Andrzej KrauzeBy Gerhard Schwehm ALL good things have to end. At around noon on 30 September, we will receive the last signal from the Rosetta spacecraft. The orbiter will end its 10-year odyssey 700 million kilometres from Earth by free-falling to the surface of 67P/Churyumov-Gerasimenko, the comet it has been orbiting for the past two years. True...