Watch a video replay of NASA’s exoplanet announcement

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.

SpaceX’s next Falcon 9 rocket rolled out of its hangar and up the ramp to launch pad 39A Sunday in preparation for liftoff on a two-day trek ferrying more than 6,400 pounds of supplies and experiments to the International Space Station.

NASA’s Cassini spacecraft sped by the moon Titan on Saturday, using the hazy world’s gravity to slingshot the probe on a trailblazing trajectory to explore the region between Saturn’s hydrogen-helium atmosphere and the planet’s famous rings for the first time.