On January 20, 2014, the European Space Agency’s Rosetta comet-chaser spacecraft tweeted “Hello, world!” in several languages. The preprogrammed message notified scientists at ESA mission control center in Darmstadt, Germany, that Rosetta is awake after a 2 ½ year sleep induced to save energy.
With recharged energy systems, the spacecraft will continue its mission of studying comets in detail. Rosetta, which has VACCO Etched Disc Filters aboard, will rendezvous with the 67P/Churyumov-Gerasimenko comet in August.
