Assessment of VTVL and VTHL Reusable First Stages

Kurzfassung

Two-stage vertical take-off vertical landing (VTVL) and vertical take-off horizontal landing (VTHL) partially reusable launcher configurations are systematically analyzed. The investigated configurations consider a reusable first stage that either performs a landing at the launch site (return to launch site RTLS) or a landing downrange of the launch site (downrange landing DRL). The considered propellant combinations include LOX/LH2, LOX/LCH4 and LOX/RP-1. Configurations based on staged combustion and gas generator cycle engines are analyzed. The same engines however with different expansion ratios are used on the reusable first stages and the expendable upper stages. Special emphasis is put on analyzing the different configurations under similar design assumptions that allow a comparison of gross lift-off masses, stage lift-off masses, stage structural indices as well as loads encountered by the reusable stages during atmospheric reentry. Based on this comparison benefits and drawbacks of the investigated RLV configurations are discussed.