The JAXA HTV can carry up to six tons of supplies during a single trip, with food, water, mechanical, and computer hardware its most likely cargo on its trips.  It is 10 meters long with a 4.4-meter diameter and will be launched into space using a JAXA H-2B launch vehicle.  The cargo ship will roll out this fall with JAXA planning to introduce at least one craft per year.

Each HTV costs $131 million for JAXA to construct, and utilizes construction help from Mitsubishi Electric and Mitsubishi Heavy.  Considering the high price tag of the HTV, people left and right started popping up wondering if NASA truly was going to be willing to purchase several of these multi-million transport ships that JAXA plans to roll out slowly.

Why the concern over transport ships to get supplies to the ISS?

The U.S. space agency traditionally used the space shuttle to help send supplies and astronauts to the ISS, but with the shuttle retiring and an anticipated five-year gap until the Orion space capsule is available, NASA still has an obligation to help supplies reach the ISS.  Along with purchasing an unspecified number of HTV vehicles from Japan, NASA will pay the Russian space agency for its services of ferrying supplies to space.

The ISS is currently stocked by the U.S. spacecraft, Russian and European spacecraft, with JAXA announcing plans several years ago to create its own cargo spacecraft to help offer aid in shipping supplies to space.

But NASA today issued a press release stating it hasn't been in negotiations to purchase the HTV from JAXA, instead stating it is "committed to domestic commercial cargo resupply to the space station and does not plan to procure cargo delivery services from Japan."  NASA is working with several private contractors to build a new spacecraft to get food, water and other supplies to the International Space Station, but it is unknown if the project can be concluded before 2010.

The rest of the NASA press release states the following:

As part of our original agreements as compensation for common system operating costs NASA has limited cargo capability on the Japanese and European cargo vehicles. NASA has recently issued a request for proposal for the cargo needs of International Space Station beyond those supplied by our current international agreements. NASA has chosen to depend on commercial resupply of cargo delivery to the station.

E-mails to JAXA and NASA were not answered in time for publication of this article.