LISA Pathfinder – testing eLISA/NGO technologies in space
For this purpose, one laser arm of eLISA/NGO is reduced from 1 million kilometres to 30 cm to fit into one single spacecraft. The future mother spacecraft of eLISA/NGO will contain two laser interferometers and two special test masses. The laser interferometer will be aligned with the two other satellites and measure tiniest changes in the distance between the test masses in the daughter satellites with a precision of about one picometer (1 pm = 10-12 m).
The scientific instruments of LPF are provided by two complementary payload packages: the LTP (LISA Technology Package, ESA) and the DRS (Disturbance Reduction System, NASA).
The LTP was built by a consortium of European space companies (D, I, UK, ES, NL, CH, F) led by EADS Astrium, Friedrichshafen. It contains the following key technologies:
- Inertial sensors to monitor the relative position of the test masses with respect to the satellite.
- Laser interferometry to determine the relative positions of the two test masses.
- Drag-free control system (DFACS) to adjust alignment of the satellite relative to the test masses by means of Micro-Newton ion thrusters.
The second payload package, the Disturbance Reduction System (DRS), is developed in the United States by JPL (Jet Propulsion Laboratory) under the leadership of NASA. It will provide a system of Micro-Newton thrusters complementary to the on-board LTP technology with dedicated control electronics.
LPF is being built by EADS Astrium Ltd. in Stevenage, UK, under contract of ESA.