|Country of origin||Japan|
|Payload to 250x500 km orbit
|1,200 kilograms (2,600 lb)|
|Payload to 500 km orbit
|700 kilograms (1,500 lb)|
|Payload to 500 km SSO
|450 kilograms (990 lb)|
|First flight||September 14, 2013|
|First stage - SRB-A3|
|Specific impulse||284 seconds|
|Burn time||116 seconds|
|Second stage - M-34c|
|Specific impulse||300 seconds|
|Burn time||105 seconds|
|Third stage - KM-V2b|
|Specific impulse||301 seconds|
|Burn time||90 seconds|
|Fourth stage (optional) - CLPS|
|Specific impulse||215 seconds|
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 as 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.
Requirements for the improvement:
- Apogee ≧ 28700 km (summer launch), ≧ 31100 km (winter launch) of a 365 kg payload
- Sun-synchronous orbit (500 km) of a ≧ 590 kg payload
- Larger fairing
- Height: 26.0 m
- Diameter: 2.5 m
- Mass: 95.1 t (95.4 t with optional 4th stage (post-boost stage))
Epsilon rockets are launched from a pad at the Uchinoura Space Center previously used by Mu rockets. The maiden flight, carrying the SPRINT-A scientific satellite, lifted off at 05:00 UTC (14:00 JST) on September 14, 2013. The launch was conducted at a cost of $38 million.
On August 27, 2013, the first planned launch of the rocket had to be aborted 19 seconds before liftoff because of a botched data transmission. A ground-based computer had tried to receive data from the rocket 0.07 seconds before the information was actually transmitted.
The initial version of Epsilon has a payload capacity to low Earth orbit of up to 500 kilograms, with the operational version expected to be able to place 1,200 kilograms (2,600 lb) into a 250 by 500 kilometres (160 by 310 mi) orbit, or 700 kilograms (1,500 lb) to a circular orbit at 500 kilometres (310 mi) with the aid of an hydrazine fueled stage.
|Date/Time (UTC)||Stages||Payload||Orbit (km)||Outcome||Remarks|
|September 14, 2013, 05:00||4||SPRINT-A (HISAKI)||950 x 1,150 x 31°||Successful||340 kg satellite|
Epsilon's second mission was originally scheduled for 2015 with a mission to study solar storm effects on Earth, but this has been postponed to the 2016 financial year due to satellite development delays.
Internet data leak
In November 2012, JAXA reported that there had been a possible leak of rocket data due to a computer virus. JAXA had previously been a victim of cyber-attacks, possibly for espionage purposes. Solid-fuel rocket data potentially has military value, and Epsilon is considered as potentially adaptable to an intercontinental ballistic missile. The Japan Aerospace Exploration Agency removed the infected computer from its network, and said its M-V rocket and H-IIA and H-IIB rockets may have been compromised.
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- Epsilon Launch Vehicle Information
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