NASA astronauts, from left, Rex Walheim, Jack Fischer and Cady Coleman cheer as they watch the landing of the Orion test flight on a television at the Kennedy Space Center on Friday in Cape Canaveral, Fla. The unmanned test flight ended 4½ hours after it began.

In this image provided by NASA, the Orion spacecraft descends before splashing down in the Pacific Ocean on Friday.

In this frame grab from NASA-TV, the Orion capsule floats after splashing down in the Pacific Ocean on Friday.

NASA's Orion spacecraft, atop a United Launch Alliance Delta 4-Heavy rocket, lifts off on its first unmanned orbital test flight from the Cape Canaveral Air Force Station on Friday in Cape Canaveral, Fla.

Spectators cheer as the United Launch Alliance Delta 4-Heavy rocket, with NASA’s Orion spacecraft mounted atop, lifts off from the Cape Canaveral Air Force Station on Friday in Cape Canaveral, Fla.

This photo provided by NASA shows NASA's Orion spacecraft, atop a United Launch Alliance Delta 4-Heavy rocket, on the launch pad before its first unmanned orbital test flight from the Cape Canaveral Air Force Station Friday.

Liftoff begins for the Orion spacecraft.

Spectators watch as the spacecraft lifts away from the launch pad.

Smoke billows away from the capsule atop a Delta IV rocket, in its first unmanned orbital test flight.

This photo provided by NASA-TV shows the view from the Orion spacecraft atop a United Launch Alliance Delta 4-Heavy rocket as it climbs to orbit during the first test flight.

The Delta IV Heavy rocket with the Orion spacecraft lifts off from the Cape Canaveral Air Force Station in Cape Canaveral.

ASA Administrator Charles Bolden and his wife Jackie Bolden watch as the spacecraft lifts off.

Spectators see a glow of yellow light as the spacecraft rises into the early-morning sky.

An Orion capsule mock-up stands at the front of the theater as visitors at the U.S. Space and Rocket Center watch the launch of Orion from Kennedy Space Center in Huntsville, Ala.

Photographers follow the launch of the NASA Orion space capsule atop a Delta IV rocket, in its first unmanned orbital test flight. The Associated Press

A bird flies overhead as the Delta IV Heavy rocket with the Orion spacecraft lifts.

The spacecraft rises into the early-morning sky.