H-I

H-1

Mission Profile

The H-I (H-1) was a three-stage Japanese launch vehicle in the Delta family, a domestically improved variant of the American Delta series using a Japanese-designed cryogenic upper stage. Standing 40.3 m tall with a 2.4 m diameter and a liftoff mass of 139 tonnes, it generated 1,563 kN of liftoff thrust and could deliver 3,200 kg to low Earth orbit or 1,080 kg to geostationary transfer orbit. First flying in August 1986, the H-I launched Japanese communications and broadcasting satellites and represented a critical stepping stone toward the fully indigenous H-II.