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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
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


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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