Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.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, 20 Jan 91 02:07:49 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 20 Jan 91 02:07:45 -0500 (EST) Subject: SPACE Digest V13 #062 SPACE Digest Volume 13 : Issue 62 Today's Topics: Galileo Update - 01/18/91 CRRES experiments continue after four successes (Forwarded) Astronauts in the Van Allens Re: Fwd: NASA Plans To Redesign Space Station Future of the Shuttle (was: space news from Dec 17 AW&ST) Re: Salyut 7 burn-up Re: Planetary Society [Part 2 of 2] Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 18 Jan 91 18:57:30 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Galileo Update - 01/18/91 GALILEO STATUS REPORT January 18, 1991 The status of the Galileo spacecraftas of end of day January 17 is as follows: o System Power Margin - 66 watts o Spin Configuration - All-Spin - cruise mode o Spin Rate/Sensor - 2.89rpm/star scanner o Spacecraft Attitude Sun Point Angle - approximately 1.7 degrees plus or minus 0.3 degree o Downlink telemetry rate/antenna - 40 bps (uncoded)/LGA-2 (Low Gain Antenna) o General Thermal Control - all temperatures within acceptable range o RPM (Retro Propulsion Module) Tank Pressures - all within acceptable range Yesterday on the Galileo spacecraft, the CDS "B" (Command Data Subsystem) memory copy activity was successfully completed; spot-check memory readouts indicated no anomalies or parity errors. Today, cruise science memory readouts were completed for the EUV (Extreme Ultraviolet Spectrometer), MAG (Magnetometer) and DDS (Dust Detector) instruments. In addition to the science readouts, a planned sun acquisition was successfully completed. A total of 2950 real-time commands have been transmitted to Galileo. Of these, 1557 have been pre-planned in the sequence design and 1393 were not. In the past week, a total of 149 real time commands were sent; 141 were preplanned and 8 were unplanned. Over the coming weekend, spacecraft activity will be limited to a planned radio science calibration on Saturday and a sun acquisition on Sunday. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 18 Jan 91 18:49:10 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: CRRES experiments continue after four successes (Forwarded) Brian Dunbar Headquarters, Washington, D.C. January 17, 1991 (Phone: 202/453-1547) Jerry Berg Marshall Space Flight Center, Huntsville, Ala. (Phone: 205/544-6540) RELEASE: 91-9 CRRES EXPERIMENTS CONTINUE AFTER FOUR SUCCESSES The Combined Release and Radiation Effects Satellite (CRRES) is scheduled to resume experiments early Friday morning following four successful chemical releases in the last week. The next release opportunities will be for either a lithium or large barium release early Friday morning, with possible times of 12:20 a.m., 12:50 a.m., 1:20 a.m., 1:40 a.m. and 1:55 a.m. EST. Weather permitting, the release will be visible in the south- southeastern sky, slightly more than halfway between the horizon and the zenith. The CRRES releases aid scientists studying the way that charged particles interact with the Earth's magnetic and electric fields by creating artificial auroras. Natural auroras occur when high-energy particles from the sun strike the Earth's upper atmosphere. Understanding the Earth's magnetic field is important because disturbances in the field, such as those that create natural auroras, can disrupt high-frequency communications, produce damaging currents in terrestrial power systems and create magnetic storms that affect sensitive instruments on Earth and in space. Last weekend, one release each of barium and lithium were performed, and two more barium experiments were completed Monday night and early Wednesday morning. "The chemical release operations went off without a hitch during these opportunities," said Dr. David Reasoner, CRRES project scientist at the Marshall Space Flight Center, Huntsville, Ala. "The satellite and the U.S. Air Force satellite control facility have performed flawlessly. The optical instruments at the observing sites were pointed precisely at the release." The current CRRES chemical release "campaign" involves seven planned releases, with four opportunities to make the remaining three releases through Jan. 24. Late Saturday night and early Sunday morning, two releases were completed as scheduled. Cloudy weather over much of the United States did not permit the glowing barium and lithium gas clouds to be seen from the ground, but a more than sufficient number of observation stations in North America and the Caribbean were able to provide good observation support for the experiments. The 3.3-lb. barium release at 9:17 p.m. EST Saturday resulted in a cloud that glowed bright green initially and then changed to a dimmer purplish-blue as the barium atoms ionized upon exposure to sunlight. At 2:05 a.m. Sunday morning, the 1.6-lb. lithium release produced a red glow in the night sky, with observers estimating its size as approximately the diameter of the full moon and remaining visible for a few seconds. Its apparent brightness was relatively dim because of the human eye's low response in the red region of the spectrum, Reasoner said. Nevertheless, the cloud was reported, for its brief duration, to be the brightest object in the sky, he added. The lithium release was timed to coincide with certain positions of CRRES and NASA's Dynamics Explorer-1 satellite as well as the Japanese AKEBONO satellite. All three satellites have instruments for detecting the artificially injected lithium ions. The Monday night barium release occurred at 11:11 p.m. EST. Afterward, Reasoner hailed the operation, saying, "We believe we have accomplished a significant experiment. Excellent optical data were obtained from many sites, with one particular site tracking the barium ions for two hours." The fourth barium release took place at 1:25 a.m. EST Wednesday morning. Given clear weather, remaining releases should be visible from the entire continental United States, most of Canada, Central America, the Caribbean and much of South America. During some of the release opportunities, the clouds may be visible low in the western skies from western Africa and Europe, several hours before dawn. For current information about upcoming release opportunities, the CRRES Coordination Center "hotline" message may be heard by calling 205/544-5356. This is not a toll-free number. CRRES is a joint program of NASA, through its Marshall Space Flight Center and the Department of Defense's Space Test Program. CRRES is operated and controlled from the Air Force's Consolidated Space Test Center, Sunnyvale, Calif. ------------------------------ Date: 16 Jan 91 22:12:19 GMT From: hpcc05!hpcc01!flower@hplabs.hpl.hp.com (Graham Flower) Subject: Astronauts in the Van Allens I recently read that manned space missions about the earth are limited to altitudes below 300 km or so due to the Van Allen belts. Could somebody explain to me just why this is? Apparently transit through them is ok (Apollo missions) so what is going on here? Graham Flower ms 90-TT | Better to have convictions and act on Hewlett-Packard 350 W Trimble Rd | them, even if they are wrong, than to Microwave Semiconductor Division | waffle in indecision endlessly. San Jose, California, 95131 | ------------------------------ Date: 16 Jan 91 20:09:18 GMT From: usc!samsung!rex!rouge!dlbres10@apple.com (Fraering Philip) Subject: Re: Fwd: NASA Plans To Redesign Space Station In article <395@borg.cs.unc.edu> leech@homer.cs.unc.edu (Jonathan Leech) writes: >If adopted, this would help vindicate Oliver Harwood's modular >tetrahedral station approach. Having the temerity to propose it got him >kicked out of Rockwell in the mid-80s. >Jon Leech (leech@cs.unc.edu) __@/ You mean they're still doing things like kicking people out of organizations for coming up with different ideas on how to do things? Doesn't most of the benefits of the Space program come not from the actual hardware we've built (except for the weather and comm sats) but because it pushes new technology? Confused in Lafayette, Phil dlbres10@pc.usl.edu ------------------------------ Date: Fri, 18 Jan 91 10:09:14 -0500 From: "Allen W. Sherzer" Subject: Future of the Shuttle (was: space news from Dec 17 AW&ST) Newsgroups: sci.space Cc: In article <1991Jan17.232621.19639@zoo.toronto.edu> Henry Spencer writes: |>I think it is clear that the Shuttle will no longer be a significant |>part of NASA planning. But then, with a man-rated HLV costing far less |>than the Shuttle and a space station, there is little need ... |Uh, where is this "man-rated HLV"? I don't see it in current inventory. We have three options available to us. All three options could be built for about the cost of one new orbiter. In the mean time, we have options to put people up using Delta or Atlas. |And if it's not, then the Shuttle *does* figure in NASA's plans for this |decade, at least, and that means replacement orbiters will be needed. For what? Most of the missions can go up on Titan IV for far less money. For those missions which must use the Shuttle, we will have four left. |Maintenance of the shuttle fleet requires an orbiter supply, and said |maintenance can be abandoned only when the fleet itself is about to be |abandoned. That won't happen soon. All this means is that the transition is beginning now. The HLV will be available in three to five years. Is this burning our bridges behind us? To some extent, yes. I think that is the only way to motivate NASA to make real change. The Shuttle costs too much and is sucking up all the money which could go to building cheaper alternatives. Under the current budget situation the choice is either another orbiter or a HLV, but not both. Allen -- +----------------------------------------------------------------------------+ |Allen W. Sherzer | America does best when it accepts a challenging mission. | | aws@iti.org | We invent well under pressure. Conversely, we stagnate | | | when caution prevails. -- Buzz Aldrin | ------------------------------ Date: 13 Jan 91 21:39:20 GMT From: isis!scicom!wats@uunet.uu.net (Bruce Watson) Subject: Re: Salyut 7 burn-up In article <580@research.cc.flinders.oz>, phacb@research.cc.flinders.oz (A.C.Beresford) writes: > Since it is already in atmosphere the question has no meaning > It is however an observed fact that re-entring satellites > have been observed at heights of 109Km in the self-luminous > phase. You can model the process approximately both > numerically and analytically ( DG King-Hele Satellite > orbits in an atmosphere) which gives a figure something > like 1 day left by time orbit height = 160Km ....and one orbit left at 117 kms. ------------------------------ Date: 9 Jan 91 18:26:33 GMT From: netcom!teda!ditka!mcdchg!tellab5!balr!clrcom!rmartin@apple.com (Bob Martin) Subject: Re: Planetary Society [Part 2 of 2] In article <9101050539.AA13070@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: > >Perhaps some kind person could post the "official position" of the Planetary >Society on this subject. I just happen to have a copy of the Planetary Societies "Mars Declaration" right here. Mars is the world next door, the nearset planet on which human explorers could safely land. Although it is sometimes as warm as a New England October, Mars is a chilly place, so cold that some of its thin carbon dioxide atmosphere freezes out at the winter pole. There are pink skies, fiekdls of boulders, snad dunes, vast extinct volcanos that dwarf anything on Earth, a great canyon that would cross most of the United States, sandstorms that sometimes reach half the speed of sound, strange bright and dark markings on the surface, hundreds of ancient river valleys, mountains shaped like pyramids and many other mysteries. Mars is a storehouse of scientific information - important in its own right but also for the light it may cast on the origins of life and on the safeguarding the environment of the Earth. If Mars once had abundant liquid water, what heppened to it? How did a once Earthlike workd become so parched, figid and comparatively airless? Is ther something important on Mars that we need to know about our own fragile world? The prospect of human exploratoin of Marse is ecumenical- remarkable for the diversity of supporting opinion it embreaces. It is being advocated on many grounds: -As a potential scientific bonanza-for example, on climatic change, on the search for present of past life, on the understanding of enigmantic Martian landforms, and on the application of new knowledge to understanding our own planet - As a means, through robitic precursor and support missions to Marse, of reviving a stagnant U.S. planetary program. - As providing a coherent focus and sense of purpose to a dispirited NASA for many future research and development activities on an appropriate timescale and with affordable costs. -As giving a crisp and unambiguous purpose to the U.S. space station - needed for in-orbit assembly of the interplanetary transfer vehicle or vehicles, and for study of long-duration life support for space travelers. - As the next freat human adventure, able to excite and inspire people of all ages the world over. - As an apeture to enhanced national prestige and technological development - As a realistic and possibly unique opportunity for the United States and the Soviet Union to work together in the spotlight of world public opinion, and with other nations, on behalf of the human species. - As a model and stimulant for mutually advantageous U.S. / Soviet cooperation here on Earth. - As a means for economic reconversion of the aerospace industry if and when massive reductions in strategic weapons - long promised by the United States and the Soviet Union - are implemented. - As a worthy application of the traditional military virtues of organization and valor to great expeditions of discovery. - As a step towards the long-term objective of establishing humanity as a multi-planet species. - Or simply as the obvious response to a deeply felt perception of the future calling. Advances in technology now make feasible a systematic process of exploration and discovery on the planet Mars- beginning with robot roving vehicles and sample return missions and culminating in the first footfall of human beings on another planet. The cost would be no greateer than that of a single major strategic weapons system, and if shared among two or more nations, the cost to each nation would be still less. No major additional technological advances seem to be reuired, and the step from today to the first landing of humans on Mars appears to be technologically easier than the step from President John F. Kennedy's announcement of the Apollo program on May 25, 1961 to the first landing of humans on the Moon on July 20, 1969. We represent a wide diversity of backgrounds in the fields of science, technology, religion, the arts, plitics and government. Few of us adhere to every on of the arguments listed above, but we share a common vision of Mars as a historic, constructive objective for the technological ambitions of the human species over the next few decades. Hope this answers a few questions. -- +-Robert C. Martin-----+:RRR:::CCC:M:::::M:| Nobody is responsible for | | rmartin@clear.com |:R::R:C::::M:M:M:M:| my words but me. I want | | uunet!clrcom!rmartin |:RRR::C::::M::M::M:| all the credit, and all | +----------------------+:R::R::CCC:M:::::M:| the blame. So there. | ------------------------------ End of SPACE Digest V13 #062 *******************