Photos: Atlas 5 rolls out for launch

Boeing’s first Starliner spacecraft designed to fly to the International Space Station rolled out of a converted space shuttle hangar before dawn Thursday.

Concerns about the health of the Juno spacecraft’s main engine have compelled NASA managers to keep the research probe in its current arcing, high-altitude orbit around Jupiter, a decision that will delay the full science return from the $1.1 billion mission but should still allow it to meet all predetermined objectives.

Giving every opportunity for the storm clouds to blow clear after a four-hour hold, the United Launch Alliance Delta 4-Heavy rocket counts down Thursday afternoon at Cape Canaveral until the clocks had to be halted for the day.