Missions to parts of our solar system may be routine these days but Nasa knows only too well that they remain extremely difficult. Losing two Mars spacecraft in a short period of time, through glaringly stupid errors, did the agency no good at all. Had things worked out the public would be logging on to the Nasa website to hear the Martian breeze whistle across the landscape and scientists would be drowning in data. Instead Nasa is now scrambling around for a new Mars mission that will be both cheap and a sure-fire success.