SpaceX has notched up another important victory in its march toward fully reusable rocketry and spacecraft, with the safe return of its Dragon spacecraft following a recent stint docked at the International Space Station (ISS). Its safe splashdown in the Pacific Ocean marks completion of that particular spacecraft's second mission to the station, following its inaugural visit in 2015.
SpaceX has been resupplying the International Space Station for more than five years and has more than a dozen successful missions under its belt. But the CRS-13 mission that lifted off on December 15 marked new territory, with the company using a refurbished Falcon 9 rocket and Dragon spacecraft together for the first time.
The Falcon 9 booster originally flew as part of an ISS resupply mission in June 2017, while the Dragon spacecraft first docked with the orbiting laboratory in April of 2015. Even taking into account the expense of refurbishing these vehicles, SpaceX says reusing them in this way promises to greatly reduce the costs of spaceflight.
Dragon performed three departure burns as it departed from the ISS, followed by a deorbit burn and splashdown west of Baja, California on January 13. As it stands, Dragon is the only ISS resupply spacecraft currently in operation that can safely return cargo to Earth, so astronauts aboard the ISS loaded it up with plenty of scientific goodies before waving goodbye.
This amounts to almost 4,100 lb (1,859 kg) of cargo, and includes samples from human and animal research trials, hardware from an investigation into making fiber optics in space and another looking into stress reactions in plants in response to limited oxygen. Some of these samples are time-sensitive, so NASA got to work on them right away, while the Dragon spacecraft is on its way to SpaceX's test facility in Texas for final processing.