Watch a live view of the Atlas 5 launch pad with countdown audio (members only)

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.

The Atlas rocket to launch four formation-flying spacecraft for NASA in March began to take shape Wednesday at the assembly building adjacent to the Complex 41 pad.

Watch as NASA holds a briefing at the Kennedy Space Center on the four agency technology payloads that are part of the STP-2 mission flying into orbit aboard a SpaceX Falcon Heavy rocket.