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ALS General Dynamics
ALS General Dynamics -

Credit: Lockheed Martin. 22,715 bytes. 191 x 416 pixels.



Launch Vehicle: ALS.

In the late 1980’s the deployment of the ‘Star Wars’ ballistic missile defence system was expected to require launch of a small number of heavyweight chemical laser satellites, a moderate number of x-ray laser nuclear-pumped satellites, or a huge number of ‘brilliant pebble’ kinetic interceptors. Existing launch vehicles did not have the lifting capacity to support such a program and cost too much per launch. With the ALS, the Air Force hoped to develop a flexible, modular, heavy-lift, high launch rate vehicle with a factor of ten reduction over existing cost per kilogram of payload.

Seven contractors were awarded five million dollar, one year study contracts in July 1987, with the studies to recommend a family of modular boosters with low earth orbit payloads from 2,400 kg to 90,000 kg. The new launch vehicle was expected to make its first flight in 1998, reach full operational capability of up to 30 flights per year in 2000, and replace all existing expendable launch vehicles by 2005. The studies covered not only the launch vehicle but the ground support equipment as an integrated system. Unfortunately there was no single breakthrough new technology that would lead to a common conclusion by the contractors. Proposed were expendable and partially reusable vehicles; fly-back boosters and recoverable propulsion/avionics modules; use of existing engines, solid rockets, or various new liquid engines.

By late 1989 the cold war was winding down and ‘Star Wars’ was essentially dead. Even if the immense technical problems of developing an operational missile defence could be overcome, it had become possible to reduce or eliminate the ballistic missile threat using treaties rather than technology. Total development cost of ALS was estimated as $15 billion through its first flight in 1998, and the low launch rates expected could not pay back this investment, even with a substantial reduction in costs per launch. By 1990 the program was reduced to a $150 million per year propulsion development effort. However the technologies identified for use in ALS would be found in 1990’s upgrades to the space shuttle, the USAF Evolved Expendable Launch Vehicle program, and numerous commercial booster programs and proposals.


Launch Vehicle: NLS.

The New (or National) Launch System (NLS) followed the demise of the ALS and was yet another 1980’s proposal to develop a family of launch vehicles to replace existing ‘high cost’ boosters derived from 1950’s missile designs. This joint NASA/USAF effort was aimed at first launch of an NLS in 2002. NLS required development of these major new systems:

  • STME (Space Transportation Main Engine, a simplified, low-cost LOX/LH2 engine with 295,000 kgf
  • Family of three new launch vehicles to covering the payload weight classes expected in the 21st century
  • High-energy upper stage to reach geosynchronous orbits and interplanetary trajectories
  • Cargo transfer vehicle for transporting payloads to the (then) Space Station Freedom
  • New booster processing facilities and launch pads at Cape Canaveral Air Force Station
  • Modified and new facilities at the Kennedy Space Center.
Three versions of the NLS were planned:
  • NLS-1 heavy-lift vehicle consisting of core vehicle with four liquid-fuelled engines and two strap-on Solid Rocket Boosters. Payload of 45,000 kg to 400 km/28 degree orbit planned for Space Station Freedom
  • NLS-2 medium-lift vehicle, using only the core vehicle of the NLS-1. Payload capability of 23,000 kg to low Earth orbit (matching USAF’s heaviest payloads).
  • NLS-3 would use a single STME on a lower-diameter core stage, and could deliver 9,000 kg to low earth orbit. This would launch DOD and NASA medium class payloads and was expected to be a competitor in the international communications satellite launcher market
As in the case of the ALS, the NLS was estimated to cost $12 billion range to develop, including $2 billion for the STME engine. Again the development cost could not be recouped in recurring launch costs, and the NLS was terminated in 1991. Boeing attempted to stimulate government interest in development of the ‘Spacelifter’ version of its NLS design but failed. Since development costs were similar to development of a new airliner, Boeing obviously did not feel the actual operating cost of an NLS would be low enough to justify the development cost on a purely commercial basis

Launch Vehicle: NLS HLV. NLS Heavy Lift Version. Lower cost expendable launch vehicle studied by NASA/USAF in late 1980's.

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Last update 3 May 2001.
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© Mark Wade, 2001 .