ESA launches LISA Pathfinder to test gravity wave detection

A European Space Agency (ESA) aircraft designed to test technology that could one day help scientists find ripples in spacetime predicted by Einstein’s theory of relativity launched Thursday from a spaceport in Kourou, French Guiana, NASA officials have confirmed.

The LISA Pathfinder will use a pair of cube-shaped masses to test the concept of detecting these unusual ripples, better known as gravitational waves, but they will not directly detect them. Instead, it will demonstrate technology that could one day be used by observatories to detect the waves.

According to the US space agency, these test masses are objects made out of gold and platinum which are dense, non-magnetic and designed to respond only to gravity. Each weighs about four pounds (two kilograms) and measures 1.8 inches (4.6 centimeters) on each side, and both will float in separate vacuum chambers 15 inches (38 centimeters) apart, they added.

It will take the LISA Pathfinder approximately seven weeks to reach its operational orbit, which is known as Lagrange Point L1 and is about 930,000 miles (1.5 million kilometers) from Earth in the direction of the sun. It will then begin a six-week commissioning period followed by an eight month period of technical demonstrations.

Spacecraft also features cutting-edge thruster technology

The spacecraft’s position will be adjusted regularly using high-precision thrusters to ensure it maintains a central position between the two test masses. The objects’ positions will be measured using lasers to ensure accuracy to 100,000th of the width of a single hair.

In addition, the LISA Pathfinder has been outfitted with a new type of thruster developed by a team at the Jet Propulsion Laboratory (JPL) in Pasadena, California. Known as the Disturbance Reduction System (DRS), this technology used first-of-their-kind colloid micronewton thrusters to keep the spacecraft stable and to help compensate for solar pressure, according to NASA.

“The DRS is one of the most precise thruster systems for a spacecraft ever qualified for use in space,” Phil Barela, DRS project manager at JPL, explained in a statement. Developed by Busek Co., the thrusters electrically charge small liquid droplets and fire them through an electric field in order to generate a continuous thrust of between five and 30 micronewtons.

“A system akin to the DRS could be used on a future gravitational-wave mission for stability,” added Charles Dunn, project technologist for the DRS at JPL. It could aid in the development of similar next-gen thruster technology for other spacecrafts, and could be used to stabilize vehicles exploring exoplanets or for keeping satellites flying in a synchronous formation.

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Image credit: ESA/NASA