Astrium's Grace Probes For February Launch (Jan. 14)
FRIEDRICHSHAFEN, Germany---In the ice cold of northern Russia, the hot phase of the preparations for the launch of the two Astrium-built Grace satellites is beginning at the start of February. The identical satellites have been completed and are scheduled for launch on the 5th March from Plesetsk, 800 km north of Moscow. Until then the Astrium employees are expecting another 5 busy weeks, from the 2nd February, in order to get the satellites ready for take off. The satellites will orbit the Earth in formation flight and will measure the gravity field of our Earth with unprecedented accuracy.
At the moment, the Grace team is still in Friedrichshafen, working on the last tests and the packaging of the small satellites. On the 31st January the transportation of the first satellite will begin. It will be firstly transported by lorry to Friedrichshafen airport, and from there will be flown aboard a Russian Ilyushin 76 airplane 3500-km to Archangelsk on the Barents Sea. The next day, a transport helicopter will take the satellite and additional equipment in two separate flights to the rocket launch pad in Plesetsk, which lies about 180 km south of Archangel and 800 km north of Moscow. Two days later the second Grace satellite will follow the same route. Two members of the Grace team will accompany each satellite transport, in order to secure an appropriate handling of the delicate freight. On February 2nd, the rest of the start team members will begin their journey to Russia. They will first fly to Moscow and will then continue to the launch pad by train.
The name Grace stands for Gravity Research And Climate Experiment. It will also be a climate experiment for the Astrium employees, who are to spend five weeks in northern Russia in order to prepare the satellites for launch. In Plesetsk, the temperatures at this time of year can plummet to under V20 degrees. During the 5 week campaign, the team will work in two shifts seven days a week until the satellites are finally ready for take off. After their unpacking, the Grace twins must be integrated, refueled and mounted on the launcher's upper stage "Breeze KM". During the launch campaign frequent tests will be carried out, in order to ensure the faultless operation of the two scientific satellites after their launch.
On the 5th March the satellites will finally be launched by a Rockot launch vehicle. Rockot is a modified version of a Russian SS-19 intercontinental rocket. Satellite launches with these launchers are offered and realized by Eurockot GmbH, a West European-Russian joint venture, of which Astrium has a 51 percent share.
Grace is a joint project of the U.S. space agency, NASA and the German Aerospace Center, DLR. The DLR is also responsible for mission management and satellite operation, which will be carried out from the German Space Operation Control Center GSOC in Oberpfaffenhofen. As the main contractor, Astrium is responsible for the construction of the two satellites. The results of the Grace mission will aid scientists of the most diverse disciplines to better understand the terrestrial system and more precisely predict the influence of human activity on the fragile equilibrium of the biosphere.
The Grace twins will circle the earth at a distance of 220 kilometers from one another in a polar orbit at a height of 500 kilometers. Both satellites will constantly and precisely measure the distance between them. Because this distance changes under the influence of the earth's gravitational field, it is possible to measure the gravity field of our planet with previously unattainable accuracy. During the five-year duration of the mission the measurements will provide an updated model of the terrestrial gravitational field very thirty days. In addition, each satellite is to provide daily up to 200 temperature distribution and water vapor concentration profiles in the atmosphere and ionosphere.
NASA has chosen the Grace experiment as the second mission of its Earth System Science Pathfinder Project (ESSP). NASA's Jet Propulsion Laboratory (JPL) is responsible for the project management. Astrium in Friedrichshafen, Germany built the satellites. Scientists of the University of Texas in Austin and of the GeoForschungsZentrum Potsdam will carry out the scientific analysis of the data delivered by Grace.
