Prospects for scramjet engines in reusable launch applications: A review

Partially or completely reusing launch vehicles significantly reduces expenses for manufacturing and testing in space missions. Thus, Reusable Launch Vehicles (RLV) can be a solution to achieving technological and financial goals associated with space programs. Scramjet engines have a higher specific impulse than rocket engines and the capability to operate efficiently at extremely high speeds. This paper reviews the requirements in reusable launch vehicle technologies and how the scramjet engines can be used with their advantages and limitations, and possible solutions to meet future requirements of reusable launch systems. The review covers different aspects of the launch requirements of a reusable launch vehicle, the applicability of scramjet in the RLV, and the key parameters to enhance the performance of the scramjet engine. With the possibility of hydrogen as fuel, it is inferred that the scramjet is a plausible candidate for the successful, sustainable, greener, and cost-effective operation of the RLV. The combination of Scramjet-RLV holds the promise of significantly bringing down the cost of space missions.