The unmanned craft will carry supplies to the ISS

Sep 10, 2009 08:06 GMT  ·  By
A comparison of available unmanned cargo delivery systems, from Russia (Soyuz and Progress), Europe (ATV) and Japan (HTV)
   A comparison of available unmanned cargo delivery systems, from Russia (Soyuz and Progress), Europe (ATV) and Japan (HTV)

The Japanese space agency JAXA is currently entering the latest stages of preparations for its first H-2 Transfer Vehicle (HTV) launch, scheduled for later today, at 1701 GMT. The new mission will also mark another premiere, as the craft will rise to low-Earth orbit aboard a new H-2B rocket, a more powerful design than its H-2 predecessor, able to carry a much bigger cargo to orbit. The rocket was never tested in a mission before, and the cargo module it carries is equally new, Space reports.

“From the JAXA perspective this is a test flight. But we will bring several payloads to support ISS logistics and crew,” JAXA Houston Office Deputy Manager Masazumi Miyake explains. The take-off will see the HTV-1 vehicle rising from the Tanegashima Space Center, in southern Japan, carrying some 3.5 tons of much-needed supplies for the orbital outpost. However, if the flight is successful, then the next couple of days could mark one of Japan's greatest space achievements.

With the space shuttles currently scheduled to be retired by 2010 or 2011, there is a growing need for alternative ways of delivering astronauts and supplies to the ISS. The Russian Soyuz capsule can take care of the human part of the project, while the Europeans are planning on buying one capsule each year, so as to send their astronauts aboard the station. The European Space Agency (ESA) also has the Automated Transfer Vehicle (ATV) cargo spacecraft at its disposal, while the Russians have their Progress systems. Now, the Japanese craft could be added to the list, reducing the burden of the former two agencies.

“The launch vehicle is on its first flight, but most components and subsystems are the same as H-2A launch vehicle. The difference is that we have four [solid rocket] boosters rather than the two on H-2A, and two main engine thrusters rather than the one on H-2A,” Miyake adds. At 187 feet (57 meters) in height, the new rocket needs to reach very high standards. Its predecessor has registered just one failure in 15 launches, which ranks it as one of the most effective delivery systems out there today.