During the 1970s, Ishikawajima-Harima Heavy Industries had built under license the Rocketdyne
MB-3 for the
N-I rocket, for which it had also developed the second stage
attitude control system.[1][2] In the 1980s it also developed the thrusters for
ETS-4 (
Kiku-3), the first to be built in Japan. In 2000 it acquired and merged with the aerospace division of
Nissan and became
IHI Aerospace.[2]
The use on the A2100 platform has allowed IHI to export the BT-4 even to American military programs such programs as the
MUOS and
AEHF.[10][11][12][13][14]
On March 9, 2006, IHI Aerospace announced that the
AEHF-2 BT-4 engine had successfully performed its mission, unlike
AEHF-1's.[14][15][16]
On November 29, 2010 IHI Aerospace announced that it had received and order from
Lockheed Martin of four BT-4 engines for
AEHF-4,
MUOS-4,
MUOS-5 and
Vinasat-2. With this order, it achieved its 100th-unit foreign engine export since it started selling abroad in 1999.[17][18]
For the
HTV project, IHI developed a new version, the HBT-5, which enabled them to replace the American
R-4D from the
third flight onward.[19][20]
On October 3, 2013, with the successful berthing of the
Cygnus Orb-D1 mission, IHI announced that the propulsion was based on their 500N Delta-Velocity Engines.[21]
In January 2018, a BT-4 kick motor was used on the
GovSat-1 geosynchronous commsat flight.[22]
Versions
The BT-4 is a family that has been used as liquid apogee engine,
orbital maneuvering engine and as a thruster. Known variations:
BT-4 (Cygnus): Used mainly as thruster, it burns
MMH/
N2O4 with a thrust of 450 N (100 lbf). It weighs 4 kg (8.8 lb) and is 65 cm (26 in) tall.[9][10]
BT-4 (450N): Used mainly as
LAE, it burns
Hydrazine/
N2O4 in a 1.69
O/F ratio. It has a thrust of 450 N (100 lbf), a specific impulse of 329 s (3.23 km/s) and an input pressure of 1.62 MPa (235 psi). As of 2014, it had a demonstrated life of 32,850 seconds.[18]
BT-4 (500N): Used mainly as
LAE, it burns
Hydrazine/
N2O4 with a thrust of 500 N (110 lbf), a specific impulse of 329 s (3.23 km/s). It weighs 4 kg (8.8 lb) and is 80 cm (31 in) tall.[14]
490N MON Thruster: Burns
MMH/
MON-3 with a 478 N (107 lbf) nominal thrust, a specific impulse of 316 s (3.10 km/s) and an inlet pressure of 1.72 MPa (249 psi). As of 2014, it had a demonstrated life of 15,000 seconds.[18]
HBT-5: Developed for the
HTV to crew-rated standards, it burns
MMH/
MON-3, and has a thrust of 500 N (110 lbf). Used in
HTV-3 and since
HTV-5 onward.[19][23]
SELENE OME: Based on the
DRTSLiquid apogee engine, the
SELENE Orbital Maneuvering Engine burned a
Hydrazine/
MON-3 mixture. It had a thrust of 547 ± 54 N (123 ± 12 lbf) and a specific impulse of 319.8 ± 5.1 s (3.136 ± 0.050 km/s) with an input pressure of 1.77 MPa (257 psi).[24][25]
References
^Wade, Mark.
"MB-3-3". Astronautix.com. Archived from
the original on September 15, 2016. Retrieved 2016-08-29.