The Ofeq 3 satellite is the first in a series of Israeli space platforms being offered to customers worldwide

Tim Furniss/London

Israel's Ofeq 3 satellite, which was launched into orbit by the country's Shavit booster on 5 April, is the first demonstration of a new, lightweight spacecraft bus able to carry a variety of payloads. "Israel has entered the space market," says Avi Har Even, director of the Israel Space Agency (ISA). Because of financial problems, the launch had been delayed for almost two years.

As had been widely assumed, the Ofeq 3 carries an observation camera. Possibly developed by El-Op Electro Optics of Rehovot, the camera is probably the Earth Resources Monitoring Scanner, which El-Op is known to have been developing, and is capable of returning images with a resolution of 16m.

Although the Ofeq has been mistakenly dubbed a "spy satellite", it is of limited military use as it orbits at 370 x 730km - too high for its limited sensor capability - and at an inclination of 37¡, which does not guarantee regular flights over target areas. Nevertheless, "...its deterrent effect is evident", says Moshe Arens, a former Israeli defence minister. "The Ofeq shows our enormous technological advance," he adds.

When equipped with higher-resolution cameras capable of returning 2m images, and payloads such as electronic-intelligence equipment, the new spacecraft bus will be capable of supporting military operations. This capability would support, but not replace, data provision from US intelligence satellites.

To be of optimum use as a national intelligence satellite, future Ofeqs would need to be launched into low polar orbits, which is impossible from the national Palmachin launch base, south of Tel Aviv. From there, launches into retro-grade orbits, west over the Mediterranean Sea and against the Earth's rotation, are possible because this is the only flightpath not over land.

The Ofeq 3 is a 225kg 2.3m-diameter six-faced cylinder with twin solar arrays of three panels apiece. The bus has a precise, three-axis stabilisation system, enabling fine pointing for payloads. It was developed to carry communications, astronomy, astrophysics and remote sensing payloads for use in Israel and, if required, by international commercial customers. Israel Aircraft Industries (IAI) Electronics Division's MBT Systems and Space Technology business unit, which developed Ofeq 3, describes it as a scientific, experimental satellite only.

The Ofeq 3 launch was the third generated by the national, 18m-tall, all-solid-propellant Shavit booster, which is a potential commercial launch vehicle for low-Earth-orbit satellites. The first Shavits were used to launch the smaller 160kg-class Ofeq 1 and 2 spacecraft in 1988 and 1990. The Shavit is based on the two-stage Jericho, which reportedly had a 1,400km-range flight in June 1989 from South Africa's Overberg launch site near Cape Town.

The third stage of the Shavit is powered by the Rafael AUS-51 motor, which is being marketed commercially with the USA's Atlantic Research. Israel was unsuccessful with its offer of the three-stage Shavit for a contract to launch the NASA-funded Comet spacecraft. Called the Next and equipped with a fourth stage which consists of a Bi-propellant Module (BPM), with an independent inertial-navigation unit and a GPS receiver, it is being marketed by IAI as a commercial launcher.

In the USA, IAI is marketing the Next in conjunction with American Space Vector. Launched from Vandenberg AFB, California, for example, the Next could carry 400kg into a 500km polar orbit.

IAI is also developing a cryogenic-transfer module (CTM), which could be used as the upper stage on a geostationary orbit (GEO) launcher. The 1,000kN CTM would carry a 2,100kg satellite into GEO from a low-Earth orbit, using up to five burns, with a total burn time of 2,100s.

ISRAELI FIRST

Israel's first communications satellite, the Amos 1, will be launched on an Ariane 4 booster in September. Built by an IAI/Daimler-Benz consortium, with assistance from France and the USA, and using tried and tested components, the 940kg satellite, based on a 1.5 x 2.2m spacecraft bus, is equipped with seven Ku-band transponders for television, telephone and data-communications services for Israel and countries within the footprint of its three spot beams, which centre on Israel, Hungary and Portugal.

Hungary is the first customer for the Amos regional services being marketed by Israel's Spacecom Satellite Communications and Magyarsat of Hungary. The lightweight, low-cost, Amos geostationary spacecraft bus could also be offered commercially as a proprietary communications or other space platform. A second Amos or Central European Communications Satellite, will be owned by Magyarsat. Other potential customers are in Poland and Romania (Flight International, 10-16 March).

The development of the Amos (with no back-up satellite) has depended largely on the Israeli Government's assurance that it will purchase $30 million-worth of communications services over the first ten years. In 1991, emergency Government funding of $150 million virtually saved the programme, which has now cost an estimated $275 million.

Source: Flight International

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