The Cygnus cargo delivery spacecraft. Photo: NASA.

A United Launch Alliance (ULA) Atlas 5 rocket carrying the OA 7 resupply spacecraft to the International Space Station (ISS) lifted off from Space Launch Complex-41 on Tuesday morning. The OA 7 mission represents the first execution of a RapidLaunch service contract, with contractual agreements finalized five months ago.

ULA flew the mission for Orbital ATK under NASA’s commercial resupply services contract, and the payload will deliver supplies, equipment and experiments to astronauts aboard the ISS. This is ULA’s fourth launch in 2017.

ULA launched this mission aboard an Atlas 5 401 configuration vehicle, which includes a 4-meter Extra Extended Payload Fairing (XEPF). The RD Amross RD-180 engine powered the Atlas booster, and the Aeroject Rocketdyne RL10C engine powered the Centaur upper stage.

The Cygnus spacecraft consists of a common Service Module (SM) and a Pressurized Cargo Module (PCM). Orbital ATK assembled and tested the SM at its Dulles, Virginia, satellite manufacturing facility, and incorporated in the SM systems from Orbital ATK’s LEOStar and GEOStar satellite product lines. The PCM is based on the Multi-Purpose Logistics Module (MPLM), developed and built by Thales Alenia Space of Italy.

ULA’s next launch is the Tracking and Data Relay Satellite-M (TDRS-M) mission for NASA, scheduled for Aug. 3 from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida.