![]() Epsilon flight F2 before launch in December 2016 | |
Function | Launch vehicle |
---|---|
Country of origin | Japan |
Cost per launch | US$39 million[1] |
Size | |
Height | 24.4 m (Demonstration Flight) / 26 m (Enhanced) |
Diameter | 2.5 m |
Mass | 91 t (Demonstration Flight) / 95.4 t (Enhanced) |
Stages | 3–4 |
Capacity | |
Payload to 250x500 km orbit Standard 3 stages configuration | |
Mass | 1,500 kilograms (3,300 lb) |
Payload to 500 km orbit Optional 4 stages configuration | |
Mass | 700 kilograms (1,500 lb) |
Payload to 500 km SSO Optional 4 stages configuration | |
Mass | 590 kilograms (1,300 lb) |
Launch history | |
Status | Active |
Launch sites | Uchinoura |
Total launches | 4 |
Success(es) | 4 |
First flight | September 14, 2013 |
Last flight | January 18, 2019 |
First stage – SRB-A3 | |
Engines | 1 solid |
Thrust | 2,271 kN[2] |
Specific impulse | 284 seconds[2] |
Burn time | 116 seconds[2] |
Second stage (Demonstration Flight) – M-34c | |
Engines | 1 solid |
Thrust | 371.5 kN[2] |
Specific impulse | 300 seconds[2] |
Burn time | 105 seconds[2] |
Second stage (Enhanced) – M-35 | |
Engines | 1 solid |
Thrust | 445 kN[2] |
Specific impulse | 295 seconds[2][failed verification] |
Burn time | 129 seconds[2][failed verification] |
Third stage (Demonstration Flight) – KM-V2b | |
Engines | 1 solid |
Thrust | 99.8 kN[2] |
Specific impulse | 301 seconds[2] |
Burn time | 90 seconds[2] |
Third stage (Enhanced) – KM-V2c | |
Engines | 1 solid |
Thrust | 99.6 kN[2] |
Specific impulse | 299 seconds[2][failed verification] |
Burn time | 88 seconds[2][failed verification] |
Fourth stage (Optional) – CLPS | |
Thrust | 40.8 N |
Specific impulse | 215 seconds[2] |
Burn time | 1100 sec. (max.) |
Fuel | Hydrazine |
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.[3]
The development aim is to reduce costs compared to the US$70 million launch cost of an M-V.[4] The Epsilon costs US$38 million (£23m) per launch, which is half the cost of its predecessor.[5] Development expenditures by JAXA exceeded US$200 million.[5]
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.[6]
The Epsilon is expected to have a shorter launch preparation time than its predecessors.[7][8][9] Due to a function called "mobile launch control",[10] the rocket needs only eight people at the launch site, compared with 150 people for earlier systems.[11]
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.[12][13]
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).[14]
Requirements for the improvement:[14]
Planned characteristics:[14]
Catalog performance according to IHI Aerospace:[15]
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.[17]
Major changes of Epsilon S from Epsilon are:[17]
Planned performance of Epsilon S is:[17]
The first launch of Epsilon S is planned in 2023.[17]
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.[18]
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.[19]
The initial version of Epsilon has a payload capacity to low Earth orbit of up to 500 kilograms,[20][21] 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 a hydrazine fueled stage.[5]
Flight No. | Date / time (UTC) | Rocket, Configuration |
Launch site | Payload | Payload mass | Orbit | Customer | Launch outcome |
---|---|---|---|---|---|---|---|---|
1 | September 14, 2013 05:00:00 |
Epsilon 4 Stages[22] | Uchinoura Space Center | SPRINT-A (HISAKI) | 340 kg | LEO | JAXA | Success[5] |
Demonstration Flight | ||||||||
2 | December 20, 2016 11:00:00[23] |
Epsilon 3 Stages | Uchinoura Space Center | ERG (ARASE) | 350 kg[24] | Geocentric | JAXA | Success[23] |
3 | January 17, 2018 21:06:11[25] |
Epsilon 4 Stages[26] | Uchinoura Space Center | ASNARO-2[26] | 570 kg[26] | SSO | Japan Space Systems | Success[23] |
4 | January 18, 2019 00:50:20[27] |
Epsilon 4 Stages | Uchinoura Space Center | RAPIS-1 MicroDragon RISESAT ALE-1 OrigamiSat-1 AOBA-VELOX-IV NEXUS |
200 kg | SSO | JAXA | Success[23] |
Innovative Satellite Technology Demonstration-1; Component demonstration and technology validation.[28] |
Date / time (UTC) | Rocket, Configuration |
Launch site | Payload | Orbit | Customer |
---|---|---|---|---|---|
2021 | Epsilon | Uchinoura Space Center | RAISE-2 TeikyoSat-4 Hibari Z-Sat DRUMS ASTERISC ARICA NANODRAGON KOSEN-1 |
||
2022 | Epsilon | Uchinoura Space Center | RAISE-3 Kanazawa-SAT NUCube1 KOSEN-2 WASEDA-SAT-ZERO TRIFNE |
||
2023 | Epsilon | Uchinoura Space Center | JASMINE | JAXA | |
2023 | Epsilon S | Uchinoura Space Center | LOTUSAT-1[29] | ||
2024 | Epsilon S | Uchinoura Space Center | DESTINY+ | High Earth | JAXA |
2024 | Epsilon | Uchinoura Space Center | Innovative Satellite Technology Demonstration-4 | ||
2026 | Epsilon S | Uchinoura Space Center | Solar-C_EUVST[30][31] | SSO | JAXA |
Sources: Japanese Cabinet[32]
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.[33] Solid-fuel rocket data potentially has military value,[33] and Epsilon is considered as potentially adaptable to an intercontinental ballistic missile.[34] 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.[35]
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