The Epsilon Launch Vehicle, or (formerly ''Advanced Solid Rocket''), is a Japanese

solid-fuel rocket A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants (fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder; they were used in warfare by the Arabs, Chinese, Persia ...

designed to launch

scientific Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for ...

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioiso ...

s. 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 The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into o ...

(JAXA) began developing the Epsilon in 2007. It is capable of placing a 590 kg payload into

Sun-synchronous orbit A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...

Vehicle description

The development aim is to reduce the US$70 million launch cost of an M-V; the Epsilon costs US$38 million per launch. 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 A solid rocket booster (SRB) is a large solid propellant motor used to provide thrust in spacecraft launches from initial launch through the first ascent. Many launch vehicles, including the Atlas V, SLS and space shuttle, have used SRBs to gi ...

on the

H-IIA H-IIA (H-2A) is an active expendable launch system operated by Mitsubishi Heavy Industries (MHI) for the Japan Aerospace Exploration Agency. These liquid fuel rockets have been used to launch satellites into geostationary orbit; lunar o ...

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-I The J-I was a Solid-fuel rocket expendable launch vehicle developed by the National Space Development Agency of Japan and the Institute of Space and Astronautical Science. In an attempt to reduce development costs, it used the solid rocket booster ...

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 The Mu, also known as M, was a series of Japanese solid-fueled carrier rockets, which were launched from Uchinoura between 1966 and 2006. Originally developed by Japan's Institute of Space and Astronautical Science, Mu rockets were later operate ...

upper stages. The Epsilon is expected to have a shorter launch preparation time than its predecessors; a function called "mobile launch control" greatly shortens the launch preparation time, and needs only eight people at the launch site, compared with 150 people for earlier systems. The rocket has a mass of and is tall and in diameter.

Enhanced version

After the successful launch of the Epsilon first flight (demonstration flight), the improvement plan was decided to handle the planned payloads (

ERG The erg is a unit of energy equal to 10−7joules (100 nJ). It originated in the Centimetre–gram–second system of units (CGS). It has the symbol ''erg''. The erg is not an SI unit. Its name is derived from (), a Greek word meaning 'work' o ...

and ASNARO-2). 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 Planned characteristics: * Height: 26.0 m * Diameter: 2.5 m * Mass: 95.1 t (Standard) / 95.4 t (optional 4th stage (post-boost stage)) Catalog performance according to IHI Aerospace: * Low-earth orbit 250 km × 500 km for 1.5 t * Sun-synchronous orbit 500 km × 500 km for 0.6 t Final characteristics: * Height: 26.0 m * Diameter: 2.6 m (max), 2.5 m (fairing) * Mass: 95.4 t (standard) / 95.7 t (optional)

Epsilon S

Epsilon's first stage has been the modified SRB-A3 which is the solid-rocket booster of H-IIA. As the H-IIA is to be decommissioned and to be replaced by H3, Epsilon is to be replaced by new version, named Epsilon S. Major changes of Epsilon S from Epsilon are: * The first stage is based on SRB-3, the strap-on solid-rocket booster of H3. * The third stage is a new design, whereas Epsilon's third stage was based on the M-V's third stage. New third stage is three-axis stabilized using Post-Boost Stage (PBS), whereas Epsilon's third stage was spin-stabilized. Also the third stage is outside the fairing, whereas Epsilon's fairing covered the third stage. * The Epsilon S Post-Boost Stage is mandatory, whereas Epsilon's PBS was optional. Planned performance of Epsilon S is: * Sun-synchronous orbit (350 - 700 km): ≧ 600 kg * Low-earth orbit (500 km): ≧ 1400 kg The first launch of Epsilon S is planned in 2023.

Launch statistics

Launch outcomes

Launch history

Epsilon launch vehicles are launched from a pad at the Uchinoura Space Center previously used by Mu launch vehicles. The maiden flight, carrying the SPRINT-A scientific satellite, lifted off at 05:00 UTC (14:00 JST) on 14 September 2013. The launch was conducted at a cost of US$38 million. On 27 August 2013, the first planned launch of the launch vehicle 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 launch vehicle 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 into a orbit, or to a circular orbit at with the aid of a

hydrazine Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...

fueled stage.

Planned launches

Sources: Japanese Cabinet

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 An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than , primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads). Conventional, chemical, and biological weapo ...

. 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.

References

External links

Epsilon launch vehicle
JAXA
Epsilon Photobook "EPSILON THE ROCKET"
*

IHI Aerospace {{Japanese launch systems 2013 in spaceflight Solid-fuel rockets Space launch vehicles of Japan Vehicles introduced in 2013 Expendable space launch systems