The LISA Pathfinder mission ends on 18 July 2017 after a successful demonstration of the technology needed to detect gravitational waves in space. These vibrations in spacetime, first predicted by Einstein over a hundred years ago, are produced by huge astronomical events – such as two black holes colliding – and will allow scientists to open new windows into our universe.
The success of the LISA Pathfinder mission has paved the way for the newly selected LISA mission which, when built and launched, will detect gravitational waves from objects up to a million times larger than our Sun.
The film features interview soundbites from Dr Paul McNamara, LISA Pathfinder Project Scientist, at the European Space Agency’s European Technology and Science facility (ESTEC) in The Netherlands.
This timelapse video shows the preparations for LISA Pathfinder’s launch at Europe’s Spaceport in Kourou, French Guiana. The video spans three weeks, starting on 12 November 2015 with the completed and fuelled spacecraft and ending on the 3 December launch day.
Over this period, the spacecraft was attached to the payload adaptor of the Vega launcher, encapsulated within the half-shells of the rocket fairing, transferred to the launcher assembly area, and installed on top of Vega inside the mobile gantry, which was rolled back shortly before liftoff.
LISA Pathfinder will test key technologies for space-based observation of gravitational waves – ripples in the fabric of spacetime that are predicted by Albert Einstein’s general theory of relativity.
Credit/Copyrights: Directed by Stephane Corvaja, ESA; Edited by Manuel Pedoussaut, Zetapress; Music: Hubrid-Gravity
ESA’s LISA Pathfinder mission is a technology demonstrator that will pave the way for future spaceborne gravitational-wave observatories. It will operate about 1.5 million km from Earth towards the Sun, orbiting the first Sun–Earth ‘Lagrangian point’, L1.
The animation of the spacecraft build-up begins with two freely falling test masses. Between them lies the central component of LISA Pathfinder’s payload: the 20 x 20 cm optical bench interferometer. A set of 22 mirrors and beam-splitters directs laser beams across the bench. There are two beams: one reflects off the two free-falling test masses while the other is confined to the bench. By comparing the length of the different paths covered by the beams, it is possible to monitor changes accurately in distance and orientation between the two test masses.
A box surrounds the two masses without touching them, shielding them from outside influence and constantly applying tiny adjustments to its position. This internal payload is housed in a central cylinder, isolating the test masses from the other components of the science payload and spacecraft.
The solar array provides power to the instrumentation and acts as a thermal shield. Microthrusters control the spacecraft to keep the master test mass centred in its housing, opposing the force of the solar radiation pressure – the main source of ‘noise’ – impinging on the solar array.
Although LISA Pathfinder is not aimed at the detection of gravitational waves themselves, it will prove the innovative technologies needed to do so. It will demonstrate that the two independent masses can be monitored as they free-fall through space, reducing external and internal disturbances to the point where the relative test mass positions would be more stable than the expected change caused by a passing gravitational wave, equal to much less than the size of an atom.
