SpaceX's unmanned Dragon spacecraft splashed down in the Pacific Ocean in October carrying a heavy load of NASA cargo and scientific samples from the International Space Station that experts hope could yield significant results. Dragon also carried crew supplies, hardware and computer resources.
The SpaceX vessel is the only spacecraft currently capable of returning from the ISS with cargo. Its last mission to the space station was in April.
NASA lost its ability to reach the space station alone when the shuttle program ended in 2011 after 30 years. The US space agency has helped fund private companies in the race to restore US access to the ISS.
In 2010, SpaceX became the first private company to send a spacecraft to the ISS.
Copyright Agence France-Presse, 2014