Epsilon (rocket)

from Wikipedia, the free encyclopedia
Epsilon missile

The Epsilon ( Japanese イ プ シ ロ ン ロ ケ ッ ト , Ipushiron roketto ) is a Japanese solid carrier rocket with an optional liquid fuel upper stage . Epsilon, named after the 5th Greek letter ε , is the successor to the Mu-V rocket. The first launch took place on September 14, 2013.

stages

Like the Mu-V, the Epsilon has four stages. It differs u. a. from this by replacing the expensive Mu-V first stage with a cheaper SRB-A solid booster of the H-IIA as the first stage. Also new is the optional fourth stage, called Post Boost Stage , which the Epsilon uses the Compact Liquid Propulsion System with liquid fuel in order to increase the accuracy of the shot. It replaces the previous optional fourth solids stage of the Mu-V. The second stage is a revised third stage of the Mu-V. The third stage of the epsilon, on the other hand, is also a new development.

Details

The payload fairing of the Epsilon surrounds not only the payload but also the fourth and third stages, but not their thrust nozzle. The third stage is spin stabilized . The optional fourth stage can reverse the spin before the payload is released. Like the SRB-A boosters of the H-IIA rocket, the Epsilon is 2.5 meters in diameter, 24 meters long and has a launch mass of 91 tons. Your payload capacity in an elliptical orbit between 250 km and 500 km altitude is 1200 kg when using the first three stages. In four stages it transports 700 kg in a circular 500 km orbit, or 450 kg in a circular 500 km high sun-synchronous orbit . The use of stronger carbon fibers for the manufacture of the CFRP combustion chambers for the solid stages means that they are even lighter than the Mu-V. Thanks to a new manufacturing process, you can do without baking the CFRP.

Due to the solid rocket engine and high throwing weight , this system is suitable as an ICBM . Only the payload and the steering system would have to be replaced.

From the second start of the Epsilon, a modified version (Epsilon-2 or Enhanced Epsilon) was used. It is characterized by the fact that the second stage, type M-35, has an increased thrust from 327 kilonewtons to 445 kilonewtons compared to the pre-production model M-34c and a burning time that is 15 seconds longer. The height of the rocket increases from 24.4 m to 26.0 m and the payload capacity for an SSO orbit from 450 kg to 590 kg.

Technical specifications

The first three stages run on solid fuel. The fourth stage is used when the payload is to be brought into an SSO runway. It can also compensate for the rotation of the spin-stabilized third stage, which is otherwise taken over by the third stage itself.

Model epsilon Epsilon-2
stages 3..4
height 24.4 m 26.0 m
diameter 2.6 m 2.6 m
Takeoff mass 91 t 95.1 t
Start thrust 2150 kN 2150 kN
payload 1200 kg LEO
450 kg SSO
1500 kg LEO
590 kg SSO
365 kg HEO
1st stage
Type SRB-A3 SRB-A3
height 11.68 m 11.68 m
diameter 2.5 m 2.5 m
Fuel mass 66 t BP-207J 66 t BP-207J
Takeoff mass 75.5 t 75.3 t
Engine 2150 kN starting thrust
2305 kN vacuum thrust
Nominal pressure 11.1 MPa
Specific impulse 283 s
2150 kN starting thrust
2350 kN vacuum thrust
Nominal pressure 11.1 MPa
Specific impulse 283 s
Burn time 112 p 109 s
2nd stage
Type M34c M35
height 4.3 m 5.16 m
diameter 2.2 m 2.5 m
Fuel mass 10.8 t BP-205J 15.0 t BP
Takeoff mass 12.3 t 15.0 t
Engine 371.5 kN vacuum thrust
specific impulse 300 s
445 kN vacuum thrust
specific impulse 295 s
Burn time 105 s 129 s
3rd stage
Type KM-V2b KM-V2c
height 2.3 m 2.25 m
diameter 1.4 m 1.45 m
Fuel mass 2.5 t HTPB 2.5 t HTPB
Takeoff mass 3.3 t 2.9 t
Engine 99.8 kN thrust
specific impulse 301 s
99.6 kN thrust
specific impulse 299 s
Burn time 90 s 89 p
4th stage
Type PBS PBS
height 1.18 m 1.5 m
diameter 1.2 m 1.2 m
Fuel mass 120 kg of hydrazine in three tanks 145 kg hydrazine in a central tank
Takeoff mass 300 kg 300 kg
Engine 0.4 kN thrust
specific impulse 215 s
0.4 kN thrust
specific impulse 215 s
Burn time up to 1100 s up to 1300 s

Start preparations

The Epsilon takes off from the modified former launch site of the Mu-V. The assembly of the rocket should be faster than with the previous model, so that the launch should take place seven days after the start of construction on the launch site. With its computer systems, the Epsilon also controls itself during the countdown and take-off, which is why it only needs a very small team for take-off preparation and take-off monitoring. During its flight into the target orbit, the rocket is to monitor itself completely independently from 2017 with further developed computer systems, so that path tracking stations, etc. a. for sending a self-destruct signal , become unnecessary. Although a launch should only cost half as much as a Mu-V, the Epsilon's lower payload capacity means that the launch price per kg of payload is only 25% lower than that of the Mu-V.

The Epsilon has been in development since 2007. Development costs are approximately $ 255 million. At $ 47 million, an Epsilon start is said to be about half as expensive as a Mu-V start ($ 94 million).

Start list

The first take-off was scheduled for August 27, 2013 04:45 UTC, but was canceled 19 s before take-off due to irregularities. It took place on the second attempt on September 14th.

List as of December 31, 2019

Serial No. Date ( UTC ) Launch site payload Type of payload Payload in kg (gross 1 ) Orbit 2 Remarks
1 September 14, 2013
5:00 am
Uchinoura Space Center Hisaki (SPRINT-A) Space telescope for studying the atmospheres and magnetospheres etc. a. the planets Venus, Mars and Jupiter in the EUV approx. 320 kg 1,150 x 950 km success
2 December 20, 2016
11:00
Uchinoura Space Center Arase (ERG) Research satellite 365 kg success
3 January 17, 2018
9:06 PM
Uchinoura Space Center ASNARO-2 Earth observation satellite 495 kg success
4th January 17, 2019
12:50 am
Uchinoura Space Center RAPIS-1
MicroDragon
RISESAT
ALE-1
OrigamiSat-1
AOBA-VELOX-IV
NEXUS
Technology testing success

Planned launches

List updated: August 21, 2019

Serial No. Date ( UTC ) Launch site payload Type of payload Payload in kg (gross 1 ) Orbit 2 Remarks
5 2020 Uchinoura Space Center RAISE-2 Technology testing
2022Template: future / in 2 years Uchinoura Space Center Destiny Plus Technology testing / asteroid probe
2022Template: future / in 2 years Uchinoura Space Center RAPIS-3 Technology testing
2024Template: future / in 4 years Uchinoura Space Center RAPIS-4 Technology testing
1Take-off mass of the payload including carried fuel ( wet mass ).
2Runway height at which the payload was or is to be suspended; not necessarily the target orbit of the payload.

Individual evidence

  1. DW: Japan launches new "cheap rocket" Epsilon , September 14, 2013
  2. ^ Gunter Krebs: Epsilon. In: Gunter's Space Page. Retrieved November 11, 2012 .
  3. ^ A New Type of Launch Vehicle: A Rocket with Artificial Intelligence. JAXA, December 28, 2010, p. 2 , accessed November 11, 2012 (English).
  4. ^ Epsilon Large Image. (No longer available online.) JAXA, 2012, archived from the original on September 14, 2013 ; accessed on May 21, 2013 .
  5. ^ Norbert Bruges: ASR Epsilon. Retrieved May 21, 2013 .
  6. ^ H-IIA Launch Vehicle. (PDF; 6.6 MB) (No longer available online.) JAXA, archived from the original ; Retrieved May 21, 2013 (Japanese / English).
  7. Major Characteristics. (No longer available online.) JAXA, archived from the original on June 10, 2013 ; accessed on May 21, 2013 .
  8. ^ A b A New Type of Launch Vehicle: A Rocket with Artificial Intelligence. JAXA, December 28, 2010, p. 1 , accessed on November 11, 2012 .
  9. der-orion.com: Epsilon in use for the second time , accessed on December 26, 2016
  10. a b spaceflight101: Enhanced Epsilon - Rockets ( Memento from December 26, 2016 in the Internet Archive ), accessed on December 26, 2016
  11. ASR Epsilon: ASR Epsilon , access date: December 29, 2016
  12. spaceflight101: Epsilon - Rockets ( Memento from April 27, 2019 in the Internet Archive ), accessdate: December 29, 2016
  13. ^ A b A New Type of Launch Vehicle: A Rocket with Artificial Intelligence. JAXA, December 28, 2010, p. 3 , accessed on November 11, 2012 (English).
  14. Stephen Clark: Japan schedules launch of innovative Epsilon rocket. Spaceflight Now, November 5, 2012, accessed November 11, 2012 .
  15. Launch of Spectroscopic Planet Observatory for Recognition of Interaction of Atmosphere (SPRINT-A) by Epsilon-1. JAXA, August 9, 2013, accessed August 9, 2013 .
  16. "Epsilon": Engine failure stops Japanese rocket. Retrieved August 27, 2013 .
  17. a b c Japan's 'affordable' Epsilon rocket triumphs on first flight. spaceflightnow, September 14, 2013, accessed on September 14, 2013 .
  18. ^ Gunter Krebs: SPRINT A (EXCEED). In: Gunter's Space Page. Retrieved November 11, 2012 .
  19. ^ Epsilon Launch Report. Retrieved September 18, 2013 .
  20. ASNARO-2 at Gunter's Space Page (English).
  21. a b c 宇宙 基本 計画 工程 表 (平 成 29 年度 改 訂). (PDF) 宇宙 開 発 戦 略 本部, December 2017, p. 16 , accessed on August 21, 2019 (Japanese).
  22. JAXA Japan: Destiny +: Deep Space Exploration Technology Demonstrator and Explorer to Asteroid 3200 Phaeton. (PDF) August 15, 2017, accessed on September 13, 2017 .

Web links