News

Sentinels in Space

by Serge Brosselin
Paris SCIENCE ET VIE
Sep 95 pp 78-80


[FBIS Translated Text] Europe is practically defenseless against the twenty or so countries that have short or medium-range ballistic missiles in their arsenals. France is studying a two-satellite warning system to identify and thwart any would-be aggressor.

Observation satellites make it possible to monitor the development of a strategic crisis and deduce therefrom the intentions of a potential adversary. The nuclear deterrent force is supposed to dissuade any country from attacking us out of fear of reprisal. But what about a country whose rulers might be indifferent to such a threat, who would not hesitate to attack anyway?

The proliferation of ballistic missiles and weapons of mass destruction noted in the last several years heightens this type of risk. And it is a threat to be taken seriously, since about twenty countries currently have short-range (less than 1,000 km) or medium-range (between 2-5,000 km) missiles. Not to mention the other countries attempting to acquire this technology or procure it directly from ex- Warsaw Pact forces.

In face of such a threat, Europe as a whole is more or less defenseless. This is why France is trying to convince its European partners to build a satellite-based early warning system. As was remarked recently by Francois Heisbourg, former director of the Institute of Strategic Studies in London and now director of strategic development at Matra Defense Space, "Europe cannot continue to do without some means to detect operational, accidental, or test firings of rockets from the East or South. The Gulf war showed the importance of satellites, at the same time as it highlighted the limits to the capacities of the American DSP (Defense Support Program), on which Europe remains totally dependent."

The technologies needed to create a European warning system have been available for at least the last 4 years. The cost, according to the Paecht report--named after the deputy who published an analysis of French military space policy last January--would be slightly less than the Helios program. The system would include two warning satellites, and the entire information processing network could be built for no more than Fr10 billion.

If the program were launched in 1997, the two satellites could go into service about 2003-2005. Two countries might collaborate with France in the project: Italy and Germany. Great Britain publicly declared itself favorable to such a project early this year. In France, in the industrial sector, Matra and Aerospatiale have been working for the last 3 years, under the aegis of the General Delegation for Armaments (DGA), on the architecture of a system of this kind. Matra is doing studies on the so- called "ASAT" (from "warning satellite") project, designed to detect firings of Scud-type tactical ballistic missiles, track them in flight, and determine their point of impact with sufficient advance notice to be able to try to intercept them.

Wide-Area Viewing

ASAT would be based on two geostationary satellites in orbit over Kenya. Matra has opted for satellites equipped only with infrared sensors. Each of the satellites would be equipped with two cameras, operating in different frequency bands (2-5 microns and 5-7 microns). The two cameras would serve separate functions. One, sensitive to temperatures close to 2,000[DEG]C., would detect missiles at time of launch. The other, sensitive to temperatures on the order of several hundred degrees, would determine trajectories of missiles during their ballistic phase, above earth's atmosphere.

The cameras, being maneuverable, could sweep a vast zone around their normal axis of sight. With each camera able to "see" an area of 2,000 x 2,000 km, the complete system will be able to observe a multitude of zones, each covering 4 million square kilometers: a surface area equal to 8 times that of France.

Baltic to Reunion

Judicious orientation of the cameras will permit sensitive regions to be monitored. "Double vision"--in which the lines of observation of two cameras, one in each satellite, converge on the same point--would furnish stereoscopic views, providing the information needed to directly calculate a missile's trajectory. At the same time, the other two cameras, aimed separately (non- stereoscopically) at various parts of the region in question, could serve to pinpoint the launch-site. Thus a missile's launch can be detected and its trajectory calculated anywhere within the zone covered by the two satellites. A satellite positioned over Kenya could monitor a vast zone extending from the longitude of Dakar to that of the Caucasus, from the Baltic Sea to Reunion. In other words, all countries presenting a potential threat to Europe would be under surveillance.

Specialists working on the architecture of an early warning system say that the warning and trajectory-tracking data furnished would be efficacious against any attack by "primitive" ballistic missiles (those armed with a single warhead, a single military payload). Advance notice would be 5 minutes for a short-range Scud-type missile, 15 minutes for an intermediate-range missile (about 5,000 km). The system would thus permit positive identification of states that have conducted--or are going to conduct--test firings of tactical ballistic missiles. It would give authorities and populations a certain amount of time to react to hostile missiles (get the populace to shelter and launch antimissiles). It would also enable the launch site of any missile to be pinpointed and the enemy identified, so retaliatory measures could be taken. In addition to determining the precise point of impact of the incoming missile.



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