When a rocket carrying a new crew vehicle lifts off at Cape Canaveral next year, it will be the first big step in a decades-long odyssey to see humans travel farther into space than ever before.
That ambitious program, called Orion, has goals that sound as if they were lifted from the pages of a sci-fi novel: the capture of near-Earth asteroids, bringing them into lunar orbit, a return to the moon, and putting astronauts on Mars.
Baby steps in the odyssey are already being taken in labs and testing facilities across the nation. One is at Aerojet in Rancho Cordova, Calif. There, inside solemn buildings surrounded by fields of dry grass, rockets destined for the dark reaches of space are being designed and tested.
Aerojet is supplying the large and small rockets that will allow the Orion multipurpose crew vehicle, designed to house four astronauts, to orient itself during space flight and during the re-entry to Earth's atmosphere, said Sam Wiley, head of human space at Aerojet.
The company is also supplying a launch-abort system, which would pull the crew module to safety in a life-threatening event during launch.
Next year's unmanned test flight will determine whether NASA is on target to safeguard the lives of astronauts. The heat shield has to be strong enough to sustain the furnace-like heat that will surround the module as it re-enters Earth's atmosphere after orbit. For Orion, that return will happen at 20,000 mph; the space shuttle entered at 12,500 mph.
A successful test flight would bode well for NASA's plans for a first unmanned lunar orbital flight in 2017. That flight would take four astronauts into high orbit -- 3,600 miles into space -- the farthest an astronaut has gone since Apollo 17 in 1972. A full-crew mission to recover an asteroid is slated for 2021.
After that, the milestones get more exotic, the risks more pronounced, and the plans and funding sketchier. Orion will be the taxi-like conveyer of astronauts from Earth to space. It is less clear what craft will take astronauts from the crew module to a landing on Mars or the moon.
This year's presidential budget request for NASA seeks $2.7 billion for space exploration.
Some in Congress, such as Rep. Dana Rohrabacher, R-Calif., vice chairman of the House Committee on Science, Space and Technology, remain skeptical about funding the massive Orion program and its launch system.
In a recent editorial in the Orlando Sentinel, Rohrabacher stated: "I've never seen NASA accomplish a large mission on budget and on schedule. NASA should work on these projects, but it needs better cost estimates, and better program management. ...
''NASA is incapable and unwilling to include technologies that have not yet been proved in space. NASA has lost its edge," Rohrabacher wrote.
Regardless of the use of established technology, Orion is expected to travel to Mars and it moons, said Larry Price, Orion deputy program manager for Lockheed Martin, NASA's prime contractor for the Orion project.
''The biggest challenge is combining all of the technology and putting it into the largest spacecraft that has ever been built, other than the shuttle, and be able to sustain life for months and go great distances into the solar system," Price said.
''The point is to follow up on all of the groundwork that the Mars rovers have been doing, with human exploration capability."
Having humans rather than rovers on the Red Planet means they could make immediate decisions and wouldn't always have to wait for radio communication with Earth -- a 20-minute delay each way with Mars.
However, the introduction of humans brings physiological challenges.
The most vexing is the high radiation exposure astronauts would encounter on a months-long trip to and from Mars, as well as time spent on the planet, said NASA astronaut Stan Love. A former shuttle astronaut, Love is examining the feasibility of sending the Orion crew vehicle to near-Earth objects for NASA.
''We're still trying to understand what the exact radiation environment is out there - and we're still trying to understand the effect of that radiation on people," Love said. "It's a kind of a tricky subject - if you were studying this with rats you would irradiate a bunch of them, half would die and you would know what the dose is and you can adjust for that. ... We can't really do that with people."