The NASA Mars Odyssey probe, launched in April of of this year, will complete its journey to Mars shortly. If it survives the firing of its main engine for orbital insertion, it will begin a several week process of aerobraking to get into the desired orbit. NASA has a status page where you can get updates on the probe's status. Since less than one third of all robotic probes sent to Mars survive, it should be an interesting few hours for NASA.