During the early 1990s, Japan's National Space Development Agency studied a small unmanned spaceplane planned for launch in 1999 using its H-II rocket. This H-II Orbiting Plane, or HOPE spaceplane, was to be an 11-m-long, 10-metric-ton unmanned ballistically launched vehicle with a wingspan of 6 m. Its mission was to lift 1 metric ton of cargo to an American space station (which later became the ISS). Later, these specifications were upgraded in a HOPE-X unmanned experimental 13-m-long vehicle with a 9-m span, able to deliver 3 metric tons to ISS. The eventual goal was a manned HOPE spaceplane with a crew of four and a liftoff weight of 22 metric tons.
The original unmanned HOPE and its H-II booster rocket would lift off from the Tanegashima launch center, landing on a conventional runway at another location. As with other spaceplane concepts, HOPE would be an operational, reusable vehicle. It would carry no crew, relying instead on the US Space Shuttle to transport astronauts to and from the space station. The mission of the 10-ton vehicle would be to deliver a relatively small cargo of 1 ton to the Japanese Experimental Module, using the new H-II booster then under development.
From the beginning, it was recognized that this was not the most efficient way to launch cargo into space, since the H-II booster could just as easily deliver a 10-ton payload to low Earth orbit as it could a 10-ton spaceplane with 1 ton of cargo. And yet, this was not the sole motivation behind the concept. HOPE was to use a phased approach in eventually developing an air-breathing spaceplane able to lift itself all the way from a horizontal take-off to orbital space. The real value of HOPE was in its potential as a first-generation reusable vehicle leading eventually to an advanced spaceplane. With the dissolution of NASDA and the origin of JAXA, the HOPE spaceplane project ended by 2004 in favor of other priorities.5,6
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