Astronaut Rick Mastracchio is shown participating in a spacewalk in this image provided by NASA and taken April 13. (Reuters Photo/NASA)
They've lived with each other for extended periods of time in very close quarters, but that doesn't mean America's astronauts see eye-to-eye.
As President Obama prepares to unveil his new plan for space travel, the men and women who have been in space are lining up in favor -- or against the new vision for space exploration and the cancellation of the planned space shuttle replacement.
Sally Ride is the latest heroic astronaut to join the fray, voicing support for Obama's plan on Thursday. A physicist and an astronaut, Ride become the first American woman in space after riding the Challenger shuttle in 1983.
In a statement released by the White House, she called the President's plan "a bold strategic shift that will enable NASA to return to its roots: developing innovative technologies aimed at enabling human exploration and tackling the truly challenging aspects of human spaceflight -- venturing beyond Earth orbit, beyond the Earth-Moon system, and into the solar system."
Ride was most enthusiastic about the news that Obama will set specific goals for NASA's space program, with stepping-stone missions leading to a clear end goal: Mars. "The proposed program articulates a strategy for human exploration that will excite and energize the next generation ... Astronauts will travel to near-Earth asteroids and to distant space telescopes; they will visit the lunar surface and the moons of Mars."
Other astronauts disagree. Neil Armstrong, the first man to walk on the moon, penned an open letter with other outer space legends Tuesday blasting off at the Obama administration for plans to shelve NASA's manned moon missions.
"The ... decision to cancel the Constellation program, its Ares 1 and Ares V rockets, and the Orion spacecraft, is devastating," they wrote.
"America's only path to low Earth orbit and the International Space Station will now be subject to an agreement with Russia to purchase space on their Soyuz (at a price of over 50 million dollars per seat with significant increases expected in the near future) until we have the capacity to provide transportation for ourselves. The availability of a commercial transport to orbit as envisioned in the President's proposal cannot be predicted with any certainty....
"It appears that we will have wasted our current $10-plus billion investment in Constellation," the former astronauts wrote.
Famed astronaut Buzz Aldrin weighed in Wednesday evening following the revelations of Obama's plans, also endorsing the president's new direction for NASA.
"The truth is, that we have already been to the moon -- some 40 years ago. A near-term focus on lowering the cost of access to space and on developing key, cutting-edge technologies to take us further, faster, is just what our nation needs to maintain its position as the leader in space exploration for the rest of this century," Aldrin said.
The second man to walk on the moon, Aldrin told Fox News on Thursday that targeting the moon alone wasn't good enough. He called for the creation of a public/private international lunar development corporation that would open the moon up for exploration and development.
"We should have the European Space Agency invite China to become a member of the Space Station community, and that can lead to this activity at the moon," Aldrin said. "We will barter off our experience for assistance," he argued, calling for a two-phase, 25-year program to establish a permanent base on Mars.
Gene Cernan, the last man to walk on the moon, believes Obama's current budget lacks the funding to support such a plan. "If Buzz can find a penny in that budget for American human space flight, to go to Mars, to go back to the moon -- there's no focus, there's nothing out there that we can put our hands around and look forward to!"
White House Press Secretary Robert Gibbs defended President Obama against Armstrong's open letter, saying the president's "renewed strategy" will be better for the economy, astronauts and the space program as a whole. Gibbs, citing an independent commission that found the program was over-budget and behind schedule, said that Thursday's announcements should ease concerns that the president is somehow relegating NASA to the back of the budget.
"The president will outline a renewed strategy tomorrow in Florida that will provide more jobs for the area, greater investment in innovation, more astronaut time in space, more rockets launching sooner, and a more ambitious and sustainable space program for America's future," Gibbs said.
At the Kennedy Space Center in Florida Thursday, Obama plans to announce a set of stepping-stone achievements aimed at taking the United States farther into space, along a range of destinations including lunar orbit, so-called "Lagrange points" (prime destinations for permanent, orbiting fuel depots), near-Earth asteroids, the moons of Mars, and eventually Mars itself.
But Armstrong and other astronauts continued to express concerns that scrapping the moon program would had deep consequences in terms of America's standing in the world.
Apollo 13 astronaut Jim Lovell, who signed the letter with Armstrong, told Fox News he believes Obama's plan is "short-sighted."
"We're going to be a third-rate nation. China and Russia are going to be premier," he said.
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