Epsilon (rocket)

Epsilon

Artist's impression
Function	Launch vehicle
Country of origin	Japan
Size
Height	24.4m
Diameter	2.5m
Mass	91t
Stages	3–4
Capacity
Payload to 250x500 km orbit 3 stages	1,200 kilograms (2,600 lb)
Payload to 500 km orbit 4 stages	700 kilograms (1,500 lb)
Payload to 500 km SSO 4 stages	450 kilograms (990 lb)
Launch history
Status	Active
Launch sites	Uchinoura
Total launches	2
Successes	2
First flight	September 14, 2013
First stage - SRB-A3
Engines	1 solid
Thrust	2,271 kN
Specific impulse	284 seconds
Burn time	116 seconds
Second stage - M-34c
Engines	1 solid
Thrust	371.5 kN
Specific impulse	300 seconds
Burn time	105 seconds
Third stage - KM-V2b
Engines	1 solid
Thrust	99.8 kN
Specific impulse	301 seconds
Burn time	90 seconds
Fourth stage (optional) - CLPS
Thrust	40.8 N
Specific impulse	215 seconds
Burn time	1100 sec. (max.)
Fuel	hydrazine

The Epsilon rocket (イプシロンロケット, Ipushiron roketto^?) (formerly Advanced Solid Rocket) is a Japanese solid-fuel rocket designed to launch scientific satellites. It is a follow-on project to the larger and more expensive M-V rocket which was retired in 2006. The Japan Aerospace Exploration Agency (JAXA) began developing the Epsilon in 2007. It is designed to be capable of placing a 1.2 tonne payload into low Earth orbit.

The development aim is to reduce costs compared to the US$70 million launch cost of an M-V. The Epsilon costs US$38 million (£23m) per launch, which is half the cost of its predecessor. Development expenditures by JAXA exceeded US$200 million.

To reduce the cost per launch the Epsilon uses the existing SRB-A3, a solid rocket booster on the H-IIA rocket, as its first stage. Existing M-V upper stages will be used for the second and third stages, with an optional fourth stage available for launches to higher orbits. The J-1 rocket, which was developed during the 1990s, but abandoned after just one launch, used a similar design concept, with an H-II booster and Mu-3S-II upper stages.

The Epsilon is expected to have a shorter launch preparation time than its predecessors. The rocket has a mass of 91 tonnes (90 long tons; 100 short tons) and is 24.4 metres (80 ft) tall and 2.5 metres (8.2 ft) in diameter.

Due to a function called "mobile launch control", the rocket needs only eight people at the launch site, compared with 150 people for earlier launches.