In a report titled "NASA's Journey to Mars: Pioneering Next Steps in Space Exploration," agency administrator Charles Bolden said that NASA is closer to sending American astronauts to Mars than at any point in our history.
"In the coming weeks, I look forward to continuing to discuss the details of our plan with members of Congress, as well as our commercial and our international and partners, many of whom will be attending the International Astronautical Congress next week," he said in a statement.
The journey to Mars crosses three thresholds, each with increasing challenges as humans move farther from Earth.
The "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," Bolden added.
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.
"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," he stated.
"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.
Living and working in space require accepting risks - and the journey to Mars is worth the risks.
A new and powerful space transportation system is key to the journey, but NASA also will need to learn new ways of operating in space, based on self-reliance and increased system reliability.
"We will use proving ground missions to validate transportation and habitation capabilities as well as new operational approaches to stay productive in space while reducing reliance on Earth." the statement further read.
With the Space Launch System, Orion crewed spacecraft, and revitalised space launch complex, the US space agency is developing core transportation capabilities for the journey to Mars and ensuring continued access for commercial crew and cargo partners to maintain operations and stimulate new economic activity in low-Earth orbit.