The U.S. Mars Odyssey spacecraft is closing in on Mars less than two-years after a pair of spacecraft were lost on the red planet within months of each other.
If the rendezvous early Wednesday at 0230 UTC is successful, the Odyssey will begin mapping surface minerals and look for traces of water in the U.S. space agency's continuing search for life there. NASA has taken extreme precautions to ensure that this mission does not fail.
NASA hopes the Mars Odyssey will continue its effort to learn the planet's geologic history to better understand Earth's evolution. The spacecraft carries instruments to measure the distribution of minerals and chemical elements in the surface.
The instruments are especially seeking traces of water, which is thought to have flowed when the red planet was warmer, early in its evolution. Water could indicate past or present life, but would also be a resource for eventual human visits.
The instruments will seek surface hydrogen, one element of water. Project scientist Steve Saunders says they will also look for evidence of surface heat that might indicate hot water below. He said, "We will be able to do the entire planet in this way: We will do one side in the daytime for minerals and then we will do it at nighttime looking for hot springs. If there is a hot place some place on the planet, we will see it."
Mars Odyssey is to expand on evidence gathered by the U.S. Global Surveyor orbiter that has been circling the planet since 1997. When Odyssey completes its main mapping job in 2004, it will become a communications relay for a series of U.S. and international orbiters and landers to follow.
NASA Mars scientist Jim Garvin says Odyssey and each successive wave of robotic visitors is to continually narrow the number of locations to which to send a mission to return a Martian soil sample by 2014. Mr. Gavin said, "Odyssey will indeed help us target those rovers to places where we expect to get answers to these questions that, today, we have no ability to answer. Did Mars harbor environments that were hospitable to biology as we understand it? Are the physical processes different? Odyssey sets us on the course of this path of exploration and I think will be the vital step that will get us to the point where we can make those informed decisions about [a] sample return."
Mars Odyssey one of the most intensely scrutinized missions NASA has ever mounted. Only 60 percent of U.S. spacecraft bound for the planet have reached it.
After the twin 1999 failures, the agency's former Mars program director, Scott Hubbard, says it is not taking any chances this time. "We must do better," he said. "So we introduced a series of changes to maximize the probability of mission success."
An investigation into the loss of the 1999 Mars orbiter and lander missions revealed that both suffered from inadequate budget and staff. This time, NASA has spent millions of dollars more on the spacecraft and assigned more people, restructuring its previously fragmented Mars exploration program with a new headquarters office in charge.
"The question on everyone's mind now is, is it going to work?" This is Mars Odyssey project manager George Pace. He says to boost chances of success, 16 separate NASA and aerospace industry teams tried to anticipate every conceivable hardware and software problem that might arise.
They conducted exhaustive checks and re-checks of 22,000 items that must work for a successful flight. "You can imagine if you are going on trip and before you started your car you had to double check 22,000 parameters. So it has taken a little time, but we are there now," he said.
With all this at stake, Mr. Pace says failure is not an option. "It has got to work," he said. "Even the cab drivers I take to the airport tell me that."