LISA Pathfinder, gravitational-wave observatory, European Space Agency, Paris, France


LISA Pathfinder launch animation

Published on Sep 1, 2015

Artist’s impression of the launch of LISA Pathfinder, ESA’s technology demonstration mission that will pave the way for future gravitational-wave observatories in space.

Scheduled to lift off on a Vega rocket from Europe’s Spaceport in French Guiana in late 2015, LISA Pathfinder will operate at the Lagrange point L1, 1.5 million km from Earth towards the Sun. After launch, the spacecraft will take about eight weeks to reach its operational orbit around L1.

The Vega rocket is designed to take small payloads into low-Earth orbit. The animation shows the rocket shortly after launch, rising above our planet and releasing the fairing.

Vega will place the spacecraft onto an elliptical orbit with perigee at 200 km, apogee at 1540 km and angled at about 6.5° to the equator. Then, LISA Pathfinder will continue on its own, using its separable propulsion module to perform a series of six manoeuvres and gradually raise the apogee of the initial orbit.

Eventually, LISA Pathfinder will cruise towards its final orbiting location, discarding the propulsion system along the way, one month after the last burn. Once in orbit around L1, the spacecraft will begin its six months of operations devised to demonstrate key technologies for space-based observation of gravitational waves.
 

Gravitational waves

Published on Sep 1, 2015

Gravitational waves are ripples in the fabric of spacetime produced by accelerating massive bodies to Albert Einstein’s general theory of relativity.

In general relativity, gravity manifests itself as massive objects bending the structure of spacetime. In addition, something else happens if the gravitational field varies, for example when two massive objects orbit each other.

The motion of massive bodies through spacetime perturbs its very fabric, imprinting a signal that travels away as a disturbance to the structure of spacetime itself: gravitational waves. The animation visualises the effect of these oscillations, which consist of sequential stretches and compressions of spacetime, rhythmically increasing and reducing the distance between particles as a wave propagates through the surroundings.

It is thought that gravitational waves are abundant across the Universe, typically produced by powerful sources such as supernova explosions and pairs of orbiting black holes. However, despite the attempts of ground-based experiments to detect them directly, gravitational waves so far remain elusive.
 

Lisa Pathfinder mission overview

Published on Nov 13, 2015

LISA Pathfinder will pave the way for future missions by testing in flight the very concept of gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. LISA Pathfinder will use the latest technology to minimise the extra forces on the test masses, and to take measurements.

The inertial sensors, the laser metrology system, the drag-free control system and an ultra-precise micro-propulsion system make this a highly unusual mission.

LISA Pathfinder is an ESA mission, which will also carry a NASA payload.
 

LISA Pathfinder - Window on the gravitational universe

Published on Nov 25, 2015

LISA Pathfinder’s name, Laser Interferometer Space Antenna, clearly indicates the role of precursor that this mission plays. Its goal is to validate the technology required to detect gravitational waves from space. Gravitational waves will open a new door in our understanding of the Universe, and at the same time help to verify Einstein’s General Theory of Relativity. LISA Pathfinder will be launched early December 2015 on a Vega rocket from Kourou in French Guiana.
 

Liftoff of Vega Flight VV06 with LISA Pathfinder

Published on Dec 2, 2015

The Vega mission with Europe’s pioneering LISA Pathfinder technology demonstrator is now underway following tonight’s liftoff from the Spaceport in French Guiana.

LISA Pathfinder will be placed in an initial elliptical Earth orbit at 1 hr., 45 min., 33 sec. after liftoff. The spacecraft’s own propulsion module then will be utilized to reach the operational orbit around the first Sun-Earth Lagrange point (L1) – located approximately 1.5 million kilometers from Earth.

Produced to study the ripples in space-time predicted by Albert Einstein’s General Theory of Relativity, LISA Pathfinder was developed in a European Space Agency (ESA) program and built by prime contractor Airbus Defence and Space.
 

LISA Pathfinder results

Published on Jun 7, 2016

Launched in December 2015, LISA Pathfinder travelled to its operational orbit, 1.5 million km from earth towards the Sun, where it started its scientific mission on 1 March.

At the core of the spacecraft, two identical gold-platinum cubes, are being held in the most precise free-fall ever produced in space.

Placing the test masses in a motion subject only to gravity is the challenging condition needed to build and operate a future space mission to observe gravitational waves. Predicted by Albert Einstein a century ago, gravitational waves are fluctuations in the fabric of space-time, which were recently detected directly for the first time by the Laser Interferometer Gravitational-Wave Observatory.

Over the first two months of scientific operations, the LISA Pathfinder team has performed a number of experiments on the test masses to prove the feasibility of gravitational wave observation from space.

These results are explained in this video with interviews of Paul McNamara, LISA Pathfinder Project scientist, ESA and two LISA Pathfinder Principal investigators : Rita DOLES, University of Trento and Martin Hewitson, University of Hannover.
 

Lisa Pathfinder end of mission

Published on Jul 18, 2017

The LISA Pathfinder mission ends on 18 July 2017 after a successful demonstration of the technology needed to detect gravitational waves in space. These vibrations in spacetime, first predicted by Einstein over a hundred years ago, are produced by huge astronomical events - such as two black holes colliding - and will allow scientists to open new windows into our universe.

The success of the LISA Pathfinder mission has paved the way for the newly selected LISA mission which, when built and launched, will detect gravitational waves from objects up to a million times larger than our Sun.

The film features interview soundbites from Dr Paul McNamara, LISA Pathfinder Project Scientist, at the European Space Agency’s European Technology and Science facility (ESTEC) in The Netherlands.
 

How LISA Pathfinder detected dozens of 'Comet Crumbs'

Nov 18, 2019

LISA Pathfinder, a mission led by ESA (the European Space Agency) that included NASA contributions, successfully demonstrated technologies needed to build a future space-based gravitational wave observatory, a tool for detecting ripples in space-time produced by, among other things, merging black holes. A team of NASA scientists leveraged LISA Pathfinder's record-setting sensitivity for a different purpose much closer to home — mapping microscopic dust shed by comets and asteroids.

Most of these particles, known as micrometeroids, have masses measured in micrograms, similar to a small grain of sand. But at speeds reaching 40,000 mph (64,000 kph), even micrometeoroids pack a punch.

The NASA team, led by Ira Thorpe at NASA's Goddard Space Flight Center in Greenbelt, Maryland, detected 54 impacts during the mission, which lasted from 2015 to 2017. Modeling the strikes allowed the researchers to determine what kinds of objects shed the dust. The findings are broadly consistent with existing ideas of what generates micrometeroids found near Earth. The dusty culprits are mostly short-period comets whose orbits are determined by Jupiter. Comets with longer periods, like Halley’s comet, also contributed dust that LISA Pathfinder sensed.

The new measurements could help refine dust models used by researchers in a variety of studies, from understanding the physics of planet formation to estimating impact risks for current and future spacecraft.
 
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