Please create an account to participate in the Slashdot moderation system


Forgot your password?
Space Communications EU Earth

ESA Approves Gravitational-Wave Hunting Spacecraft For 2034 ( 49

The European Space Agency has approved the Laser Interferometer Space Antenna mission designed to study gravitational waves in space. The spacecraft is slated for launch in in 2034. New Scientist reports: LISA will be made up of three identical satellites orbiting the sun in a triangle formation, each 2.5 million kilometers from the next. The sides of the triangle will be powerful lasers bounced to and fro between the spacecraft. As large objects like black holes move through space they cause gravitational waves, ripples which stretch and squeeze space-time. The LISA satellites will detect how these waves warp space via tiny changes in the distance the laser beams travel. In order to detect these minuscule changes, on scales less than a trillionth of a meter, LISA will have to shrug off cosmic rays and the particles and light from the sun. The LISA Pathfinder mission, a solo probe launched in December 2015, proved that this sensitivity was possible and galvanized researchers working to realize the full LISA mission.
This discussion has been archived. No new comments can be posted.

ESA Approves Gravitational-Wave Hunting Spacecraft For 2034

Comments Filter:
  • by Maritz ( 1829006 ) on Friday June 23, 2017 @04:07AM (#54673779)
    First 300k or so years of this universe was opaque to light, but not to gravitational waves (obviously). So we need these kinds of 'telescope' to see earlier than 300k years or so. Cool mission. Will be interested to see if the Brits are involved or if they're still too busy disappearing up their own arses. Time will tell.
    • I was wondering why it had been approved. So far as I know the first detector was built just to prove the theory. It's such a miniscule effect though that I wonder how effective it'll be.
    • by ivano ( 584883 )
      Luckily (or unluckily) the UK's involvement with the ESA is independent from the EU discussions, AFAIK
  • The changes in cost to orbit per pound just in the last two years have been game-changing. For all we know in 17 years Elon is going to be negotiating their payload fees from his HQ compound built into the side of the Mariner Valley.

    Get the lead out a little, ESA.

    • by j-b0y ( 449975 ) on Friday June 23, 2017 @05:33AM (#54673965)

      Because the technology involved will take some time to develop. You have to have 2 spacecraft pointing a laser at another spacecraft 2,500,000 kilometers away, and measure the change in distance between the two arms to an incredible precision. That's... not easy.

      • If I read TFS correctly, they're planning on having three spacecraft with each pointing lasers at the other two. If I'm right, that gives you six sets of data to work with instead of the two that your way does, making it easier to correct for the inevitable station-keeping issues. Alas, even if this goes off on schedule, I'll be in my mid-80s when it launches and I'll be very lucky if I survive long enough to see any results. Still, it sounds like a great idea and I hope they pull it off.
        • Depending on how you count it, it's actually 6 spacecraft, specifically to eliminate the vast bulk of station-keeping issues. Each of the three nodes is actually two separate craft, one nested inside the other, without making any contact, in a "zero-drag satellite" configuration.

          The inner craft contains all the measuring equipment, laser emitters, etc, and is only influenced by gravity. The outer "shell" is there specifically to enable the "only influenced by gravity" orbital path - it intercepts the sola

    • In the 80s I used to walk by one of the LIGO prototypes at Caltech. Gravity waves take a long time to transverse the universe, and it takes a long time for us to detect them!
  • LISA was in development for quite a few years (10 maybe ?) when it was cancelled.
    Now that LIGO did find evidence for gravitational waves ESA wants to be at the winner's table, so the bad project is good again.

    I think we should call that "having a vision".

    • Re: (Score:2, Informative)

      by Anonymous Coward

      LISA was started as a joint ESA-NASA mission.
      Only NASA cancelled their participation in 2011 because of budget
      Since then it has been an ESA mission - and it had the support of the agency (reaffirmed in 2013 in the "cosmic vision" mission selection).

      So it was never a "bad project" for ESA - you could say the US congress is lacking vision if they reduce NASA's budget so they can't afford missions like that anymore....

    • by j-b0y ( 449975 ) on Friday June 23, 2017 @05:40AM (#54673991)

      LISA was cancelled because JWST was eating the NASA astrophysics budget; ditto IXO cancellation. LISA survived in a much reduced form as NGO, and IXO as ATHENA.

      There wasn't any real chance of LISA scooping LIGO/E-LIGO if gravitational waves were really detectable, but the sensitivity of LISA will open up detection of many more classes of GW emitters.

      • by Anonymous Coward

        Actually it is the very long distance between the satellites that will open up detection of many more classes of GW events, not so much the sensitivity. GW detectors are essentially antenna and the longer distances tune it for much lower frequencies, and thus a different class of events.
        For high frequencies events, like the colliding black holes LIGO detected, the Crests and Troughs of the gravity wave will mostly cancel each other out over the length of the detection path making detection actually harder.

        • The reduced noise from not being near the ground is also a big bonus. But yes, the difference in detection frequencies is the most significant difference.

  • by Anonymous Coward

    A triangular formation of 3 probes? Seriously? What's needed, bare minimum, is a suite of 4 probes in a tetrahedonal configuration. That way, we get a much more accurate vector reading for the event. They cannot be defeated, we need to know what direction to run!

    • This doubles the number of optical components and likely the cost.
      • Nah, the construction cost of the satellite itself isn't all that important, not compared to the launch cost. The other commenters have it right: it's about orbital mechanics. You can organize the satellites in a triangle so that they maintain the same shape. I don't think it's possible to add a fourth satellite and keep it in an orbit that's actually stable.

        I don't think that a fourth satellite would improve the science all that much anyway.

        • While I agree that the orbital considerations are most important, I think you are way off on cost. Are you even aware of the components that go into these lasers? This system is amazingly complex. The budget right now is 2.4 billion dollars, surely that isn't mostly launch costs.
  • by iridium_ionizer ( 790600 ) on Friday June 23, 2017 @01:05PM (#54676469)
    From summary:

    In order to detect these minuscule changes, on scales less than a trillionth of a meter

    I think these are called picometers (10^-12 m)

  • President John F. Kennedy announced the goal of "landing a man on the Moon and returning him safely to the Earth" on May 25, 1961, and Apollo 11 landed on the moon July 20, 1969.

    So Europe plans to take twice as long as the entire Apollo program took to get to the moon to launch three unmanned probes.

    All of this is just moonbeams anyway. By 2034, Europe will be too broke [] to pay for space probes...

When you make your mark in the world, watch out for guys with erasers. -- The Wall Street Journal