A United Launch Alliance (ULA) Atlas V rocket carrying Orbital ATK's uncrewed Cygnus cargo spacecraft will lift off from Complex 41 at the Cape Canaveral Air Force Station in Florida on the OA-4 mission.
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OA-4 mission is the fourth of Orbital ATK's cargo delivery flights to be launched toward the International Space Station under NASA's Commercial Resupply Services contract. OA-4 marks a return to flight for the Cygnus after the loss of Orb-3 in October 2014.