The first stage of a United Launch Alliance Atlas V rocket is lifted into the Vertical Integration Facility at Launch Complex 41 on June 13.
It will take Juno five years to reach Jupiter and begin its year of research work, but the launch team will know about an hour after launch if all their work paid off.
"In real time, we'll immediately start to see power generated, we'll see temperatures increasing on the panels, and we'll see the vehicle respond to the fact that wings deployed," said Russ Gehling, the solar array subsystem's lead engineer with Lockheed Martin. "We'll get all that data in. That's how we'll assess that the wings are out and the spacecraft is safe" and on its way to Jupiter, he said.