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, 7 Apr 91 01:24:16 -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, 7 Apr 91 01:24:08 -0500 (EST) Subject: SPACE Digest V13 #372 SPACE Digest Volume 13 : Issue 372 Today's Topics: Magellan Status for 04/04/91 (Forwarded) Magellan achieves primary mission objective early (Forwarded) Re: space news from Feb 18 AW&ST NASA Prediction Bulletins, Part 2 Re: Railguns, EM launchers 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: 5 Apr 91 18:55:15 GMT From: usenet@ames.arc.nasa.gov (Peter E. Yee) Subject: Magellan Status for 04/04/91 (Forwarded) [Posting this until Ron gets back on the net. -PEY] MAGELLAN STATUS REPORT April 4, 1991 The Magellan spacecraft and its radar system are performing well. Six of seven star calibrations were successful Wednesday with nominal attitude updates. The Goldstone Deep Space Network station experienced some equipment problems during Wednesday's track and low rate telemetry was lost for a short period. The problems were quickly corrected. The project announced it had achieved more than 70 percent mapping coverage of Venus. That was the first of the prime mission objectives. By the time the first cycle ends on May 15, project officials said they expect to have acquired 84 percent of the planet's surface in captured data. ------------------------------ Date: 5 Apr 91 18:55:57 GMT From: usenet@ames.arc.nasa.gov (Peter E. Yee) Subject: Magellan achieves primary mission objective early (Forwarded) Paula Cleggett-Haleim Headquarters, Washington, D.C. April 4, 1991 (Phone: 202/453-1547) Robert MacMillin Jet Propulsion Laboratory, Pasadena, Calif. (Phone: 818/354-5011) RELEASE: 91-49 MAGELLAN ACHIEVES PRIMARY MISSION OBJECTIVE EARLY The Magellan Project at NASA's Jet Propulsion Laboratory, Pasadena, Calif., claimed an early victory today and announced that the spacecraft had achieved its objective for the primary phase of the Venus mission more than a month before the end of the first 243-day mapping cycle. That is one Venus rotation beneath the orbiting spacecraft. Project Manager Tony Spear said because of the quality of the radar images and the excitement they have generated in the scientific community, an extended mission for a second 243-day mapping cycle has been approved by NASA and will begin May 16. Magellan reached its goal of mapping 70 percent of the planet on Wednesday, said Spear, adding that by the end of the first mapping cycle May 15, the spacecraft will have acquired 84 percent of the planet's surface. The radar imager used to penetrate the thick clouds of Venus and map the surface has worked flawlessly, Spear said. He added that the spacecraft is sufficiently healthy to continue mapping Venus well into this decade, "providing a windfall of additional, exciting science return." The first objective of the extended mission is to collect the remaining 16 percent of the map, including the south pole, which has never been imaged. Other surface features will be imaged from a different view angle to yield a new perspective, and image comparisons from one mapping cycle to the next will be made to look for surface activity, Spear said. Beginning in mid-November, every fourth orbit will be dedicated to acquiring gravity data. Instead of mapping the surface on those orbits, Magellan's high-gain antenna will point to Earth and slight changes in the radio signal, resulting from variations in Venus' tug on the spacecraft, will help scientists determine local gravity changes. That information will provide insight into the interior processes of the planet. Additionally, a number of experiments are under study which would use the radar in different modes to acquire higher resolution topography. Finally, near the end of the Magellan mission, the spacecraft may be dipped into the upper atmosphere of Venus to drag it into a circular orbit, a previously untried process called aerobraking. The maneuver would be a valuable engineering demonstration for future missions, Spear said. "More importantly," he said, "a circular orbit would greatly enhance science returns by permitting global, high- resolution gravity and imaging data acquisition." Magellan is managed by JPL for NASA's Office of Space Science and Applications, NASA Headquarters, Washington, D.C. The Hughes Aircraft Co. developed and operates the radar instrument, and the Martin Marietta Corp. built and operates the spacecraft. ------------------------------ Date: 5 Apr 91 19:04:37 GMT From: agate!bionet!uwm.edu!spool.mu.edu!samsung!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo!henry@ucbvax.Berkeley.EDU (Henry Spencer) Subject: Re: space news from Feb 18 AW&ST In article <113800003@primerd> os@primerd.prime.com writes: >>[March issue of Spaceflight mentions that astronaut William F. Fisher has >>left NASA to return to medical practice. No big surprise... > >... Things are becomming so political that one can >destroy one's career by succeeding at one's assigned tasks... Actually, NASA has *always* been sensitive to being embarrassed in public. Aldrin's recent book ("Men From Earth", I think) is an unremarkable read in most ways, but one real eye-opener is the look at astronaut politics it gives here and there. By his account, the astronauts figured out early that making NASA look bad could easily kill your career stone cold dead. -- "The stories one hears about putting up | Henry Spencer @ U of Toronto Zoology SunOS 4.1.1 are all true." -D. Harrison| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 6 Apr 91 01:06:19 GMT From: udecc.engr.udayton.edu!blackbird.afit.af.mil!tkelso@tut.cis.ohio-state.edu (TS Kelso) Subject: NASA Prediction Bulletins, Part 2 The most current orbital elements from the NASA Prediction Bulletins are carried on the Celestial BBS, (513) 427-0674, and are updated several times weekly. Documentation and tracking software are also available on this system. As a service to the satellite user community, the most current of these elements are uploaded weekly to sci.space. This week's elements are provided below. The Celestial BBS may be accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop bit, no parity. - Current NASA Prediction Bulletins #831b - GPS BII-03 1 20185U 89 64 A 91 57.34599602 .00000016 00000-0 99999-4 0 1766 2 20185 54.8906 188.1900 0021289 164.8064 195.2144 2.00568043 11161 GPS BII-04 1 20302U 89 85 A 91 41.91577973 -.00000024 00000-0 99999-4 0 1785 2 20302 54.4598 307.3315 0032510 329.9999 29.8633 2.00556091 9656 Meteor 3-3 1 20305U 89 86 A 91 88.80296795 .00000043 00000-0 99999-4 0 3296 2 20305 82.5517 16.5478 0016184 342.7902 17.2685 13.15944004 68518 COBE 1 20322U 89 89 A 91 94.55162511 .00000559 00000-0 38231-3 0 2646 2 20322 99.0232 107.1204 0008532 284.9943 75.0244 14.03034218 70340 Kvant-2 1 20335U 89 93 A 91 94.89343573 .00072758 00000-0 70274-3 0 6233 2 20335 51.6088 299.1833 0014198 142.4769 217.7027 15.65666936 77344 GPS BII-05 1 20361U 89 97 A 91 94.27896796 .00000013 00000-0 99999-4 0 1368 2 20361 55.0316 128.8202 0062922 60.9080 299.7837 2.00558030 188 SPOT 2 1 20436U 90 5 A 91 88.68536931 -.00007637 00000-0 -35903-2 0 5090 2 20436 98.7045 164.0636 0001256 39.6588 320.4404 14.20015423 61263 UO-14 1 20437U 90 5 B 91 94.21793448 .00001517 00000-0 61478-3 0 3235 2 20437 98.6741 174.1246 0011759 27.5854 332.5834 14.29030011 62425 UO-15 1 20438U 90 5 C 91 92.20318592 .00001016 00000-0 42014-3 0 2021 2 20438 98.6752 172.0187 0010696 33.7934 326.3925 14.28636895 62126 PACSAT 1 20439U 90 5 D 91 93.69744985 .00001512 00000-0 61186-3 0 2140 2 20439 98.6758 173.8797 0012006 30.7659 329.4213 14.29119657 62359 DO-17 1 20440U 90 5 E 91 88.71131811 .00001733 00000-0 69780-3 0 2139 2 20440 98.6768 168.9601 0011690 43.9493 316.2645 14.29180356 61649 WO-18 1 20441U 90 5 F 91 94.70463820 .00001466 00000-0 59205-3 0 2138 2 20441 98.6731 174.9599 0012978 27.7203 332.4623 14.29254042 62508 LO-19 1 20442U 90 5 G 91 93.42294664 .00001472 00000-0 59351-3 0 2156 2 20442 98.6749 173.7379 0013062 31.7226 328.4666 14.29326164 62323 GPS BII-06 1 20452U 90 8 A 91 67.75229359 .00000004 00000-0 99999-4 0 1530 2 20452 54.3982 245.2075 0046174 52.4825 307.8626 2.00554625 8154 MOS-1B 1 20478U 90 13 A 91 94.18515243 .00000444 00000-0 35652-3 0 5279 2 20478 99.1526 167.6836 0000813 66.1480 293.9746 13.94850032 58704 DEBUT 1 20479U 90 13 B 91 93.91871044 .00000043 00000-0 14529-3 0 1905 2 20479 99.0237 90.1908 0541434 109.7385 256.2927 12.83174670 54039 FO-20 1 20480U 90 13 C 91 86.98392873 .00000105 00000-0 28514-3 0 1834 2 20480 99.0230 84.5750 0541449 125.5056 239.7812 12.83179882 53143 MOS-1B R/B 1 20491U 90 13 D 91 93.04620643 -.00000131 00000-0 -22146-3 0 2129 2 20491 99.0200 101.2385 0471195 71.7776 293.4005 13.02811548 54140 LACE 1 20496U 90 15 A 91 94.53486482 .00013981 00000-0 72658-3 0 4863 2 20496 43.0947 157.0041 0018556 19.6165 340.5392 15.15804704 62729 RME 1 20497U 90 15 B 91 94.23308430 .00029462 00000-0 58625-3 0 5171 2 20497 43.1022 64.8563 0017608 104.9616 255.3225 15.46214501 63717 Nadezhda 2 1 20508U 90 17 A 91 94.30954967 .00000434 00000-0 45428-3 0 2684 2 20508 82.9557 205.2298 0043219 255.7573 103.8757 13.73296259 54966 OKEAN 2 1 20510U 90 18 A 91 94.94584045 .00006094 00000-0 90712-3 0 4556 2 20510 82.5283 188.7946 0020855 43.9697 316.3151 14.74654709 59044 INTELSAT-6 1 20523U 90 21 A 91 91.55355126 -.00000992 00000-0 -77177-4 0 4503 2 20523 28.3374 172.8868 0015279 28.8362 331.3048 15.03589821 57875 GPS BII-07 1 20533U 90 25 A 91 91.09691664 -.00000034 00000-0 99999-4 0 1472 2 20533 55.1876 4.3259 0034689 96.5964 263.7984 2.00566505 7396 PegSat 1 20546U 90 28 A 91 94.24677925 .00025957 00000-0 13570-2 0 4879 2 20546 94.1393 10.6774 0135622 2.3419 357.8425 15.08088527 53816 HST 1 20580U 91 93.55178018 .00007055 00000-0 75344-3 0 4046 2 20580 28.4693 199.4006 0005665 253.8939 106.1024 14.87067503 51190 Glonass 44 1 20619U 90 45 A 91 94.10594158 -.00000018 00000-0 99999-5 0 4278 2 20619 65.0505 28.9660 0022351 218.4309 141.4147 2.13102902 6820 Glonass 45 1 20620U 90 45 B 91 94.22382088 -.00000018 00000-0 99999-4 0 4448 2 20620 65.0455 28.9610 0008342 24.0831 335.9637 2.13102850 6833 Glonass 46 1 20621U 90 45 C 91 94.28264494 -.00000018 00000-0 99999-4 0 3804 2 20621 65.0682 28.9676 0012300 210.6929 149.2403 2.13102500 6837 Kristall 1 20635U 90 48 A 91 94.89342307 .00072717 00000-0 70274-3 0 4235 2 20635 51.6020 299.1850 0014091 140.1652 219.9345 15.65654440 48229 ROSAT 1 20638U 90 49 A 91 94.27010650 .00008624 00000-0 69777-3 0 2278 2 20638 53.0036 196.9989 0017148 133.7125 226.5211 15.00381324 45939 Meteor 2-19 1 20670U 90 57 A 91 90.91212057 .00000404 00000-0 35409-3 0 1659 2 20670 82.5424 60.2634 0015213 194.8707 165.1978 13.83934106 38311 CRRES 1 20712U 90 65 A 91 93.82490464 .00003065 00000-0 32741-2 0 1895 2 20712 18.0139 303.1209 7117377 33.3239 355.9742 2.44199337 6160 GPS BII-08 1 20724U 90 68 A 91 55.54435681 .00000016 00000-0 99999-4 0 845 2 20724 54.6996 186.1883 0096447 122.6748 238.2165 2.00563932 4103 Feng Yun1-2 1 20788U 90 81 A 91 93.95439479 .00001055 00000-0 72566-3 0 1278 2 20788 98.9396 128.9952 0014960 31.2418 328.9624 14.01107544 29817 Meteor 2-20 1 20826U 90 86 A 91 94.15089793 .00000667 00000-0 59727-3 0 1215 2 20826 82.5322 356.7772 0014882 84.2858 275.9995 13.83321721 25977 GPS BII-09 1 20830U 90 88 A 91 83.50103202 .00000012 00000-0 99999-4 0 883 2 20830 54.9179 127.4127 0074658 116.7093 244.1254 2.00567571 3740 GPS BII-10 1 20959U 90103 A 91 76.43064871 .00000017 00000-0 99999-4 0 262 2 20959 54.9591 186.9802 0045402 213.8318 146.2541 2.00567535 2193 DMSP B5D2-5 1 20978U 91 94.43826266 .00001762 00000-0 66503-3 0 1043 2 20978 98.8434 129.9757 0080949 356.2244 3.8321 14.30804329 17706 Soyuz TM-11 1 20981U 90107 A 91 94.95725344 .00072793 00000-0 70274-3 0 1273 2 20981 51.6086 298.8601 0014377 142.0772 218.0443 15.65675260 19349 Glonass 47 1 21006U 90110 A 91 94.32174536 .00000020 00000-0 99999-4 0 1100 2 21006 64.8356 148.5060 0061864 186.7350 173.2550 2.13102082 2512 Glonass 48 1 21007U 90110 B 91 94.02915662 .00000020 00000-0 99999-4 0 1257 2 21007 64.8592 148.5465 0039270 181.1337 178.9315 2.13100272 2503 Glonass 49 1 21008U 90110 C 91 94.38122721 .00000020 00000-0 99999-4 0 1062 2 21008 64.8407 148.5196 0010812 289.7852 70.1644 2.13100223 2513 INFORMTR-1 1 21087U 91 94.13517494 .00000295 00000-0 29999-3 0 274 2 21087 82.9417 288.5236 0036580 103.5879 256.9355 13.74363411 8859 Cosmos 2123 1 21089U 91 7 A 91 90.20658587 .00000339 00000-0 34936-3 0 294 2 21089 82.9282 161.9091 0029955 133.3412 227.0248 13.73881132 7433 MOP-2 1 21140U 91 15 B 91 93.30029275 .00000001 00000-0 99999-4 0 298 2 21140 1.1519 296.8769 0002337 11.4195 347.4511 1.00295032 119 INMARSAT 2 1 21149U 91 18 A 91 92.28410505 .00000039 00000-0 99999-4 0 163 2 21149 2.6899 295.7828 0005580 334.1341 25.3237 1.00260191 283 1991 018B 1 21150U 91 18 B 91 94.51885931 .00014049 00000-0 10296-2 0 282 2 21150 24.9621 163.0874 0527286 70.8445 294.8389 14.31061693 3800 1991 018C 1 21151U 91 18 C 91 89.60279699 .00045325 00000-0 61813-2 0 153 2 21151 23.6969 321.1458 7323833 199.1640 104.3207 2.24438222 488 Nadezhda 3 1 21152U 91 19 A 91 94.16516663 .00000006 00000-0 00000 0 0 152 2 21152 82.9244 113.7134 0040590 229.0007 130.7640 13.73323521 3071 1991 019B 1 21153U 91 19 B 91 93.56020761 .00000579 00000-0 59446-3 0 242 2 21153 82.9229 114.1258 0038340 210.9053 148.9872 13.74768729 2999 Progress M7 1 21188U 91 20 A 91 94.95733166 -.00080375 00000-0 -78955-3 0 404 2 21188 51.6109 298.8571 0017749 130.6478 229.8793 15.65561893 2585 Cosmos 2137 1 21190U 91 21 A 91 93.15458588 .00019776 00000-0 63069-3 0 215 2 21190 65.8503 329.3708 0035004 334.2252 25.7126 15.31969428 2235 1991 021B 1 21191U 91 21 B 91 94.18581749 .00033844 00000-0 10201-2 0 329 2 21191 65.8372 325.9897 0037258 349.1645 10.8675 15.33470312 2397 1991 022A 1 21196U 91 22 A 91 92.90649108 .00000200 00000-0 10768-2 0 178 2 21196 62.8487 312.4326 7433393 280.4579 10.6288 2.00745254 244 1991 022B 1 21197U 91 22 B 91 92.55158953 .25189034 43669-4 43370-3 0 340 2 21197 62.8062 271.0340 0022763 133.7532 226.6568 16.45597799 1780 1991 022D 1 21199U 91 22 D 91 90.80579986 .00000027 00000-0 -77387-3 0 61 2 21199 62.8477 312.5711 7378050 280.7000 10.9576 2.05628335 209 1991 014E 1 21201U 91 14 E 91 94.49094643 .00003254 00000-0 16242-2 0 96 2 21201 47.4873 239.3153 7228843 9.1047 358.8223 2.32989325 848 1991 014F 1 21202U 91 14 F 91 91.84349476 .00008713 00000-0 15798-2 0 67 2 21202 47.4583 239.9362 7244752 8.4852 358.8807 2.33667277 789 1991 023A 1 21203U 91 23 A 91 95.16142316 .00688680 27566-4 39503-3 0 250 2 21203 67.1475 344.1937 0114984 67.2603 294.1598 16.05240520 1545 1991 023B 1 21204U 91 23 B 91 87.84647494 .18280002 30103-4 33209-3 0 134 2 21204 67.1627 8.6511 0046059 91.9560 269.0962 16.41670542 375 1991 024A 1 21213U 91 24 A 91 94.08022943 .00110733 62300-5 21611-3 0 183 2 21213 72.7010 92.9923 0009742 261.0214 91.1055 16.00037000 569 1991 024B 1 21214U 91 24 B 91 92.22001654 .13031554 13419-4 17927-3 0 104 2 21214 72.7053 97.8249 0025034 58.1287 302.6246 16.46817551 265 STS 37 1 21224U 91 27 A 91 95.65050502 .00000248 00000-0 32191-5 0 16 2 21224 28.4682 238.4333 0008760 266.0250 93.9346 15.37932365 10 -- Dr TS Kelso Assistant Professor of Space Operations tkelso@blackbird.afit.af.mil Air Force Institute of Technology ------------------------------ Date: 5 Apr 91 18:01:23 GMT From: agate!bionet!uwm.edu!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo!henry@ucbvax.Berkeley.EDU (Henry Spencer) Subject: Re: Railguns, EM launchers In article <9104050305.AA00517@ucbvax.Berkeley.EDU> space+%ANDREW.CMU.EDU@msu.edu writes: >>Brute force. Just give it enough extra velocity to punch on through, and >>enough ablator to keep the payload temperature under control... > >I won't bore you with details, but based on first run calculation, since the >friction to be overcome increases with speed, and since you can never get a >coefficient less than about .25, assuming perfect aerodynamics (which would >preclude much payload), you just can't do it... I'd suggest careful re-examination of the assumptions. Several groups who have done major studies of it say you can do it, I believe. >>... You could get useful gains by catapulting them at such speeds >>*vertically*, and in fact there was a recent Japanese proposal to do >>just that. > >Sounds neat. Any details? The proposal, if I recall correctly, was to catapult something like an H-2 at roughly transonic velocity, which was calculated to boost orbital payload a great deal. I didn't pay attention to the details. -- "The stories one hears about putting up | Henry Spencer @ U of Toronto Zoology SunOS 4.1.1 are all true." -D. Harrison| henry@zoo.toronto.edu utzoo!henry ------------------------------ End of SPACE Digest V13 #372 *******************