The journey to Mars crosses three thresholds, each with increasing challenges as humans move farther from Earth. NASA is managing these challenges by developing and demonstrating capabilities in incremental steps:
Earth Reliant exploration is focused on research aboard the International Space Station. From this world-class microgravity laboratory, we are testing technologies and advancing human health and performance research that will enable deep space, long duration missions.
In the Proving Ground, NASA will learn to conduct complex operations in a deep space environment that allows crews to return to Earth in a matter of days. Primarily operating in cislunar space—the volume of space around the moon featuring multiple possible stable staging orbits for future deep space missions—NASA will advance and validate capabilities required for humans to live and work at distances much farther away from our home planet, such as at Mars.
Earth Independent activities build on what we learn on the space station and in deep space to enable human missions to the Mars vicinity, possibly to low-Mars orbit or one of the Martian moons, and eventually the Martian surface. Future Mars missions will represent a collaborative effort between NASA and its partners—a global achievement that marks a transition in humanity’s expansion as we go to Mars to seek the potential for sustainable life beyond Earth.
It is a logical approach, and nice to contemplate, yet the one thing I do not see are the dates for human missions. That has always been the big question and it remains so.