Science

Gravitational wave-detecting satellite LISA Pathfinder launch postponed

The launch of an experimental satellite that will test a technique to detect ripples in space and across time has been postponed.

Detector contains small metal cubes that would oscillate as a gravitational wave passes through

The LISA Pathfinde satellite is expected to break ground in the search for the ripples, known as gravitational waves, caused by fast-moving, massive celestial objects such as merging black holes. (ESA)

The launch of an experimental satellite that will test a technique to detect ripples in space and across time has been postponed.

From a vantage point 1.5 million kilometres (930,000 miles) from Earth, the European-built spacecraft, known as LISA Pathfinder, is expected to break ground in the search for the ripples, known as gravitational waves, caused by fast-moving, massive celestial objects such as merging black holes. 

It was originally scheduled to launch at  0415 GMT Wednesday (11:15 p.m. ET) from the European Space Agency's Kourou, French Guiana, launch site. 

But less than 12 hours before launch, ESA reported a problem with the Vega rocket carrying the satellite. That problem requires further investigation. Depending on the results of the investigation, the launch could go ahead on Dec. 3, ESA said. 

Scientists have high hopes for the satellite once it launches.

At a news conference prior to the launch delay, European Space Agency deputy mission scientist Oliver Jennrich said the LISA Pathfinder "will really open up a new window into the universe. God knows what we will learn." 

Like light, gravity travels in waves. Unlike light, gravitational waves bend the interwoven fabric of space and 
time, a phenomenon conceptualized by physicist Albert Einstein a century ago. Before Einstein's general theory of relativity, gravity was seen as a force between two bodies.

In the pre-Einstein view of physics, if the sun disappeared one day, people on Earth would feel it instantly. In Einstein's view, the effects would not be felt for eight minutes, the time both light waves and gravitational waves take to travel from the sun to Earth.

So far, attempts to detect gravitational waves using Earth-based detectors have been unsuccessful.

The LISA Pathfinder will blast off aboard a Vega rocket, seen readying for launch above, from ESA's Kourou, French Guiana launch site tonight at 11:15 p.m. ET. (ESA)

Massive objects such as black holes bend space and time more than smaller bodies like the sun, similar to how a bowling ball warps the surface of a trampoline more than a baseball.

"There's a whole spectrum of gravitational waves, just like there's a whole spectrum of electromagnetic waves," said 
astrophysicist Ira Thorpe of NASA's Goddard Space Flight Center.

Like a buoy rising and falling on the ocean

An operational gravitational wave observatory under development would require three satellites, flying in a triangle 
formation about 1 million kilometres (621,000 miles) apart. The satellites would contain small metal cubes that would oscillate as a gravitational wave passes through, similar to a buoy rising and falling on the ocean.

Using a laser to measure tiny changes in distance between the cubes, scientists hope to track the subtle flexing of space and time. LISA (Evolved Laser Interferometer Space Antenna) Pathfinder will demonstrate the concept with two metal cubes 38 centimetres (15 inches) apart inside a single spacecraft.

The mission, designed to last six months, cost about 400 million euros ($568 million Cdn).

With files from CBC News