Japan Test Fires Engine for New H3 Launch Vehicle

H3 launch vehicle variants (Credit: JAXA)

by Douglas Messier
Managing Editor

Japan continues to make progress toward the first flight of its new H3 launch vehicle with a successful test firing of the booster’s LE-9 first-stage engine on April 30.

JAXA reports that the engine fired for the planned duration of 240 seconds (4 minutes) at the space agency’s Tanegashima Space Center. It was the seventh hot fire of the new engine, which is powered by liquid oxygen and liquid hydrogen.

Seventh LE-9 Engine Test

Test dayApril 30, 2020
Test purposeConfirmation of functions and performance of LE-9 engine certified type
Ignition time16:01
test time240.0 seconds (240.0)
Main combustion pressure10.59MPa (10.55)
Liquid hydrogen turbo pump speed40,280 rpm (40,175)
Liquid oxygen turbo pump speed17,327 rpm (17,252)
Credit: JAXA

JAXA plans H-3’s first test launch by the end of the nation’s 2020 fiscal year, which began on April 1 and will end on March 31, 2021. It is not known whether work slow downs resulting from the coronavirus (COVID-19) pandemic will affect the schedule.

The two-stage H3 is intended to be a more affordable and flexible replacement for the H-IIA and H-IIB boosters now in use. The new rocket is designed to place payloads weighing 4,000 kg (8,818 lb) or more into sun-synchronous orbit at 500 km (310.7 miles) or 6,500 kg (14,330 lb) into geosynchronous transfer orbit.

LE-9 engine (Credit: JAXA)

H-3’s first stage will be powered by two or three LE-9 engines. The engines have a specific impulse of 425 seconds and weight 2.4 metric tons (2.65 tons).

LE-9 First Stage Engine Specifications

ItemLE-9 Engine
(H3)
LE-7A Engine (H-II)
(Reference)
Engine cycleExpander bleed2-stage combustion
Thrust in vacuum1471kN (150tonf)
63% Throttling
1100kN (112tonf)
Specific thrust (Isp)425s440s
weight2.4ton1.8ton
full length3.75m3.7 m
Engine mix ratio5.95.9
Combustion pressure10.0MPa12.3MPa
FTP discharge pressure19.0 MPa28.1MPa
OTP discharge pressure17.9MPa26.6MPa
Valve drive system
Continuous control of electric valve operating point

Adjust operating point with pneumatic valve orifice
Credit: JAXA

Two to four SRB-3 solid-fuel motors can be attached to the first stage to increase the rocket’s payload capacity. SRB-3 will burn for 1 minute 45 seconds with a specific impulse of 283.6 seconds.

SRB-3 engine (Credit: JAXA)

H3’s second stage will be powered by the LE-5B-3 engine, which is an upgraded version of the LE-5B-2 motor used on the H-IIA and H-IIB launch vehicles. The engine is powered by liquid oxygen and liquid hydrogen.

JAXA’s website says that the 15th certification hot fire of the LE-5B-3 engine was conducted on Feb. 18, 2019, at the space agency’s Tsunoda Space Center in Miyagi Prefecture.

Mitsubishi Heavy Industries (MHI) is the prime contractor for the H3, H-IIA and H-IIB boosters.

JAXA’s logs for the LE-9 and SRB-3 engine tests follow.

LE-9 First Stage Engine Tests

Test Location: Tanegashima Space Center (Kagoshima Prefecture)

Figures in parentheses are planned values

Seventh Test

Test dayApril 30, 2020
Test purposeConfirmation of functions and performance of LE-9 engine certified type
Ignition time16:01
test time240.0 seconds (240.0)
Main combustion pressure10.59MPa (10.55)
Liquid hydrogen turbo pump speed40,280 rpm (40,175)
Liquid oxygen turbo pump speed17,327 rpm (17,252)
Credit: JAXA

Sixth Test

Test dayApril 25, 2020
Test purposeConfirmation of functions and performance of LE-9 engine certified type
Ignition time17:00
test time120.1 seconds (140.0)
Main combustion pressure10.50MPa (10.58)
Liquid hydrogen turbo pump speed40,197rpm (40,491)
Liquid oxygen turbo pump speed17,235rpm (17,325)
RemarksSince the inlet pressure of the liquid hydrogen turbo pump reached the preset lower limit value, it automatically stopped.
Credit: JAXA

Fifth Test

Test dayApril 17, 2020
Test purposeConfirmation of functions and performance of LE-9 engine certified type
Ignition time16:00
test time210.0 seconds (210.0)
Main combustion pressure10.6MPa (10.55)
Liquid hydrogen turbo pump speed41,003 rpm (40,898)
Liquid oxygen turbo pump speed17,389rpm (17,348)
Credit: JAXA

Fourth Test

Test dayApril 7, 2020
Test purposeConfirmation of functions and performance of LE-9 engine certified type
Ignition time16:26
test time6.55 seconds (210.00)
Main combustion pressure
Liquid hydrogen turbo pump speed
Liquid oxygen turbo pump speed
RemarksIt was manually stopped due to an abnormality in the test equipment.
Credit: JAXA

Third Test

Test dayMarch 31, 2020
Test purposeConfirmation of functions and performance of LE-9 engine certified type
Ignition time17:49
test time100.0 seconds (100.0)
Main combustion pressure10.6MPa (10.3)
Liquid hydrogen turbo pump speed40,910 rpm (40,722)
Liquid oxygen turbo pump speed17,355rpm (17,327)
Credit: JAXA

Second Test

Test dayFebruary 21, 2020
Test purposeAcquisition of technical data for LE-9 engine certification type
Ignition time16:07
test time95.0 seconds (95.0)
Main combustion pressure10.8MPa (11.0)
Liquid hydrogen turbo pump speed41,499 rpm (41,582)
Liquid oxygen turbo pump speed17,332rpm (17,408)
Credit: JAXA

First Test

Test dayFebruary 13, 2020
Test purposeAcquisition of technical data for LE-9 engine certification type
Ignition time16:00
Test time101.4 seconds (117.0)
Main combustion pressure9.39MPa (9.38)
Liquid hydrogen turbo pump speed39,992rpm (41,250)
Liquid oxygen turbo pump speed16,360rpm (16,950)
RemarksThe number of rotations of the liquid hydrogen turbo pump reached the preset lower limit value, so it automatically stopped.
Credit: JAXA

SRB-3 Engine Tests

Test Location: Tanegashima Space Center Takezaki Solid Rocket Proving Ground (Kagoshima Prefecture)

Third Test

Test dateSaturday, February 29, 2020 11:00 ignition
WeatherSunny Wind: 2.7 m / sec Temperature: 19.1 ℃
Burning time107.5 seconds (predicted value 108.6 seconds)
Maximum thrust2173kN (predicted value 2145kN)
Maximum combustion pressure11.0MPa (predicted value 10.9MPa)
Credit: JAXA

Second Test

Test dateWednesday, August 28, 2019 11:00 ignition
WeatherSunny Wind: 8.0 m / sec Temperature: 29.7 ℃
Burning time105.5 seconds (predicted value 106.0 seconds)
Maximum thrust2209kN (Predicted value 2215kN)
Maximum combustion pressure11.3MPa (Predicted value 11.3MPa)
Credit: JAXA

First Test

Test dateIgnition on Sunday, August 26, 2018 at 16:00
WeatherSunny wind: 4.5 m / sec Temperature: 29.1 ℃
Burning time110.1 seconds
Maximum thrust2137 kN
Maximum combustion pressure10.7 MPa
Credit: JAXA