Though still 20-plus years in the offing, NASA officials say their first manned mission to Mars would aim to create a permanent operations base that could be revisited.

The comments, made by Ben Bussey, the chief exploration scientist in NASA's Human Exploration and Operations Mission Directorate, indicate the plan would not be to create a permanent human outpost on the Red Planet, but a base of operations that would allow future manned missions a place to start.

"The idea here is that you would have your exploration zone that you set up for the first crew," Bussey added. "And that crew would leave, and then you send another crew at the next good launch opportunity. So it isn't permanently occupied, but it is visited multiple times."

The possibility of a NASA-backed manned mission to Mars is still a "long way down the road," Bussey said. Such an operation might not happen until the late 2030s, at the earliest.

However, NASA released a new map of gravity on Mars, which they say is the most accurate ever created. Such a map would serve as a useful tool for planned missions there, by allowing astronauts to look at a sort of X-ray of the planet and pinpoint places where a landing site might prove ideal.

The possibility of a human mission to Mars is not necessarily dependent on NASA, however. SpaceX, the company founded by billionaire Elon Musk, has made it a goal to create rapidly reusable rockets that could carry out continued manned missions from Earth to Mars, with the goal of creating a large human colony there.