President Barack Obama announced Tuesday (Oct. 11) that NASA will send astronauts to Mars before the end of the 2030s, reaffirming a directive he gave the space agency back in 2010. But there's no guarantee that NASA will get there first; several other organizations also have the Red Planet in their sights, and on more aggressive timelines.
Here's a brief rundown of these ambitious Mars projects — what they hope to accomplish, and when. [Buzz Aldrin: How To Get Your Ass To Mars (Video)]
NASA: Stepping stones to Mars
The journey begins in low Earth orbit aboard the International Space Station (ISS), which has hosted rotating crews continuously since November 2000. During this time, NASA and its ISS partners have been learning more and more about how to support astronauts on space missions.
This effort took a big step forward this past March, when NASA astronaut Scott Kelly and cosmonaut Mikhail Kornienko wrapped up an unprecedented 11-month mission aboard the orbiting lab that gave researchers new data about the physiological and psychological effects of long-duration spaceflight. (A Mars mission will be long-duration; it takes six to nine months to get to the Red Planet using currently available propulsion technology.)
In the next 10 years, NASA plans to extend the reach of human spaceflight out near the moon, to test spaceflight gear — such as the Space Launch System (SLS) megarocket and Orion crew capsule, both of which are in development — in a "proving ground" in deep space. For example, in the mid-2020s, the agency plans to send astronauts out to lunar orbit, to visit an asteroid boulder dragged there by a robotic spacecraft. (The boulder-snagging first part of this Asteroid Redirect Mission is scheduled to launch in the early 2020s.)
After the proving ground comes the journey to Mars itself. Current plans call for sending astronauts to Mars orbit in the early 2030s, with trips to the surface coming sometime after that. NASA officials have said they hope to eventually set up a small outpost on the Red Planet, where astronauts would search for signs of Mars life and perform other research. [6 Private Deep Space Habitats to Pave Way to Mars]
Mars Base Camp
NASA officials have stressed that the agency's journey to Mars will be a group effort.
In this spirit of cooperation, earlier this year, aerospace company Lockheed Martin unveiled its proposal for "Mars Base Camp," a 132-ton (120 metric tons) Red Planet space station composed primarily of two Orion capsules and two habitat modules/science laboratories.
Mars Base Camp — a collaboration involving NASA, its international partners and private industry — would support up to six astronauts, who would stay aboard for a year or so. During this time, they would operate robots on the Martian surface, look for signs of life in samples of Red Planet dirt and rock, and take trips to the Martian moons Phobos and Deimos, among other tasks, Lockheed representatives have said.
Mars Base Camp could conceivably be established as early as 2028, Lockheed representatives have said. The space station would also be a way station of sorts: Shortly after the first orbital mission, other crews would head down to the Red Planet, company representatives have said, though they have not yet discussed those surface plans in detail.
SpaceX: A huge Mars colony
SpaceX's dreams are bigger than an orbiting Martian space station or small research outpost on the surface. Last month, the company's billionaire founder and CEO, Elon Musk, announced that SpaceX aims to help establish a million-person Mars colony in the next 50 to 100 years.
To make this happen, SpaceX plans to build the Interplanetary Transport System (ITS), which will combine the most powerful rocket in history with a 100-person spaceship that will ferry settlers to and from the Red Planet. [SpaceX's Interplanetary Transport for Mars in Images]
If everything goes perfectly, Musk said, the fully reusable ITS could launch its first crews in 2024. But SpaceX also aims to launch uncrewed missions using its Dragon capsule and Falcon Heavy rocket beginning in 2018, to test out landing systems and other technologies critical to the colonization effort.
This is no lark on SpaceX's part. Musk has stressed repeatedly that he founded SpaceX back in 2002 primarily to help humanity become a multiplanet species, and he said during the ITS unveiling last month that the main reason he has been "accumulating assets" over the years is to fund Mars colonization.
Mars One: One-way trip
SpaceX isn't the only group angling for a Mars colony. The Netherlands-based nonprofit Mars One has the same goal, though on a much smaller scale.
Mars One plans to launch robotic precursor missions to the Red Planet in 2020, 2022 and 2024, to lay the groundwork for the first settlers, who will launch in 2026 and land on Mars in 2027. (Earth and Mars align favorably for interplanetary missions just once every 26 months.)
If everything works out, Mars One will continue sending four-person crews to the Red Planet at every launch opportunity, gradually building up a permanent, self-sustaining settlement. At the moment, there are no plans to bring any of these colonists home. (That's in contrast to SpaceX's system, in which spaceships will be flying back and forth between Earth and Mars repeatedly, giving Mars pioneers the option to come back.)
Mars One has estimated that it will cost about $6 billion to get the first four pioneers to Mars. The organization aims to raise most of this money by staging a global media event around the entire project, from astronaut selection, to launch, to the colonists' time on the Red Planet.
Other projects possible
It's possible other crewed Mars efforts will take shape in the near future.
For example, billionaire Amazon.com founder Jeff Bezos, who leads the private spaceflight company Blue Origin, has said he aims to help get millions of people living and working in space eventually. Blue Origin has already launched multiple test flights of its suborbital New Shepard vehicle and recently announced that it's developing a big orbital rocket known as New Glenn.
Bezos also mentioned that the company plans to develop something called New Armstrong but revealed no details about the project. Will New Armstrong, or another Blue Origin effort down the road, help get astronauts to Mars? We'll just have to wait and see.
In the past, both the European Space Agency and Russia have expressed interest in putting boots on Mars, as has China (though China is working on getting people to the moon first). These players could end up making a push toward the Red Planet, either alone or as part of a coalition — perhaps NASA's coalition (though current U.S. laws prohibit extensive cooperation with China in spaceflight endeavors). To make a long story short: There's a lot happening, so stay tuned!
Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.