Concerns over NASA's Jupiter spacecraft

NASA's Juno spacecraft has switched to safe mode, something it does when it encounters problems, after flying past Earth.

NASA says its Jupiter-bound spacecraft is in safe mode soon after it used Earth as a gravity slingshot to hurtle toward the outer solar system.

The Jet Propulsion Laboratory said on Wednesday the Juno spacecraft is in contact with Earth, but is returning a low rate of data.

Spacecraft are programmed to go into safe mode when they encounter an unknown event.

Engineers were troubleshooting the problem, which occurred after Juno zipped past Earth in a momentum-gathering flyby to power itself towards Jupiter.

Juno was launched in 2011 and is scheduled to arrive at Jupiter in 2016.