it's a very direct way of measuring the curvature of space. at least in theory. in practice it was such a delicate measurement that, by the time it was done, it was confirming a theory that we not only believe, but are already questioning / extending in other ways.
so it's a beautiful but largely pointless exercise that nasa is spinning in a "romantic" way because, well, astronomy and space science depend hugely on public goodwill for government funding.
