The first test flight of NASA's Orion spacecraft this week marks a critical step on humanity's journey to Mars, agency officials say.
Orion is scheduled to blast off Thursday (Dec. 4) at 7:05 a.m. EST (1205 GMT) from Florida's Cape Canaveral Air Force Station on an unmanned mission called Exploration Flight Test-1 (EFT-1).
If all goes according to plan, the capsule will zoom 3,600 miles (5,800 kilometers) from Earth, then come barreling back home to test out Orion's heat shield, avionics and other systems.
EFT-1 will mark the farthest journey of a human-spaceflight vehicle since 1972, when the last of NASA's Apollo missions flew to the moon and returned to Earth. But the agency envisions Orion traveling even farther afield — to near-Earth asteroids and, eventually, to Mars.
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