Dawn, now with 33% more Vesta
From Emily Lakdawalla at The Planetary Society
http://www.planetary.org/blog/article/00002124/
"A seemingly modest improvement in solar array power" over what was budgeted for in the original mission profile results in Dawn's ion engine performance being "even better than engineers had been counting on. The probe will be able to reach Vesta about 6 weeks earlier than had previously been planned."