The Reusable Vehicle Testing (RVT) project was conducted by the Japanese Space Agency (JAXA) from 1998 until 2003. The project involved a series of experimental vehicles to test repeated flights of a reusable rocket. Four complete vehicles were developed during the project. The design of the experimental vehicles addressed various technical challenges for future Reusable Launch Vehicles (RLV) such as flight on demand, quick turnaround, higher performance, lightweight structures and materials.