About LISA Pathfinder

Housed at the core of LISA Pathfinder are two freely falling test masses separated by 38 cm. The spacecraft surrounds the test masses without touching them, shielding them from outside influence by constantly applying tiny adjustments to its position.

This will allow scientists to demonstrate whether it is possible to put two test masses into a near-perfect gravitational free-fall – the most challenging condition for detecting gravitational waves.

LISA Pathfinder is not aimed at the detection of gravitational waves themselves. Rather, its goal is to prove the innovative technologies needed to reduce external influences on two test masses and to measure their relative motion with unprecedented accuracy, tracking their free-fall by more than two orders of magnitude better than any past, present or planned mission.

In a full-scale gravitational-wave observatory, the test masses would be housed in two individual spacecraft separated by about a million km: on this scale, passing gravitational waves would change the distance between the cubes at the level of picometres (10^–12 m) and would thus become measurable.

LISA Pathfinder consists of a science module and a separable propulsion module that will gradually raise the initial orbit until it reaches the operational one, and will be discarded shortly before the science module enters the final orbit. The spacecraft will operate from the first Sun–Earth Lagrange point, L1, 1.5 million km from Earth towards the Sun.

The designation ‘LISA’ in the mission’s name stands for Laser Interferometer Space Antenna, an earlier concept for a spaceborne observatory for gravitational waves, and now used to describe a class of missions based on the original LISA concept.

For further information, please contact:

Markus Bauer 



ESA Science and Robotic Exploration Communication Officer




Tel: +31 71 565 6799





Mob: +31 61 594 3 954





Email: markus.bauer@esa.int




Paul McNamara



LISA Pathfinder Project Scientist


Tel: +31 71 565 8239
Email: paul.mcnamara@esa.int

César García Marirrodriga
LISA Pathfinder Project Manager


Tel: +31 71 565 5172
Email: Cesar.Garcia@esa.int