Top Qs
Timeline
Chat
Perspective
Epsilon (rocket)
JAXA small-lift rocket family From Wikipedia, the free encyclopedia
Remove ads
The Epsilon Launch Vehicle, or 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 capable of placing a 590 kg payload into Sun-synchronous orbit.[7]
Remove ads
Remove ads
Vehicle description
Summarize
Perspective
The development aim is to reduce the US$70 million launch cost of an M-V;[8] the Epsilon costs US$38 million per launch.[9] Development expenditures by JAXA exceeded US$200 million.[9]
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-I 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.[10]
The Epsilon is expected to have a shorter launch preparation time than its predecessors;[11][12][13] a function called "mobile launch control" greatly shortens the launch preparation time, and needs only eight people at the launch site,[14] compared with 150 people for earlier systems.[15]
The rocket has a mass of 91 t (90 long tons; 100 short tons) and is 24.4 m (80 ft) tall and 2.5 m (8 ft 2 in) in diameter.[16][17]
Enhanced version
After the successful launch of the Epsilon first flight (demonstration flight), the improvement plan was decided to handle the planned payloads (ERG and ASNARO-2).[18]
Requirements for the improvement:[18]
- 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:[18]
- 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:[19]
- Low Earth orbit 250 km × 500 km for 1.5 t
- Sun-synchronous orbit 500 km × 500 km for 0.6 t
- 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 a new version, named Epsilon S.[21]
Major changes of Epsilon S from Epsilon are:[21]
- 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:[21]
- 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.[21]
On July 14, 2023, the solid-fuelled second stage of Epsilon S failed during a test firing.[22] The root cause was determined to be the "melting and scattering of a metal part from the ignition device", which damaged the propellant and insulation.[23] Corrective measures were implemented and the stage was tested again on November 26, 2024; however, the second test also resulted in a failure 49 seconds after ignition.[24]
Remove ads
Launch statistics
Launch outcomes
1
2013
'14
'15
'16
'17
'18
'19
2020
'21
'22
- Failure
- Partial failure
- Success
- Planned
Launch history
Summarize
Perspective
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.[25]
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.[26]
The initial version of Epsilon has a payload capacity to low Earth orbit of up to 500 kilograms,[27][28] with the operational version expected to be able to place 1,200 kg (2,600 lb) into a 250 by 500 km (160 by 310 mi) orbit, or 700 kg (1,500 lb) to a circular orbit at 500 km (310 mi) with the aid of a hydrazine fueled stage.[9]
Remove ads
Planned launches
Sources: Japanese Cabinet[48]
Remove ads
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.[49] Solid-fuel rocket data potentially has military value,[49] and Epsilon is considered as potentially adaptable to an intercontinental ballistic missile.[50] 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.[51]
Remove ads
See also
References
External links
Wikiwand - on
Seamless Wikipedia browsing. On steroids.
Remove ads