’s 11-year-old Mars Odyssey spacecraft has been repositioned along its polar orbit around the red planet to provide a near-real-time communication link with Earth during the Mars Science Laboratory’s Aug. 6 entry and landing.
News of the $2.5 billion rover mission’s fate should reach’s in Pasadena, Calif., through Odyssey on Aug. 6 at 1:31 a.m. EDT, nearly 14 min. after the actual landing — the time it will take X-band transmissions to cover the 154 million mi. separating the two planets.
Concerns arose over Odyssey’s relay role on July 11, when the spacecraft entered safe mode, the latest of multiple difficulties it has experienced this year, including the loss of a reaction wheel. After a JPL-orchestrated recovery, Odyssey was advanced about 6 min. ahead in its orbit on July 24 with a 6-sec. propulsive maneuver.
“Information we are receiving indicates the maneuver has completed as planned,” Mars Odyssey Program Manager Gaylon McSmith said.
The maneuver places Odyssey on an orbital track above MSL during the final minutes of its dynamic entry and descent, and for up to 2 min. after its anticipated touchdown.
UHF transmissions from MSL will be received by NASA’s Mars Reconnaissance Orbiter (MRO) and the European Space Agency’s Mars Express orbiter as well. Only Odyssey, however, is configured to immediately relay the transmissions in X-band to NASA’s Deep Space Network receivers in Goldstone, Calif., Madrid, and Canberra, Australia. Without the July 24 maneuver, Odyssey’s overflight would have occurred about 2 min. after the landing.
MRO and Mars Express will record the data for playback later, details that could be critical to reconstructing events if the mission is lost.
Launched on Nov. 26, MSL must slow from 13,200 mph as it plunges into the Martian atmosphere to a full stop at the base of Mount Sharp in Gale Crater within 7 min. During the final moments of the parachute-assisted descent, the spacecraft will propulsively hover over the surface on a “sky crane” as the 1-ton MSL rover is lowered to the surface on a bridle.
The mobile chemistry lab serves as the cornerstone of a two-year mission to determine whether Mars hosts, or once hosted, environments suitable for microbial life.