Launch time: 4:03 p.m. EDT

Launch site: Vandenberg Air Force Base, California

A SpaceX Falcon 9 rocket will launch five satellites for the Iridium next mobile communications fleet and two Gravity Recovery and Climate Experiment Follow-On (GRACE Follow-On) satellites for NASA and the German Research Centre for Geosciences (GFZ). The Falcon 9 rocket will launch with a previously-flown first stage. Delayed from March 21, April 14, April 28 and May 10. [April 9]