This artist's animation shows how orbiters over Mars will monitor the landing of NASA's Curiosity rover.
The animation starts with the path of NASA's Mars Science Laboratory spacecraft capsule -- which has the Curiosity rover tucked inside -- speeding towards its Martian landing site in Gale Crater. Then, the paths of NASA's Mars Odyssey orbiter and Mars Reconnaissance Orbiter become visible. Curiosity will be sending some basic radio-frequency tones straight back to Earth during its entry, descent and landing, on Aug. 5 PDT (Aug. 6 EDT). But sending more detailed engineering data about the landing is more complicated. Those kinds of data will be sent by Curiosity to the orbiters Odyssey and MRO, which will then relay them back to NASA's Deep Space Network antennas on Earth. Curiosity can only send the data to Odyssey and MRO when it can see the orbiters -- as soon as they rise above and before they set below the Martian horizon.