|Space Launch Report: H3 Data Sheet|
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Illustration of H3 with Four SRB-A Boosters
Japan's H3 Launch Vehicle, planned for a first launch by 2020, will use two liquid hydrogen/oxygen core stages augmented by up to four strap-on solid rocket boosters. Although similar in those respects to Japan's existing H-2A and H-2B launch vehicles, H3 will cover a wider range of payload masses and orbits than the most-often-flown H-2A while still handling the H-2B low earth orbit payloads like HTV. H3 will use lower cost main engines and streamlined launch processing techniques. Plans call for launch cost reductions of 50% compared to H-2A. The new rocket will lift payloads ranging from 4 tonnes to a 500 km sun synchronous orbit using no solid boosters to 6.5 tonnes to geosynchronous transfer orbit using four boosters.
Japan Aerospace Exploration Agency (JAXA) officially began development of H3 during 2013, but work on the heart of the new machine - its innovative first stage engine - began in 2006. That is when Mitsubishi and IHI began work on the LE-X Expander Bleed Cycle (EBC) engine. LE-X led to the LE-9 engine that will power H3. The expander bleed cycle diverts hydrogen from the engine turbopump to the main combustion chamber's cooling channels and uses the resulting heated hydrogen to drive the turbines before it is injected into the engine exhaust. Expander cycle engines have flown on low-thrust upper stages before - Japan's LE-5A and LE-5B were second stage EBC engines - but have never been used for a high-thrust first stage application. The design is simpler than a staged combustion design and results in a more robust engine operating at lower pressures and temperatures. A tradeoff is slightly lower specific impulse. LE-9 will be the highest thrust EBC engine ever developed.
The H3 Launch Vehicle will be a 2 to 2.5 stage rocket. The first stage, likely loaded with more than 200 tonnes of propellant, will be powered by two or three new LE-9 engines, each producing about 150 tonnes of thrust at a 432 second vacuum specific impulse. Two or four SRB-A type solid rocket boosters can be attached to the first stage, each making about 220 tonnes of thrust. These will be about 2.5 meters diameter. The second stage will be powered by one or two improved LE-5B engines each making 14 tonnes of thrust at a specific impulse of at least 448 seconds. H3 will stand about 63 meters tall and will be about 5.2 meters in diameter.
H3 will launch from Tagenashima's Yoshinobu launch pad No. 2, currently used by H-2B. The launch facilities will be modified for H3.
In many ways, H3 appears to be an improved H-2B.
It uses a 5.2 meter diameter core like H-2B, an improved LE-5B powered second stage, and
SRB-A boosters like H-2B. The big difference is that the core stage will be able to
lift itself, using the higher-thrust LE-9 engines, without SRBs for smaller payload
missions. Cost reduction will result from the elimination of the 4 meter diameter
H-2A production line. Another difference is that both the second stage and the
payload fairing will expand to the same 5.2 meters diameter as the first stage.
Comparison of H2A/H2B and H3
A system requirements review (SRR) was completed during July 2014, when Mitsubishi Heavy Industries was selected as the prime contractor. During February and March 11, 2015, a system definition review (SDR) was completed. A PDR basic design review was expected to be complete by the end of 2015. Critical Design Review (CDR) was planned for mid 2017, allowing flight hardware production to begin.
Current planning calls for the first H3 to fly without boosters in 2020 and with boosters a year later.
Geosynchronous Earth Orbit
** Beginning with F14
DATE VEHICLE ID PAYLOAD MASS(t) SITE* ORBIT** ------------------------------------------------------------------------------------- 02/03/94 H-2 1F OREX 3.256 TA Y1 GTO [1a] 08/28/94 H-2 2F ETS-6/LAPS 3.80 TA Y1 GTO [1b] 03/18/95 H-2+SSB 3F SFU/GMS-5 4.747 TA Y1 GTO [1c] 08/17/96 H-2 4F ADEOS/JAS 2 3.70 TA Y1 LEO/S 11/27/97 H-2 6F TRMM/ETS-7 6.52 TA Y1 LEO [1d] 02/21/98 H-2 5F COMETS 3.90 TA Y1 [EEO]  11/15/99 H-2S [LE5B] 8F MTSAT 2.90 TA Y1 [FTO]  08/29/01 H-2A-202 TF1 VEP-2/LRE 4.00? TA Y1 GTO 02/04/02 H-2A-2024 TF2 MDS/DASH 0.572 TA Y1 GTO [3a] 09/10/02 H-2A-2024 TF3 USERS/DRTS 3.30 TA Y1 GTO [3b] 12/14/02 H-2A-202 TF4 ADEOS 2/3xusats 3.856 TA Y1 LEO/S 03/28/03 H-2A-2024 F5 IGS-Optical 1/Radar 1 2.05 TA Y1 LEO/S 11/29/03 H-2A-2024 F6 IGS-Optical/Radar 2.05 TA Y1 [FTO]  02/26/05 H-2A-2022 F7 MT-Sat 1R 3.30 TA Y1 GTO 01/24/06 H-2A-2022 F8 ALOS 4.00 TA Y1 LEO/S 02/18/06 H-2A-2024 F9 MTSAT-2 4.65 TA Y1 GTO 09/11/06 H-2A-202 F10 IGS-Optical 2 0.85 TA Y1 LEO/S 12/18/06 H-2A-204 F11 ETS-8 5.80 TA Y1 GTO 02/24/07 H-2A 2024 F12 IGS-Radar 2/Optical 3V ~2.05 TA Y1 LEO/S 09/14/07 H-2A-2022 F13 SELENE Lunar Orbiter 3.09 TA Y1 HTO 02/23/08 H-2A/2024 F14 KIZUNA (WINDS) 4.85 TA Y1 GTO 01/23/09 H-2A-202 F15 GOSAT (Ibuki) 1.98 TA Y1 LEO/S 09/10/09 H-2B-304 TF1 HTV 1 16.00 TA Y2 LEO/ISS 11/28/09 H-2A-202 F16 IGS Optical 3 - TA Y1 LEO/S 05/20/10 H-2A-202 F17 Akatsuki/Ikaros 0.81 TA Y1 HCO  09/11/10 H-2A-202 F18 Michibiki 4.00 TA Y1 GTO/i 01/22/11 H-2B-304 F2 HTV-2 16.00 TA Y2 LEO/ISS 09/23/11 H-2A-202 F19 IGS-Optical 4 - TA Y1 LEO/S 12/12/11 H-2A-202 F20 IGS-Radar 3 - TA Y1 LEO/S 05/17/12 H-2A-202 F21 GCOM W1/Kompsat 3 2.848 TA Y1 LEO/S 07/21/12 H-2B-304 F3 HTV-3(Kounotori) 15.90 TA Y2 LEO/ISS 01/27/13 H-2A-202 F22 IGS Radar 4/Optical 5 - TA Y1 LEO/S 08/03/13 H-2B-304 F4 HTV-4 15.90 TA Y2 LEO/ISS 02/27/14 H-2A-202 F23 GPM Core Observatory 3.85 TA Y1 LEO 05/24/14 H-2A-202 F24 ALOS 2 + 4usats 2.275 TA Y1 LEO/S 10/07/14 H-2A-202 F25 Himawari 8 3.5 TA Y1 GTO 12/03/14 H-2A-202 F26 Hayabusa 2 0.71 TA Y1 HCO  02/01/15 H-2A-202 F27 IGS-Radar Spare - TA Y1 LEO/S 03/26/15 H-2A-202 F28 IGS Optical 5 TA Y1 LEO/S 08/19/15 H-2B-304 F5 HTV-5 16.2 TA Y2 LEO/ISS ------------------------------------------------------------------------------------- NOTES: [1a] Test flight sent 2.39 tonne Vehicle Evaluation Payload (VEP) dummysat to GTO and 0.865 tonne Orbital Re-entry Experiment (OREX) to LEO. OREX completed one orbit and reentered to acquire re-entry data for HOPE spaceplane project. [1b] H-2 successfully inserted ETS 6 (Engineering Test Satellite) and its LAPS (Liquid Apogee Propolsion Stage) into GTO, but LAPS failed to raise orbit to GEO. Left in 8,565 x 38,677 km x 13.23 deg orbit. ETS 6 weighed 2 tonnes. LAPS weighed 1.8 tonnes. [1c] GMS 5 (Geostationary Meteorological Satellite) and Star 27 AKM weighing 0.747 tonnes were placed into GTO. SFU 1 (Space Flyer Unit) weighing 4 tonnes placed in LEO x 28.4 deg. SFU 1 was retrieved by STS-72 on 01/13/96. [1d] TRMM (Tropical Rainfall Measuring Mission) weighed 3.62 tonnes. ETS 7 docking experiment consisted of 2.5 tonne target and 0.4 tonne chaser. All placed in LEO x 35 deg.  COMETS (Communication Engineering Test Satellite) left in unusable orbit. The second Stage 2 burn cut off after 44 seconds instead of planned 3m 12s due to LE-5A engine nozzle failure.  1st stg engine H2 leak, failed at T + 4 minutes. [3a] DASH (Demonstrator of Atmospheric reentry System with Hyperbolic velocity) was intended for LEO reentry test, but failed to separate. [3b] 2.8 tonne DRTS (Data Relay Test Satellite) to GTO. 0.5 tonne USERS (Unmanned Space Experiment Recovery System) to LEO for reentry test.  One SRB-A failed to separate. RSO signal transmitted at T + 11 minutes.  First H-2B with dual-engine core, carrying first HTV 1 cargo spacecraft to ISS.  Akatsuki toward Venus orbit. Ikaros a solar sail demonstrator in HCO.  Asteroid sample return, 6 year mission. HCO mass includes three microsats. ABBREVIATIONS: [FTO]: Failed to Orbit [EEO]: Unintended Eliptical Earth Orbit [GTO]: Unintended Geosynchronous Transfer Orbit [LEO]: Unintended/Improper Low Earth Orbit "KA" = Kagoshima Space Center "TA" = Tanegashima Space Center "Y" = Yoshinobu Launch Complex References
H-IIA Brief Description, NASDA, December 2001
Last Update: November 14, 2015