The National Aeronautics and Space Administration (NASA) in the United States has confirmed three cargo supply contracts to private companies, which include South African born-Elon Musk’s company, SpaceX.

At a press conference on Thursday afternoon, NASA announced the Commercial Resupply Services (CRS­2) contracts were for cargo delivery to the International Space Station (ISS).

The contracts involved delivery of supplies and the return of research samples back to Earth, which could total $14-billion.

This has come just before private rocket company SpaceX attempts a second rocket launch and landing this Sunday, four weeks after successfully landing a Falcon 9 rocket for the first time.

One of the purposes of the cargo contracts was to enable the continued research on the ISS into a manned mission to Mars.

NASA Administrator Charles Bolden referred back to US President Barack Obama’s statement in 2010 to work with private companies.

“Today’s announcement is a big deal that will move the President’s vision further into the future,” said Bolden.

This was a continued effort by NASA to cooperate with commercial carriers for further research and development into space technology.

Kirk Shireman, ISS program manager at NASA’s Johnson Space Center in Houston, said that this would be the second generation of commercial cargo services.

“By engaging American companies for cargo transportation, we can focus our attention on using this one ­of ­a ­kind laboratory in the sky to continue advancing scientific knowledge for the benefit of all humanity,” Shireman said.

The contracts were for US companies Orbital ATK, Corporation of Sparks and SpaceX.

In their 2015 Annual Report released on Wednesday, Nasa affirmed their plan to put humans on Mars in the future, having stated that it was definitely on their “horizon”.

Musk has also previously declared his intention to put humans on the Red Planet and possibly start a colony.

Planned science, research and technology experiments aboard the ISS are scheduled for 2019 to 2024.