Known as LISA Pathfinder, the mission has cost the European Space Agency about 430 million euros ($490 million), but it is just the first step in a long-term program to study the “invisible universe” by observing unseen gravity waves created from the motion of massive objects like black holes.
“This is an extremely challenging mission that will pave the way for future space-based projects to observe gravitational waves, opening a new window to explore the cosmos,” said Paul McNamara, ESA’s LISA Pathfinder project scientist.
Lasers buried inside the LISA Pathfinder spacecraft will measure the motion of two gold-platinum alloy cubes 46 millimeters (1.8 inches) on a side. Free-floating inside vacuum enclosures, the motion of the cubes will be measured to one thousandth of one millionth of a millimeter.
Micro-thrusters mounted outside the probe, coupled with specialized control software, will carefully regulate the movement of the spacecraft to keep the gold-platinum test masses floating inside their housings. The goal of the spacecraft is to keep the test cubes floating in an electrostatic field free from outside influence, demonstrating the masses can remain in near-perfect free-fall.