In the July 28th edition of SpaceNews, Dan Leone of SpaceNews reports that it is announced that the Solar Probe Plus mission will change from the Atlas V launch vehicle to the Delta IV Rocket.
The Solar Probe Plus, a flagship heliophysics mission NASA expects to cost some $1.5 billion to build and launch around July 2018, needs a bigger rocket than United Launch Alliance’s Atlas 5, according to a senior official at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, where the solar observatory is being built.