LISA Pathfinder is the revised name for SMART-2 or Small Missions for Advanced Research in Technology-2, an ESA/NASA space probe to be launched in 2015.
The aim of the LISA Pathfinder is to test technologies needed for the Laser Interferometer Space Antenna, a joint ESA/NASA gravitational wave detector. It will contain one arm of the LISA interferometer, shortened from 5 Gm (5 million km) to 35 cm.
In particular, it will verify:
- Drag-free attitude control of a spacecraft with two proof masses,
- The feasibility of laser interferometry in the desired frequency band (which is not possible on the surface of Earth), and
- The reliability and longevity of the various components—capacitive sensors, microthrusters, lasers and optics.