The launch of Japan's next space station resupply craft will likely be rescheduled for next June, giving engineers time to make up testing of the freighter's H-2B rocket after the deadly earthquake in March, according to NASA and Japanese space officials.

File photo of an H-2B rocket launch from Tanegashima Space Center in Japan. Credit: JAXA
 
The timing of the launch, which was previously expected in February, will also permit two U.S. commercial logistics vehicles to fly to the International Space Station in the first half of 2012.

The H-2 Transfer Vehicle is Japan's robotic spaceship for delivering scientific equipment, clothing, food, maintenance gear and unpressurized experiments and spare parts. The disposable craft completed two successful flights in 2009 and 2011.

Japan developed the H-2B rocket, a beefed-up version the proven H-2A launcher, to loft HTV payloads into orbit.

Major components of the third HTV were delivered to the launch site on Tanegashima Island this summer, but hardware for the mission's H-2B launch vehicle has not been delivered, according to Makoto Miwada, a senior spokesperson at the Japan Aerospace Exploration Agency.

Miwada said the H-2B rocket, which consists of two liquid-fueled stages and four solid rocket boosters, is almost complete at Mitsubishi Heavy Industries Ltd. in Nagoya.

"The big earthquake in March affected the manufacturing and test schedule by several weeks, but the related manufacturers as well as JAXA engineers did tough work to recover the schedule," Miwada said.

The 9.0-magnitude quake March 11 spawned a powerful tsunami and damaged JAXA's space station control center in Tsukuba, Japan.

The second HTV spacecraft approached the space station in January 2011. Credit: NASA
 
According to Miwada, a delay in the launch of HTV 3 beyond April 1 would need to be addressed within the next Japanese government budget. The Japanese fiscal year begins April 1.

"A new schedule requires coordination of budget postponement, and we need some time," Miwada said.

NASA space station officials have penciled in the HTV flight for liftoff June 26. The 32-foot-long, barrel-shaped would approach the space station six days later for capture with the lab's robot arm.

Miwada said JAXA has yet to formally agree to the date change.

The mission will haul various supplies, a Japanese experiment package designed to observe the atmosphere, and a NASA space communications and navigation testbed.

Space station managers must carefully coordinate flights of international resupply freighters because the HTV and two planned U.S. vehicles use the same berthing port on the outpost's Harmony connecting module.

SpaceX's privately-developed Dragon spaceship and the Orbital Sciences Corp. Cygnus spacecraft require access to the same port as the HTV.

The station manifest currently calls for SpaceX to launch its Dragon capsule to the complex in January, followed in May by the first flight of the Cygnus craft. Both missions will demonstrate the Dragon and Cygnus for the first time in close proximity fo the space station.

NASA tapped SpaceX and Orbital to resupply the space station in the wake of the space shuttle's retirement.