Orbital and Rockwell are developing the X-34 small re-usable launcher in an industry-led/government-assisted partnership with NASA. The companies have formed joint-venture American Space Lines - "an American Arianespace" - to develop, operate and market the air-launched X-34 and will together invest $100 million in the enterprise, with NASA contributing $70 million to develop and test X-34 technologies.
The two companies own roughly equal shares in the venture, with Orbital as the managing partner and five NASA centres as "subcontractors". Sub-orbital flight tests are scheduled to begin in late 1997, leading to a first orbital launch in 1998 and two NASA RLV-technology testbed missions in 1998 and 1999.
There are two parallel agreements, explains Orbital's Elias. The first, between Orbital and Rockwell, covers development and commercialisation of a small re-usable launch vehicle and extends beyond development of the X-34 itself. The second agreement, between the team and NASA, terminates at the end of the development phase, after which NASA becomes a customer.
The X-34 design goal is to reduce the launch cost for lightweight satellites by a factor of three relative to Orbital's current Pegasus and Taurus small commercial launchers. These boosters have already reduced launch costs by a factor of two to three relative to the previous-generation Scout small launch vehicle, says Elias.
The X-34 is an air-launched, mostly re-usable, two-stage launcher consisting of a liquid-fuelled fully re-usable booster and a low-cost, expendable, orbital vehicle carrying the satellite. After separation from the carrier aircraft, the booster will ascend to 95km and accelerate to Mach 12 to release the orbital vehicle. The booster will then re-enter the atmosphere and land horizontally on a conventional runway, be refurbished and be prepared for another flight, in less than 20 days.
The booster will have an all-composite structure, re-usable cryogenic fuel-tanks and an advanced thermal-protection system. Liquid-oxygen/kerosene propulsion will be used for low-cost ease of operation, and for environmental reasons, and the team plans to modify an existing expendable rocket motor to extend its life over several missions.
By the end of the development phase, the Orbital/Rockwell venture plans to have in place the infrastructure for commercial launch-services, using the X-34. Orbital's own Lockheed L-1011 TriStar, used to launch the Pegasus, and NASA's Boeing 747 Shuttle Carrier Aircraft are being considered as launch platforms, says Elias.
The team is examining two design options: an X-34A able to loft a 550kg payload into low-Earth orbit after launch from the L-1011; and a larger X-34B, able to place a 1,150kg payload into orbit after release from the 747. A selection between the 35,000kg gross-weight X-34A and 50,000kg X-34B will be taken in May.
Commercialisation will require the capability to produce the expendable orbital vehicles at a target cost and this will be developed outside the NASA agreement. The small orbital stage will account for 10% of total launch-vehicle mass.
Source: Flight International
