Stop us if this sounds familiar. Come Saturday morning, if all goes according to plan, a spacecraft from Earth will speed through the Martian atmosphere in hopes of deploying its rockets, parachutes and airbags all in sequence and touching down on the Red Planet. Shortly after landing the rover vehicle will supposedly deploy and start talking to another satellite from Earth orbiting overhead. It's the same script European Space Agency controllers hoped would unfold without incident in the Beagle 2 mission. So far, Beagle has failed to bark. European officials now hope that its mothership, Mars Express, will be able to talk with Beagle once its in an orbit low enough to facilitate communications. No, in this case, we're talking about the first of two American probes to land o