Jonathan's Space Report No. 472 2002 Feb 16 Cambridge, MA ------------------------------------------------------------------------------- Shuttle and Station -------------------- The next Shuttle launch is STS-109, the Hubble Servicing Mission 3B. Orbiter OV-102 Columbia will fly to rendezvous with HST, grapple it with the RMS and berth it on the FSS pallet in Columbia's payload bay. In the course of five spacewalks, the crew will install new equipment on HST. This is the first flight of Columbia since the launch of Chandra in 1999; it's been in the garage undergoing refurbishment. In the first two spacewalks, two new solar arrays will be installed, and the two old arrays will be stowed on the RAC carrier. The RWA-1R reaction wheel assembly on the MULE carrier will replace the faltering RWA-1 in the telescope. The third spacewalk is the most difficult, as HST will be entirely powered down while astronauts replace its power controller unit, not designed for on-orbit replacement. They'll have to cover some key equipment with thermal blankets before the shutdown. The fourth spacewalk will see the astronauts remove the European FOC camera, aboard HST since launch in 1990, and replace it with the new ACS (Advanced Camera for Surveys). They will also install the CASH wire harness, part of the aft shroud cooling system. On the final spacewalk, the astronauts will install the NCS (NICMOS cooling system) cryocooler in the aft shround and the associated NCS radiator on the telescope's exterior. The NICMOS infrared camera has been idle since its original thermal control system failed, and it's hoped that NCS will allow it to resume science. On the next servicing mission, an extra cooling system, the ASCS, will be connected to ACS and STIS. Jonathan's cargo manifest estimate: Mass/kg (middeck) 4 EMU spacesuits 480? Bay 4 RAC (Rigid Array Carrier) 2393 Bay 7-8 SAC (Second Axial Carrier) 2517 Bay 11 FSS (Fixed Servicing Structure) 2111 Bay 12 MULE (Multi Use Light Eqpt Carrier) 1409 Sill RMS arm No 201 410 ------------------------------------------------------------------------- Total 9320? The RAC carries the two folded SA-III rigid solar arrays which will replace the SA-II roll-up arrays. It calso carries the DBA2 diode box assembly which controls the arrays, and a wire harness and containers associated with the NICMOS cooling system. The RAC is a Spacelab pallet, and it's possible that it is the same pallet that flew as ORUC on the three earlier servicing missions (and probably on earlier flights, but I don't know the pallet's serial). The SAC is a specially designed pallet that flew on the first two Hubble SM flights, STS-61 and STS-82. On this flight it carries the ACS camera up (and the FOS camera down) as well as the NCS cryocooler, the PCU-R power controller, the CASH wire harness, and the thermal covers used in the PCU replacement. The FSS first flew on STS 41-C (the Solar Max Repair) and was reused for each of the HST SM flights. It carries the BAPS Berthing and Positioning System, which is the docking ring for HST. Stowed on the FSS are a support post for BAPS and a cover for the HST low gain antenna. The MULE carries the NCS radiator, the NCS electronics support module, and the RWA-1R reaction wheel unit. MULE first flew on STS-48 carrying the UARS satellite, and then on STS-95 carrying the HOST payload which tested out the NCS. With the removal of FOC, the COSTAR device (which deployed contact lenses for the original instruments) is obsolete, since the newer instruments make the corrections to the incorrect HST mirror internally. A final servicing mission will replace WFPC-2 and COSTAR with the WFC-3 and COS instruments. Let's review the list of HST instruments in each of the five instrument bays: Radial instrument: WFPC (1990-1993) Optical imaging WFPC-2 (1993-2004?) Optical imaging WFC-3 (2004?) Optical imaging (planned) Axial +V3/+V2: FOC (1990-2002) UV imaging ACS (2002?-) Optical/UV imaging Axial +V2/-V3 HSP (1990-1993) Photometer COSTAR (1993-2004?) Corrective optics for FOC, GHRS, FOS COS (2004?) Spectrograph (planned) Axial -V3/-V2 GHRS (1990-1997) High res spectrograph STIS (1997-) Spectrograph Axial -V2/+V3 FOS (1990-1997) Low res spectrograph NICMOS (1997-) IR imaging Launch of STS-109/HST SM-3B is scheduled for Feb 28. Crew are Scott Altman (commander), Duane Carey (pilot), Nancy Currie (flight engineer), John Grunsfeld (payload commander and spacewalker), Rick Linnehan, James Newman, and Michael Massimino (mission specialists and spacewalkers). Grunsfeld, on his fourth flight, is the Ph.D. astronomer on the crew, and we his earthbound colleagues will be eagerly looking over his shoulder and wishing him well. The International Space Station lost attitude control on Feb 4 for several hours. After Zvezda computers developed communications problems and failed to transfer data to the US gyros on the Z1 module, the GNC MDM computer on the US side stopped stabilizing the station. The computer problems also prevented Z1 from handing over control to the backup thruster system on Zvezda.. At 1318 UTC the Station tumbled, in danger of losing electrical power, and experiments were shut down as systems were put in emergency mode. In fact, the crew were able to manually point the US solar arrays, preventing any loss of power. The station was restored to operation later in the day, with attitude control resuming at 1843 UTC on thrusters and 1920 UTC on gyros. Although I don't think this situation endangered the crew, it was still potentially quite serious - more so perhaps than the tone of NASA's press release would lead one to believe, and indeed an internal status report admitted `free drift with GNC MDM nonfunctional can become quite problematic'. The rapid response of ground controllers and crew in fixing things is good news and shows that even when the station's systems are massively degraded, it can be recovered (albeit one would rather not reach that point in the first place). Losing attitude control can be really bad news - Japan's Yohkoh observatory is still cold and almost dead two months after a comparable problem, and is unlikely to be revived. Of course, spacecraft with human crews are built with more redundancy anyway, and as in this case the astronauts contribute to keeping the systems going, so such vehicles are less likely to be lost, but some observers of the Station program had expressed concern that its fault-tolerance margins were too slim. Recent Launches --------------- Japan's second H-2A rocket was launched on Feb 4. The MDS-1 was deployed successfully but no contact has been made with DASH. The H-2A rocket is developed by Japan's applications space agency NASDA. The first launch used the basic H-2A 202 variant with the 4S fairing. The 202 consists of two SRB-A large solid boosters, the cryogenic H-2A main stage with the LE-7A engine, and the H-2A second stage with a cryogenic LE-5B engine. This second H-2A was the 2024 variant, which features an extra set of four smaller Thiokol Castor IVXL solid boosters in addition to the two SRB-As. It used the 4/4D-LC fairing which has an extra cylindrical adapter containing a second payload. On this test flight, the upper satellite position was basically empty, but attached to the adapter was the VEP-3 monitoring payload and the DASH reentry test satellite. The main payload, MDS-1, was carried in the lower position. Launch was at 0245 UTC from Tanegashima Space Center's Yoshinubu complex. The second stage began its first burn at 0251 UTC and at 0257 UTC entered a 500 km circular parking orbit. After a 12 minute coast the second burn put stage 2 in geostationary transfer orbit. At 0315 UTC the small DASH vehicle was meant to separate from the upper adapter, but this apparently did not occur. At 0325 UTC VEP-3/upper adapter/DASH combination separated from the second stage, followed by two semi-cylindrical side panels, revealing the previously enclosed MDS-1 satellite which was ejected at 0331 UTC. At 0425 UTC the second stage was scheduled to make a third burn to test engine restart, completing the H-2A-2F mission. MDS-1 is NASDA's Mission Demonstration Satellite, built by NEC with a mass of 449 kg. The satellite is a technology demonstrator to flight-qualify commercial subsystems, including a parallel computer, a solid state recorder, a nickel-hydrogen battery, and solar cells. It carries a space environment experiment to monitor heavy ions and magnetic fields. MDS-1 is 3.3m by 1.6m in size after deployment of its two solar panels. The upper adapter is a 1.0m long 4.0m diameter cone, with a mass of perhaps 100 kg or so. The VEP-3 launch instrumentation package mounted on top has a mass of 33 kg. The side adapter panels are halves of a 4.1m long 4.0m diameter cylinder. DASH (Demonstrator of Atmospheric Reentry System and Hypervelocity) is a small secondary payload built by ISAS, the scientific space agency whose operations are to be merged with NASDA over the next few years. DASH's mission was to test the reentry system for the MUSES-C asteroid probe. The main spacecraft is 0.7 x 0.5m in size with a mass of 70 kg including the solid deorbit motor and two small orbit adjust thrusters. Attached to this is a reentry capsule which is 0.4m in diameter and 0.2m high, with a mass of only 16 kg. The plan was to fire the deorbit motor three days after launch, then separate the reentry capsule which would enter the Earth's atmosphere at 10 km/s and land in the Hodh el Gharbi region of Mauritania at about 8.5W 17.2N. Typical satellite reentries are at only 7.5 km/s, while hyperbolic (escape) velocity at the top of the atmosphere is over 11 km/s, so DASH would have been travelling much faster than typical reentry vehicles, but not quite at escape velocity. Space Command has cataloged three objects in a 480 x 35740 km x 28.5 deg orbit. These three objects are presumably MDS-1, the DASH/VEP-3/adapter combination, and the H-2A second stage, but it is not yet clear which is which or where the side adapter panels are. Orbital Sciences successfully launched a Pegasus XL rocket on Feb 5, carrying NASA's HESSI solar telescope into orbit. The L-1011 Stargazer aircraft took off at 1929 UTC from the Cape Canaveral Skid Strip RW30/12, and headed out to the drop area at 28.0N 78.5W over the Atlantic. Drop was at 2058 UTC, with ignition 5 seconds later. The three stage Pegasus reached orbit at 2107 UTC and separated from HESSI a minute later in a 588 x 609 km x 38 deg orbit. On the first pass it was confirmed that the solar panels had opened. HESSI, the sixth Small Explorer, is a Spectrum Astro satellite derived from the SA-200S design, with a mass of 304 kg carrying a rotating modulation collimator transform telescope. The satellite rotates at 15 rpm, imaging hard X-ray flares from the Sun by reconstructing the Fourier components from the time modulation of the flux through a set of 9 grids each 9 cm in diameter. It is expected to make images with a resolution of 2 arcseconds at 40 keV energies and 36 arcseconds at 1 MeV energies. Launch delays mean HESSI has missed some of the best flares at solar max, but it should still see quite a few reasonably big ones. Five Motorola Iridium satellites were launched from Vandenberg on Feb 11 by a Boeing Delta 7920-10C rocket. The satellites are owned by Iridium Satellite LLC, the new company that bought out the bankrupt Iridium LLC, and this is the first system replenishment launch since the bankruptcy. If anyone knows the individual designations or serial numbers of the five new satellites, please let me know and I'll update everyone in the next report. Table of Recent Launches ----------------------- Date UT Name Launch Vehicle Site Mission INTL. DES. Jan 16 0030 Milstar FLT-5 Titan Centaur Canaveral SLC40 Comms 01A Jan 23 2347 Insat 3C Ariane 42L Kourou ELA2 Comms 02A Feb 4 0245 MDS-1 ) H-2A Tanegashima Tech 03A DASH ) Tech 03 VEP-3 ) Tech 03 Feb 5 2058 HESSI Pegasus XL Canaveral Astronomy 04A Feb 11 1743 Iridium ) Delta 7920 Vandenberg SLC2W Comms 05A Iridium ) 05B Iridium ) 05C Iridium ) 05D Iridium ) 05E Current Shuttle Processing Status _________________________________ Orbiters Location Mission Launch Due OV-102 Columbia LC39A STS-109 2002 Feb 28 HST SM-3B OV-103 Discovery VAB Maintenance OV-104 Atlantis OPF Bay 2? STS-110 2002 Apr 4 ISS 8A OV-105 Endeavour OPF Bay 1? STS-111 2002 May 2 ISS UF-2 .-------------------------------------------------------------------------. | Jonathan McDowell | phone : (617) 495-7176 | | Harvard-Smithsonian Center for | | | Astrophysics | | | 60 Garden St, MS6 | | | Cambridge MA 02138 | inter : jcm@cfa.harvard.edu | | USA | jmcdowell@cfa.harvard.edu | | | | JSR: http://hea-www.harvard.edu/~jcm/space/jsr/jsr.html | | Back issues: http://hea-www.harvard.edu/~jcm/space/jsr/back | | Subscribe/unsub: mail majordomo@head-cfa.harvard.edu, (un)subscribe jsr | '-------------------------------------------------------------------------'