The HTV is an unmanned cargo transporter to be launched by the H-IIB launch vehicle (under development). It is designed to deliver up to six tons of supplies to the ISS in orbit at an altitude of about 400 kilometers and return with spent equipment, used clothing, and other waste material. The waste material will be incinerated when the HTV makes a re-entry into the atmosphere. This transport operation involves a rendezvous flight with and docking to the ISS, in a situation requiring a highly reliable transfer vehicle. The system is being developed based on the technical know-how accumulated through work on the Engineering Test Satellite VII (ORIHIME/HIKOBOSHI), and with the application of fuselage design techniques accumulated during the development of the H-II and H-IIA launch vehicles. When completed, the system will offer a low-cost and highly reliable means of transport to the ISS. It is expected that the practical operation of HTV will allow Japan to accumulate know-how that can serve as basic technology for its future projects on the Space Flyer Unit and on manned transportation.
HTV is four meters across and about 10 meters long, a size large enough to accommodate a sightseeing bus. It consists primarily of three parts: (1) A propulsion module installed at the rear and composed of main engines for orbit change, Reaction Control System (RCS) thrusters for position control, fuel and oxidizing reagent tanks, and high-pressure air tanks; (2) An avionics module installed in the center part, with electronic equipment for guidance control, power supply, and telecommunications data processing; and (3) A logistics carrier that stores supplies. JAXA will broadcast a live launch report of the H-IIB Launch Vehicle with the HTV Demonstration Flight onboard from the Tanegashima Space Center and the docking of the HTV to the International Space Station through the Internet as well as at some public viewing sites.
