Tag Archives: Lisa Pathfinder

LISA Pathfinder switched off

After a successful mission proving the technology for a full scale orbiting gravitational wave detector, LISA Pathfinder was shut off yesterday.

After 16 months of science measurements an international team deactivated the LISA Pathfinder satellite on the evening of the 18th of July 2017. The gravitational-wave laboratory in space powered down after receiving the last commands in the evening and circles the Sun on a safe parking orbit. LISA Pathfinder has tested key technologies for LISA, the future gravitational-wave observatory in space, and has demonstrated their operative readiness. LISA is scheduled to launch into space in 2034 as an ESA mission and will “listen” to the entire Universe by measuring low-frequency gravitational waves.

The idea is laudable, but for Europe to need another seventeen years to build and launch the full scale telescope is absurd. They now know what needs to be done. It should be relatively easy and quick to get it into orbit. And even if it isn’t easy, seventeen more years? Give me a break.

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Success of test mission paves way for orbiting gravitational wave detector

The success of LISA Pathfinder during the past year to test the technology for building an orbiting gravitational wave detector has now made it possible for Europe to approve construction of the full scale telescope, set to launch in the 2030s.

The LISA Pathfinder mission, launched in late 2015, beat its precision target by a factor of 1,000 and quieted critics who have doubted its potential, says project scientist Paul McNamara, an astrophysicist at ESA in Noordwijk, the Netherlands. “This is not the impossible task that some people believed it was.”

Currently set to fly in 2034, the full-scale Laser Interferometer Space Antenna (LISA) will be the space analogue of the Laser Interfero-meter Gravitational-Wave Observatory (LIGO), two machines in the United States — each with a pair of 4-kilometre-long arms — that first detected the ripples by ‘hearing’ the merger of two black holes. LISA’s three probes will fly in a triangle, millions of kilometres apart, making the mission sensitive to much longer gravitational waves, such as the ripples produced by the collisions of even larger black holes.

The article also notes that the European Space Agency also approved two other large missions, one to launch in 2022 and go the moons of Jupiter, another an X-ray observatory that will launch in 2028.

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LISA Pathfinder proves space-based gravity wave detection technology

Engineers have announced that the gravity wave detection technology being tested in orbit by Europe’s LISA Pathfinder works.

To show that the necessary sensitivity is possible, LISA Pathfinder measures the distance between two masses, both of which are inside the spacecraft. “We’ve shrunk the arm of a large gravitational wave antenna to 35 centimeters so we could show it works properly,” Paul McNamara, LISA Pathfinder project scientist, told the press conference.

LISA Pathfinder was launched in December 2015 to a spot 1.5 million kilometers from Earth. When its test masses where first released to float free in February, “the relief was unbelievable,” McNamara says. Science operations began on 1 March and on that first day the team was able to measure distance variations between the masses much smaller than LISA Pathfinder’s mission requirements, Stefano Vitale, the mission’s principle investigator, told reporters. After a month, the variations were even smaller, “very close to [eLISA] requirements,” he says.

They now hope to launch an array of at least three such spacecraft by the mid-2030s.

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LISA Pathfinder cubes in freefall

After a week of testing scientists have now completely released LISA Pathfinder’s two gold-platinum cubes so that they are floating free within the spacecraft.

With the cubes released, the spacecraft is now measuring the position of each cube and using thrusters to adjust its position and keep the cubes floating within it. This success has essentially proven that the technology works, though they now have to see if the technology can be maintained in orbit for a long enough period of time to be worthwhile. If so, this mission will be followed by multiple similar spacecraft, flying in formation while also measuring their positions precisely relative to each other. If a gravitational wave rolls past, they will detect it by the tiny differences of each cube’s position, kind of like beach balls floating on the ocean as a wave rolls past.

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LISA Pathfinder’s cubes floating free

More gravitational wave news: LISA Pathfinder’s two gold-platinum 46mm cubes have been released and are now floating free inside their spacecraft.

After a week of further testing, they will stop controlling the cube’s positions with electrostatic force. They will then watch them very precisely with lasers to test whether the equipment is capable of detecting distance shifts small enough for a future version, made up of three such spacecraft, to detect gravitational waves. The idea is that, as a wave rolls by, the cubes will shift positions at slightly different times, just as different beach balls will do so on ocean waves.

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Lisa Pathfinder lifts off

Lisa Pathfinder, an experimental probe to test the technologies for measuring gravity waves in space, was successfully launched today by Arianespace’s Vega rocket.

At its core is a pair of free-floating, identical 46 mm gold–platinum cubes separated by 38 cm, which will be isolated from all external and internal forces acting on them except one: gravity. “LISA Pathfinder will put these test masses in the best free-fall ever produced in space and monitor their relative positions to unprecedented precision,” says Karsten Danzmann, who also is the Co-Principal Investigator for the LISA Pathfinder Technology Package, the scientific heart of the satellite. “This will lay the foundations for future gravitational-wave observatories in space such as eLISA.”

It is important to point out that this probe will not measure gravity waves. It doesn’t have the sensitivity to do it. Instead it is testing the engineering, as described above, for building a later probe that will have sensitivity. To gain that sensitivity the floating cubes must be much farther apart, and likely will require several independent satellites flying in formation.

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