Juno won't perform lowering orbit burn

[VaPaL]

The helium valves performed oddly during a systems check, taking several minutes to open so, due to risks of putting the spacecraft in a least favorable orbit or even damaging it, it was decided that Juno will remain in it's capture orbit. It will perform 12 orbits until the planned mission end (July 2018) instead of initial 36 planned orbits, but a mission extension is likely. The science collected will be almost the same with the bonus of a more extensive study on Jupiter's magnetosphere.

More details here: 

http://spaceflight101.com/juno-to-remain-in-elongated-capture-orbit/

Also, some more discussion about Juno here:

 

[YNM]

Sad news there...

But I hope this does mean possibly longer lifetime ?

[VaPaL]

Yes, it will last longer, but just because it will take longer time to perform 36 orbits. The limiting factor for Juno are the number of 'dives' it can make into the radiation.