• Forum
• SITREP
• Military
• WMD
• Intelligence
• Homeland Security

• Space

• Introduction
• Systems
• Facilities
• Agencies
• Countries
• Hot Documents
• News
• Reports
• Policy
• Budget
• Congress
• Links

• Public Eye

Further Reading

ETS

Japan's Engineering Test Satellite (ETS) series began in 1975, and two years later NASDA's first GEO platform ETS II (also known as Kiku-2) was launched by an N-l booster and stationed at 130 degrees E. This mission not only validated the GEO launch technique but also tested spacecraft control systems vital to future communications satellites. Experimental communications at 1.7 GHz, 11.5 GHz, and 34.5 GHz were tested. The 130-kg, spin-stabilized ETS II was finally retired in 1991.

The first ETS series spacecraft to have a specific communications objective was ETS V (Kiku-5), launched on 27 August 1987 by an H-I booster and stationed at 150 degrees E. ETS V was Japan's first 3-axis stabilized GEO satellite with an on-station mass of 550 kg. The spacecraft carried two 1.6/1.5 GHz transponders to test an INMARSAT compatible mobile communications system. The spacecraft bus measured 1.4 m by 1.7 m with a twin solar panel span of 9.7 m. At the end of 1994, ETS V was still positioned near 150 degrees E.

ETS Vl, with a wide assortment of communications systems and experiments, was launched on the second mission of the new H-II vehicle on 28 August 1994. Although the H-11 performed as expected and placed the spacecraft into a GTO, the Liquid Apogee Propulsion System (LAPS) malfunctioned, leaving ETS VI in an elliptical orbit of approximately 7,800 km by 38,700 km at an inclination of 13.1 degrees. The spacecraft remained operational, but its non-nominal orbit posed severe experimental limitations and presented unanticipated environmental stresses.

The 2.0-metric-ton (on-station) ETS VI was designed and manufactured by prime contractors Toshiba and Mitsubishi. The spacecraft bus is 2 m x 2.8 m x 3 m and supports two solar arrays (total power = 4.2 kW) with a span of approximately 30 m. The 660-kg payload includes numerous transponder systems, primarily at the higher frequencies of 30/20 GHz and above. A major mission objective was the testing of an inter-satellite communications system utilizing Ka-band, S-band and O-band links. A laser space-ground link was also planned, as were tests of a new ion propulsion system. The design 10-year lifetime will probably not be met, but most of the experiments are expected to be carried out, if not as extensively as planned (References 161-170).

Prior to the ETS VI failure, the next communications-oriented ETS mission was the proposed ETS N which would be launched about 2001 to test cellular phone technologies. Also under consideration is an ETS VIII which could combine the objectives of ETS VI and N (References 171-172)