CAPE CANAVERAL, Fla. - Call it NASA: The Next Generation. The president is pointing America toward a new direction in space, and some heroes from NASA's long-ago glory days don't like it.

New rockets to the moon have been canceled. And the space shuttles are about to be mothballed. Instead, the Obama administration wants to rely more on private companies to fly into space over the next few years, while also working to develop a big, new government rocket ship.

But the plan lacks details, and neither a specific initial destination nor a spacecraft has been settled on.

The old space hands aren't buying it. From Neil Armstrong, the first man on the moon, to the last astronaut to leave his footprints there, many Apollo-era space veterans are upset. They especially don't like President Barack Obama's cancellation of President George W. Bush's return-to-the-moon mission. They accuse Obama of abandoning American leadership in space to the Chinese and Russians.

But others in a younger generation - including Internet pioneers of the 1990s - are excited about the president's vision. NASA will spend $6 billion to encourage private companies to build their own spaceships to ferry astronauts to the International Space Station. They see the Obama plan as the only way to eventually get astronauts to Mars.

"This is a generational shift in the space program," said MIT astronautics professor Ed Crawley, who served on a White House-appointed panel last year to re-evaluate the space program.

In a visit to Cape Canaveral on Thursday, the president will try to sell a skeptical space community on his concept. He is bringing some new adjustments to the plan to demonstrate his commitment to exploring space, building spacecraft and keeping local jobs, administration officials said.

The Obama plan extends the space station's life by five years and puts billions into research to develop the big new rocket ship capable of reaching a nearby asteroid, the moon or other points in space. Those stops would be stepping stones on an eventual mission to Mars. But the specifics have not been worked out.

PayPal founder Elon Musk said his company SpaceX hopes to fly astronauts to the space station by the end of 2013. He figures he will charge NASA about $20 million an astronaut. That's a bargain compared with the more than $300 million a head it was going to cost NASA under the Bush plan, and the $56 million NASA will pay Russia for trips on Soyuz rockets in the short term.

Musk's Falcon 9 unmanned rocket is sitting on a Cape Canaveral pad with its initial launch a month away. Several companies are competing with Musk, including one run by Amazon founder Jeff Bezos.

Musk said what's happening is "the new generation of space."

But Armstrong, Eugene Cernan, who was the last man to walk on the moon, and Apollo 13 commander Jim Lovell spent much of March together, touring the Persian Gulf. They talked about how much they dislike the change in space priorities, Cernan said.

"We have just given up manned spaceflight," Cernan said. "It is the demise of American people in space except in someone else's vehicle. This is a catastrophe."

Lovell said the concept of putting more money into technology is fine, but the plan lacks vision.

"The whole idea of any program is you have to set a goal," Lovell said. "You don't just build technology and figure out what to do with it. ... The whole thing is flawed."

And the famously private Armstrong said in an e-mail to The Associated Press that he had "substantial reservations" about the Obama plan.

The split is not entirely along generational lines: Armstrong's Apollo 11 moonwalking partner back in 1969, Buzz Aldrin, has publicly supported the president's plan, while some younger shuttle astronauts oppose it.

On Monday, 27 former astronauts and senior NASA officials wrote an open letter to the president, contending that canceling the moon program would cede American leadership in space technology.

"One of the greatest fears of any generation is not leaving things better for the young people of the next," the letter said. "In the area of human spaceflight, we're about to realize that fear; your NASA budget proposal raises more questions about our future than it answers."

Musk, who was born two years after Armstrong's "one giant leap for mankind," said there is a lot of anger about the president's plan.

"This is a pretty revolutionary move and revolutions generate anger," Musk told the AP. "But if we don't do it, there's no future in space."

Add to all that angst a shrinking work force because the 29-year-old space shuttle fleet will be retired after three more flights.

Many critics of the president's space plan, such as Chris Kraft, the legendary engineer who ran Mission Control from Mercury through Apollo, say the end of the shuttle is a major mistake. They say it will force America to rely on the Russians for increasingly expensive rides into orbit until new ships are built.

The decision to retire the shuttle fleet was actually made in 2004 to fund Bush's moon mission plan. Obama killed the moon mission in February. But the White House argues that astronauts will actually be spending twice as much time in space under the new plan as under the Bush plan because Obama extended the life of the space station.

In response to the criticism and in an effort to relieve Florida job fears, Obama administration officials said Tuesday that the president will announce two changes:

• Reviving the Orion crew capsule designed under the Bush moon plan.

• Speeding up development of the massive new rocket. It could be ready around the end of the decade, a few years earlier than previously planned.

Overall, the Obama program would mean 2,500 more Florida jobs than the old Bush program, administration officials say.

The Orion capsule wouldn't be used for its original purpose - landing on the moon. It would be sent unmanned to the space station to be used as an escape vehicle. That would mean U.S. astronauts wouldn't have to rely on the Russian Soyuz for an emergency flight home.

NASA Administrator Charles Bolden called the president's plan "pretty dynamic and pretty bold. The thing that makes it different from any other vision is that it's funded."

The Bush plan had some serious drawbacks: It had already cost NASA $9.1 billion. Because of earlier budget cuts, the new moon rocket was way behind schedule, and there was no money to build a lunar lander, White House and NASA officials said.

One problem with the Obama plan is that the White House botched the job of explaining the concept, said space scholar John Logsdon of George Washington University.

"It's absolutely crucial that Obama articulate a clear sense of what we're up to," he said. "It's hard because it's a relatively sophisticated strategy."