Will NASA's Mars rover land safely? Glitch could delay news. (+video)

Questions about communications

To add even more drama to the situation, Curiosity's mission managers may have to wait several minutes before finding out whether the rover survived its landing.

In early June, a NASA spacecraft in orbit around the Red Planet, called Mars Odyssey, suffered a malfunction on one of its reaction wheels, an instrument that helps control the probe's attitude in space.  

"Odyssey looks like it may not be where we expect it to be," McCuistion said.

The glitch does not pose a risk to Curiosity's impending arrival at the Red Planet, officials said. But Mars Odyssey's original orbit would have given it a complete view of Curiosity's landing, so the probe had been pegged to act as an orbiting outpost to relay communications and data back to mission managers on Earth.

With Odyssey in the picture, mission managers may be able to confirm Curiosity's touchdown by 10:31 p.m. PDT on Aug. 5 (1:31 a.m. EDT Aug. 6). Without Odyssey, however, mission controllers may not know the outcome of the landing maneuver until 10:35 p.m. PDT or later.

Engineers are currently assessing whether they can move Odyssey to prevent any significant communications delays, but a final decision has yet to be made.

Still, all is not lost on the communications front. NASA's Mars Reconnaissance Orbiter and the European Space Agency's Mars Express will be monitoring Curiosity from above as it attempts to land on Mars. Both probes, however, will not have a full view of the event, and both are only able to collect and store information before sending it to Earth three to four hours later.

"It's simply how the data gets returned to us, and how timely that data is," McCuistion said.

In the meantime, mission controllers are awaiting Curiosity's landing with a mix of nerves and excitement, NASA officials said.

"I think the team feels that they've done everything they can do to make this successful," Theisinger said. "That being said, success is not assured. Any one of different kinds of problems could end up in end-of-mission, but I think the team is very positive. Morale is good."

Follow Denise Chow on Twitter @denisechow or SPACE.com @Spacedotcom. We're also on Facebook & Google+.

• Mars Rover Curiosity: Mars Science Lab Coverage
• Occupy Mars: History of Robotic Red Planet Missions (Infographic)
• The Best (And Worst) Mars Landings in History

Copyright 2012 SPACE.com, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Previous

1 | 2