LISA Pathfinder lifts off to prove 100-year-old Einstein theory

3 Dec 2015

An illustration of LISA Pathfinder in orbit. Image via ESA/ATG medialab

From its base in French Guiana, the European Space Agency (ESA) has launched its latest satellite, the LISA Pathfinder, to demonstrate technology for observing gravitational waves from space.

Launched aboard the space agency’s Vega rocket at 5:04 CET this morning, the LISA Pathfinder is aiming to help demonstrate a way of observing a cosmic phenomenon that Albert Einstein predicted almost 100 years ago to the day, on 2 December 1915.

As the LISA Pathfinder enters into space, the devices on the craft will hope to record examples of gravitational waves, which Einstein had predicted, soon after he had announced his General Theory of Relativity.

With regard to gravitational waves, Einstein’s theory had predicted that the fluctuation of gravitational waves should be universal, generated by accelerating massive objects.

The problem is, however, that they have yet to be directly detected because they are so small that the ripples emitted by a pair of orbiting black holes would stretch a 1m km-long ruler by less than the size of an atom.

LISA Pathfinder taking off

Liftoff of Vega VV06 carrying LISA Pathfinder. Image via ESA–Stephane Corvaja, 2015

To help it detect one of the best hidden of the universe’s secrets, the LISA Pathfinder has on board a pair of identical 46mm gold–platinum cubes separated by 38cm, which will be isolated from all external and internal forces acting on them, except for gravity, of course.

The technology launched aboard it today and subsequent testing, the ESA hopes, will lead to the eventual development of future gravitational wave observatories deployed in space.

It will now spend the next two weeks raising itself into its highest orbit around Earth in the area referred to as L1, a distance of 1.5m kilometres from our planet.

‘A new window on the universe’

Once it has reached its designated orbit in March, it will then spend the next six months scanning the universe, but before it does that, the two cubes will be released from the locking mechanisms that hold them during launch and cruise before being completely detached from the parent craft in final orbit.

“Gravitational waves are the next frontier for astronomers. We have been looking at the universe in visible light for millennia and across the whole electromagnetic spectrum in just the past century,” said Alvaro Giménez Cañete, the ESA’s director of science and robotic exploration.

“But by testing the predictions made by Einstein 100 years ago with LISA Pathfinder, we are paving the road towards a fundamentally new window on the universe.”

Colm Gorey was a senior journalist with Silicon Republic