LISA Pathfinder satellite reports major gravitational wave results

A European Space Agency mission designed to demonstrate the technology needed to built a space-based gravitational wave detector has exceeded expectations on its first day of operation and has reported record-breaking observations of spacetime rippled over a two month span.

According to BBC News and Scientific American, the ESA’s LISA Pathfinder satellite was sent into orbit in order to test components of a laser measurement system that would be utilized on a future observatory, and its early success indicates that said observatory would be effective when it comes to locating evidence of merging supermassive black holes.

At the heart of the spacecraft are two 4.6-centimeter gold-platinum cubes that are falling freely through space, influenced solely by gravity and unperturbed by any other external force, agency officials explained in a statement. Thus far, they have been able to remain almost perfectly still, according to New Scientist, and have been five-times more precise than initially required.

“During commissioning, the requirements were being met already,” co-principal investigator Karsten Danzmann told BBC News. “We hadn’t tweaked anything; we’d just turned everything on to see if the laser was running and, bang, there it was. And the performance has just got better and better ever since.”

Pathfinder's instrument

Lisa Pathfinder’s instrument. Credit: AIRBUS DS

Instruments precise enough to detect waves anywhere in the universe

The LISA Pathfinder’s mission has generated a lot of excitement in the scientific community, as the ability to reliably detect gravitational waves has been highly sought after since these ripples in space time were first detected last year by the US-based Advanced LIGO project centers.

That discovery has been widely hailed as one of the greatest scientific discoveries in decades, BBC News noted, and the ultimate goal is to take the ability to detect these phenomena into space, thus expanding the range of such searches beyond what is capable using a ground-based observatory. First, however, the technology must be tested and proven effective.

To that end, the ESA launched the LISA Pathfinder last December, hoping the test cubes released by the satellite would be able to maintain a separation of 38 centimeters during a free-fall while being measured with a laser interferometer. So far, so good, as a team of ESA scientists reported Tuesday in a paper published online by the journal Physical Review Letters: the performance of the cubes appears promising for a space-based gravitational wave observatory.

ESA Lisa Pathfinder

The laser interferometer system inside Lisa Pathfinder. Credit: ESA

“LISA Pathfinder’s test masses are now still with respect to each other to an astonishing degree,” Alvaro Giménez, the ESA’s Director of Science, explained in a statement Tuesday. He added that the results of the test demonstrate “the level of control needed to enable the observation of low-frequency gravitational waves with a future space observatory.”

Paul McNamara, a project scientist on the LISA Pathfinder mission, said that the measurements “have exceeded our most optimistic expectations,” and Danzmann added that “at the precision reached by LISA Pathfinder, a full-scale gravitational wave observatory in space would be able to detect fluctuations caused by the mergers of supermassive black holes in galaxies anywhere in the Universe.”

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Image credit: ESA