Richard Cook, Mars Polar Lander project manager of NASA's Jet Propulsion Laboratory, is shown at...

Richard Cook, Mars Polar Lander project manager of NASA's Jet Propulsion Laboratory, is shown at a late night briefing at NASA's Jet Propulsion Laboratory in Pasadena December 3. Cook told reporters that scientists had not yet received a signal from the spacecraft, which was due to land on Mars earlier December 3. The 1,270 pound lander, developed by NASA's Jet Propulsion Laboratory, will also deploy two small probes that are set to crash into the ground and search for water. Once on Mars, the lander will study the planet's climate and dig samples and relay back data.