The centerpiece was a plan to return humans to the moon by 2020. The moon missions, he said, would be initial steps toward human missions to Mars and beyond.
Space scientists often refer to the speech as the moon-Mars document.
According to NASA administrator Griffin, the 2007 budget "demonstrates our national commitment to implementing the vision for space exploration."
The first step, he added, is to meet preexisting obligations to complete the International Space Station, which requires use of the space shuttle. (See top photos taken from the space station.)
"When those obligations are completed, the other major pieces of our portfolio will be able to do better," he said.
The agency hopes to complete the space station by September 30, 2010, with 17 shuttle flights.
NASA also plans to have the Crew Exploration Vehicle, the next generation shuttle, operational no later than 2014. The vehicle is to ferry humans to the moon.
The Planetary Society issued a statement criticizing the Bush Administration's 2007 NASA spending plan as too focused on the current space shuttle and the International Space Station.
That focus, the society says, comes at the expense of other provisions in the President's stated space plan.
For example, the society points out, the 2004 vision document also calls for missions to "explore Jupiter's moons, asteroids, and other bodies to search for evidence of life, to understand the history of the solar system, and to search for resources."
Friedman said that to stick with the vision, the space agency should curtail spending on the space shuttle program, which is scheduled to be terminated in 2010.
NASA should focus efforts on science and exploration, Friedman says.
Robert Pappalardo is a planetary scientist and expert on Jupiter's moon Europa at the University of Colorado at Boulder. He agreed that the NASA budget blurs the space vision.
"It's too simple to remember 'moon-Mars' and not go back to the document and read what it says," he said.
A "top-level theme" at NASA is to understand life and to search for life beyond Earth, Pappalardo said.
"If NASA is not exploring Europa, then NASA is clearly not serious about that mission statement," he said.
"Europa likely is a habitable environment today, and so [the Jupiter moon] seems central to any vision that is organized around a theme of understanding habitability and understanding the context for life in the solar system and in the universe," he added.
Seth Shostak is a senior astronomer at the Mountain View, California-based SETI (Search for Extraterrestrial Intelligence) Institute. The nongovernmental organization heads a program to sweep the skies with radio telescopes in search of signs of intelligent life.
The "reduction in the astrobiology budget is lamentable," Shostak said.
The institute's own radio-astronomy program will continue. But the indefinite postponement of NASA programs such as Terrestrial Planet Finder means SETI's searches will remain less targeted than they potentially could be.
In addition, reduced astrobiology funding will likely work against Bush's stated goal of encouraging more young Americans to pursue science and technology careers, Shostak said.
Astrobiology "is one of those areas that resonate very well with young people by combining geology, astronomy, and biology," Shostak said.
"What can be more sexy than looking for life beyond Earth?"
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