Rosetta has ended its mission around comet 67P with a gentle thump.
Mission engineers at the European Space Agency sent the probe to a careful crash-landing on the comet's surface. In the control room on Friday, its communications signal flatlined.
ESA project scientist Matt Taylor told NPR, "There's mixed emotions here. You know, people have invested their lives and their mentality, I think, as well — their psychology — on this mission."