Leery of risk, NASA prepares for capsule's debut flight in December Thu Nov 6, 2014 2:43pm EST (Reuters) - Mindful of two U.S. space accidents last week, NASA unveiled plans on Thursday for the first test flight of its Orion capsule, designed to eventually fly astronauts to Mars. The capsule, built by Lockheed Martin (LMT.N), will fly without a crew on its debut test run scheduled for Dec. 4, from Cape Canaveral Air Force Station in Florida. Orion will launch aboard a United Launch Alliance Delta 4 Heavy rocket, built by a partnership of Lockheed Martin and Boeing (BA.N). The test flight follows unrelated accidents last week involving two commercial space companies. On Oct. 28, an unmanned Orbital Sciences (ORB.N) Antares rocket exploded seconds after liftoff from Virginia, destroying a cargo ship bound for the International Space Station for NASA. On Friday, a pilot with Mojave, California-based Scaled Composites, a unit of Northrop Grumman (NOC.N), died, and another was injured during a test flight of SpaceShipTwo. The suborbital space plane, owned by Virgin Galactic, an offshoot of Richard Branson's London-based Virgin Group, was destroyed in the crash. Space operations is hard and they proved that last week ... It's a tough business we're in," NASA Deputy Associate Administrator William Hill said during a press conference at the Kennedy Space Center in Florida. "We have not changed any of our plans," added Orion program manager Mark Geyer. It just reminds us of the risk. For its test flight, Orion will fly as far as 3,600 miles (5,794 km) from Earth so that it can slam back into the atmosphere at a speed of about 20,000 mph (32,187 kph). The planned 4.5-hour flight will end with a splashdown in the Pacific Ocean. The mission is intended to test Orion's heat shield, parachutes, computers and other equipment prior to the first crewed mission around 2021. "This is really our first step in our journey to Mars," Hill said. NASA is spending about $375 million on the test flight, not including the cost of the capsule. Total spending on Orion, including more than $8 billion under the canceled Constellation moon program, is expected to reach about $15 billion. NASA plans to use Orion capsules and its Space Launch System rocket, currently under development in a separate $15 billion effort to fly astronauts to an asteroid, the moon, and eventually, Mars.