The US economy seems to be the biggest obstacle so far in realising the biggest space mission of the new century, to send humans and explore the red planet Mars.

After the Apollo mission to the moon in the 1960s, people have now turned their attention to the Mars exploration, prompting some organisations to launch various initiatives which include the bizarre proposal of a one-way ticket to minimise costs.

In a survey conducted among a thousand American respondents by non-profit organisation Explore Mars and aerospace giant Boeing, budgetary constraints turned out as the biggest problem faced by people behind the space exploration.

Seventy five percent of respondents agree that NASA's budget should be doubled up to one percent of the US federal budget. This is to fund the Mars mission and other important initiatives.

Compared to the Apollo mission to the moon in the 1960s which received four percent of the federal budget, today's Mars mission is receiving only 0.5 percent budget.

"If we started today, it's possible to land on Mars in 20 years," G Scoot Hubbard of Stanford University said.

"It doesn't require miracles, it requires money and a plan to address the technological engineering challenges," he added. Hubbard was the first program director of the Mars program which he successfully restructured in the face of mission failures.

The biggest challenge facing the people of NASA and other private sector experts is how to be able to place a mass of about 30 to 40 tonnes which is the estimated amount required in creating a habitable area for humans in the red planet. This is aside from the other huge problem of transporting or producing sufficient fuel to enable the mission team to get back, according to Hubbard.

In August last year, the Curiosity rover took seven minutes of tension-filled landing on Mars and it weighed only tonne.

The Curiosity mission which cost US$2.5 billion and was intended to last at least two years was sent off to study the existing environment in Mars and try to find out if water exited as well in preparation for manned missions in the future.

Despite the budgetary problems, however, Americans surveyed remain upbeat that in 2033, humans will have landed on the red hot planet. They also favour sending astronauts to the Mars mission.

On Monday, key officials of NASA and Buzz Aldrin join other big names in space explorations as they discuss the status of the current projects in a three-day conference to be held in Washington. Buzz Aldrin is the second man to have set foot on the moon.

Meanwhile, a spaceship bankrolled by Sir Richard Branson, a British business magnate and founder of the Virgin Group, has recently embarked on its first powered flight, a test that pushes Virgin Galactic closer to its goal of conquering outer space late this year.

Although SpaceShip Two did not burst forth onto atmosphere during its test flight, Virgin Galactic still considers it as an important milestone prior to their plan of taking passengers on subortbital rides later on.

The SpaceShip Two, which was strapped beneath a twin-fuselage jet during the early morning test flight, took off from a Mojave Desert airport runaway, north of Los Angeles.