GX (rocket)

Galaxy Express (GX)

GX (Shown with Atlas III first stage as in early development)
Function	Medium expendable Launch vehicle
Manufacturer	Galaxy Express (JAXA/ULA/IHI)
Country of origin	Japan/United States
Size
Height	48 m (157 ft)
Diameter	3.3 m (11 ft)
Mass	190,500 kg (420,000 lb)
Stages	2
Capacity
Payload to LEO
Mass	3,600 kg (7,900 lb)
Payload to 800km SSO
Mass	1,814 kg (3,999 lb)
Launch history
Status	Cancelled 2010
Launch sites	Vandenberg SLC-3E
First stage – Atlas CCB
Powered by	1 RD-180
Maximum thrust	4,152 kN (933,000 lbf)
Specific impulse	311 seconds (3.05 km/s)
Burn time	253 seconds
Propellant	RP-1/LOX
Second stage – GX
Powered by	1 LE-8
Maximum thrust	118 kN (27,000 lbf)
Specific impulse	323 seconds (3.17 km/s)
Burn time	480 seconds
Propellant	LNG/LOX
[edit on Wikidata]

GX was a design for an expendable launch system intended to compete in the commercial satellite launch sector. The system had developed by Galaxy Express Corporation, a joint venture between IHI Corporation (IHI), the Japan Aerospace Exploration Agency (JAXA), United Launch Alliance (ULA), Lockheed Martin Corporation (LM) and several other Japanese companies.^[1]

The GX design uses a two-stage rocket. The first stage would have been the Atlas Common Core Booster, currently used as the first stage of the Atlas V rocket, which would have been provided by United Launch Alliance.^[2] The second stage was to be a newly designed stage produced by IHI, using liquefied natural gas as fuel and liquid oxygen as an oxidizer. The GX would have been the only space vehicle to use that combination of fuel and oxidizer.

The Japanese government finally abandoned the GX program in December 2009. Galaxy Express disbanded around March 2010.^[3][4]