Jonathan's Space Report No. 154 1993 May 18 ------------------------------------------------------------------------------ Shuttle ----------------- Columbia returned to KSC aboard the 747 on May 14 and is now in the Orbiter Processing Facility being turned around for the STS-58 mission in August. Next mission is Endeavour/STS-57 due for June 3; according to the magazine Space News, pad workers have been unable to locate the source of a crash-bang-clatter sound heard emanating from the orbiter during pad tests. Doesn't that give you a great feeling? STS-57 will carry the Spacehab experiment module and retrieve the European EURECA satellite. Mir --- Gennady Manakov and Aleksandr Poleshchuk remain in orbit aboard the Mir complex. Soyuz TM-16 is docked to the Kristall axial port and Progress M-16 is docked to the Kvant port. A new Progress mission is due for launch on May 18 and will dock to the forward Mir port. Apologies for misspelling Poleshchuk's name in previous reports; the new spelling is consistent with the transliteration scheme I normally use. Launches -------- Date Name Launch Vehicle Site Mission INTL. DES. Apr 16 0800? Kosmos-2242 Tsiklon Plesetsk SIGINT 24A Apr 21 0030? Molniya-3 Molniya Plesetsk Comsat 25A Apr 25 1244 Alexis Pegasus Edwards/NB52 Astronomy 26A Apr 26 1450 Columbia ) Shuttle Kennedy LC39 Spaceship 27A Spacelab D-2 ) Apr 27 1230? Kosmos-2243 Soyuz Baykonur Recon 28A Apr 28 0335? Kosmos-2244 R-36 Baykonur Ocean Rec. 29A May 11 1450? Kosmos-2245 ) Tsiklon Plesetsk Comsat 30A Kosmos-2246 ) 30B Kosmos-2247 ) 30C Kosmos-2248 ) 30D Kosmos-2249 ) 30E Kosmos-2250 ) 30F May 12 0056 Astra 1C ) Ariane 42L Kourou Comsat 31A Arsene ) Comsat 31B May 13 0007 Navstar GPS 37 Delta 7925 Canaveral Navsat 32A Reentries --------- Apr 17 Discovery Landed at KSC Apr 29 Kosmos-925 Reentered May 6 Kosmos-2243 Reentered May 6 Columbia Landed at Edwards AFB Six small Gonets class communications satellites, Kosmos-2245 to Kosmos-2250, were launched into a 1400 x 1420 km orbit at an inclination of 82.6 degrees on May 11. The satellites are built by NPO Prikladnoi Mekhanikoi of Krasnoyarsk. It has been reported that the Kosmos-2243 recon satellite launched on Apr 27 was destroyed due to an explosion in the Blok-I third stage of the Soyuz launch vehicle near the end of third stage burn. Space Command cataloged the satellite (or its main fragment) as reentering on May 6. The Ariane launch vehicle made its much delayed first launch of the year on May 12. The main payload was the Astra 1C television broadcasting satellite for SES (Societe Europeene des Satellites, based in Luxembourg) and it will be stationed at 19 degrees E over the equator. This satellite is the fifth Hughes HS-601 comsat to be launched; two of the five have been lost in launch accidents. A second payload was the ARSENE satellite built by the French amateur radio group RACE (Radio Amateur Club de L'Espace). This launch was the first flight of the Ariane 42L variant, with two liquid strapon boosters. The basic Ariane 4 variant without strapons is the 40, which has made two flights. The 42P (4 flights) and 44P (2 flights) have two and four liquid strapons; the 44LP (6 flights) has two liquids and two solids; and the 44L (13 flights) has 4 liquid boosters. Ariane 4 has made a total of 28 flights of which one was a failure. Its main rival, the Delta II, has now made 34 flights with no failures. The latest Delta II flight also marked the 600th launch of McDonnell Douglas' Thor first stage. The Thor started life in 1957 as an intermediate range ballistic missile; it is one of the most used large rocket stages, beaten only by the Minuteman (about 760 launches of the M55A1/M55E1 first stage) and OKB-1's R-7 ICBM (at least 1490 launches, of which 1424 put a payload in orbit, since pre-Sputnik suborbital tests in 1957 to the Apr 27 launch of Kosmos-2243). The Delta's payload was a Rockwell Navstar navigation satellite GPS/SVN 37, which carries an atomic clock and operates in a 20000 km high circular orbit. The last Navstar launch, GPS/SVN 31, carried an interesting secondary payload, the SEDS tether experiment. Enrico Lorenzini, one of the scientists involved in the experiment, graciously gave me some technical details on the mission, so I include a detailed recap of the flight below. Opinions and errors are, of course, mine. The SEDS 1 Mission ------------------- Space tethers were experimented with on the Gemini XI and XII missions in 1966 with the idea of eventually using them to provide artificial gravity. At the time the true potential of space tethers was not understood. Recent theoretical work has led to the idea that long tethers can be used to generate electricity, alter a spacecraft's orbit, and deliver probes to study the upper atmosphere. In August 1992 an ambitious Italian Space Agency experiment on the Shuttle, TSS-1, attempted to deploy a long tether. However, there were problems with the deployer mechanism and the tether only got out to a quarter of a kilometre. Although a lot was learned about tether dynamics during retrieval - a time when the tether is least controllable - the mission was a failure. The first fully successful tether mission was carried out on 1993 Mar 30. The SEDS (Small Expendable Deployer System) consisted of a small 10 kg deployer cylinder 33 cm long and a tiny 23 kg satellite (`end mass') of similar size. The satellite was connected to the cylinder by a rope made of Spectra-1000 which was 0.75 mm in diameter and 20 km long. The cylinder remained attached to the Delta second stage rocket in orbit. Here is a log of the mission events. 1993 Mar 30 Time (UTC) 0309 A Delta model 7925 launch vehicle, Delta 219, ignited on Launch Complex 17A at Cape Canaveral. 9 solid Hercules GEM strapon boosters and an Extra Extended Long Tank Thor liquid first stage propelled the Delta onto a suborbital trajectory. 0314? The Delta ignited its single Aerojet AJ10-118K engine for the first time. 0320? Delta main engine cut off; the spacecraft entered a 184 x 746 km orbit inclined 34.0 deg to the equator. 0321? The Delta's main payload separated: a PAM-D solid rocket carrying the Navstar GPS 31 navigation satellite. 0330? The PAM-D ignited, placing itself and GPS 31 in an elliptical 150 x 20415 km orbit inclined 34.8 degrees. The GPS 31 would later fire its internal Star 37 solid motor to end up in a 20000 km circular orbit. 0412 Delta 219 reached first apogee at 746 km. The SEDS-1 end mass was released from the deployer cylinder and began to unreel down towards Earth. 0527 The SEDS-1 end mass was now 20 km below Delta 219 - at the end of its tether (pun intended). The end mass was allowed to swing back and forth on the tether like a huge pendulum so its dynamics could be studied. 0541 A knife on the deployer cylinder aboard Delta 219 cut through the tether, while Delta 219 was at its second apogee. The end mass now found itself free in orbit at an altitude of 726 km. However, the combination of the backwards speed it picked up while swinging on the tether and the lower altitude meant that its new orbit was -50 x 726 km x 34.0 deg, with a perigee 50 km below the surface of the Earth. 0612 Delta 219 reignited its main engine to use up excess fuel. Earlier Deltas had exploded in orbit because of leftover fuel, so this maneuver was introduced to reduce the pollution of orbital debris. The Delta ended up in a 305 x 1300 km orbit inclined 36.2 deg. 0616 The path of the SEDS end mass, following its orbital trajectory, intersected the atmosphere 100 km above the Pacific Ocean just south of Baja California. The end mass and the attached tether burned up on reentry, and the SEDS 1 mission was at an end. The SEDS system was developed and built by NASA-Marshall, the Harvard-Smithsonian Center for Astrophysics, and Tether Applications of San Diego, CA; the end mass was built by NASA-Langley. A second SEDS mission this summer will investigate the electromagnetic properties of space tethers. Current Shuttle Processing Status ____________________________________________ Orbiters Location Mission OV-102 Columbia OPF Bay 2 STS-58 OV-103 Discovery OPF Bay 3 STS-51 OV-104 Atlantis Palmdale OMDP OV-105 Endeavour LC39B STS-57 ML/SRB/ET/OV stacks ML1/ ML2/STS-57/ET/OV-105 LC39B ML3/ .-----------------------------------------------------------------------------. | Jonathan McDowell | phone : (617) 495-7176 | | Harvard-Smithsonian Center for | | | Astrophysics | | | 60 Garden St, MS4 | | | Cambridge MA 02138 | inter : jcm@urania.harvard.edu | | USA | | '-----------------------------------------------------------------------------'