But while Mars remains years, if not decades away, Obama's true legacy may be something altogether different: the standing up of a commercial space industry that has ended the Government's monopoly on space.
When the space shuttle was retired in 2011, Nasa looked to the commercial sector to fly its astronauts and cargo to the International Space Station, fertilising the industry with billions of dollars in contracts. And in the past few years, the industry has begun to blossom, reinvigorating interest in space with dramatic landings of rockets on ships with other, unprecedented feats.
"Just five years ago, US companies were shut out of the global commercial launch market," Obama wrote. "Today, thanks to groundwork laid by the men and women of Nasa, they own more than a third of it."
COMPANIES IN SPACE
1 Richard Branson's Virgin Galactic and Jeffrey Bezos' Blue Origin promise suborbital tourist flights within a couple of years.
2 SpaceX and Boeing are working towards flying astronauts to the space station.
3 Bigelow Aerospace is building inflatable habitats that could ultimately succeed the station. one of the habitats is currently attached to the station.
"It will become one of the great ironies in the history of exploration into space that someone many politicians called a socialist was a champion for the possibilities of capitalism in space," said James Muncy, a space policy analyst at PolySpace, a consulting firm.
While the high-profile billionaires get the most attention, there are many companies pushing the frontiers.
Sierra Nevada Corp., another of Nasa's beneficiaries, just announced that it had signed a deal with the United Nations to fly its first-ever space mission.
Earlier this year, Moon Express, which is vying for the US$20 million Lunar XPrize, received permission to send a robotic lander on the moon, the first commercial company to get such approval from the US Government.
There is still no self-sustaining economy to keep commercial space companies alive, many of which would wither without the support of Nasa or the billionaires that are funding them with their own money.
And the two companies that have the contracts to restore human space travel from US soil both have suffered setbacks and delays.
Boeing recently confirmed an Aviation Week report that because of technical issues with its Starliner spacecraft it was pushing back flights six months and hopes to fly by the end of 2018.
SpaceX, the other company Nasa is relying on to fly its astronauts, had its Falcon 9 rocket blow up last month and still doesn't know exactly why.
Nasa's own vehicles, the Space Launch System rocket and Orion spacecraft, have had their own troubles. The Government Accountability Office recently warned that the US$23 billion programme faces additional potential cost overruns and schedule delays.
Nasa has always relied on its contractors, and Obama conceded that government cannot do it alone: "Getting to Mars will require continued cooperation between government and private innovators," he wrote.
