Wildest Private Deep-Space Mission Ideas: A Countdown

Destination: Space

Deep space isn't just for NASA and other space agencies anymore.

A number of private companies and nonprofit organizations are planning missions to the moon, asteroids, and even Mars. Here's a brief primer.

FIRST STOP: Mars One, Red Planet Reality TV

Mars One: Reality TV

Netherlands-based nonprofit organization Mars One aims to land four astronauts on Mars in 2023. The company plans to stage a global reality-TV event around the one-way mission, with cameras following every step of the way from astronaut selection to the settlers' first years on the Red Planet. [Gallery: How Mars One's Martian Colony Project Works]

NEXT: Golden Spike to the Moon

Golden Spike: Fly Me to the Moon

A company called Golden Spike plans to start flying roundtrip missions to the moon by 2020. The firm will charge $1.5 billion for each mission, which will land two astronauts on the lunar surface and return them safely to Earth. [How Golden Spike's Moon Landings Will Work (Infographic)]

NEXT: Excalibur Almaz Space Stations

Excalibur Almaz: Back in the U.S.S.R.'s Equipment

Excalibur Almaz, located on the Isle of Man, took the bold step of purchasing Soviet-era spacecraft from Russia to retrofit into vehicles for trips around the moon. So far the company owns four Soviet Almaz program three-crew capsules and two Salyut-class space station pressure vessels. [Gallery: Private Space Stations of the Future]

NEXT: Shackleton Energy Company & the Moon

Shackleton Energy Company: Let's Work

Unlike the space tourism companies, Texas-based Shackleton Energy Company intends to mine the water ice in permanently shadowed lunar craters. Shackleton wants to convert this ice to rocket fuel , then sell the propellant from in-space "gas stations." [Gallery: 3D-Printing Future Moon Bases]

NEXT: Google Lunar X Prize Competitors

Google Lunar X Prize Competitors: Space Race

The Google Lunar X Prize challenges teams to land a robot on the lunar surface, have it travel at least 1,650 feet (500 meters) and send data and images back to Earth. 23 teams currently seek $30 million in prize money. [Gallery: Meet the Google Lunar X Prize Teams]

Some of the Lunar X Prize teams aim to use the competition as a springboard to bigger things. Moon Express, for example, plans to extract resources from the moon eventually.

NEXT: Tapping Into Planetary Resources

Planetary Resources: Digging in the Dirt

Planetary Resources plans to build a fleet of asteroid-mining robots. The company counts Google execs Larry Page and Eric Schmidt among its financial backers, and its co-founders, Peter Diamandis and Eric Anderson, are pioneers in the private spaceflight industry. [Gallery: Planetary Resources' Plan for Asteroid Mining

NEXT: Bigelow Aerospace's Inflatable Space Modules

Bigelow Aerospace's Inflatable Space Modules

The Las Vegas-based Bigelow Aerospace has set its sights on privately built space stations made of inflatable modules that could form the core of a deep-space exploration fleet. The company has already flown two unmanned prototype modules, called Genesis 1 and Genesis 2, and signed a $17.8 million deal with NASA to provide an inflatable room for the International Space Station as a demonstration of its technology. [Gallery: Private Space Stations by Bigelow Aerospace]

Company founder Robert Bigelow has also unveiled a grand vision for Bigelow Aerospace's spacecraft, a plan that would use the inflatable space rooms as a potential deep-space outpost near the moon, or even a manned base on the lunar surface.

NEXT: Asteroids and Deep Space Industries

Deep Space Industries: Firefly

Deep Space Industries is the brainchild of private space veterans Rick Tumlinson and David Gump, among others. DSI follows Planetary Resources in the jump into the asteroid-mining gold rush. The company plans to start with a fleet of small, unmanned spacecraft called Fireflies in 2015 to assess nearby space rocks' stores of water, hydrogen and other volatiles, as well as metals. [Gallery: Asteroid Mining by Deep Space Industries

NEXT: B612 Foundation to Protect Earth

B612 Foundation: Scoping Out the Scene

The B612 Foundation — which takes its name from the classic children's book "The Little Prince" — is building a private deep-space telescope called Sentinel, which is slated to launch in 2018. Sentinel should find 500,000 near-Earth asteroids in less than six years of operation, B612 officials say. Former NASA astronaut Ed Lu serves as chairman and CEO of the nonprofit organization.[Sentinel Space Telescope Asteroid Mission in Pictures]

NEXT: Inspiration Mars

Inspiration Mars: Married to the Mission

Original space tourist Dennis Tito spearheads the nonprofit Inspiration Mars Foundation's "Mission for America," which aims to launch two spaceflyers (preferably a married couple) on a roundtrip Mars journey in January 2018. [Inspiration Mars: Private Mars Voyage in 2018 (Gallery)]

The spacecraft would just fly around the Red Planet, not touch down.

NEXT: SpaceX's Red Dragon Mars Flight