CRS-10 was the first launch from Pad 39A since the final Shuttle mission in 2011. The pad from which every Apollo lunar flight and most Shuttle missions had departed had been leased and rebuilt by a commercial company, and its return to service carried obvious symbolic weight.
The primary payload was an atmospheric instrument mounted on the station's exterior to measure ozone, aerosols and water vapour by observing the Sun and Moon through the limb of the atmosphere at sunrise and sunset — continuing a measurement series begun on earlier satellites.
It also carried a Department of Defense experiment package and around 2,500 kilograms of supplies and scientific hardware, including experiments on stem cells and antibody production.
The first stage returned to a landing at Cape Canaveral, and the mission proceeded without incident — a description that increasingly applied to these flights and which represents the actual achievement of the commercial resupply programme.
The pad has since launched crewed flights, lunar missions and the heavy lift vehicle, making it the busiest launch complex in the world and giving it a continuous operational history spanning from Apollo to the present.
