When the European Space Agency managed to successfully land the Philae probe on a comet, lots of scientists were understandably thrilled.
But none reacted in quite the same way as Professor Monica Grady, of the Open University, who helped to build one of the instruments on board.
Her tool - Ptolemy - is a gas analysis instrument. It tool years of work to finish, and then another decade to see it land on the comet.
Her reaction is a priceless example of the importance of the mission to those who worked on it.