If all goes to plan, a man and woman will take a historic space journey to Mars in 2018 and return to earth a full year and a half later.

Dubbed the "Human Mission to Mars," the flight will be entirely funded by private investment.  NASA will partner with the mission, with the space agency's efforts reimbursed by the non-profit private enterprise.

The risky mission would confine two astronauts to a spacecraft the size of a small recreational vehicle for 501 days, with no possibility to abort once underway.  Life support is a major concern, considering the challenge of keeping humans happy and healthy in deep space for that long of a time.

"Our Apollo 8 moment "

While the manned Mars mission will not yield much more science than the many unmanned probes that have proceeded it to Mars, it larger intent is to inspire young people who missed the Apollo moon program of the 1960s and 1970s and to keep their thirst for space exploration alive.

Medical Officer for Inspiration for Mars, Jonathan Clark has worked on Space Shuttle missions and last year's Red Bull Stratos jump by daredevil Felix Baumgartner.  

Clark called the mission "our Apollo 8," referencing the first manned space mission that left earth orbit and travelled to the moon.  The Christmas 1968 flight sent back the first images of the whole earth, and forever changed the way we look at ourselves and our place in space.

Clark's role will be to help keep the crew alive for a year and a half in space, in part by using knowledge learned from extended crew missions aboard the both the Russian MIR and International Space Stations.  

However, deep space travel offers a unique set of risks, primarily radiation.  Clark will use data gathered from the Mars Curiosity mission to determine how much radiation the crew should expect to encounter during their interplanetary trip.

Concern for the crew's mental health in deep space.

Another team member, Jane Pointer, is also tasked with managing the well being of the crew.   

Pointer experienced long term isolation when she ran the farm in the Biosphere 2 mission in Arizona from 1991-1993.   She and her team mates were cut off from the outside world for "two years and 20 minutes," as she intensely characterized it, and they suffered the consequences of total isolation including mood swings, depression and conflict with each other that at times created "warring factions" and periods when crew members were not on speaking terms.

The current record for the longest continuous time spent in space is held by a Russian cosmonaut who spent 438 days in space, well short of the 501 day Mars Mission.  There are other longer isolation case studies to work from, including a 500 day test that was conducted in an earth bound laboratory and inhabitants of Antarctica research laboratories that are cut off from the rest of the world for months during winter.

At today's announcement in Washington, D.C., Pointer said that the Mars crew will be kept busy with exercise, mission related science and repair tasks.  The repair tasks will likely result from planners reducing automated systems aboard the space craft.  The idea is to keep working systems simple and serviceable and minimizing technical glitches too complicated for in-flight repair. "Simple" increases the crew's odds of survival in a no abort mission.

Pointer added that the crew will receive psychological support before and during the mission.

Sending a married couple

The crew module will barely support two members, so mission planners have decided to choose a married couple for psychological, social and symbolic reasons.

"A couple can better share a remarkable moment together during their mission," said Pointer. 

A couple will also be better suited to support each other through inevitable challenges, and thus increasing their productivity millions of miles away from home.  

A man and woman space team also sends a symbolic message representing the human race on the historic mission, and provides inspiration to both boys and girls watching back on earth.

The now "barely feasible" mission, as Clark characterized it, will have the fastest re-entry speed into earth's atmosphere ever attempted by a manned vehicle, which is another major technical hurdle facing mission planners.

The Human Mission to Mars is spearheaded by Dennis Tito, who was the first space tourist when he paid $20 million dollars for an eight day trip to the International Space Station in 2001.

Space flight has been a life long passion for the 72 year old from Queens, New York, who began his career as an aerospace engineer and later made his fortune by founding an investment firm in California.

Tito is reportedly interested in UFOs and considers Iinfrared imaging as a preferred method to capture images of alien craft, according to his Wikipedia profile.

Tito will personally fund the Mars Mission for the first two years of development, through 2014.  He will devote considerable time to raising the bulk of the mission's cost, which is estimated to be about a billion dollars.  The mission will save money by using available commercial spacecraft and technology modified for the long round trip. Tito believes that selling media rights alone to the mission will raise considerable sums.

Tito told reporters gathered in Washington, D.C. today for the announcement that "the time is now" for the mission, and that it would it would launch in 2018 when the planets are properly aligned for the shortest possible roundtrip to Mars.

Tito cited a 1997 study that helped him determine the flight trajectory of the mission. The mission will save a lot of money and additional risk by not landing on Mars.  The crew will instead fly by Mars as close as 100 miles from the surface of the red planet, without reaching its atmosphere.

The mission will be a stripped down operation, compared by the planners as a "Lewis and Clark" styled enterprise.

Water and oxygen will be repeatedly recycled to minimize supply tanks aboard the spaceship.  The bulk of the rocket's weight will be fuel used for lift off from earth, with momentum and celestial mechanics propelling the ship to Mars and back, eliminating the need for heavy fuel tanks after leaving earth.