Stats: Delta 4 history and backlog (updated March 30)

The launch of a European Ariane 5 rocket was aborted moments after its main engine ignited Tuesday. The dramatic last-second hold was the first time an Ariane rocket launch was aborted after engine start since March 2011. Arianespace has not set a new target launch date for the mission, which will loft two U.S.-built communications satellites for Intelsat and B-SAT.

United Launch Alliance and SpaceX recently won contracts worth $739 million to send six missions into orbit for the U.S. military, and the Air Force has announced a new title for its flagship launcher program, dropping “expendable” from the name in a new era of reusable rockets.

The penultimate satellite in the current generation of Global Positioning System spacecraft will be deployed Friday, capping a hectic four weeks with three launches from two coasts for the Atlas 5 rocket fleet.