Japan’s Kounotori 6 cargo carrier will get a boost from a powerful H-2B rocket to send the supply ship and its 4.5 tons of provisions and experiments on a four-day pursuit of the International Space Station.
The sixth H-2 Transfer Vehicle is set for liftoff at 1326 GMT (8:26 a.m. EST; 10:26 p.m. Japan Standard Time) Friday in an instantaneous launch opportunity to catch up with the space station.
The two-stage, 186-foot-tall (56-meter) H-2B rocket is Japan’s most capable launcher. It is an upgrade from the Japanese H-2A rocket.
The H-2B features two LE-7A first stage engines instead of one, four solid rocket boosters instead of the two normally aboard H-2A missions, and a first stage with a diameter of nearly 17.1 feet (5.2 meters), an increase from the 13.1-foot-wide (4-meter) core of the H-2A rocket. The H-2B’s first stage is also more than 3 feet — about 1 meter — longer than the H-2A’s first stage.
That allows the H-2B rocket to carry 1.7 times the liquid hydrogen and liquid oxygen propellants that can be flown on the H-2A, effectively doubling the heavier launcher’s lift capacity.
After liftoff, the H-2B will turn southeast over the Pacific Ocean, aligning with the International Space Station’s flight path. It will take about 15 minutes for the rocket to deliver the Kounotori 6 spacecraft to an initial orbit, kicking off its chase of the research complex.
A Russian Progress resupply and refueling freighter launched Thursday from the Baikonur Cosmodrome in Kazakhstan on top of a Soyuz booster. The cargo craft completed the fastest rendezvous in the history of the International Space Station program with a successful docking less than three-and-a-half hours later.
SpaceX completed Friday the last drop test of the Dragon crew capsule’s parachutes before the first launch of astronauts on the human-rated ship May 27, while technicians at Cape Canaveral have mated the spacecraft’s crew module with its unpressurized trunk section.
After four years of brainstorming, custom tool development and training, two astronauts plan to venture outside the International Space Station Friday for the first of four spacewalks to repair a $2 billion cosmic ray detector. The excursions are considered the most challenging since work to service the Hubble Space Telescope.