AAS 95-449

Effect of Laser Power Limitation on Single-Stage to GEO Launch

J.-S. Chern, Chung Shan Institute of Science and Technology, Lungtan, Taiwan, Z.-C. Hong and J.-M. Liu, National Central University, Chungli, Taiwan

Abstract

Investigations have been given to the optimal trajectory for vertical ascent to GEO. Two constraints have been considered, the thrust acceleration constraint is 2.5gR and the dynamic pressure constraint is 30000 N/m2. The peak laser power required for specific impulse of 1500 s and initial mass of 10000 kg is 4.5 GW. The purpose of this paper is to investigate the effect of laser power limitation on the payload ratio. The available peak laser power will be reduced from 4.5 GW to 4 GW, then to 3.5 GW, and so forth till 0.5 GW. If the ground station can provide the required peak laser power of 4.5 GW, the payload obtained is 10.80%. When the peak laser power is limited to 4.0 GW, the payload ratio is reduced to 9.80%. The variation of payload ratio as a function of the peak laser power is presented. When the peak power is limited at 2.7 GW, the initial thrust acceleration is reduced to 1.5gR only. Therefore, for even smaller peak laser power, the initial mass of the launching vehicle must also be reduced proportionally to obtain a meaningful launch.