Mars Rover officials at NASA’s Jet Propulsion Laboratory announced Thursday that “a serious anomaly” occurred onboard the robot Spirit Wednesday, stopping the transmission of direct data for almost 24 hours. Peter Theisinger, Mars Exploration Rover project manager, began Thursday’s press conference by telling reporters that they had not received contact from Spirit, either through relays from the Mars Global Surveyor or the Mars Odyssey spacecraft now orbiting the red planet.