LISA Pathfinder

LISA Pathfinder (SMART -2 ) is the name of an approved in November 2000 ESA's satellites. EADS Astrium has been selected by the European Space Agency for the construction of the satellite and is responsible for the delivery of integrated satellite start preparing. He is - initially been scheduled for 2008 and then postponed several times - now 2015 start with a Vega rocket and 12 months test instruments used for the LISA mission, ESA and NASA wanted to perform together, but then in 2011 - because of budget cuts - the mission by NASA abandoned.

To prove with LISA (Laser Interferometry Space Antenna ) gravitational waves, the instruments must capture gravitational changes on the order of 10-16 g and changes in distance in the order of 10-12 m in a frequency range from 0.001 to 0.1 Hz. In LISA Pathfinder one is content with an order of magnitude lower measurement accuracy. While LISA distance measurements between satellites performs that are about 5 million kilometers apart, measure the distance between two LISA Pathfinder reference body ( about 40 cm) within the satellite.

The measuring instrument used a 64 × 38 × 38 cm and 150 kg heavy technology test equipment is to be installed on board the satellite, which consists of a special optical bench and various measuring, control and monitoring systems substantially. It contains two vacuum container and each having a cube-shaped test weight of a gold -platinum alloy with 46 mm edge length, which is free floating in the measurement at a distance of about 40 cm. Main payload is a laser interferometer, which determines the distance of the two dice. The laser light is fed through two optical fibers in the board. For precise position control of the satellite very weak electric engines are used with cesium as the driving medium and a thrust force of 0.1 to 150 ìN ( Field Emission Electric Propulsion ).