Summary

LISA Pathfinder does not possess a classical payload with which to perform its scientific investigation, for the spacecraft as a whole is used to pursue its objective. The core of the experiment is the inertial sensor, the LISA Technology Package (LTP), containing the proof masses and the accurate metrology system. Two micro-propulsion systems are present: one based on Field Emission Electric Propulsion (FEEP) developed in Europe and one based on Colloidal thrusters, developed in the USA and provided by NASA. The inertial sensor and the two micro-propulsion systems are controlled by two drag-free control software packages, one residing in the European on-board computer and one provided by JPL, called the Disturbance Reduction System (DRS), residing on a dedicated computer.

The launch of LISA Pathfinder is planned for 2012. Following the transfer to its operational orbit, initial set-up and calibration phases, the in-flight demonstration of the LISA technology will take place (90 days LTP, 70 days DRS), providing timely feedback for the development of the LISA mission.

History

Approval - November 2000
LISA Pathfinder was approved by the ESA Science Programme Committee (SPC).

Definition Phase (Phase-A/B1) - September 2001 to July 2002
Two parallel studies were carried out by Astrium (UK) and CASA (Spain) as prime contractors. These studies assumed a variety of mission scenarios (with and without the DRS, with and without a Darwin Technology Package) involving one or two spacecraft.

Extended Definition Phase - November 2002 to June 2003
Two parallel studies were carried out by the same prime contractors, but now focusing on only one mission scenario: LISA technology (LTP and DRS) and only one spacecraft.

Selection - mid 2003
Astrium (UK) was selected as the prime contractor for the Implementation Phase (Phase-B2/C/D).

Extended Definition Phase - until January 2004
As the implementation phase could not be started immediately, the Extended Definition Phase was continued with only Astrium (UK) as prime.

Implementation Phase (Phase-B2/C/D) - since February 2004
In February 2004 LISA Pathfinder entered the Implementation Phase.

Development Phase (Phase C) - February 2006
After successful completion of the Mission Preliminary Design Review in February 2006, the Development Phase started. In the current phase the detailed design of the mission in all its constituents will be undertaken.

Formal approval

In November 2003, ESA's Science Programme Committee (SPC) decided that the long-term space science plan will include LISA Pathfinder, subject to affordable cost-at-completion and formally secured LTP payload funding. Final formal approval of the LISA Pathfinder mission was given at the June 2004 SPC meeting. Signature of the Multilateral Agreement by ESA and those national funding agencies making contributions to the LTP, was perfomed in February 2005.