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 ; Fri, 25 Jan 91 10:57:00 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 25 Jan 91 10:56:55 -0500 (EST) Subject: SPACE Digest V13 #074 SPACE Digest Volume 13 : Issue 74 Today's Topics: NASA Headline News for 01/22/91 (Forwarded) Re: Ultimate Weapon Tenth planet? Re: space news from Dec 17 AW&ST Re: Spacing Organizations An Atlas Story (1 of 2) Galileo Update #2 - 01/24/91 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: 22 Jan 91 18:38:56 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 01/22/91 (Forwarded) Headline News Internal Communications Branch (P-2) NASA Headquarters Tuesday, January 22, 1991 Audio Service: 202 / 755-1788 This is NASA Headline News for Tuesday, January 22, 1991 The plasma physics experiments with the Combined Release and Radiation Effects Satellite continued over the weekend. Sunday morning at 12:30 am, a large barium cannister was released into the Earth's magnetosphere by the CRRES. Of the seven planned releases scheduled for January, six have been accomplished. CRRES management at the Marshall Space Flight Center is currently examining dates for the remaining release. * * * * * * * * * * * * * * * * * * * * * * * * * * In Florida, orbiter ground processing technicians continued work on Discovery over the weekend. Swab samples were taken on all main engine drain lines with the result being a clean bill of health. Rocketdyne technicians might take another sample on engine #3 today. The samples were being taken to determine whether there was possible contamination in the main engines from hydraulic fluid. Discovery's Ku-band antenna has been stowed for flight. Following crossfeed leak checks on the orbiter's twin orbital maneuvering system pods, workers replaced both primary and secondary seals on all the crossfeed lines. Activities scheduled for Discovery today include structural checks on the wings and leak checks on the forward reaction control system. The rollover date for moving Discover from the Orbiter Processing Facility to the Vehicle Assembly Building is still under review. Also over the weekend, work on Atlantis advanced. Hatch functional checks were completed, as were fuel cell coolant loop and system inspections. All three main engines have now been installed. Work on Atlantis this week will include potable water servicing, Ku-band antenna testing, and waste containment system inspection. Atlantis' STS-37 stack is well on its way to completion in the Vehicle Assembly Building. The left-hand solid rocket booster stack is completed. The right-hand aft center segment has been stacked and work is in progress on mating the forward center segment. Still awaiting a spot in the OPF, Columbia remains in the VAB where technicians continue work on orbiter tile refurbishment and replacement. Preparations are also underway to access the waste-water dump-line nozzle for failure analysis. * * * * * * * * * * * * * * * * * * * * * * * * * * The STS-39 pre-flight briefings get underway tomorrow at 9:30 am EST from the Johnson Space Center. The first briefing will be by STS-39 lead flight director Ron Dittemore. That briefing will be followed by a payload briefing from the Department of Defense at 11:00 am EST. The flight crew briefing will be at 2:00 pm. Michael Coats is mission commander and Blaine Hammond, Jr. is mission pilot. Mission specialists for the flight, now scheduled for early March, are Guion Bluford, Richard Hieb, Charles Veach, Gregory Harbaugh, and Donald McMonagle. The briefings will be carried live on NASA Select TV. Here's the broadcast schedule for Public Affairs events on NASA Select TV. All times are Eastern. **indicates a live program. Tuesday, 1/22/91 12:00 pm "Education: A NASA Commitment." 12:40 pm Aeronautics & Space Report #254. 1:00 pm "Live via Satellite. 1:15 pm "Delta: America's Space Ambassador." Wednesday, 1/23/91 9:30 am **STS-39 Flight Director briefing from JSC. 11:00 am **STS-39 DOD payload briefing from JSC. 2:00 pm **STS-39 crew briefing from JSC. Thursday, 1/24/91 11:30 am NASA Update will be transmitted. All events and times may change without notice. This report is filed daily, Monday through Friday, at 12:00 pm, EST. It is a service of Internal Communications Branch at NASA Headquarters. Contact: CREDMOND on NASAmail or at 202/453-8425. NASA Select TV: Satcom F2R, Transponder 13, C-Band, 72 degrees West Longitude, Audio 6.8, Frequency 3960 MHz. ------------------------------ Date: 23 Jan 91 16:27:16 GMT From: sdcc6!kingkong!ewa@ucsd.edu (Eric Anderson) Subject: Re: Ultimate Weapon In article <1991Jan22.221547.6521@jarvis.csri.toronto.edu> wayne@csri.toronto.edu (Wayne Hayes) writes: > >To make the Earth into a black hole, you would have to >squeeze it into a ball about the size of a grape. A black hole of such small mass is inherently unstable, and will generally "evaporate" (by a somewhat complex process). The other poster who mentioned a black hole over Siberia was referring to a proposition that a black hole of much less mass than the Earth was responsible for the blast. >The largest black holes postulated, in >the centre of some galaxies with masses of several million Suns, >*may* just be big enough to swallow a solar system. A black hole doesn't have to be *nearly* as large as a solar system to swallow it, it just needs sufficient "suck"... :-) >If a black hole the size of the solar system was coming, you'd see >gravitational effects long before you even saw the growing disk >of black, missing sky as it got within visual range. Don't forget that light would bend around it, so you'd actually see starts, but in the wrong places in the sky. Eric Anderson, UC San Diego ewa@cs.ucsd.edu ------------------------------ Date: Wed, 23 Jan 91 19:51:39 PST From: fermat!r@la.tis.com (Richard Schroeppel) Cc: henry@zoo.toronto.edu Subject: Tenth planet? We were debating the evidence for a tenth planet, based on perturbations of the other nine. Henry Spencer wrote: > ...(A very careful reassessment of observations of the orbit of Neptune by some folks at JPL concluded that there are no unexplained perturbations.) ... I countered with a long quote from the 1988 Astronomical Almanac, page L1; I have capitalized one sentence for emphasis: > Fundamental ephemerides of the Sun, Moon and planets were calculated by a simultaneous numerical integration at the Jet Propulsion Laboratory in a cooperative effort with the U.S. Naval Observatory. Optical, radar, laser, and spacecraft observations were analyzed to determine starting conditions for the numerical integration. In order to obtain the best fit of the ephemerides to the observational data, some modifications to the IAU (1976) System of Astronomical Constants were necessary. These modification of the constants are listed on page K7. A SATISFACTORY EPHEMERIS FOR URANUS FOR THE 1980'S COULD BE COMPUTED ONLY BY EXCLUDING OBSERVATIONS MADE BEFORE 1900. This integration, designated DE200/LE200, is available on magnetic tape for the period 1800-2050. Additional information about the new ephemerides is included in the *Supplement to the Astronomical Almanac for 1984.* I commented on the quality of the old data: > Astronomical photography was inaugurated in 1858. It should be possible to remeasure the position of Uranus accurately from old photos. Henry responded: > The JPL work I refer to was quite recent, as I recall, enough so that it might not be reflected in a three-year-old book. I've checked some additional years of the AA: The same paragraph is present in the all the editions I checked, for the years 1985, 86, 88, 90, and 91, always on page L1, the explanation chapter. So, can someone from USNO or JPL help us out? Is the orbit of Neptune ok, but that of Uranus damaged? Is JPL concealing the existence of a tenth planet? Is general relativity wrong? Is Pluto really a black dwarf? Are the Uranians manipulating their orbit just to confuse us? Was the 1991 AA printed before the Voyager Neptune flyby? Can Henry remember his reference? Rich Schroeppel rcs@la.tis.com ------------------------------ Date: 24 Jan 91 17:22:12 GMT From: swrinde!elroy.jpl.nasa.gov!freedom!cornutt@ucsd.edu (David Cornutt) Subject: Re: space news from Dec 17 AW&ST aws@ITI.ORG ("Allen W. Sherzer") writes: >The public will accept risk if given an accurate assessment of the risks. I realize that this is getting way off the thread here, but IHMO this statement is fundementally untrue. Today's American public will accept NO RISK WHATSOEVER, no matter how small, if it is not something that has existed in society prior to World War II. This is grounded in a fundemental lack of understanding of probability. Just look at all of the ruckus that is raised whenever a researcher supposes that some environmental influence (marginal magnetic fields, Teflon-coated cookware, Coca-Cola, etc.) might just be a contributing factor to a handful of cancer death each year. The public cries for ban of the offending substance are immediate and strident; only later do people start to think about the consequences of such a ban. There is a deep-seated mistrust of all forms of rational thinking (and the disciplines that arise from them) in our society that, I think, stems from fundemental educational failures. This especially effects the space program, which is a national symbol of scientific and technological progress. You can see that in the content of this newsgroup, which seems to me to be about 75% flames and misinformation. People are afraid of technological change, and the space program (anybody's space program) is sure to be adversely affected by this. -- David Cornutt, New Technology Inc., Huntsville, AL (205) 461-6457 (cornutt@freedom.msfc.nasa.gov; some insane route applies) "The opinions expressed herein are not necessarily those of my employer, not necessarily mine, and probably not necessary." ------------------------------ Date: 24 Jan 91 19:23:48 GMT From: usc!cs.utexas.edu!news-server.csri.toronto.edu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Re: Spacing Organizations In article mcdaniel@adi.com (Tim McDaniel) writes: >(2) Near the end of last year, I saw a report that Iraq had launched > something into orbit... This was a misreporting of a rocket launch that may have been part of a program to develop an orbital capability. -- If the Space Shuttle was the answer, | Henry Spencer at U of Toronto Zoology what was the question? | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 24 Jan 91 00:49:59 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!Mark.Perew@ucsd.edu (Mark Perew) Subject: An Atlas Story (1 of 2) The following was posted to the Unisys A Series Mail Network back when CRRES was launched. With the recent discussion of pre-historic computers I thought it would be timely to cross- post it here. ============================================================= Reading about the Atlas-Centaur launch vehicle for the CRRES brought to mind a long-ago experience and a particularly interesting (at least to me) episode. When I first came to Burroughs (Great Valley Labs) in the late 50's I was leader of the logic design group for the Atlas Ground Guidance Computer for the Atlas ICBM program. This was all highly classified stuff, and were the days when every few months a thing would be shot up from Cape Canaveral and hopefully splash down in the right place in the South Atlantic. Our system provided the launch guidance for this. It has been a long time, so some of the details I recall may be inaccurate, but the gist is right. The process for each test flight (our part) was this: first the Technical Director, at that time the Ramo- Wooldridge Corp., the predecessor of TRW, would send us the "guidance equations" and flight parameters and we would "program" them. Actually a big part of the programming was scaling to preserve the significance of the operands; the machine only had fixed point, single precision arithmentic instructions. (This was partly the state of the art, but more importantly for reliability -- we would SWEAT BLOOD to eliminate a couple of and-gates or a flip-flop to reduce the component count.) Then we would wire the program into re-usable program trays (yes, hard-wired each program for each flight, again for reliability -- *nothing* could corrupt that code) and ship them out to RW in California, where they put them in a test bay hooked up to a large IBM system which simulated the flight, with variations, to test the programming. Then the trays were sent to Cape Canaveral (we had a big team there), and ultimately used for the flight. As I recall, the cycle for each test was about 9 months to a year and a half. The gist of the equations was to calculate the present predicted impact point on the earth's surface from the radar inputs, and issue continuous steering commands, and the engine cut-off command when the present predicted impact point matched the target point. (Actually there were several; booster cut-off, booster jettison, ... until finally sustainer engine cutoff.) This Atlas launch vehicle (we called it a missile) was the first version of the one being used with Centaur for CRRES. -- Mark Perew Internet: Mark.Perew@ofa123.fidonet.org Compuserve: >internet:Mark.Perew@ofa123.fidonet.org -------------------------------------------------------------------------- ------------------------------ Date: 25 Jan 91 00:47:57 GMT From: swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Galileo Update #2 - 01/24/91 GALILEO STATUS REPORT January 24, 1992 As of noon (PST) Thursday, January 24, 1991, the Galileo spacecraft is 22,659,670 miles from the Earth and traveling at a heliocentric speed of 82,880 miles per hour; distance to the Sun is 85, 374,930 miles (0.91 AU). Round trip light time is 4 minutes, 0 seconds. A command was successfully sent on January 21 to set the Command Loss Timer to its new value of 144 hours in preparation for the LGA-2 (Low Gain Antenna-2) to LGA-1 antenna switch on January 31. A separate command was also sent on January 21 to modify the system fault protection state to select LGA-1. Another command to reset the Command Loss Timer to 144 hours was sent, as planned, on January 24. Cruise Science Memory Readouts (MROs) were successfully completed on January 19 for the EUV (Extreme Ultraviolet Spectrometer), DDS (Dust Detector) and MAG (Magnetometer) science instruments; MROs for the DDS and MAG were also performed on January 21. Two USO (Ultra Stable Oscillator) calibration tests were successfully completed on January 19 and 21. These tests provide trend information to characterize this ultra-stable downlink frequency source. A total of four sun acquisition activities were successfully performed; the sun acquisitions were performed, as planned, on January 18, 20, 21 and 23 to maintain a thermally safe sun pointed attitude. To date four sun acquisitions out of the 17 planned in VE-12 (Venus Earth-12) have been completed. Following each sun acquisition activity, star buffer memory readouts were succesfully completed. These readouts provide valuable star intensity information data which is being used to update the attitude control star catalog. The CDS A (Command Data Subsystem) prime and extended memory was successfully read out on January 22; no parity errors were observed with the memory readout. The CDS B memory readout is planned for January 30. At the end of the planned uplink for the CDS "A" memory readout activity, the number of command lock change indications observed in both CDS A and B was two more than expected (62 vs. 60). This is second occurrence using the 70 meter station in Australia and third occurrence overall. The first occurence was on September 13, 1990. The second occurrence at the 70 meter Goldstone station on November 7, 1990 and resulted from a CPA (Command Processor Assembly) hardware failure. There was no indication of any abnormal spacecraft operation as a result of any of these indications. The spacecraft continues to properly receive and process all commands. Investigation of these unexplained indications is in process. The AC/DC bus imbalance measurements exhibited some minor activity. The AC measurement dropped about 1 DN and now reads 46.4 volts. The DC bus measurement dropped about 20 DN and now reads 11.6 volts; the DC measurement reduction occurred during a period of no spacecraft activity. All other power-related measurements and spacecraft telemetry are normal. The Project reviewed and approved the final profile design for the VE-14 sequence on January 22, 1990. The VE-14 sequence controls spacecraft activities from February 18 to April 29, 1990. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |___ M/S 301-355 | It's 10PM, do you know /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | where your spacecraft is? |_____|/ |_|/ |_____|/ | We do! ------------------------------ End of SPACE Digest V13 #074 *******************