The Japan Aerospace Exploration Agency (JAXA) completed its Mitsubishi Heavy Industries H-IIB rocket’s first stage firing test on 2 April, after delays caused first by a lack of coolant supply and then by a leak in the fire prevention system

The H-IIB rocket will launch the first H-IIB Transfer Vehicle (see above in the JAXA produced image) to resupply the International Space Station later this year. In a double first the launch will also be the MHI H-IIB’s maiden flight

The H-IIB is the H-II rocket but with a new first stage that has two engines not one. This multiple engine stage is a first for JAXA and that is the challenge

A now former European Space Agency ISS manager once told Hyperbola that he thought the Japanese were “very brave” to have such a double first. See JAXA’s successfull firing test text in the extended portion of this blog post

Below is the text from the JAXA statement about the test

The Japan Aerospace Exploration Agency (JAXA) and Mitsubishi Heavy Industries, Ltd. performed the first captive firing test (CFT) for the first stage flight model tank of the H-IIB Launch Vehicle on April 2, 2009 (Japan Standard Time,) at the Tanegashima Space Center. The test went smoothly as follows.

Test purpose
 -To verify the safety of firing two engines simultaneously.
 -To confirm the interface between the launch vehicle and the ground
  facility.
 -To confirm the countdown sequence up to liftoff.

Firing time
 2:00 p.m.

Firing duration
 10 seconds (10)

Main combustion pressure
 No. 1 Engine About 12.0 Mpa (11.7 to 12.9)  No. 2 Engine About 12.0 Mpa (11.7 to 12.9)

 Numbers in (   ) are scheduled values

We would like to express our profound appreciation to all people and parties related with this CFT. For your information, the weather at the time of the CFT was fine, wind was 2.7m/s from the north-east, and the temperature was 14.0 degrees Celsius.