AIRBUS DEFENCE AND SPACE

For the development of the LISA Pathfinder satellite and measurement equipment that is sensitive enough to detect gravitational waves.

The Laser Interferometer Space Antenna (LISA) Pathfinder satellite was designed for the European Space Agency to test the technology needed for a planned mission (eLISA) to establish a dedicated gravitational-wave detector in space. The sensitivity of Earth-based detectors of gravitational waves is limited: they are subject to interference from seismic noise and nearby moving masses, and there is also a practical limit to their size. The LISA Pathfinder mission has successfully demonstrated that a more sensitive detector can be established in orbit.

Gravitational waves are ripples in spacetime: as they move they alter the spatio-temporal relationships between objects. This means that they can be detected by measuring changes in the relative positions and orientations of two test masses. However, for this method of detection to be sufficiently sensitive, the test masses need to be shielded from all other forces and new technology is required to accurately measure their relative positions.

LISA Pathfinder used the latest technology – inertial sensors, a drag-free control system and an ultra-precise micro-propulsion system – to minimise the extra forces on the test masses and demonstrated that they could be placed in a near-perfect gravitational free-fall. The mission also demonstrated the feasibility of laser interferometry at a frequency that is not possible on Earth. This meant that the distance of test masses 40cm apart could be measured to an unprecedented accuracy of 0.01nm.

The company

Airbus Defence and Space is a major aerospace systems provider covering satellites, launchers, transport and fighter aircraft, UAVs, communications services, and cyber-security. Airbus DS is the world’s number two in the space industry with more than 40,000 employees and €13bn in revenue.