SFU : Space Flyer Unit


The Space Flyer Unit (SFU) is an unmanned platform with reusable capability for experiments and observations in space. Development started in 1987 as a cooperative project among three Japanese governmental agencies : MITI(presently METI)/NEDO, MOE(presently MEXT)/ISAS(presently JAXA) and STA(presently MEXT)/NASDA(presently JAXA).
SFU is scheduled to be launched by NASDA's H-II launch vehicle and retrieved by NASA's space shuttle after several months of operation on orbit.
The Institute for Unmanned Space Experiment Free Flyer (USEF ;presently J-spacesystems) is responsible for developing and operating the SFU core module and industrial experiment devices under contracts with MITI and NEDO.
Outline of SFU
The SFU employs a modular-type structure which provides high versatility of payload integration. It's structure consists of an octagonal truss with attached unit boxes, allowing the replacement of payloads for each flight in compliance with user's needs.
Outline of Mission
The SFU is a multi-mission free flyer for microgravity experiments, technology development, astronomical observations and more. The first flight missions are scheduled in 1995.
USEF developed three furnaces for industrial experiments and conducted the crystal growth of compound semiconductors in space.
Industrial experiments
GHF | Gradient heating furnace Crystal growth of GaAs by Bridgeman method Crystal growth of InP by Bridgeman method Vapor phase deposition of CdTe thin film Vapor phase epitaxy of InGaP |
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MHF | Mirror heating furnace Crystal growth of InP by Travelling heater method Crystal growth of InGaAs by Travelling heater method |
IHF | Isothermal heating furnace Non contact crystal growth of CdTe Bridgeman method Crystal growth of AlGaAs from solution |

Operation
The SFU is launched from the NASDA Tanegashima Space Center by the H-II launch vehicle and separated at an altitude of 330km. After the solar array paddles are extended , the SFU boosts up to its mission altitude of 480km. The SFU stays on orbit approximately several months, during which time the operation is conducted from the ISAS Sagamihara Operation Center with the support of NASA's Deep Space Network (DSN) and other communication networks.
The space shuttle lifts off from Kennedy Space Center (KSC), flies to the retrieval orbit, rendezvous with the SFU which has descended to the retrieval orbit, and grapples it. After landing at KSC, the SFU is transported to Japan and refurbished for the next flight.

SFU Flight Model returned from space which exhibited at National Science Museum, Tokyo
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- ASNARO : Advanced Satellite with New system Architecture for Observation
- SERVIS : Space Environment Reliability Verification Integrated System
- ALSET : Air Launch System Enabling Technology
- SSPS : Space Solar Power System
- ASTER : Advanced Spaceborne Thermal Emissionand Reflection radiometer
- HISUI : Hyper-spectral Imager SUIte
- PALSAR : Phased Array type L-band Synthetic Aperture Radar
- Space Utilization
- International cooperation
- Other research activities
- Achievements so far