Yesterday at the Senate Commerce Committee hearing on the future of U.S. human spaceflight, Neil Armstrong, the first man on the moon, and Eugene Cernan, commander of Apollo 17 and the last man on the moon, provided testimonies opposing President Obama’s proposed space plan.

The former astronauts were passionate that the new plan, which they say was not subjected to a substantial review, presents no challenges, has little focus, and is a blueprint for a mission to “nowhere.” Armstrong, Cernan, and Jim Lovell, commander of Apollo 13, also recently released a letter to the White House calling the president’s plan “devastating” and a “slide to mediocrity”.

The plan calls for the cancellation of the Constellation program, which would see the development of two new rockets, Ares I and V, and a crew capsule, and would return humans to the moon by 2020. Instead, it focuses on the using the commercial industry to ferry astronauts to the International Space Station, and extending the life of the station to 2020. Until commercial rockets are ready, America will be buying rides to low earth orbit from the Russians. (During the hearing the NASA administrator, Charles Bolden, Jr., said the first commercial rocket would be a SpaceX Falcon 9 rocket, which should be ready in 2015.)

Armstrong questioned this deadline. “The most experienced rocket engineers with whom I have spoken believe that it will require many years and substantial investment to reach the necessary level of safety and reliability,” he said. Cernan predicted it would take the private sector 10 years to access low earth orbit safely, “leaving us hostage to foreign powers” and costing $10-12 billion.

Both former astronauts backed the Constellation program, emphasizing the depth of scrutiny it endured before being accepted by Congress both in 2004 and 2008. “It seems appropriate that the reason for discarding all this work should be explained to this committee,” said Armstrong.

While Armstrong and Cernan opposed the new plan, other Apollo astronauts, including Buzz Aldrin, support it. Aldrin has said that our focus should be on human exploration to Mars, and has his own ideas for getting us there. Aldrin says there has been no direct communication between him and the other Apollo astronauts.