Site: Mitsubishi Electric Corporation (MELCO)
Kamakura Works
325, Kamimachiya-Kamakura
Kanagawa 247, Japan

Date Visited: October 22, 1992

Report Author: E. Miller

ATTENDEES

NASA/NSF:

W. Brandon
E. Miller

HOSTS:

Keiichiro Eishima

Deputy Manager, Space Systems Development

Nobuhiro Matsuda

Business Administration and Planning, Space
Programs and Satellite, Communication Systems Division

BACKGROUND

The MELCO Kamakura Works produces electronic products for defense and space systems, as well as communications and industrial electronics products. MELCO is Japan's top satellite manufacturer and leading supplier of earth station facilities. MELCO Kamakura is a spacecraft integrator and supplier of systems and components for spacecraft. The staff and budget fluctuate with the specific projects under way. Typically, there are about 500 employees in the space area.

MELCO has a broad list of customers including government organizations, private communications firms, various consortia, and INTELSAT. In addition to prime contractor and spacecraft integrator responsibilities, they produce a wide range of subsystems and components including antennas, solar panels, amplifiers, receivers, oscillators, and ion thrusters (1988 MELCO Fact Sheets).

RESEARCH AND DEVELOPMENT ACTIVITIES

Solid Sate Power Amplifiers (SSPAs) for Flight Use

MELCO has produced flight-qualified SSPAs ranging in frequency from 2.5 to 26 GHz. Developed products displayed are listed in Table Mitsubishi.1. Figure Mitsubishi.1 shows the range of flight SSPA work at MELCO.

Table Mitsubishi.1
SSPAs Developed by MELCO

Antennas

Their deployable, umbrella-type reflector antenna program was reviewed and examples displayed. A 30 m diameter design is under way. A 3 m prototype has been built. A 6 m developmental model is under construction. These antennas are self-opening, actuated by coil springs. Their design is lightweight and rigid.

An S-band phased array antenna has been built for the ETS-VI S-band ISL. A 12 GHz, 1 m square, linearly polarized flat-plate ground receive antenna, with built-in LNA, providing 47 dB gain and a G/T > 16 dB, has been developed for broadcast satellite reception. MELCO has also developed a multibeam, CS/BS-TV receive antenna using three separate feeds to receive signals from three differently located satellites without repointing.

Lightweight, rigid reflectors made of graphite-fiber plastic, were provided for the INTELSAT VII antenna systems (Mitsubishi Electric Space Community April 1992; MELCO Fact Sheet 1991).


Figure Mitsubishi.1. Mitsubishi SSPAs and Their Applications

Transponder Elements

MELCO has built receivers, channel amplifiers, oscillators, switch controllers, and complete transponders for flight programs. A 30 GHz HEMT front-end receiver with a 3 dB NF has been provided for N-STAR (MELCO Fact Sheet 1991).

Other Areas

MELCO is building a cluster of four Xenon ion engines each providing a force of 23 mN (milliNewton). A diagram and specifications are shown in Figure Mitsubishi.2 and Table Mitsubishi.2, respectively (Mitsubishi Fact Sheet; Mitsubishi Electric Space Community July 1992).


Figure Mitsubishi.2. The Xenon-Ion Thruster Operation

Table Mitsubishi.2
Specifications for Xenon Ion Thruster by Mitsubishi

The Space Flyer Unit (SFU) is a modular space experiment platform planned to be launched into low-earth orbit by Japan's H-II launcher and then, after several months in orbit, recovered by the STS. The platform would then be refurbished, fitted with new experiments and reused. MELCO is the spacecraft integrator of the SFU, scheduled for launch in 1994 (MELCO SFU Fact Sheet).

SUMMARY

MELCO Kamakura Works is a prime contractor and spacecraft integrator, as well as a supplier of subsystems and components. It is a project-oriented organization. It has delivered a relatively large number of spacecraft for Japanese customers, and has supplied subsystems and components for other customers. MELCO research is done in Kansai.

Noteworthy technology developments are the Space Flyer Unit (SFU), the Xenon ion thruster for ETS-VI, and the large, deployable antenna concept.


Published: July 1993; WTEC Hyper-Librarian