The Vehicle Evaluation Payload (VEP), renamed Myojo after launch, was a Japanese spacecraft that provided a ranging function as well as functions to measure the acceleration and deformation, in order to confirm the accuracy of the H-2 rocket orbit injection and understand the environment of the payload equipment. The Orbital Re-entry Experiment (OREX), renamed Ryusei after launch contributed to HOPE development by accumulating experience in designing and producing a re-entry vehicle and acquiring re-entry data which is difficult to acquire in ground experiments.
The H-II rocket was a Japanese satellite launch system which flew seven times between 1994 and 1999 with 5 successes. It was developed by NASDA in order to give Japan a capability to launch larger satellites in the 1990s. It was the first two stage liquid fuelled rocket Japan made using only domestic technologies.
