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 ; Fri, 18 May 90 01:34:15 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 18 May 90 01:33:42 -0400 (EDT) Subject: SPACE Digest V11 #416 SPACE Digest Volume 11 : Issue 416 Today's Topics: space news from Dec 18/25 1989 AW&ST space news from Dec 11 1989 AW&ST Terra-forming Venus Re: Terraforming Venus Re: Manned mission to Venus Carnegie Mellon University develops planetary robot for NASA (Forwarded) Re: Deep Space Relay Satellite Re: Earth Orbits (was: space news from April 9 AW&ST) ---------------------------------------------------------------------- Date: 17 May 90 02:46:30 GMT From: mcgill-vision!clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo!henry@bloom-beacon.mit.edu (Henry Spencer) Subject: space news from Dec 18/25 1989 AW&ST [Yes, I know, this is a lot out of sequence. Given that I'm more or less caught up on current issues -- I consider running a month behind to be normal, given Post Office, reading the things, etc. -- I'm going back for quick summaries of the issues I missed due to the subscription foulup. My thanks to Alex Sim of Dryden and to the Dryden library, for supplying the issues I missed, and to Mary Shafer for arranging it.] Discussion of the rumors about the "Aurora" hypersonic spyplane, successor to the SR-71, asking whether the USAF's ambivalence about the Aerospace Plane is because similar technology is already being developed in secret. Some grumbling about silly secrecy in military space operations. For example, AW&ST had considerable difficulty finding out the details of the engine-gimballing problem on the first Titan 4 flight. The USAF didn't even admit there was a problem until prodded about it (after informal reports from "friendly sources"). After the investigating team produced its final report, a request for a copy was ignored. "It was not secret, it just was not any of my business." A request under the Freedom Of Information Act was denied on the grounds that it would "reveal the deliberative process of the Air Force". [!!] USAF Space Systems Division has been ordered to terminate design work on ALS, disband the program office, and scale back the program to a technology-research effort, ALTP (Advanced Launch Technology Program). The decision apparently was because full-scale development, starting in 1992, would have involved a sharp jump in spending, and the SDI launch requirements that have been driving the program have been shrinking of late. NASA is disappointed, and hopes to continue work leading to a prototype new-technology rocket engine, at the very least. Kvant 2 is now in place on Mir. -- Life is too short to spend | Henry Spencer at U of Toronto Zoology debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 17 May 90 03:02:12 GMT From: mcgill-vision!clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo!henry@bloom-beacon.mit.edu (Henry Spencer) Subject: space news from Dec 11 1989 AW&ST [Yes, I know, this is a lot out of sequence. Given that I'm more or less caught up on current issues -- I consider running a month behind to be normal, given Post Office, reading the things, etc. -- I'm going back for quick summaries of the issues I missed due to the subscription foulup. My thanks to Alex Sim of Dryden and to the Dryden library, for supplying the issues I missed, and to Mary Shafer for arranging it.] Iraq claims successful launch of a rocket capable of launching satellites. People are concerned, not about Iraq launching satellites but about Iraq having long-range-missile technology. USSR cancels planned 1990 Energia launch, due to tight budgets. "There is a launcher ready but we no longer have a payload for it." The nature of the cancelled payload was not specified. The next flight is now set for early 1991 carrying a Buran orbiter (unmanned). Energia development work continues, however, including successful preliminary tests on using supercooled fuels to increase fuel density and therefore payload; a 1-ton payload increase has been achieved by unspecified cooling technologies. Kvant 2 docking operations at Mir being completed after a solar-array deployment problem was solved. Diagram of the approach maneuvers planned for the LDEF retrieval. Solar Max reenters and burns up Dec 2, over the Indian Ocean. Sonic boom from the Columbia landing Aug 13 caused a "mini-earthquake" in downtown Los Angeles, shaking office buildings slightly, since the dominant component of the shock waves had a period matching the resonant frequency of the ground there. Letter from Allen Thomson, observing that there are at least six unclassified radarsats set for launch in the next five years, none of them American: ERS-1 (ESA), JERS-1 (Japan), Radarsat (Canada), two Almaz platforms (USSR), and the radar system on the planned remote-sensing module for Mir. "One wonders how a nation that pioneered orbital radar imaging with Seasat (sadly, it was once called Seasat-A) in 1978 finds itself seventh in line at the end of the century." -- Life is too short to spend | Henry Spencer at U of Toronto Zoology debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 15 May 90 18:45:10 GMT From: crash!orbit!pnet51!schaper@nosc.mil (S Schaper) Subject: Terra-forming Venus What sort of Delta-V would be required to take a smaller moon of Saturn and send it on a Hohmann-type intercept with Mars? Refine it in process to get rid of cyanides, etc, and make ice-cubes, and larger chunks to connect Mare Hellas with Mare Borealis?, Likewise, send a Ni-Fe asteroid to Venus on a tangent to increase durineal speed :-) (may be totally impossible!) and blast away a lot of atmosphere. Else anitmatter bombs to reduce atmos pressure, or better yet engineered critters to return the SO2, and CO2 to water and carbonate and sulfates? Major problems with this, but what are some calculations? UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper ARPA: crash!orbit!pnet51!schaper@nosc.mil INET: schaper@pnet51.cts.com ------------------------------ Date: 17 May 90 17:37:19 GMT From: usc!cs.utexas.edu!uwm.edu!mrsvr.UUCP@ucsd.edu (Russ Brown) Subject: Re: Terraforming Venus From article <10554.7077.forumexp@mts.rpi.edu>, by Greg_d._Moore@mts.rpi.edu (Commander Krugannal): > > Umm, in a word NO! Think about it next time, perhaps its > the space or vacumn between the pieces of glass in your stove > window that keeps the heat in. Or better yet, take a look > at a thermos bottle someday. > Perhaps you were thinking of UV radiation? Glass is a very effective barrier to infrared RADIATION. you're mixing up conductive heat loss (which you insulate against) with heat lost through radiation. But I agree that the oven door is not a good example of this effect. ------------------------------ Date: 17 May 90 14:16:47 GMT From: usc!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!IDA.ORG!pbs!pstinson@ucsd.edu Subject: Re: Manned mission to Venus In article <3346@calvin.cs.mcgill.ca>, msdos@quiche.cs.mcgill.ca (Mark SOKOLOWSKI) writes: > (deleted) > Kennedy wanted a man on the Moon in 10 years, and we will remember it > forever because it was done. Nobody cares about the lunar missions after > Apollo 11, nobody cares about Skylab, Mir. The only thing HUMANITY > remembers now is that a man was on the Moon. And it will never care about > Moon colonies and space stations because all of these are now banal things > for imagination. We have to be original, Venus is so terribly harsh, such > a strange and unknown place.... > > Mark S. > ------- Maybe the average person does not care about Moon colonies now because they ARE just imaginary. But a real colony on the Moon that has grown large enough to be visible from Earth will have a profound impact on humanity. Imagine looking up at the Moon some evening and noticing the glow of manmade lights and other indirect signs of human activity up there. It is sometimes said "Out of sight ... out of mind." No activity on any of the other planets in the solar system will be noticible to the unaided eye and perhaps the man in the street would care less what happens way out there, but big active moon colonies would be hard to ignore and will have a definite cultural impact we underestimate now. ------------------------------ Date: 17 May 90 18:31:18 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Carnegie Mellon University develops planetary robot for NASA (Forwarded) Mary L. Sandy Headquarters, Washington D.C. May 17, 1990 (Phone: 202/453-2754) 10 a.m. EDT Anne Watzman Carnegie Mellon University, Pittsburgh (Phone: 412/268-2900) RELEASE: 90-69 CARNEGIE MELLON UNIVERSITY DEVELOPS PLANETARY ROBOT FOR NASA The "Ambler," a six-legged, 12-foot-tall, prototype, autonomous robot with the "brains" and motor skills to explore rugged terrain, is being developed for NASA by Carnegie Mellon University's Robotics Institute, Pittsburgh. NASA officials and university researchers say the Ambler's technology could bring an important new dimension to solar system exploration. Because the robot literally walks, it can traverse rough terrain by stepping over crevices and large boulders. Future operational rovers, based on the Ambler design, could reach areas on the Moon and Mars inaccessible to wheeled vehicles or too dangerous for humans. Since October 1987, three teams of researchers including Carnegie Mellon graduate and undergraduate students have been developing the algorithms, hardware and software necessary for the Ambler's locomotion, perception and planning capabilities. The Ambler represents an integrated, self-sufficient system that will be used to provide NASA mission managers with the confidence that legged vehicles are a realistic alternative to wheeled rovers for lunar and martian exploration. The aluminum Ambler has two sets of stacked legs, with three legs per stack. These legs separately lift, advance and circulate to their original positions, much like an egg beater. "The body is propelled in a motion similar to cross-country skiing," said Carnegie Mellon's William L. "Red" Whittaker, one of three Ambler project principal investigators. "A single leg reaches out in front of the others, places itself firmly on the ground like a ski pole and then pulls the machine forward." Because the drive motors that support the Ambler's body are separate from those that propel it, the robot remains level whether it's walking on flat or rugged ground. The design provides a stable platform for sensors, scientific equipment and sample acquisition tools. Above the legs, on the stacks, are boxes containing the machine's electronics. Above that, a cross bar connects the two sections. The electrically-powered Ambler will be energy efficient and can retain its ability to walk even if it loses mobility in two legs. The Ambler requires a set of sensors for its vision system. With input from this system, the robot creates three- dimensional maps of the surrounding topography and objects it might be interested in sampling. After studying the maps, it decides in which direction to move and where to place its feet. Future versions deployed on Mars could combine the current laser sensing system with cameras, sonar and other sensors to provide the full spectrum of information needed for sampling and navigation. "These machines will have to contend with rugged and soft terrain, low temperatures, high winds, dust and equipment failure," said principal investigator Takeo Kanade. "For autonomous operation under such conditions, a good vision system is critical." The Ambler's unique software control system, called Task Control Architecture, enables the Ambler to plan for the selection of stable and safe steps. "The system is designed for robots that operate in dynamic and uncertain environments," explained principal investigator Thomas Mitchell. "It uses a variety of sensors with different ranges and resolutions to know where it is and see where it's going." The Ambler recently took its first steps at the Carnegie Mellon University's Robotics Institute. The next step is integration of its perception, planning and control capabilities. The Ambler represents a new generation of robots to explore and work in natural terrains. The technology also has implications for Earth-bound activities such as construction, mining, timbering, hazardous waste management and emergency response. The Ambler is one of the concepts being evaluated under NASA's Planetary Rover program, which is developing robotic and manned technology to explore lunar and planetary surfaces. The program initially is focused on unmanned rover technology with both legged and wheeled options being studied. Planetary rovers must be able to make autonomous decisions because of the long transmission times for commands between Earth and planetary surfaces -- about 45 minutes one way to Mars. "The intent for the vehicles being designed is for them to be capable of operating on their own with just a very general set of directions," notes David B. Lavery, manager of NASA's Planetary Rover Program. "Robots are not susceptible to temperature changes or radiation exposure on the long flights required to reach the planets," added Whittaker. "They can spend protracted time on a mission that would be impossible for an astronaut who requires close proximity to his or her space ship." - end - A video clip and still photographs are available to media organizations to support this release and can be requested from NASA Headquarters by calling 202/453-8375. Photo numbers are: color 90-HC-305 B/W 90-H-320 The 8-minute video clip will be broadcast on NASA Select television at noon EDT, Thursday, May 17. NASA Select may be accessed via Satcom F2R, transponder 13, frequency 3960 MHz, position 72 degrees West longitude, polarization vertical, audio monaural 6.8 MHz. ------------------------------ Date: Thu, 17 May 90 14:58:22 EDT From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: Deep Space Relay Satellite >From: mojo!SYSMGR%KING.ENG.UMD.EDU@mimsy.umd.edu (Doug Mohney) >Subject: Deep Space Relay Satellite >What's the feasability of getting a mid-point "relay" station put into >place to support transmissions of deep space probes such as Voyager and >future missions? Seems a waste for them to collect all that data and >not be able to get access to it because either A) the 70 meter Deep Space >Tracking network here on Mother Earth wasn't available or B) The wattage >coming out of 'em in future years will be too low to be heard by anything >sitting on the ground. Sounds like it might be useful under certain specific conditions. For instance, it could reduce weather-related loss of data. I can think of a few problems you'd have to consider: - Space is not linear, with everything "out there" in the same direction. For instance, suppose Jupiter and Saturn at some point are on opposite sides of the sun, and you want links to both? In practice, you'd need several relays (i.e. in a ring), and pay a lot for each one. - The DSN receivers are extremely precise, sensitive, huge pieces of equipment which can be repaired if they break. The reduction in distance would relax the performance requirements of space-based relays only slightly. It might be more worthwhile to just build more ground-based receivers. Perhaps some could be built on the moon to augment the current DSN. - If the distances and signal strengths are such that a relay is *necessary*, you add a failure point to the system. It might be safer just to augment the capabilities of the ground-based equipment. If you can think of a way around these problems, it would be a neat system - sort of like a super-TDRS network. >Alternately, we'll end up designing probes which drop off three or four >football-sized relays (like a high-tech trail of bread crumbs :-) which >can pass back clear data from way-way out. Since probes spend most of their time coasting, the relays would just follow the probes closely. You could drop one off before the final positioning for each slingshot maneuver - since each relay would be somewhat off course, I don't know how well this would work. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 17 May 90 16:59:53 GMT From: usc!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Re: Earth Orbits (was: space news from April 9 AW&ST) In article <10578@sdcc6.ucsd.edu> bruno@sdcc10.ucsd.edu (Bruce W. Mohler) writes: >Just curious. Where can I learn more information about the three types >of orbits Henry mentions in the above segment? ... Hmm, didn't expect to have to repost this so soon: ------------------------------ End of SPACE Digest V11 #416 *******************