A proposed ground- based apparatus would accelerate a spacecraft to speed of about mach 1, thus making it possible to increase the payload and/or reduce the cost of launching the space- craft into orbit. The apparatus would include a track along which the spacecraft would ride on a sled. Hundreds of small water jets energized by compressed-air packs would be located under, and at small intervals along, the track. Each jet would be activated in turn as the sled passed by, aiming a high-speed (possibly supersonic) stream of water at baffles on the underside of the sled. The force of water impinging on the baffles would provide levitation and accelerate the sled along the track. Unlike a previously proposed launch-assisting linear electric motor, the water-jet apparatus would function without need for expensive electric-power-conditioning equipment. Unlike another launch-assist concept involving a piston driven along a pneumatic tube, the present concept does not present problems of how to (1) couple the piston to the sled and (2) exert fine control over acceleration. Another advantage of the water-jet concept is redundancy: even if several water jets were to malfunction, the remaining many functional water jets should suffice.

This work was done by Robert Youngquist and Frederick Adams of Kennedy Space Center. For more information, contact the Kennedy Commercial Technology Office at 321-867-8130. KSC-12257

NASA Tech Briefs Magazine

This article first appeared in the August, 2002 issue of NASA Tech Briefs Magazine.

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