A chapter of the layered geological history of Mars is laid bare in this postcard from NASA's Curiosity rover. The image shows the base of Mount Sharp, the rover's eventual science destination.
NASA may consider sending astronauts to space as part of its exploration of Mars.
In a recent report, scientists suggested the idea as one way NASA could further explore the red planet over the next decade.
The astronauts wouldn’t necessarily go to the surface of Mars, but they could meet a rover half-way between Mars and Earth to collect rock samples.
“When we return samples, somewhere we have to make sure that the samples are completely contained so there’s no chance – remote as it may be – that there is something on Mars that could contaminate Earth," said John Grunsfeld, a NASA administrator and former astronaut. "And so, you could imagine where there’s some transfer in a vacuum, in weightlessness, from one container to another that would kind of break that chain.”
Grunsfeld said robots could also collect samples, but NASA also wants to include a human element in its exploration of Mars to help engage the public’s interest in space.
There's no specific timing for future missions to Mars and no decision is expected until next year.
NASA said the new plan is needed because budget cuts earlier this year killed two future robotic flights.
NASA, so far, has explored Mars with orbiters and robots, like the rover Curiosity that landed last month. The ultimate goal has been to get a robot to collect rocks and Martian soil to send to Earth for more detailed scientific examination.