LISA Pathfinder

The main goal of the LISA Pathfinder mission of the European Space Agency (ESA) was to test key technologies for the future space-based gravitational-wave observatory LISA (the ESA-L3 mission).

Launched on 3 December 2015, LISA Pathfinder has tested in flight the very concept of gravitational wave detection: it contains two test masses in a near-perfect gravitational free-fall and an optical (laser) metrology system that controls and measures their motion with unprecedented accuracy. LISA Pathfinder is using the latest technology to minimise the extra forces on the test masses, and to take measurements. The inertial sensors, the laser metrology system, the drag-free control system and an ultra-precise micro-propulsion system make this a highly unusual mission. LISA Pathfinder also carries a NASA payload, an alternative micro-propulsion system.

Image: ESA

On June 7th, 2016, the LISA Pathfinder collaboration announced at the European Space Astronomy Center (ESAC) the success of the LISA Pathfinder mission by showing an acceleration noise sensitivity curve much better than the required initially (improvement factors are typically 5-1000 depending on the frequency range) and very close to the one required by the classic LISA mission.

IEEC’s contribution

A crucial part of this technology has been developed by the IEEC though the Gravitational Astronomy-LISA research group at the Institute of Space Sciences (ICE, CSIC). Spain is one of the eight signatories of the Multilateral Agreement (MLA) between ESA and Germany, Italy, United Kingdom, Spain, France, the Netherlands and Switzerland. The Spanish contribution started on 2004, led by Prof. Alberto Lobo, and consists in the Data and Diagnostics Subsystem (DDS), which include the payload control computer, also known as the Data Management Unit (DMU) and a set of high-precision and high-stability sensors and actuators to monitor the environment of the test masses in LISA Pathfinder, the Diagnostic Items (ITs).

The DMU is the main computer of the LTP (a mission critical component) which interfaces with the On Board Computer (OBC), the LPF master computer which communicates with the ground stations and distributes tasks to the various subsystems of both the satellite and the payload. The DMU also controls the diagnostic subsystem. The DMU contains fully duplicated hardware (redundancy). The Boot (BSW) and Application software (ASW) for the DMU have also been the responsibility of the Spanish group.

The DIs consist of: (i.1) Thermal Diagnostics that use 24 precision thermometers and 14 precision heaters. (i.2) Magnetic diagnostics that use 4 sensitive 3-axes magnetometers (fluxgate class) and 2 precision induction coils. (i.3) Charged particle counting and spectroscopy by means of a Radiation Monitor.

The group has contributed also some parts of the LISA Technology Package Data Analysis (LTPDA) tools, a MATLAB tool developed for the analysis of the LISA Pathfinder data.

More information on the ESA website

More information on the LISA Pathfinder website

Generalitat de CatalunyaUniversitat de BarcelonaUniversitat Autònoma de BarcelonaUniversitat Politècnica de CatalunyaConsejo Superior de Investigaciones CientíficasCentres de Recerca de Catalunya