H-II

H-II

H-II rocket at Tsukuba science museum & planetarium
Function	Medium-lift launch vehicle
Manufacturer	Mitsubishi Heavy Industries Nissan Motors (sub) Alliant Techsystems (sub, for the SRBs)
Country of origin	Japan
Size
Height	49 m (161 ft)
Diameter	4 m (13 ft)
Mass	260,000 kg (570,000 lb)
Stages	2
Capacity
Payload to LEO
Mass	10,060 kg (22,180 lb)
Payload to GTO
Mass	3,930 kg (8,660 lb)
Associated rockets
Family	H-II family
Based on	H-I
Derivative work	H-IIA, H-IIB
Comparable	Ariane 4
Launch history
Status	Retired
Launch sites	Tanegashima, LA-Y1
Total launches	7
Success(es)	5
Failure(s)	1
Partial failure(s)	1
First flight	3 February 1994
Last flight	15 November 1999
Boosters
No. boosters	2
Maximum thrust	1,540 kN (350,000 lbf)
Specific impulse	273 s (2.68 km/s)
Burn time	94 seconds
First stage
Powered by	1 × LE-7
Maximum thrust	1,078 kN (242,000 lbf)
Specific impulse	446 s (4.37 km/s)
Burn time	346 seconds
Propellant	LH2 / LOX
Second stage
Powered by	1 × LE-5A
Maximum thrust	121.5 kN (27,300 lbf)
Specific impulse	452 s (4.43 km/s)
Burn time	600 seconds
Propellant	LH2 / LOX
[edit on Wikidata]

The H-II (H2) rocket was a Japanese satellite launch system, which flew seven times between 1994 and 1999, with five successes. It was developed by NASDA in order to give Japan a capability to launch larger satellites in the 1990s.^[1] It was the first two-stage liquid-fuelled rocket Japan made using only technologies developed domestically.^[2] It was superseded by the H-IIA rocket following reliability and cost issues.