Either of two Japanese-owned launch vehicles, H-1 and H-2, developed for heavier payloads by the National Space Development Agency (NASDA). ‘H’ refers to hydrogen, the vehicle's liquid fuel (used with liquid oxygen). The H-1, which launched nine satellites from 1961 to 1991, is no longer used. The two-stage H-2 rocket began launching spacecraft in 1994. A later version, H-2AF, was first launched in 2001; its sixth launch on 29 November 2003 failed to jettison a solid rocket booster and the rocket had to be destroyed.

The first stage of the H-2 is powered by an LE-7 engine that can develop a thrust of 86 000 kg. The second stage is powered by an LE-5A with a 12 000-kg thrust. The rocket, made of aluminium alloy, also has two solid-fuel boosters, one on either side of the first stage, which are jettisoned into the sea when their fuel is used up. NASDA developed a third-generation rocket, the H-2A, which first flew in 2001; the rocket has launched 34 times since, with a success rate being among the highest in the world. JAXA is conducting an H-IIA upgrade project to tackle issues concerning its ageing launch facility which needs a larger payload capacity.