Largest scientific instrument ever built ...

[ChrisGreaves]

telegraph.co.uk

"The ultimate goal is to prove that this technology works, before we attempt to put three spacecraft into orbits at a distance of 5 million kilometres from one another, connected only by a laser beam that will measure their positions accurate to 40 millionths of a millionth of a metre."

Also, I suspect, a contender for this year's "Most accurate scientific instrument ever built" award.

[John Gray]

The ultimate goal is to prove that this technology works, before we attempt to put three spacecraft into orbit...

Hard to argue with that principle!