On the 7th of September at 8:42 a.m. Japan Standard Time, a H-IIA lifted off from the Tanegashima Space Center carrying the XRISM space telescope and the SLIM Lunar lander. This was the forty-seventh launch of a H-IIA with XRISM separating from the rocket 14 minutes and 9 seconds after launch and SLIM at about 47 minutes and 33 seconds after launch.
SLIM
Smart Lander for Investigating Moon, SLIM, is a seven-hundred kilogram lunar lander developed by JAXA, Japan Aerospace Exploration Agency. The lander is meant to demonstrate precision landing technology from Japan. The lander will head to the Moon over four months using a slow and fuel-efficient trajectory. For landing the spacecraft will fly like a conventional Lunar lander but before touchdown will transfer to a horizontal position and land on five fixed landing legs after a short free fall. If the spacecraft touches down successfully Japan would become the fifth country to land on the Lunar surface.
XRISM
X-Ray Imaging and Spectroscopy Mission, XRISM, is an X-ray astronomy spacecraft from JAXA, Japan Aerospace Exploration Agency, with a three-year planned mission duration. The agency aims to make breakthroughs in the studies of the universe's formation, outflows from galaxy nuclei, and dark matter.
What are the H-II rockets?
The H-IIA and H-IIB rocket are Japanese medium-lift expendable launch vehicles derived from the H-II rocket. All three H-II rockets burn liquid hydrogen and liquid oxygen on their first and second stages with either two or four solid rocket boosters attached to the first stage. All H-II rockets so far have been launched from Tanegashima Space Center in southern Japan. Mitsubishi Heavy Industries is the manufacturer of the H-II rockets.
H-II was the first to fly of the three and the least flown with seven launches with five successes and is currently retired. For engines H-II had one LE-7, producing 110 tons of thrust, on the first stage and one LE-5A, producing 12 tons of thrust, on the second stage. The first flight was on February 3rd 1994 and its last was on November 15th 1999. The rocket could have sent 10,060 kilograms to low Earth orbit or 3,930 kilograms to geosynchronous transfer orbit.
H-IIA was the next to fly and is the only one that remains an active launch vehicle, so far it has launched forty-seven times with only one failure. For engines the H-IIA has one LE-7A, producing 112 tons of thrust, on the first stage and one LE-5B, producing 14 tons of thrust, on the second stage. Its first flight was on August 29th 2001. H-IIA keeps its four-meter diameter up the entire vehicle, unlike the H-IIB. The rocket can send 10,000 or 15,000 kilograms to low Earth orbit and 4,100 or 6,000 kilograms to geosynchronous transfer orbit depending if two or four solid rocket boosters are used.
H-IIB was the last to fly launching nine times, all successfully, while active. For engines the H-IIB used two LE-7A's, producing 224 tons of thrust, on the first stage and one LE-5B, producing 14 tons of thrust, on the second stage. The first launch was on September 10th 2009 and flew for the last time on May 20th 2020. The rocket could have sent up to 19,000 kilograms to low Earth orbit or 8,000 kilograms to geosynchronous transfer orbit. The H-IIB did use a wider and taller first stage that was 38 meters tall and 5.2 meters wide, whereas H-IIA's first stage is 37.2 meters tall and 4 meters wide.