With its protective cover removed, technicians prepare to fuel the Juno spacecraft on June 27 inside Astrotech's Hazardous Processing Facility in Titusville, Fla.
Hydrazine is typically used for most spacecraft because of its stored energy. Engineers won't need to do a lot of driving and steering of Juno on its five-year trip out to Jupiter. It will coast most of the way and get pulled along by Jupiter's gravitational forces. One critical maneuver, however, will take place in 2016, as the spacecraft gets inserted into Jupiter's orbit.