Lisa Pathfinder, the satellite that senses gravitational waves, has reached its destination some 1.5 million km away from Earth ahead of the commencement of a scientific programme designed to prove (or disprove) Einstein’s theory of relativity.
Launched on 3 December 2015, Lisa Pathfinder took six weeks to reach the so-called Lagrangian point 1 (L1) - one of the points between the Earth and the Sun, where the gravitational pull of both bodies is equal, allowing the spacecraft to stay stabilised in its position.
According to an announcement by the European Space Agency, Lisa Pathfinder will soon start testing its technologies designed to detect gravitational anomalies predicted by Albert Einstein.
The spacecraft carries two gold-platinum cubes that are both 46 mm in size and placed 38 cm apart. The cubes are completely isolated from all external forces, barring gravity. As the cubes will be in the state of perfect free fall, scientists on Earth will be able to obtain data on how the expected gravitational differences affect them.
Soon after reaching L1, the satellite ditched its propulsion module, which helped it reach the destination through six precise firings at various altitudes. The final thruster burn took place on 20 January 2016.
“Heat and vibration from the regular, hot thrusters on the propulsion module would cause too much disturbance during the spacecraft’s delicate technology demonstration mission,” said Ian Harrison, Spacecraft Operations Manager at ESA’s ESOC operations centre in Darmstadt, Germany.
“Primary propulsion during the rest of the mission will be provided by cold-gas microthrusters to keep us at L1. We had planned two burns to get us into final orbit at L1, but only one was needed.”
Over the weekend, the engineers have stabilised the satellite and turned it to point towards the Earth to establish a communication link with a ground station in Australia.
Watch Lisa Pathfinder's journey to L1: