A Conceptual System Design Study for a Linear Aerospike Engine Applied to a Future SSTO Vehicle

For application to a reference single-stage-to-orbit (SSTO) vehicle, a con-ceptual study of an aerospike engine was conducted. The aerospike engine employs an expander-bleed cycle. Resulting thrust at sea-level was about 1300 kN, and resulting specific impulse in a vacuum was more than 455 sec. Thrust and specific impulse satisfy the requirements of the vehicle. Based on these engine-cycle analyses, engine weight analyses were conducted. The estimated thrust-to-weight ratio was less than 35, which cannot satisfy the required value of 45 of the vehicle. Use of lightweight materials was investigated. By changing materials, aerospike engine weight was significantly reduced. The achieved thrust-to-weight ratio was about 50. The resulting aerospike engine sufficiently satisfied all the requirements of the vehicle.