Launch failures put pressure on space station project
Tim Furniss/LONDON
Already four years behind schedule, the fledgling International Space Station (ISS) faces a crisis in 2000. The critical launch of the Russian Zvezda service module is on hold until the Proton booster can be cleared for flight again following two launch failures in the last 12 months.
Further launch failures or accidents in the coming months could spell disaster, as the ISS - and Russian participation in the project - comes under increasing pressure from the US Congress. The ISS consists of two components: the Russian Zarya control module and the US Unity node, which have been orbiting unmanned since May - longer than the much-maligned Mir space station operated unoccupied during its 12-year history. Mir is a further complication, with Russia keen to keep the station operational, and fearful of the safety implications of de-orbiting as planned in March.
According to schedules set in the late 1980s the ISS should have been completed by 1996, but this will not now take place until at least 2004. Further logistics and assembly missions - and the first expedition crew occupation - cannot proceed until the Zvezda is safely in orbit, so that it is once again inevitable that the ISS Space Shuttle schedule will be jeopardised.
The Proton is not the only booster facing make-or-break launches in 2000. The Boeing Delta III, with two failures in two launches, is set to fly again, and although officially manifested to carry an ICO Global Services communications satellite, the booster may well launch without an operational payload on what amounts to a demonstration flight to restore customer confidence.
With development of the Delta IV evolved expendable launch vehicle (EELV) under way and heading for a maiden flight in 2001, it seems likely that the Delta III will be shortlived, superseded by a Delta IV Medium vehicle which may take on some of the earlier-generation launcher's bookings. The Delta IV will also eventually take over the work of the elderly Delta II - still in service.
The maiden flight of the Lockheed Martin Atlas IIIA, meanwhile, is due early in 2000, carrying a Eutelsat satellite. This International Launch Services (ILS) commercial booster is the first US launcher to be powered by a Russian first-stage powerplant, the RD-180 derivative of the RD-170 used on the former Soviet Energia heavy lift booster.
In Europe, all eyes will be on the Ariane 5, which, with one failure, one partial success and one full success, needs a series of successful commercial missions in 2000 to enhance its reputation. If it flies as many successful consecutive missions as the Ariane 4 (numbering 49), it will be another success for Arianespace, which is just ahead in the commercial launcher market, with ILS - aided by government work - close behind.
The Boeing-led Sea Launch company is also poised to earn its laurels in 2000. Its booster of the same name is based on an uprated version of the Ukrainian Zenit 2 (again powered by an RD-170 first stage engine), together with a Russian third stage, designated the Zenit 3SL.
The booster has flown two missions from the Pacific to geostationary transfer orbit (GTO). A third Sea Launch mission, and a second commercial flight, is to carry an ICO satellite in late January. The Zenit 3SL offers a GTO transportation capability almost equal to that of the Ariane 5, although the latter can launch two payloads to the Sea Launch's one.
The Sea Launch and Ariane 5 will soon face competition from Boeing and Lockheed Martin derivatives of the EELVs, which could begin commercial flights in 2002, making a successful 2000 imperative. The EELVs are set eventually to replace the Atlas II-III, Delta III and Titan IV fleets. The latter, when it finally makes a further flight to make up for consecutive launches spoiled by upper-stage failures this year, will be having its swansong.
In the international market, it is possible that India may test-fly its Geostationary Satellite Launch Vehicle, the first versions of which will be powered by a Russian upper-stage engine. Japan's commercial hopes for the enhanced H2A booster were thwarted by an H2 failure in November, and it is unlikely that commercial customers will be attracted to the new H2A without at least two successful launches.
China, meanwhile, has demonstrated its prowess with the test launch of a new Long March 2F, which could lead to a manned mission, with two astronauts, as early as the end of of 2000. China's commercial launch backlog is small, thanks to restrictions imposed on US firms moving satellites to China for launches cheaper than those offered in the West.
The failure of two NASA Mars spacecraft - worth over $350 million in 1999 - will result in a detailed review of the US agency's future Mars plans and activities, and of administrator Dan Goldin's "faster, better, cheaper" policy.
ICO Global Communications plans its first launch in 2000, building a 10-satellite constellation providing worldwide mobile communications in operational medium-Earth orbit. Like bankrupt Iridium, ICO has experienced severe funding difficulties, and is not clear of trouble. While Globalstar is operational, and apparently free of the funding woes, market analysts will be watching the commercial viability the this market carefully.
Source: Flight International
