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 ; Sat, 17 Mar 90 01:45:37 -0500 (EST) Message-ID: <8a0Rnpa00VcJACVU4h@andrew.cmu.edu> Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 17 Mar 90 01:45:10 -0500 (EST) Subject: SPACE Digest V11 #158 SPACE Digest Volume 11 : Issue 158 Today's Topics: Re: Commercial Titan/Intelsat Launch Failure Re: Coilgun on a 747 - supplies to orbit at $20/lb? Mass drivers Re: Coilgun on a 747 - supplies to orbit at $20/lb? NASA Headline News for 03/16/90 (Forwarded) Re: Coilgun on a 747 - supplies to orbit at $20/lb? Galileo Update - 03/16/90 HST ---------------------------------------------------------------------- Date: 16 Mar 90 21:21:30 GMT From: agate!brahms.berkeley.edu!gumbyltd@ucbvax.Berkeley.EDU (Dmitry Gokhman) Subject: Re: Commercial Titan/Intelsat Launch Failure In article <1990Mar16.033349.25657@agate.berkeley.edu> gwh@OCF.Berkeley.EDU (George William Herbert) writes: >Yesterdays attempted launch of a commercial Titan III with an Intelsat VI >comsat aboard apparently failed. From sketchy reports, it looks like the >transfer stage did not seperate from the second stage, and the Intelsat VI >was stranded in LEO after being jettisoned from the second/kick stages after >the seperation failure. > Reports [unconfirmed] stated that there was a loss of signal with the > sattelite. >Additional reports from NORAD's space tracking people suggested that the >Intelsat was in a orbit that was stable for at least twelve days, and could be >stabilized further with the use of the onboard thrusters. > >If anyone has better info that this please post it asap, as a large number of >people are interested... thanks > >-George William Herbert From what I heard on the network news, the satellite was stranded but stable (for longer than twelve days from the sound of it). It is the remaining stage(s) that are also in a similar orbit but with no means of stabilization that is/are due to come down fairly soon hopefully not on our heads. --------------------------------------------------------------- - Mr. Gumby * \oo7 Dmitry Gokhman says: `/v/-* Brahms Gang/University of Cauliflower/ MY BRAIN HURTS J L Broccoli CA 94720 --------------------------------------------------------------- ------------------------------ Date: 16 Mar 90 21:19:12 GMT From: sam.cs.cmu.edu!vac@PT.CS.CMU.EDU (Vincent Cate) Subject: Re: Coilgun on a 747 - supplies to orbit at $20/lb? Jim Kasprzak >Ever hear of recoil? Henry Spencer: >Whoa, Nelly. Remember that accelerating a mass to near-orbital velocity >in the space of a hundred meters or less involves very high accelerations, >i.e. very large forces. >... >Try thinking in terms of grams, not thousands of kilograms, and it >might work. I guess I did not make myself clear. I was thinking of many small projectiles. One of the questions I asked was: >How small would the projectiles have to be so that the force did >not hurt the 747? I am thinking along the lines of 50 lb projectiles with the gun able to recoil inside the 747. If the gun weighs 50,000 lbs the gun will go backwards at 1/1000th the velocity of the 50 lb projectile. If the projectile is doing 15,000 MPH relative to the plane then the gun will go back at 15 MPH relative to the plane. At 1/3 g something moving at 15 MPH can stop in a couple seconds and about 20 feet. If the gun is 50,000 lbs at 1/3 g the rest of the plane should be feeling less than 1/6 g for these 2 seconds (since a 747 is over 100,000 lbs). Anyone on the plane would have their seatbelt pull on them but the plane should be ok. If this is still too much the projectile can be made smaller. So, will it work if I think in terms of 10 to 20 kg? One problem is that small projectiles have greater air resistance per lb. This could make launching from the ground more economical even if the plane method were possible. Paul Dietz, when you said such guns are to large to fit on a 747 were you thinking of todays guns or always? What size projectiles were you thinking of? Is there any other type of gun (maybe a real railgun) that might be made to work? (weigh under 50,000 lbs, less than 300 feet long, fire small objects at near orbital speed...) Another thing that might not have been clear in the first post is from an airplane a 5 to 10 degree launch angles should work where we must use 15 to 90 when firing projectiles from the ground due to the air resistance. At 20 degrees, when fired from the ground, the delta-v needed to get the projectile into a circular orbit is still around 2 km/s (IEEE trans on Magnetics Vol 25 No 1 p 393). A 10 kg object needing a 2000 m/s delta-v can be about 1/3 payload. If it only needs a 1000 m/s delta-v then it can be 0.62 payload. The graph in the paper does not show payload fractions for lower delta-v but from other information it is clear that a projectile fired at 5 degrees from 30,000 feet would need less than 500 m/s of delta-v to get into orbit. It looks like a projectile fired from a plane could be 3/4ths payload. It still seems like a this type of approach (maybe using some other type of gun, but firing from a high flying airplane) has the potential for sending supplies into orbit for something like $20/lb. -- Vince ------------------------------ Date: Fri, 16 Mar 90 09:53:14 PLT From: Wayne Fellows <90717459%WSUVM1.BITNET@vma.cc.cmu.edu> Subject: Mass drivers The latest Scientific American has an article about an investment group that wa nts to build a mass driver in Hawaii for polar launches. Aparently they hope t hat this will be a good showcase for the technology. Does anyone know how seri ous this effort is and how one might invest in such a corporation? ------------------------------ Date: 16 Mar 90 09:14:35 GMT From: zaphod.mps.ohio-state.edu!rpi!jimcat@think.com (Jim Kasprzak) Subject: Re: Coilgun on a 747 - supplies to orbit at $20/lb? In article <8444@pt.cs.cmu.edu> vac@sam.cs.cmu.edu (Vincent Cate) writes: > > [speculations on the possibility of launching stuff to orbit with a > 747-mounted coil gun deleted] > >What are the hard parts of this type of approach? > Not wrecking the 747 in the process. Ever hear of recoil? I think that even from 747 cruising altitude, the recoil generated by any reasonably large payload is going to wreak havoc on your plane. But hell, why settle for a 747? We have those retired SR-71's now, right? Put a coil gun on one of *those*, and you've got a lot better starting altitude and velocity... (-: (If it wasn't obvious, that paragraph was not serious.) -- Jim Kasprzak kasprzak@mts.rpi.edu (internet) RPI, Troy, NY userfe0u@rpitsmts.bitnet "A spirit with a vision is a dream with a mission." -Rush ------------------------------ Date: 16 Mar 90 19:42:02 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 03/16/90 (Forwarded) ----------------------------------------------------------------- Friday, March 16, 1990 Audio: 202/755-1788 ----------------------------------------------------------------- This is NASA Headline News for Friday, March 16...... The STS-31 Space Shuttle is at Launch Pad 39-B this morning. Rollout was delayed Thursday morning until last night while shuttle managers investigated data on the nose landing gear axle on the orbiter Discovery. Nose wheel axle problems had been previously observed on Columbia and Atlantis. If further analysis indicates a problem on Discovery...and it would jeopardize the STS-31 mission...the stack would be rolled back to the Vehicle Assembly Building for demating and repair. The ozone layer over the north pole is thinning. That's the finding of a coordinated study conducted last fall by NASA, NOAA and a variety of other research organizations. Data indicate from 15 to 17 percent of the ozone over certain parts of the north polar region has been destroyed. Research studies indicate the north polar ozone hole will grow larger, but not as large as the ozone hole known to exist over the Antarctica. Space Fax Daily says the Tokyo Broadcasting System will announce in April which of two Japanese journalists will go into space in December. The TV reporters have been in training since last fall for an eight day mision aboard the Mir space station. The TV network will pay the Soviets close to $10-million for the cosmonaut training and space flight. Engineers from Intelsat are closely watching the Intelsat 6 spacecraft that's marooned in a low Earth orbit following an abortive launch attempt earlier this week aboard a commercial Titan 3. They're now beginning to stabilize the spacecraft to allow on-board thrusters to boost it into a higher, safer and longer-life orbit. In its present orbit it would decay in a few weeks. A rescue attempt has been mentioned, but NASA says it has not yet been approached for assistance to rescue the spacecraft. The final frames of a 64-frame mosaic of our solar system taken by the Voyager 1 cameras will be beamed back to Jet Propulsion Laboratory beginning today. Transmission of the frames will run through March 27. Seven of the nine planets in our solar system should be seen in the mosaic. ***** ----------------------------------------------------------------- Here's the broadcast schedule for public affairs events on NASA Select TV. All times are Eastern. Today.............. 12 noon Video tape replay of STS-31 rollout at KSC Monday, March 21..... From Johnson Space Center 9:30 A.M. STS-31 flight directors mission overview 10:30 A.M. Secondary middeck student experiments 11:30 A.M. STS-31/HST flight crew news conference Wednesday, March 21....... 1-2:30 P.M. Total Quality Management in Action Colloquium Thursday, March 22...... 11:30 A.M. NASA Update will be transmitted All events and times are subject to change without notice ----------------------------------------------------------------- These reports are filed daily, Monday through Friday, at 12 noon, Eastern time. ----------------------------------------------------------------- A service of the Internal Communications Branch (LPC), NASA HQ ------------------------------ Date: 16 Mar 90 16:56:00 GMT From: usc!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Re: Coilgun on a 747 - supplies to orbit at $20/lb? In article <8444@pt.cs.cmu.edu> vac@sam.cs.cmu.edu (Vincent Cate) writes: >I don't know, :-), but to continue on let me make some guesses. >Assume that coilgun and support takes up 50,000 lbs and that 2/5ths of >the weight of a projectile ends up being overhead. Starting with >100,000 lbs on the plane, we would still end up sending 30,000 lbs >to orbit... Whoa, Nelly. Remember that accelerating a mass to near-orbital velocity in the space of a hundred meters or less involves very high accelerations, i.e. very large forces. Be generous and call it a hundred meters long (I forget how long a 747 is, but this is probably too long already). Now, v^2 = 2ad for a body starting from rest, and orbital velocity is circa 8000 m/s, so acceleration is 32000G. If the payload is 30000lbs, we're talking about forces of circa one *billion* pounds. Your coilgun will rip itself out of the 747 instantly. Also, accelerating 13000kg to 8000m/s requires 416 GJ of energy, which is a Whole Lot, something like half a second's electrical power output for the entire US. Your power-storage gear will not fit in a 747. Try thinking in terms of grams, not thousands of kilograms, and it might work. -- MSDOS, abbrev: Maybe SomeDay | Henry Spencer at U of Toronto Zoology an Operating System. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 16 Mar 90 22:00:01 GMT From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ames.arc.nasa.gov (Ron Baalke) Subject: Galileo Update - 03/16/90 GALILEO MISSION STATUS REPORT March 16, 1990 As of noon Friday (PST), March 16, 1990, the Galileo spacecraft is 63,810,650 miles from the Earth, 10,496,450 miles from Venus and was travelling at a heliocentric velocity of 87,640 miles per hour. Round trip light time is 11 minutes, 18 seconds. Galileo is in cruise mode-dual spin with a spin rate of 3.15 rpm. The spacecraft attitude sun point angle is at 0.4 degrees. Several SITURNS to lead the sun were successfully accomplished on March 10, 12, 14 and 16. Spacecraft performance for all events was as expected and without incident. A switch from LGA-2 (Low Gain Antenna) to LGA-1 was successfully completed on March 12. The antenna switch was necessary to assure adequate command and telemetry link performance to accommodate for the changing sun, earth, and spacecraft relative geometries. After the switch to LGA-1, the telecommunications performance was near predicted levels. The ninth RPM thruster "flushing" activity was completed on March 15, as planned. The activity "flushed" the Z, L and S thruster only. The P-thrusters were not flushed since they are used to perform the SITURNS. Unlike earlier "flushing" activities performed at 1200 bps, the temperature profiles for the thrusters were not available due to the low telemetry rate of 10 bps. Successful "flushing" was inferred from other spacecraft measurements/events, including attitude control performance and thruster counts. The AC/DC bus imbalance continued to be relatively stable for about 7 weeks. The DC measurement has varied between about 21.3 and 21.6 volts; the AC measurement has varied between 48.36 and 48.75 volts. All other power-related measurements (bus voltages, bus currents and shunt current) and other subsystem measurements have all been as expected. The Earth Venus Earth (EVE) Integrated Cruise Activity Plan (ICAP) was reviewed and approved by the project on March 7. The EVE ICAP is the highest level product integrating engineering and science activities and covers the period from VE-3 (April 23, 1990) to VE-15 (April 29, 1991). The VE-2 Preliminary Sequence was reviewed and approved by the project on March 15. The VE-2 sequence controls spacecraft activities from March 26 to April 23. The Galileo project participated in an acceptance test of the new Deep Space Network (DSN) Telemetry Processor Assembly (TPA) software during a Goldstone track of the Galileo spacecraft. The new TPA software will provide a new standard for telemetry time tagging that will eliminate differences between different TPA configurations and projects. The new software is expected to begin operations support on March 29th after the completion of Multimission Verification Tests (MVTs) scheduled next week. Ron Baalke | baalke@mars.jpl.nasa.gov Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov 4800 Oak Grove Dr. | Pasadena, CA 91109 | ------------------------------ Date: 17 Mar 90 03:12:00 GMT From: zaphod.mps.ohio-state.edu!rpi!rpitsmts!forumexp@think.com (Commander Krugannal) Subject: HST I know that when Hubble was designed, tehy actually ground two mirrors. I don't think that the second was ever coated, it was kept as a backup in case the primary one was scratched or somehow ruined. My question is, does anyone know what if anything happened to the second mirror? If it is still around, do you think it would be possible to finish the grinding, coat it and fit it out with the needed gear and send it up as a second HST? Seems like this would be a cheap way to get a second one. (Since they know most of the problems they would run into and that it would hopefully not have to sit around too long. Just a thought. Greg_d._Moore@mts.rpi.edu Disclaimer: Why do I need one? everyone else has one! ------------------------------ End of SPACE Digest V11 #158 *******************