WASHINGTON — Engineers with NASA and prime contractor Lockheed Martin Space Systems have finished building the prototype Orion capsule that will launch on an uncrewed test mission aboard a United Launch Alliance Delta 4 rocket Dec. 4 from Cape Canaveral Air Force Station in Florida, the agency said in an Oct. 30 press release.

The mission, called Exploration Flight Test (EFT)-1, is primarily a test of the capsule’s heat shield, which would protect astronauts on future missions from the extreme temperatures of atmospheric re-entry. The flight also will test other critical systems including the capsule’s avionics suite, flight software and parachutes, all of which will be substantially the same as those the spacecraft will use for future missions to lunar space scheduled for late 2017 and 2021. Only the 2021 mission would be crewed.

In EFT-1, Orion will orbit Earth twice, then re-enter the atmosphere at about 80 percent of the velocity the craft would reach on re-entry from lunar orbit. It will splash down in the Pacific Ocean off the coast of California and be recovered by a single Navy ship. The EFT-1 spacecraft arrived at the Kennedy Space Center in Florida for integration in 2012, NASA said in its press release.

Lockheed’s Orion prime contract with NASA, awarded in 2006, is worth more than $11 billion and requires the company to deliver three spacecraft: the EFT-1 Orion and those slated to launch in 2017 and 2021 aboard the Space Launch System, the capsule’s intended carrier rocket that is under development at NASA’s Marshall Space Flight Center in Huntsville, Alabama.