Lander (spacecraft) a landing which should have come on 25 December 2003 was not received. Indeed, no communication was ever established and "Beagle 2" was declared lost on 6 February 2004. The proposed 2009 British Beagle 3 lander mission to search for life, past or present was not adopted. The French/ESA NetLander mission for 2007 or 2009, with an orbiter and 4 landers, was cancelled because it was too expensive. Its successor, Mars MetNet, a multi-lander mission for 2011–2019 was not adopted by the ESA. The American Mars Exploration Rovers "Spirit" and "Opportunity" were launched in June and July 2003. They reached
Life on Mars little is known about the growth of microorganisms at pressures close to those on the surface of Mars. Some teams determined that some bacteria may be capable of cellular replication down to 25 mbar, but that is still above the atmospheric pressures found on Mars (range 1–14 mbar). In another study, twenty-six strains of bacteria were chosen based on their recovery from spacecraft assembly facilities, and only "Serratia liquefaciens" strain ATCC 27592 exhibited growth at 7 mbar, 0 °C, and CO-enriched anoxic atmospheres. Liquid water is a necessary but not sufficient condition for life as we know it, as habitability