Japan plans in 2010 to drop-test a subscale engine that will accelerate to Mach 2 over Sweden's Esrange test area.
The Japan Aerospace Exploration Agency is developing the pre-cooled-cycle turbojet, the Small (S)-Engine, as a subscale testbed for air-breathing propulsion systems.
The S-Engine is 2.2m (7.2ft) long, 230mm (9in) wide, burns 0.06kg (0.13lb) of hydrogen per second and is expected to generate 269lb of thrust (1.2kN) with an initial specific impulse of 2,100s. A full-scale production engine would be used in the first stage of a two-stage to orbit launcher.
Originally planned for 2008, the engine is designed to ignite 30s after being released. For the drop test, the S-Engine is fitted to JAXA's balloon-operated vehicle, which looks like a missile, and raised to 131,000ft.
If it is successful, JAXA says that "a subscale engine could be ground-tested in 2011 and by 2018 another subscale engine could be flight-tested, but it will require an improved combustor and [related] materials".
In October 2009 the S-Engine to be air dropped was ground-tested using liquid hydrogen as the fuel. The 2010 drop test is the fourth for the balloon-operated vehicle, although it is to be called BOV three. Vehicles one, two and four were used for microgravity experiments.
Source: Flight International