The Ada Resource Association
Ada Flies Envisat Accurately

BURLINGTON, MASS (MARCH 8, 2002)--The Ada Resource Association (ARA) announced another Ada success story today with the Ariane 511's launch of the Envisat 1 within the one-second tolerance allowed for the Sun-synchronized spacecraft. As the biggest satellite ever built in Europe, Envisat 1 also boasts being the largest environment survey satellite ever launched.

"The extraordinary accuracy of the Ariane's launch once again validates Ada for realtime use," said S. Tucker Taft, President of the ARA.

With flight control systems in Ada, the Ariane 511 for the first time succeeded in launching a "polar" satellite; i.e., towards the North instead of the traditional easterly direction. The Envisat 1 also depends on many Ada realtime software subsystems, including the radar altimeter.

The Envisat mission plan set a series of very specific and narrow windows for the launch and orbit. For example, the time for the Kourou, French Guiana, launch was 22:07 and 59 seconds, and Ada made sure that Flight 145 lifted off at one second before 22:08.

Also, fuel-saving algorithms in Ada allowed the engine to turn off when the Envisat 1 reached its precise orbit three seconds before the scheduled time. It began orbiting within the right 100 meters where tolerance was 7.5 kilometers. As a result, the 26-meter long (when deployed), 8211-kilogram rocket carries a minimum of fuel.

For the next five years, the satellite will record data on how humans are affecting Earth's health, including through patterns of land use and its effect on soil moisture and fertility; the quantity and size of ice flows; and the amount of ozone and other chemicals in the atmosphere observed on the planet's "limb" or edge.

Developed in a European Space Agency program, the satellite will be operated from ESA's European Space Operations Center (ESOC) in Darmstadt, Germany. Europe's Astrium led an industry consortium of 50 companies to produce the Envisat spacecraft.

For more information on Ada and the Envisat, please write to
Ann Brandon,
Communications Director
Ada Resource Assoc.

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