This story was updated at 5:38 p.m. EDT.
Neil Armstrong, the first man to walk on the moon, blasted NASA's new plans for future space exploration Wednesday, adding that President Barack Obama was poorly advised when he canceled the space agency's previous course for U.S. human spaceflight earlier this year.
Armstrong, who commanded the historic Apollo 11 moon landing mission in July 1969, criticized what he billed as an air of secrecy that preceded Obama's February announcement which cancelled NASA's Constellation program aiming for the moon. That plan, he told a Senate subcommittee, was a surprise to many among NASA, academia and the military.
"A plan that was invisible to so many was likely contrived by a very small group in secret who persuaded the President that this was a unique opportunity to put his stamp on a new and innovative program," Armstrong, 79, said in a statement to a Senate subcommittee reviewing NASA's new space plan. "I believe the President was poorly advised."
The United States is risking losing its role as a leader in space exploration with its new plan, Armstrong said, adding that he was concerned with the looming gap in American human spaceflight.
"Other nations will surely step in where we have faltered," Armstrong said.
NASA's future at stake
In February, President Obama announced his intent to cancel NASA's Constellation program in charge of building the new Orion spaceships and their Ares rockets. Those new spacecraft were envisioned to replace NASA's retiring space shuttles and return astronauts to the moon by 2020 under a space vision laid out in 2004 by former President George W. Bush.
A White House-appointed panel found that the Constellation program suffered from severe underfunding and was not sustainable to push U.S. human spaceflight beyond low-Earth orbit in the near future.
White House science adviser John Holdren said President Obama's space plan decision "was not hasty."
"The president heard from a lot of people in this process," Holdren told the Senate Committee of Commerce, Science and Transportation Wednesday, adding that the list included himself, NASA chief Charles Bolden and lawmakers, among others. "He got to the best and most balanced program for NASA, including its human spaceflight dimension, that the country can afford."
The Constellation program's cancellation has sparked much criticism from lawmakers concerned over a gap in U.S. spaceflight capability and expertise.
"Our 40-year legacy of leadership in space is on the line," said Sen. Kay Bailey Hutchison (R-Texas), who represents the home state of NASA's Mission Control. "And we need to have a credible plan to take the next step forward."
NASA's new space plan is aimed at developing new technologies, spacecraft and rockets that would allow the United States to launch astronauts on the first crewed mission to an asteroid by 2025.
A manned mission to Mars would follow in the 2030s, President Obama said during an April 15 speech at NASA's Kennedy Space Center in Florida. Obama has proposed a $19 billion budget for NASA in 2011 and added another $6 billion over five years onto that in his April speech.
To that end, NASA will retire its three aging shuttles after three more missions (the shuttle Atlantis' final flight is set for Friday) and rely on Russian Soyuz vehicles to send astronauts to the International Space Station ? which would be extended to at least 2020 under the new plan ? until commercial U.S. spacecraft became available.
The design for a new heavy-lift rocket, vital for launching huge payloads on missions to Mars or an asteroid, would be selected by 2015, Obama said.
While Obama scrapped the Constellation program as part of his 2011 budget request for NASA, he revived the Orion crew capsule to launch unmanned missions and serve as an emergency escape ship for the space station.
Armstrong on Constellation
Armstrong said that while the Constellation program had the benefit of flexibility, it was also going to be costly. At the time of its proposed cancellation, NASA had already spent more than $9 billion on the program.
But the new goal of an asteroid mission and Mars is a stark departure, Armstrong said.
"These are vastly different plans and choosing the proper path is vital to America's continued space leadership," Armstrong said in his statement.
Armstrong and fellow Apollo astronauts Jim Lovell (Apollo 13 commander) and Eugene Cernan, who commanded Apollo 17 and was the last man to walk on the moon, have publicly denounced NASA's new space exploration plan. They called it "devastating" in a statement sent to the media last month.
Cernan also spoke before the Senate subcommittee.
"We (Armstrong, Lovell and myself) have come to the unanimous conclusion that this budget proposal presents no challenges, has no focus, and in fact is a blueprint for a mission to 'nowhere,'" Cernan said in a statement.
Armstrong said he supported the idea of new players in the spaceflight arena, but was skeptical of commercial companies would be able to meet NASA's needs in a timely and cost-efficient manner.
"I support the encouragement of the newcomers toward their goal of lower cost access to space," Armstrong said. "But having cut my teeth in rockets more than 50 years ago, I am not confident."