Juno spacecraft question

On Wed, 10 Aug 2011 09:01:36 -0800, Pat Flannery
wrote:

Since Juno has three very large solar arrays on it to give sufficient
electrical power via sunlight (rather than RTGs) at Jupiter's distance
from the Sun, why wasn't it equipped with an ion engine to cut its trip
time down some?

Cost. It had to fit within the New Frontiers program budget. The
ion-powered Dawn busted that budget and had to beg to be reinstated.
Lesson learned.

Brian