Human exploration of the moon and Mars will move humanity beyond terrorism and war, inspiring the public in much the same way as Europeans who explored North America 500 years ago, author Ray Bradbury (search) said Thursday.

Bradbury praised President Bush's initiative to return humans to the moon by 2020 and later land astronauts on the Red Planet. He spoke before a presidential commission reviewing the president's proposal. The panel is to make recommendations to NASA (search) and the president in June.

"If you sell it on the basis of a new freedom, a new movement away from the politics and horror and terror on Earth, I think people will recognize how (important) that is," Bradbury said.

Bradbury, 83, faced skeptical questions from some commission members.

Commissioner Paul Spudis (search), a visiting scientist at the Lunar and Planetary Institute (search) in Houston, asked how space exploration could be sold to the "practical side" of the American public. Another panel member noted that many people complain about spending money on space exploration when there are many more pressing problems on Earth.

Bradbury said $1 billion a day is spent on war and conflicts. President Bush's proposal, announced in January, would be funded by $1 billion in new NASA funding each of the next five years.

"If we take one day each year and spend it on space travel, we could do it," Bradbury said via a satellite link from Los Angeles.

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Bradbury said such challenges did not stop Spain and England from supporting explorers such as Christopher Columbus and John Cabot.

"All sorts of problems hadn't been solved," Bradbury said. "If they had stayed there, there wouldn't have been an America."

The panel also wondered whether public support would dwindle if astronauts were killed on interplanetary missions.

Bradbury, who wrote about the human colonization of Mars in "The Martian Chronicles (search)," said thousands of people died exploring North America.

"You simply do not give up," he said.