7 ms·

A space interferometer as well. Unfortunately, the planned SIM mission was shelved. https://en.wikipedia.org/wiki/Space_Interferometry_Mission?wprov=sfti1#Pla

• perihelions 2y ago
  There's also https://en.wikipedia.org/wiki/LISA_Pathfinder https://en.wikipedia.org/wiki/LISA_Pathfinder ("LISA Pathfinder") I wonder how precisely they can control the relative separation of those interferometer spacecraft? (They advertise they can measure the separation to <0.01 nanometers—but that's not quite the same thing).
  • dotnet00 2y ago
    I think with those the idea is to make the arms so long that the precision of the relative separation matters less, especially since LISA is trying to listen for much longer wavelengths than LIGO. On top of that, they likely just need to get the unpredictable component of the relative acceleration to vary (unpredictable component of the relative jerk?) slower than the time taken for a gravitational wave to pass through. Probably more a matter of precisely measuring the gravitational fields and accounting for those than of controlling their relative position extremely precisely (besides of course the precision needed to target the lasers across such a large distance).