; the rocky parts of the other >inner planets are likewise oxygen-rich. Venus's atmosphere contains a >negligible fraction of that planet's oxygen. However, the surface of venus is probably oxygen-poor; most of the carbon dioxide in the atmosphere was baked out of the surface rocks, and if they ever cool below red-heat, they may be ready to react with whatever atmosphere remains. It might be embarassing to blow off the entire current excess, cool Venus off a bit, and then suddenly wind up with a vacuum when the surface rocks suck all the remainingt carbon dioxide back in... :-) On the other hand, it may be impossible to reduce the temperature without getting rid of it; one of the popular schemes for doing so (slamming big comets into Venus) also provides a way to replenish the atmosphere afterwards. Perhaps someone more familiar with the details of Venus' probable surface chemistry can comment more sensibly. ------------------------------ End of Space Digest Volume 16 : Issue 373 ------------------------------