SpaceX scored a double first today as the Dragon spacecraft returned to service and the Falcon 9 booster nailed the first ever powered landing at sea. At 4:43 pm EDT, the CRS-8 mission lifted off from Cape Canaveral Air Force Station Launch Complex 40 in Florida for the International Space Station (ISS). After delivering the unmanned cargo ship into orbit, the Falcon 9 first stage rocket made a safe touchdown on the drone barge "Of Course I Still Love You" stationed in the Atlantic Ocean.
According to SpaceX, the launch of the Dragon and deployment of its solar panels occurred without incident. Meanwhile, the Falcon 9 first stage, instead of crashing into the ocean, re-oriented itself and executed a "boostback" burn to kill its suborbital hypersonic velocity, followed by a re-entry burn three minutes later to further slow it down.
As it re-entered the atmosphere, a set of vanes deployed on the top of the booster and acted as rudders to guide the rocket down. Approaching the barge, the engines fired for a final time before touching down as aircraft returned video of the landing.
Today's launch marks the first flight of the Dragon capsule since the CRS-7 mission in 2015, which ended in an aerial fireball when a faulty strut in the second stage destroyed the launcher and spacecraft. It's the tenth flight of the Dragon to the ISS and the eighth of 20 commercial missions running through 2024 by the cargo ship to the space station.
According to SpaceX, Dragon will spend the next two days matching orbits with the station until about 7:00 am EDT on Sunday, when the ISS crew will use one of the station's robotic arms to capture the capsule and guide it to a docking port on the Tranquility module. It will remain for about a month before it returns to Earth with a second cargo of science samples.
When the Dragon arrives, the ISS will be a bit crowded with a total of six cargo and passenger spacecraft docked. In addition, this will also be the first time that a Dragon and Cygnus spacecraft will be visiting the station at the same time.
The Dragon capsule is loaded with 6,900 lb (3,130 kg) of cargo, including the 3,100 lb (1.406 kg) Bigelow Expandable Activity Module (BEAM), which is an experimental inflatable habitat module. This is carried in Dragon's unpressurised cargo bay and will be moved by the robotic arm to a berth, where it will remain for two years as its structural stability, leak rate, and ability to withstand radiation and temperature variations are evaluated.