Date: Sat, 18 Jul 92 05:02:19 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #012 To: Space Digest Readers Precedence: bulk Space Digest Sat, 18 Jul 92 Volume 15 : Issue 012 Today's Topics: Antimatter (was propulsion questions) (5 msgs) apollo 10 FOR ALL MANKIND on TBS Sunday, July 19 (APOLLO lunar missions) Galileo Update - 07/17/92 How to find limiting magnitude? (was Re: Solar Power Satellites) Looking gif horse in mouth Now, where at last ? (Re: apollo 10) Pathogens and the Orbiting Quarantine Facility Space Transportation Infrastructure Costs THE DIGEST IS BACK!!!! Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu". Please do **NOT** send (un)subscription requests to that address! Instead, send a message 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: 17 Jul 92 14:32:00 GMT From: Jim Carr Subject: Antimatter (was propulsion questions) Newsgroups: sci.space,sci.physics In article <1992Jul17.123315.28475@inmos.co.uk> nick@inmos.co.uk () writes: > > I have brought this question over into sci.physics > because I think this question belongs there, and > re-directed followups back there. I put this answer on sci.physics too, but put the followup on sci.space > On sci.space there is a discussion about spacecraft > propulsion systems, in particular ones using antimatter > annihilation to generate the power source. Can anyone > tell me just how much energy (Joules please) would > be generated if 0.5 grams of X is annihilated with > 0.5 grams of anti-X. Gee, if you want Joules you should use MKS units, but no matter. ;-) When you annihilate matter and anti-matter, you get neutral bosons, usually photons, carrying off the energy. The energy is E=mc^2 if we assume the matter is essentially at rest (otherwise you must add in pc in quadrature to get the total energy available, and worry about the transformation between to the center-of-momentum frame). So given 0.5 gm + 0.5 gm = 1.0 gm = 0.001 kg, we get 9x10^{13} Joules. You will note for future reference that kg*(m/s)^2 = kg*m^2/s^2 = Joules. Also note that you could look this conversion up in the Appendix of Halliday and Resnick if you do not trust your memory of c or whatever. Remember that you have to expend several times this amount to create the anti-matter in the first place (since you effectively lose energy in making the boost from the lab to the center of momentum where the particles are created, and then you have to collect and cool the products), but the cost is probably worth it because of the concentrated form the energy is stored in. > With the different products > generated in the process does it make a defference > what we pick for X ( protons, electrons, whatever ). The physics is simplest with an elementary particle like an electron, since it just annihilates to two photons. A proton is a composite particle, and the actual annihilation takes place between a quark and anti-quark in each -- hence you get a wide variety of products possible, mostly pions I think, from the spectators. If you are considering this for propulsion, this choice would affect how you would go about using and directing this energy (which comes out isotropically if the matter is at rest) to effect propulsion. -- J. A. Carr | "The New Frontier of which I jac@gw.scri.fsu.edu | speak is not a set of promises Florida State University B-186 | -- it is a set of challenges." Supercomputer Computations Research Institute | John F. Kennedy (15 July 60) ------------------------------ Date: Fri, 17 Jul 92 15:53:29 GMT From: Ed Gruberman Subject: Antimatter (was propulsion questions) Newsgroups: sci.space In article <1992Jul17.123315.28475@inmos.co.uk> nick@inmos.co.uk () writes: > Hi > > I have brought this question over into sci.physics > because I think this question belongs there, and > re-directed followups back there. > > On sci.space there is a discussion about spacecraft > propulsion systems, in particular ones using antimatter > annihilation to generate the power source. Can anyone > tell me just how much energy (Joules please) would > be generated if 0.5 grams of X is annihilated with > 0.5 grams of anti-X. with the different products > generated in the process does it make a defference > what we pick for X ( protons, electrons, whatever ). > > Nick Nick, It's fairly easy. E=mc^2. m=.001 kg, c=3x10^8 m/s, => E=9x13 J. All in gamma rays unfortuately. The big problema are a) how to convert all the gamma rays into kinetic energy for your ship or whatever and b) how to keep your cargo from getting fried. Tough problems since gamma rays are _very_ penetrating. Have fun. :-) Ed Gruberman cary@mplode.lampf.lanl.gov (VMS) cary@dsirae.lampf.lanl.gov (unix) XXXXX XX XX XXXXX XX XX XX XX XXXXX X X X X XXX XX XX XX X X XXX X XX XXX XX XX XX XXXXX X X X X XX XXX XX XX X XXXXX X XXXXX XX XX XXXXXX XXXXX An Extensive Air Shower Array at the Meson Physics Facility Los Alamos National Labs ____________________________________________________________________________ My opinions are my own, don't you dare give someone else credit for them! ---------------------------------------------------------------------------- ------------------------------ Date: 17 Jul 92 19:25:39 GMT From: Bill Higgins-- Beam Jockey Subject: Antimatter (was propulsion questions) Newsgroups: sci.space In article <6y=mm0p@lynx.unm.edu>, cary@carina.unm.edu (Ed Gruberman) writes: > In article <1992Jul17.123315.28475@inmos.co.uk> nick@inmos.co.uk () writes: >> Can anyone >> tell me just how much energy (Joules please) would >> be generated if 0.5 grams of X is annihilated with >> 0.5 grams of anti-X. with the different products >> generated in the process does it make a defference >> what we pick for X ( protons, electrons, whatever ). > > It's fairly easy. E=mc^2. m=.001 kg, c=3x10^8 m/s, => E=9x13 J. > All in gamma rays unfortuately. Sorry, Ed. (boot to the head) *WHUMP!* Take a look at your Particle Properties book. If you interact eletrons and positrons, you get essentially 100% gamma rays. If you interact protons and antiprotons, or neutrons and antineutrons, etc., you get a mixture of stuff; for engineering purposes, it's all pions. About a third of these are pi-zeroes, 98.8% of which turn instantly to gammas. The rest of the output, positive and negative pions, decay to muons and neutrinos, and the muons decay to electrons and neutrinos. Since these are charged, you can in principle persuade them to go where you want them to go (out the engine exhaust) with big enough magnetic fields, if you grab them in the few dozen nanoseconds (pions) or microseconds (muons) of their existence. I do this for a living. (-: The correct statement is that, given enough time for everything to decay-- one second should do nicely-- the annihilation energy will be divided among gamma photons, electrons, and neutrinos, all of which are stable. A significant share of the energy (more than 1%) is carried by each species. I won't look up just what the partition is. Nick should go to the library and get *Mirror Matter* by Robert L. Forward and Joel Davis, which is fun to read and will proably answer most of his questions about antimatter. (It may cause him to think of new ones. I'm prepared to take that risk.) Jim Carr and Henry Spencer gave good answers to Nick's posting, although Henry also seems to think that everything winds up in gammas. (Don't feel bad, Henry-- Eugen Saenger made the same mistake in his book *Space Flight*, and he was a smart guy too.) I will resist giving Cary/Ed another Boot To The Head for having a long signature. Been guilty of that myself on occasion... [o] [|] /// Bill Higgins E H /// |8D:O: occc))))<)) Fermi National Accelerator Laboratory E H /// [|]// Bitnet: HIGGINS@FNAL.BITNET [|] Bumper sticker seen on a Soyuz: SPAN/Hepnet/Physnet: 43011::HIGGINS GOT HARD CURRENCY? TRY OUR MICROGRAVITY LAB! Internet: HIGGINS@FNAL.FNAL.GOV ------------------------------ Date: 17 Jul 92 19:48:08 GMT From: SCOTT I CHASE Subject: Antimatter (was propulsion questions) Newsgroups: sci.space In article <9847@sun13.scri.fsu.edu>, jac@ds8.scri.fsu.edu (Jim Carr) writes... >In article <1992Jul17.123315.28475@inmos.co.uk> nick@inmos.co.uk () writes: > >> On sci.space there is a discussion about spacecraft >> propulsion systems, in particular ones using antimatter >> annihilation to generate the power source. Can anyone >> tell me just how much energy (Joules please) would >> be generated if 0.5 grams of X is annihilated with >> 0.5 grams of anti-X. > >Gee, if you want Joules you should use MKS units, but no matter. ;-) Well, if there is no matter, then the answer is zero Joules. :-) >When you annihilate matter and anti-matter, you get neutral bosons, >usually photons, carrying off the energy. The energy is E=mc^2 if When you take a chunk of matter and bring it near a chunk of antimatter, several processes happen. Electrons annihilate positrons, producing photons for the most part, but also neutrinos a small part of the time. But most of the energy comes from nuclear annihilation where the larger rest mass means that more channels are open even at rest. So, for example, I would expect some electrons and positrons to fly out of a gold + antigold nuclear annihilation. Muons, pions, kaons, etc., are also allowed. To be strictly fair, the existence, and consequent properties of antiatoms is still an entirely open experimental question for the most part, so this is really speculation. The properties of nucleon-antinucleon annihilation are well studied, of course, but entire antinuclei are an entirely different question. No one has ever produced even an antihelium nucleus. Antideuterons are doable, as are antitritons (typically with 10-3 yield relative to antideuterons) but more complex antinuclei are too tough to make. So no one has ever produced anything other than an isotope of antihydrogen. There is antimatter in the cosmic rays, but I don't know if anyone has ever seen complex antinuclei. Is there a cosmic ray jock out there who can tell me what the heaviest antinuclei recorded in the cosmic rays is? -Scott -------------------- Scott I. Chase "The question seems to be of such a character SICHASE@CSA2.LBL.GOV that if I should come to life after my death and some mathematician were to tell me that it had been definitely settled, I think I would immediately drop dead again." - Vandiver ------------------------------ Date: 17 Jul 92 20:11:48 GMT From: SCOTT I CHASE Subject: Antimatter (was propulsion questions) Newsgroups: sci.space In article <6y=mm0p@lynx.unm.edu>, cary@carina.unm.edu (Ed Gruberman) writes... > >It's fairly easy. E=mc^2. m=.001 kg, c=3x10^8 m/s, => E=9x13 J. >All in gamma rays unfortuately. The big problema are a) how to convert >all the gamma rays into kinetic energy for your ship or whatever and b) >how to keep your cargo from getting fried. Tough problems since gamma >rays are _very_ penetrating. Have fun. :-) All in gamma rays? Most of the energy comes not from electron-positron annihilation but from nuclear annihilation, which produces pions and a whole flurry of other stuff which you need to shower in some material in order to recoup the energy. -Scott -------------------- Scott I. Chase "The question seems to be of such a character SICHASE@CSA2.LBL.GOV that if I should come to life after my death and some mathematician were to tell me that it had been definitely settled, I think I would immediately drop dead again." - Vandiver ------------------------------ Date: 17 Jul 92 15:58:22 GMT From: "Harold G. Andrews II" Subject: apollo 10 Newsgroups: sci.space In article <1992Jul12.162633.7068@kakwa.ucs.ualberta.ca> martin@space.ualberta.ca (Martin Connors) writes: >In article <1992Jul10.210335.15289@organpipe.uug.arizona.edu> >jscotti@lpl.arizona.edu (Jim Scotti x2717) writes: >> The Apollo 16 ascent stage was accidentally left in lunar orbit when >> a switch was not set properly for remote control of the spacecraft >> after it's mission was completed. It's orbit, however, had a periluna >> of about 10 NM, and its orbit apparently decayed about 6 months after >> the mission. > >Can anyone comment on why such an orbit decay would occur so rapidly in >LUNAR orbit. There is no upper atmosphere at all to consider so I wonder >what is the relative role of radiation pressure on such a low density >reflective object as an LM ascent stage, or would it simply be Earth-Sun >perturbations causing the orbital parameters to change such that the >perilune became < lunar radius? I seem to recall two reasons why the orbit of an object in a lunar orbit will decay. Neither have to do friction or radiation pressure. Please note I have really not had much experience in this field, and I could be way off base here. Reason #1) The moon is not a very homogeneous body. It has regions which are very dense and others which are not so dense. In a lower orbit, these regions vary the gravitational interaction between the moon and the object in the lunar orbit. This in return causes instabilities to occur in the orbit until either the orbit intersects the surface of the moon, or the object leaves lunar orbit. Reason #2) In a higher lunar orbit, the periodic changes in the gravitational interaction between the Earth and the object in Lunar orbit will cause a instability in the orbit of the object. It would seem that this would eventually destabilize the orbit enough so that it intersected the lunar surface, or caused the object the leave a lunar orbit. These two things could be way off base. I don't recall where I read them, or even if it wasn't in a dream I had ;-). So no flames please if this turns out to be completely the wrong answer. -Andy ******************************************************************************* * Harold G. "Andy" Andrews II * Support DAM... * * andrewsh@lonex.rl.af.mil * * * Rome Laboratory/OCPA * Mothers Against Dyslexia * * Air Force Photonics Center * * * Griffiss AFB, NY 13441-5700 * * * (315) 330-7669 (DSN Prfx 587) * (Not an official USAF viewpoint) * ******************************************************************************* ------------------------------ Date: Fri, 17 Jul 1992 18:19:36 GMT From: Larry Klaes Subject: FOR ALL MANKIND on TBS Sunday, July 19 (APOLLO lunar missions) Newsgroups: sci.astro,sci.space For those of you in the U.S. with cable television, National Geographic Explorer is presenting the film FOR ALL MANKIND on the Turner Broadcast Station (TBS) this Sunday, July 19 at 9 p.m. ET. It is a film about the APOLLO manned lunar missions, taken from thousands of hours of NASA film footage. Larry Klaes klaes@verga.enet.dec.com or - ...!decwrl!verga.enet.dec.com!klaes or - klaes%verga.dec@decwrl.enet.dec.com or - klaes%verga.enet.dec.com@uunet.uu.net "All the Universe, or nothing!" - H. G. Wells EJASA Editor, Astronomical Society of the Atlantic ------------------------------ Date: 18 Jul 92 01:06:14 GMT From: Ron Baalke Subject: Galileo Update - 07/17/92 Newsgroups: sci.space,sci.astro Forwarded from Neal Ausman, Galileo Mission Director GALILEO MISSION DIRECTOR STATUS REPORT POST-LAUNCH July 10 - 16, 1992 SPACECRAFT 1. On July 10, realtime commands were sent to change the System Fault Protection (SFP) AACS-INIT (Attitude and Articulation Control Subsystem) pointing slot from the sun to the Earth. These commands reconfigured the value to the background state assumed by the EE-6 (Earth-Earth 6) sequence memory load. 2. On July 13, a NO-OP command was sent to reset the command loss timer to 264 hours, its planned value for this mission phase. 3. On July 14, a Command Detector Unit Signal-to-Noise Ratio (CDUSNR) test along with a Radio Frequency Subsystem Automatic Gain Control (RFSAGC) test were performed using LGA-1 (Low Gain Antenna #1) over DSS-43 (Canberra 70 meter antenna). Quick look analysis indicates the test went well. Detailed analysis is in progress. 4. On July 15, the periodic RPM (Retro-Propulsion Module) 10-Newton thruster flushing maintenance activity was performed. All 12 thrusters were flushed and their performance was as expected. 5. On July 15, the Energetic Particle Detector (EPD) motor maintenance exercise was performed which stepped the motor through its eight operating positions and then returned it to the normal position (No. 4). The motor maintenance exercise was successfully verified by Memory Readout (MRO) commands. 6. On July 15, realtime commands were sent to change the System Fault Protection (SFP) to turn off the LGA-2 motor if the sequence memory load is terminated. This change prevents a continuous undervoltage situation in the low probability scenario of a relay failure causing a DC bus short circuit while retracting the LGA-2 antenna. The commands were transmitted but not successfully received due to a ground station problem. Specifically, the wrong standards and limit tables were being used in the command system at Station 43 (Canberra). Command retransmission is being planned. 7. On July 16, routine Extreme Ultraviolet Spectrometer (EUV) Memory Readouts (MROs) were performed. The MROs were received without incident. 8. On July 16, cruise science Memory Readouts (MROs) were performed for the Dust Detector (DDS) and Magnetometer (MAG) instruments. Preliminary analysis indicates the data was received properly. 9. On July 16, an Ultra-Stable Oscillator (USO) test was performed to verify the health status of the USO and collect gravitational red shift experiment data; long term trend analysis is continuing. 10. On July 16, a command threshold test was performed. Initial results, similar to the test run on May 14, indicates the command threshold to be approximately -140 to -141 dbm which is its nominal value. 11. On July 16, a Radio Frequency Subsystem Tracking Loop Capacitor (RFSTLC) test was performed over DSS-43. Preliminary analysis indicates the capacitors continue to operate normally. 12. On July 16, telemetry map changes were performed to replace the Command Detector Unit Signal-to-Noise (CDUSNR) telemetry readings to the AC/DC bus imbalance telemetry readings at the completion of the scheduled telecommunication tests. 13. During the week, the DC bus imbalance reading has continued to change significantly. The DC measurement has ranged from 97DN (11.2 volts) to 151DN (17.8 volts) and now reads 150DN (17.7 volts). This measurement variation is consistent with the model developed by the AC/DC special anomaly team. The AC measurement has decreased 1DN and reads 3.1 volts. 14. The Spacecraft status as of July 16, 1992, is as follows: a) System Power Margin - 42 watts b) Spin Configuration - Dual-Spin c) Spin Rate/Sensor - 3.15 rpm/Star Scanner d) Spacecraft Attitude is approximately 31 degrees off Earth (lagging) and 2 degrees off-sun (leading) e) Downlink telemetry rate/antenna-40 bps (coded)/LGA-1 f) General Thermal Control - all temperatures within acceptable range g) RPM Tank Pressures - all within acceptable range h) Orbiter Science- UVS, EUV, DDS, MAG, EPD, and HIC are powered on i) Probe/RRH - powered off, temperatures within acceptable range j) CMD Loss Timer Setting - 264 hours Time To Initiation - 185 hours GDS (Ground Data Systems): 1. The July System Engineers Monthly Report (SEMR) review was conducted Thursday, July 16. A review of current Project and Institutional (MOSO & DSN) system status was conducted. Pre-Earth 2 delivery schedules, past months accomplishments and potential problem areas were discussed. No significant problems or errors were reported. 2. An end-to-end GDS data flow test was successfully conducted this past week to demonstrate the ground capability to process and display 40 bps AACS Flood Mode telemetry data. First use of this telemetry format in flight is scheduled for 24 July. TRAJECTORY As of noon Thursday, July 16, 1992, the Galileo Spacecraft trajectory status was as follows: Distance from Earth 135,214,000 miles (1.46 AU) Distance from Sun 170,085,000 miles (1.83 AU) Heliocentric Speed 45,300 miles per hour Distance from Jupiter 673,747,000 miles Round Trip Light Time 24 minutes, 22 seconds SPECIAL TOPIC 1. As of July 16, 1992, a total of 8028 real-time commands have been transmitted to Galileo since Launch. Of these, 3159 were pre-planned in the sequence design and 4869 were not. In the past week, 2 real time commands were transmitted and all were pre-planned in the sequence design. In addition, 4534 mini-sequence commands have been transmitted since March 1991; 2283 were pre-planned and 2251 were not. In the past week, no mini-sequence commands were transmitted. Major command activities this week included commands to update the System Fault Protection (SFP) and to reset the command loss timer. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never |_____|/ |_|/ |_____|/ | happen. ------------------------------ Date: 17 Jul 92 18:36:08 GMT From: Bill Higgins-- Beam Jockey Subject: How to find limiting magnitude? (was Re: Solar Power Satellites) Newsgroups: sci.space,sci.astro In sci.space there has been a recent discussion about building a constellation of multi-kilometer satellites to harness solar energy and beam it to users on Earth. One drawback is that having some new bright objects in the sky would make it harder-- in some sense-- to do professional and amateur astronomical observations on the ground. In article , pgf@srl03.cacs.usl.edu (Phil G. Fraering) writes: > tjn32113@uxa.cso.uiuc.edu (Thomas J. Nugent) writes: >>ralph.buttigieg@f635.n713.z3.fido.zeta.org.au (Ralph Buttigieg) writes: rb>>> Most people will live on Earth for some time to come, rb>>> to have humanity denied the sight of the stars would be tragic. tjn>>Well, if you live anywhere near any half pint city, you are mostly denied tjn>>the sight of the stars. I live in Urbana, with the local population on tjn>>the order of 100,000. You have to go really far out of town to see more tjn>>than a dozen stars or so. > pgf> That's what bothers me about all the people griping about light pollution pgf> from the SPS's. They probably won't be much brighter than Jupiter, and pgf> in most major cities, the light pollution will be so bad you'll be lucky pgf> to see the powersats to begin with. How do you do this calculation? (It's related to "why is the sky blue?") The Sun provides direct sunlight in the daytime. But some direct light also scatters off the molecules of air above us. Blue light scatters through larger angles than red. So when the Sun is up, air all over the sky gives off blue light which is brighter than most stars. The Moon is bright enough to be seen in the daytime despite this background glow, and so is Venus, sometimes, and so are a few other bodies, maybe. At night, the Moon is bright enough to create the same sort of sky glow. The brightness of the sky when the Moon is up is enough to rule out observing many of the dimmer objects in the sky. Most people don't notice this, but astronomers (professionals and amateurs) are painfully aware of the fact. Being rather slow, I learned about this only at an advanced age, searching for Comet Halley during a full Moon. This phenomenon divides professional observers into two social classes-- "dark sky" people, who can use telescope time only during the two weeks a month when the Moon is absent from the night sky, and "bright sky" people, who are lucky enough to be studying fairly bright objects and can still do useful things with the Moon up. When the Moon is down, our sky is still not perfectly black. There is still a sky glow due to other, much dimmer sources. It would be fun to investigate the more obscure ones, but the obvious ones include starlight, planet light, and the glow scattered from sources on the ground (as Tom Nugent mentions above). So. Suppose we add another object to the sky, say, as bright as Jupiter. How much will this increase the background glow? How will it change the limiting magnitude of the dimmest object one can observe with a telescope? (I'll bet this is a homework problem in some class on observational astronomy somewhere.) How does it vary with angular distance from the bright object? If we can learn how to do this calculation, we can compare the alleged damage that any proposed configuration of powersats will do to ground-based astronomy. As Phil Fraering suggests, the effect is probably meaningless for people close to any illuminated town. But it may be significant for deep-sky professional observers. I've checked at least one handbook but it's a tougher problem than applying one simple formula. Perhaps someone else will *ahem* shed a little light on the problem. O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/ - ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap! / \ (_) (_) / | \ | | Bill Higgins Fermi National Accelerator Laboratory \ / Bitnet: HIGGINS@FNAL.BITNET - - Internet: HIGGINS@FNAL.FNAL.GOV ~ SPAN/Hepnet: 43011::HIGGINS ------------------------------ Date: Fri, 17 Jul 1992 17:27:05 GMT From: Edmund Hack Subject: Looking gif horse in mouth Newsgroups: sci.space In article <1992Jul16.231235.1@indyvax.iupui.edu> tffreeba@indyvax.iupui.edu writes: >Does anybody know if you can get gifs on discs (or send them >a disc with a wish list) from Ames? I am ftp-ing them through >school but it takes _forever_ to get them onto my machine via >Kermit. I am losing valuable sack time, what with the time >differences and all. All of the CD-ROMs that have been mounted at ames are available from the National Space Science Data Center at cheap prices. The disks are $20 for the first in an order, $6 each after that. For more info, send email to: request@nssdca.gsfc.nasa.gov and they will send you a catalog by email in a week or so. Included are Viking, Viking Orbiter, Voyager and Pioneer data. Note that most of what is send is RAW DATA, not the pretty pictures you see on TV and in magazines. Some software tools for PCs and Macs for looking at the images and limited processing is available too. -- | Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX | hack@aio.jsc.nasa.gov SpokesPersonp(Me,or(NASA,LESC)) = NIL | **** Papoon for President! You Know He's Not Insane!! **** ------------------------------ Date: 17 Jul 92 16:44:55 GMT From: Jim Scotti x2717 Subject: Now, where at last ? (Re: apollo 10) Newsgroups: sci.space In article <24597@scicom.AlphaCDC.COM> wats@scicom.AlphaCDC.COM (Bruce Watson) writes: >Satellite Situation Report, NASA, Project Operations Branch, Code 513, >Goddard Space Flight Center, Greenbelt, MD, USA 20771 is published >quarterly and is available to interested persons. > >It lists 1969 043C LM/descent in orbit around the moon and 1969 043D >LM/ascent in orbit about the sun, but there are errors in this >publication. This publication gives the LAST KNOWN ORBIT for an untracked satellite such as the Apollo 10 LM ascent and descent stages, so this is consistent with what has been said in this thread. If tracked, it also lists the time of decay. You might look up Apollo 9, and check the data on the LM. --------------------------------------------- Jim Scotti {jscotti@lpl.arizona.edu} Lunar & Planetary Laboratory University of Arizona Tucson, AZ 85721 USA --------------------------------------------- ------------------------------ Date: Fri, 17 Jul 1992 20:14:54 GMT From: Brent Kellmer Subject: Pathogens and the Orbiting Quarantine Facility Newsgroups: sci.space,rec.art.sf.science I've got a problem that I wonder if someone could help me with: I'm writing an SF story in the course of which some sort of pathogen gets through quarantine and to Earth. I'm using NASA's 1981 Antaeus Report as a model for the orbiting quarantine facility in the story. What I need is and idea or two on how such quarantine could be bypassed or broken. I've already thought of the possibility of an accident on board the OQF, as well as the possibility of Industrial Espionage, but in this case, these might be somewhat of a cliche. If there's anyone out there that could help me, I'd greatly appreciate it. Brent Kellmer kellmer@u.washington.edu ------------------------------ Date: 18 Jul 92 00:03:03 GMT From: Ron Baalke Subject: Space Transportation Infrastructure Costs Newsgroups: sci.space In article , henry@zoo.toronto.edu (Henry Spencer) writes... >I think the demand is going to have to come from the manned programs. >Most of the unmanned people are very thoroughly locked into the mindset >of never depending on new technology if they can avoid it. (As witness >Cassini being shrunk to fit on a Titan IV without the new SRBs... which >have now been successfully tested.) You left out a few pertinent details about the SRMs. To date, the SRMs has had only one successful test firing which occurred just a month ago, and they still have to undergo several more test firings before they can be declared flight ready. The first test firing resulted in a spectacular explosion that totally destroyed the launch complex and caused 120 million dollars in damage. The SRM program has been plagued by a number of setbacks, and the contractor who built the SRM's, Hercules, have already exceeded their contract cap of $700 million. Hercules now has to foot the remaining costs of the development of the SRM themselves. Hercules has sued Martin Marietta claiming that they did not assist them properly in the SRM program, and Martin Marietta is countersuing. The SRMs was originally planned to be used with the Cassini launch, but considering the track record of the SRM development, NASA decided that using the SRMs was too risky. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Most of the things you /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | worry about will never |_____|/ |_|/ |_____|/ | happen. ------------------------------ Date: Fri, 17 Jul 92 15:43:48 EST From: "Kevin R. Cain" Subject: THE DIGEST IS BACK!!!! Just a quick congratulations to all those who brought the Digest back. I was beginning to wonder what had happened. THANY YOU THANK YOU THANK YOU. (Just my $.02 worth) ************************************************************************* * KEVIN R. CAIN PHONE: (904) 599-3685 * * USER SUPPORT EMAIL: KEVIN@VM.CC.FAMU.EDU * * FLORIDA A&M COMPUTER CENTER SNAIL: KEVIN R. CAIN, 106 PERP, FAMU * * TALLAHASSEE, FL 32307 * ************************************************************************* ------------------------------ End of Space Digest Volume 15 : Issue 012 ------------------------------