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Epsilon (rocket)

Epsilon rocket.png
Artist's impression
FunctionLaunch vehicle
Country of originJapan
Cost per launchUS$39 million[1]
Height24.4 m (Demonstration Flight) / 26 m (Enhanced)
Diameter2.5 m
Mass91 t (Demonstration Flight) / 95.4 t (Enhanced)
Payload to 250x500 km orbit
Standard 3 stages configuration
1,500 kilograms (3,300 lb)
Payload to 500 km orbit
Optional 4 stages configuration
700 kilograms (1,500 lb)
Payload to 500 km SSO
Optional 4 stages configuration
590 kilograms (1,300 lb)
Launch history
Launch sitesUchinoura
Total launches3
First flightSeptember 14, 2013
First stage – SRB-A3
Engines1 solid
Thrust2,271 kN[1]
Specific impulse284 seconds[1]
Burn time116 seconds[1]
Second stage (Demonstration Flight) – M-34c
Engines1 solid
Thrust371.5 kN[1]
Specific impulse300 seconds[1]
Burn time105 seconds[1]
Second stage (Enhanced) – M-35
Engines1 solid
Thrust445 kN[1]
Specific impulse295 seconds[1][not in citation given]
Burn time129 seconds[1][not in citation given]
Third stage (Demonstration Flight) – KM-V2b
Engines1 solid
Thrust99.8 kN[1]
Specific impulse301 seconds[1]
Burn time90 seconds[1]
Third stage (Enhanced) – KM-V2c
Engines1 solid
Thrust99.6 kN[1]
Specific impulse299 seconds[1][not in citation given]
Burn time88 seconds[1][not in citation given]
Fourth stage (Optional) – CLPS
Thrust40.8 N
Specific impulse215 seconds[1]
Burn time1100 sec. (max.)

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 capable of placing a 590 kg payload into Sun-synchronous orbit.[2]

Vehicle description

The development aim is to reduce costs compared to the US$70 million launch cost of an M-V.[3] The Epsilon costs US$38 million (£23m) per launch, which is half the cost of its predecessor.[4] Development expenditures by JAXA exceeded US$200 million.[4]

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.[5]

The Epsilon is expected to have a shorter launch preparation time than its predecessors.[6][7][8] 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.[9][10]

Due to a function called "mobile launch control",[11] the rocket needs only eight people at the launch site, compared with 150 people for earlier launches.[12]

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).[13]

Requirements for the improvement:[13]

  • 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:[13]

  • 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:[14]

  • Low-earth orbit (250 km × 500 km): 1.5 t
  • Sun-synchronous orbit (500 km × 500 km): 0.6 t

Final characteristics:[2][15]

  • Height: 26.0 m
  • Diameter: 2.6 m (max), 2.5 m (fairing)
  • Mass: 95.4 t (Standard) / 95.7 t (Optional)

Launch statistics

Launch outcomes

  •   Failure
  •   Partial failure
  •   Success
  •   Planned

Launch history

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.[16]

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.[17]

The initial version of Epsilon has a payload capacity to low Earth orbit of up to 500 kilograms,[18][19] 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.[4]

Flight № Date / time (UTC) Rocket,
Launch site Payload Payload mass Orbit Customer Launch
1 September 14, 2013
Epsilon 4 Stages[20] Uchinoura Space Center SPRINT-A (HISAKI) 340 kg LEO JAXA Success[4]
Demonstration Flight
2 December 20, 2016
Epsilon 3 Stages Uchinoura Space Center ERG (ARASE) 350 kg[22] Geocentric JAXA Success[21]
3 January 17, 2018
Epsilon 4 Stages[24] Uchinoura Space Center ASNARO-2[24] 570 kg[24] SSO Japan Space Systems Success[21]

Planned launches

Date / time (UTC) Rocket,
Launch site Payload Orbit Customer
2019 Epsilon Uchinoura Space Center RAPIS-1
Innovative SatelliteTechnology Demonstration-1; Component demonstration and technology validation.[25]
2020 Epsilon Uchinoura Space Center Innovative SatelliteTechnology Demonstration-2
2020 Epsilon Uchinoura Space Center LOTUSAT-1
2022 Epsilon Uchinoura Space Center DESTINY+ High Earth
2022 Epsilon Uchinoura Space Center Innovative SatelliteTechnology Demonstration-3
2023 Epsilon Uchinoura Space Center Competitive M-class #3
2024 Epsilon Uchinoura Space Center Innovative SatelliteTechnology Demonstration-4
(TBD) Epsilon Uchinoura Space Center Competitive M-class #4

Sources: Japanese Cabinet[26]

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.[27] Solid-fuel rocket data potentially has military value,[27] and Epsilon is considered as potentially adaptable to an intercontinental ballistic missile.[28] 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.[29]

See also


  1. ^ a b c d e f g h i j k l m n o p "イプシロンロケットの開発および準備状況" (PDF). JAXA. Retrieved September 16, 2013.
  2. ^ a b "Epsilon Launch Vehicle" (PDF). JAXA. Retrieved 25 January 2018.
  3. ^ "Asteroid probe, rocket get nod from Japanese panel". Spaceflight Now. August 11, 2010. Retrieved October 29, 2012.
  4. ^ a b c d Clark, Stephen (September 14, 2013). "Japan's 'affordable' Epsilon rocket triumphs on first flight". Spaceflight Now. Retrieved September 16, 2013.
  5. ^ "J-I Launch Vehicle". Japan Aerospace Exploration Agency. 2007.
  6. ^ "Epsilon launch vehicle". JAXA. Retrieved October 29, 2012.
  7. ^ Yasuhiro Morita; Takayuki Imoto; Hiroto Habu; Hirohito Ohtsuka; Keiichi Hori; Takemasa Koreki; Apollo Fukuchi; Yasuyuki Uekusa; Ryojiro Akiba (July 10, 2009). "Advanced Solid Rocket Launcher and its Evolution" (PDF). 27th International Symposium on Space Technology and Science. Retrieved September 20, 2009.
  8. ^ Kazuyuki Miho, Toshiaki Hara, Satoshi.Arakawa, Yasuo Kitai, Masao Yamanishi (July 10, 2009). "A minimized facility concept of the Advanced Solid Rocket launch operation" (PDF). 27th International Symposium on Space Technology and Science. Retrieved September 20, 2009.
  9. ^ "JAXA readies small rocket to break cost, use barriers". Japan Times. November 9, 2012. Retrieved December 2, 2012.
  10. ^ Epsilon Launch Vehicle Information
  11. ^ "New Epsilon rocket chalks up first launch". Japan Times. Retrieved September 15, 2013.
  12. ^ "Japan's Laptop-Controlled Space Rocket Blasts Off". International Business Times. Retrieved September 14, 2013.
  13. ^ a b c 強化型イプシロンロケット プロジェクト移行審査の結果について (PDF). October 30, 2014. Retrieved July 9, 2015.
  14. ^ "EPSILON a solid propellant launch vehicle for new age" (PDF). IHI Aerospace. Retrieved 25 January 2018.
  15. ^ イプシロンロケットについて (PDF) (in Japanese). JAXA. 24 November 2016. Retrieved 25 January 2018.
  16. ^ "Epsilon rocket all aces this time". Asahi Shimbun. Archived from the original on September 23, 2013. Retrieved September 14, 2013.
  17. ^ "Launch rehearsed for new rocket". Japan Times. Retrieved September 14, 2013.
  18. ^ "Interview: Yasuhiro Morita, Project Manager, Epsilon Launch Vehicle". JAXA. Retrieved October 29, 2012.
  19. ^ Stephen Clark (November 5, 2012). "Japan schedules launch of innovative Epsilon rocket". Spaceflight Now. Retrieved November 8, 2012.
  20. ^ "Launch Result of Epsilon-1 with SPRINT-A aboard". JAXA. 14 September 2013. Retrieved 18 September 2013.
  21. ^ a b c "Success of Epsilon-2 Launch with ERG Aboard". JAXA. December 20, 2016. Retrieved December 20, 2016.
  22. ^ "JAXA | Exploration of energization and Radiation in Geospace (ERG)". JAXA | Japan Aerospace Exploration Agency. Retrieved 2016-12-20.
  23. ^ "JAXA launches Epsilon-3 rocket" (17 January 2018). NHK World. Retrieved 17 January 2018.
  24. ^ a b c "Pre-Dawn Epsilon Liftoff Sends Japanese Radar-Imaging Satellite into Orbit". Spaceflight101. Retrieved 17 January 2018.
  25. ^ "革新的衛星技術実証1号機に搭載する実証テーマ候補" (in Japanese). JAXA. Retrieved 2018-01-19.
  26. ^ "宇宙基本計画工程表 (平成29年度改訂)" (PDF) (in Japanese). Cabinet Office. 12 December 2017. Retrieved 2017-12-29.
  27. ^ a b Iain Thomson (November 30, 2012). "Malware slurps rocket data from Japanese space agency". The Register. Retrieved December 2, 2012.
  28. ^ "Japan's New Military Buildup Seen as Response to North Korea, China". National Journal. 23 August 2013. Retrieved 24 September 2013.
  29. ^ "Virus hits Japan space programme". 3 News NZ. December 3, 2012.

External links