LAUNCHERS, PROPULSION AND STABILIZATION SYSTEMS, AUTONOMOUS CONTROL

The European launch capability (Ariane 4 and in the future Ariane 5) has been commercialized by Arianespace into the world's foremost commercial launch system. Ariane has achieved good reliability while continually upgrading its capabilities, including multiple versions of Ariane 4 with solid and/or liquid strap-ons. It provides the only commercial dual-launch capability, which has enhanced its marketability for smaller payloads. It also has a natural advantage for geostationary satellites because of the low inclination of the Kourou launch site compared to Cape Canaveral.

The launch facility at Kourou is first rate, and the industrial development of the Ariane 5 launch site and solid rocket production facilities are extensive. Ariane has continued to upgrade its avionics and currently has a lead over existing U.S. commercial launches which were almost derailed by the hiatus caused by the STS commercial launch policy. Both Atlas and Delta are playing catch-up, with Atlas having the benefit of some Department of Defense (DoD) development support to upgrade its avionics. The Titan attempt at commercialization has had limited success, and is no longer marketed. In conclusion, the European program is fully supported and they are currently ahead.

The Japanese launch capability results from a long-term development managed by NASDA starting with the N-I and N-II programs (several launches, 1975 to 1986), followed by the H-I (nine launches, six to GEO orbit, 1986 to 1992) and H-II programs. The H-I is a 3-stage launch vehicle capable of launching a payload of approximately 1,100 kg into a geosynchronous transfer orbit. Performance details are listed in Figures 2.32, 2.33, 2.34, 2.35 and 2.36 and Tables 2.8, 2.9 and 2.10. The H-II launch vehicle currently under development has two stages; the first uses a new liquid hydrogen/liquid oxygen (LH(supscript 2)/LOX) engine (LE-7) with 100 t thrust in addition to two solid propellant boosters, the second stage uses an improved LE-5 engine (developed for H-I, also burning LH(subscript 2)/LOX. This launch vehicle is expected to launch a payload of approximately 4,000 kg into geosynchronous transfer orbit. First launch (ETS-VI) is expected in 1994 due to a setback in the test program of the LE-7 engine. Performance details are listed in Figures 2.37, 2.38, 2.39 and 2.40 and Tables 2.11, 2.12, 2.13, 2.14, 2.15 and 2.16. The J-I rocket is a small, 3-stage solid propellant launch system, intended as an economic, minimum-launch-operation type launcher. It is being developed from components of existing vehicles (the SRB of the H-II is the first stage). Payload capability is approximately 600 kg into 500 km circular orbit or 1 t into low earth orbit. First launch is expected in 1995. Performance details are listed in Figure 2.41, 2.42, 2.43, 2.44 and 2.45 and Tables 2.17 and 2.18.

The Japanese launch facility is located on Tanegashima, an island at latitude 30.5 degrees N located south of Kyushu. The Japanese commercial launch capability will be based on the H-II vehicle, which is one of the few new launchers specifically developed to use high efficiency propellants. Although the development program was not without problems, this launcher is expected to be a serious contender for the future commercial GEO communication satellite business.


Published: July 1993; WTEC Hyper-Librarian