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 ; Wed, 11 Apr 90 02:29:28 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 11 Apr 90 02:28:52 -0400 (EDT) Subject: SPACE Digest V11 #249 SPACE Digest Volume 11 : Issue 249 Today's Topics: News From OSCAR-11 (07-Apr-90) Pegasus launch from Valkyrie (or ... Re: Quick launches ( was: Intelsat Re: Galileo Update - 04/10/90 ---------------------------------------------------------------------- Date: 8 Apr 90 16:46:14 GMT From: att!tsdiag!ka2qhd!kd2bd@ucbvax.Berkeley.EDU (John Magliacane) Subject: News From OSCAR-11 (07-Apr-90) **UOSAT 2 COMPUTER STATUS INFORMATION** FAD1 Operating System v2.0b Today's date is 8 /4 /90 (Sunday) Universal Time is 14 :20 :58 Auto Mode is selected SPIN PERIOD IS - 281 Z MAG firings = 0 + SPIN firings = 5 - SPIN firings = 1 RAM Wash Pointer at F67 WOD commenced 8 /4 /90 at 0 :0 :10 with channels 2 ,61 , Last cmd was 109 TO 0 WITH DATA 0 Attitude control initiated, mode 1 Digitalker active **** UoSAT-OSCAR-11 BULLETIN 212 07 April 1990 UoSAT MISSION CONTROL CENTRE University of Surrey, Guildford, Surrey, GU2 5XH, England ** UoSAT-OSCAR-14 ** (de G3YJO) Preliminary tests have been carried out by G0/K8KA & G3RUH using the PACSAT Communications Experiment as a 9.6kbps digipeater, and early data has been received from the Cosmic Particle Experiment. ** UoSAT-OSCAR-15 ** The team at Stanford have succeeded in detecting local oscillator (LO) leakage from the UO-15 command receiver whilst the spacecraft was in eclipse - indicating that the on-board NiCd battery is indeed functioning. Tests to check the command system now follow. ** DOVE-OSCAR-17 ** (ASR) AMSAT Command Station N4HY is using Mode S to upload software, however, due to a low index of modulation and high Doppler shift on the DOVE S-Band transmitter, DSP techniques are being used to copy the packets transmitted on 2401.220 MHz. ** RUDAK-2 ** (DB2OS & DJ0HC/KE6MN) RUDAK-2 has now been integrated into a Soviet Geological research satellite, GEOS, scheduled to fly in July. RUDAK-2 will not only carry a Mode B linear transponder but also a variety of packet radio experiments with data rates from 400-9600 bps using various modulation schemes. It will be compatible with AX.25 protocols and those amateurs equipped for FO-20, PACSAT, LUSAT, AO-13 PSK telemetry, and UO-14. Linear Transponder Uplink: 435.030 - 435.120 MHz (90 KHz) Linear Transponder Downlink: 145.880 - 145.970 MHz (inverted) O/P Power: 12 watts max. Beacon : 145.880 MHz, CW telemetry. Gain of satellite RX/TX antennas: 2.3 dBi each (dipoles) Input sensitivity: -125 dBm (435 MHz) for a C/No of 45 dB/Hz SAT-RX-1: 435.016 MHz +-10 KHz 1200 bps, FSK, NRZIC/Biphase-M (JAS, PACSAT) SAT-RX-2: 435.155 MHz +-10 KHz (AFC) 2400 bps, BPSK, Biphase-S SAT-RX-3a: 435.193 MHz +-10 KHz (AFC) 4800 bps, RSM, NRZIC/Biphase-M SAT-RX-3b: 435.193 MHz +-10 KHz (AFC) 9600 bps, RSM, NRZI (NRZ-S) +Scrambler SAT-RX-4: 435.041 MHz +-10 KHz (digital AFC) RX for RTX-DSP experiments The downlink can be switched to the following operating modes: Transmit frequency: 145.983 MHz Mode 1: 1200 bps, BPSK, NRZI (NRZ-S) (like FO-20) Mode 2: 400 bps, BPSK, Biphase-S (AMSAT mode for OSCAR-13 beacon) Mode 3: 2400 bps, BPSK, Biphase-S (planned for OSCAR-13) Mode 4: 4800 bps, RSM, NRZIC (Biphase-M) (like 4800 bps uplink) Mode 5: 9600 bps, RSM, NRZI (NRZ-S) + Scrambler (like 9600 bps uplink) Mode 6: CW keying (only for special events) Mode 7: FSK (F1 or F2B), e.g. RTTY, SSTV, FAX, etc. (only for special events) Mode 8: FM modulated by D/A signals from DSP-RISC processor (e.g. speech) RUDAK-2 is a joint project of AMSAT-U-ORBITA, the Adventure Clubs in Moscow and the AMSAT-DL/RUDAK Group in Marburg, Munich and Hannover. ** $BID ** Please use BID $UOSAT.212 for PR BBS use. -- AMPR : KD2BD @ NN2Z (Neptune, NJ) UUCP : ucbvax!rutgers!petsd!tsdiag!ka2qhd!kd2bd "For every problem, there is one solution which is simple, neat and wrong." -- H.L. Mencken ------------------------------ Date: 11 Apr 90 05:35:44 GMT From: sam.cs.cmu.edu!vac@pt.cs.cmu.edu (Vincent Cate) Subject: Pegasus launch from Valkyrie (or ... George William Herbert: >Pegasus is a three-stage winged [first stage] solid rocket able to launch >600 lbs into a 250nm polar orbit or 900 lbs into a 250nm equitorial orbit. > >The vehicle itself is 49.2 feet long, with a diameter of 48 inches and a >wingspan of 22 feet. It weighs 40,000 pounds at launch ... > >The launch costs are estimated at $8 million per launch, or about $10,000 >per pound to orbit. This is unfavorable compared to other launchers on a >per pound basis, but the small total cost remains attractive to those not >needing large payloads. It is considerably better than other small launchers. So the 1,000 MPH difference due to the rotation of the Earth results in a 300 lb payload difference. Clearly if you had a plane that could fly South at 1,600 MPH instead of the 600 MPH that the B-52 does you could get the 300 lbs back. At $10,000/lb, this extra 300 lbs is worth $3,000,000. I don't really know what current planes could carry 40,000 lbs at such speeds; however, I know that the North American XB-70 Valkyrie flew at 2,000 MPH, could weigh over 500,000 lbs on takeoff and carried up to 300,000 lbs of fuel. It was designed to be a bomber (B-70) but became an experimental aircraft (XB-70) when funding was cut. It flew at over 70,000 feet. The extra 30,000 feet over the B-52 and the extra 1,400 MPH would really be nice for launching something like the Pegasus. This might have made the equitorial launch go from a 900 lb payload to 1,400 lbs or more. In other words, if the Valkyrie were used instead of the B-52, it might add $5,000,000 to the value of the launch. Unfortunately, the Valkyrie stopped flying 20 years ago. In the 25 years since the Valkyrie came out, has there been another plane that was better for launching something like the Pegasus into orbit? Does anything come close to the Valkyrie? What can the B-1 and B-2 do? The B-52 is really the first stage in the Pegasus out of a total of 4 stages. In general it seems that using a high and fast plane as the true first stage should be a great way to reduce the cost of getting a payload into orbit. The space plane idea of taking the whole plane all the way into orbit seems wrong. Multiple stages really are a good idea. A plane that flew to 6,000 MPH (which I think they might be able to do using hydrogen powered scram jets) would eliminate the need for the "first stage" on the Pegasus. This is most of the rocket. This would have to reduce costs alot. A really fast plane that could carry a rocket makes far more sense than a plane that goes all the way to orbit. How soon will there be a hyrogen powered scram-jet plane? Are there any other planes that have interesting possibilities? -- Vince ------------------------------ Date: 11 Apr 90 03:58:10 GMT From: cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Quick launches ( was: Intelsat In article <11376@june.cs.washington.edu> dfkling@june.cs.washington.edu (Dean F. Kling) writes: > :... I believe it is still the case that no > :Minuteman has ever been successfully test-fired from the operational > :type > :of silo. Many have been fired from the Vandenberg test silos, > :but those > :are not representative of the operational ones. There were a series of > :attempts to fire from an operational-type silo at Vandenberg... > > My recollections of attempts to do a test launch from an operational silo >were that they were all quashed due to the prospect of the multi-ton first >stage coming down somewhere in the U.S... Undoubtedly. However, that is not what I was talking about. Please re-read what I wrote, above. Note the words "type" and "Vandenberg". -- With features like this, | Henry Spencer at U of Toronto Zoology who needs bugs? | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 11 Apr 90 04:02:28 GMT From: zaphod.mps.ohio-state.edu!samsung!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Galileo Update - 04/10/90 In article <15347@bfmny0.UU.NET> tneff@bfmny0.UU.NET (Tom Neff) writes: >I'm curious about something w/r/t Gravity Assist maneuvers. Are the >positions and gravitational influences of the satellites taken into >account? In this case, do the Galileo calculations include Lunar >effects? Do they really check to make sure it won't smack into the >moon? They certainly do. I haven't seen details for the Galileo gravity assists, but the launch window diagram for Magellan was a graph with a pair of smooth curves showing window boundaries as a function of launch day... except for a neat little dip in each, lasting a few days, marked "lunar perturbation" or something like that. The Moon is much too big to ignore in this sort of planning. >Also, do mascons matter? Or the exoatmosphere? I'd suspect the mascons are not significant, on the grounds that Galileo shouldn't get close enough to the Moon for the point-mass approximation to break down, but I could be wrong. I'd be very surprised if atmospheric drag hadn't been figured in. -- With features like this, | Henry Spencer at U of Toronto Zoology who needs bugs? | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ End of SPACE Digest V11 #249 *******************