“I don’t want to go through that again. That was hard-core,” SpaceX founder and chief executive Elon Musk said during a keynote speech at the South by Southwest conference in Austin, Texas, earlier this month.
Engineers believe the glitch was caused by a blockage in a pressurization line or a stuck valve. It was cleared and the capsule made a precision rendezvous with the station with no problems. An investigation remains under way, said company spokeswoman Christina Ra.
Dragon will return to Earth with 2,668 (1,210 kg) of cargo, including a freezer filled with biological samples from the crew for medical research.
While Russian, European and Japanese freighters also service the station, only the SpaceX vessel is designed to return cargo to Earth, a critical transportation link that had been lost with the retirement of the shuttles.
SpaceX is working to upgrade the Dragon capsule to fly people as well.
A test flight with company astronauts is targeted for 2016.
In addition to enhancing the Dragon capsules, SpaceX is working on an upgraded Falcon 9 rocket. Last week, the rocket’s new Merlin engines completed a 28th and final test run, certifying it for flight, Ra said.