American astronauts should permanently inhabit the moon and visit the planet Mars during the early 21st century, a special White House panel recommended Tuesday. The Synthesis Group, led by former Apollo astronaut Thomas Stafford, said manned missions to the moon should resume in the years 2003 to 2005, and American astronauts should begin visiting Mars in the years 2014 to 2016.
"We hope this will be a road map for the next 30 years of the space program," said Stafford, a retired Air Force lieutenant general who flew four NASA space missions, including Apollo 10.
The panel submitted four proposals to accommodate different priorities in the missions to the moon and Mars: an emphasis on scientific exploration of Mars; a balanced scientific exploration of the moon and Mars; an emphasis on a permanent base on the moon with exploration of Mars as a shared goal; and the aim for maximum, early use of material and energy found on the moon and Mars.
The 180-page report aroused considerable excitement among space buffs but deep concerns among critics who are worried about the huge cost _ put at $500-billion or more by some analysts. The report, issued after 10 months of study, did not mention a price tag.
"It's no accident there are no dollars attached to it," said John E. Pike, associate director for space policy at the Federation of American Scientists. "People would have sticker shock at the price."
James Frelk, executive director of another Washington-based space policy think tank, the George C. Marshal Institute, which backs the Mars initiative, also criticized the report for not including cost estimates.
"The technology is certainly achievable," Frelk said. "The question will come down to costs. And that has to go into any policy-maker's decisions."
The report is the latest in a series of studies on the future of the space program, and Vice President Dan Quayle was asked what made the new study different.
"I don't think anybody's taken a serious look in terms of architecture of how to fulfill the president's stated objective in space, the moon and Mars mission," said Quayle, head of the National Space Council and the administration's point man on space.
President Bush set the goal of colonizing the moon and sending an expedition to Mars in a speech on the 20th anniversary of the July 1969 Apollo landing on moon.
The Synthesis report was commissioned in part because of White House dissatisfaction with NASA's proposals for meeting those goals. The NASA plan was deemed too costly ($400-billion over several decades), complicated and slow.
The Synthesis panel _ which included 27 government, industry and academic engineers and scientists _ concluded the road to Mars should begin with practice landings on the moon.
"The moon is the nearest object in space where people can live under conditions similar to those we will face on other planets," the panel concluded. "It is a natural test bed to prepare for missions to Mars."
Mars is the most logical target for planetary exploration because it has a thin atmosphere, changeable weather, seasons, a 25-hour day and may have water.
To get to the moon and Mars, the United States would have to build a rocket capable of boosting six to 18 astronauts and 150 to 250 tons of supplies and equipment, the panel reported. Part of the technology already exists.
The rocket's first stage could be powered by clusters of the huge F-1 engines that powered the first stage of the Apollo moon rockets. To go to the moon, six F-1s would be clustered, then given more power with heavy-lift solid rockets now under development.
To go to Mars, a cluster of 14 F-1s would be teamed with the heavy-lift solid rockets to lift the ship into a low Earth orbit. To leave Earth orbit to go to Mars, the spaceship would be powered by a yet-to-be-developed nuclear rocket engine.
The panel said nuclear-powered rockets are "the only prudent propulsion system" for the long trip to Mars. It also recommended development of improved nuclear systems to supply electricity in space.
U.S. interplanetary robot spacecraft already use a type of nuclear power for electricity. And the administration already has asked Congress to revive nuclear rocket propulsion research begun in the 1960s because it would drastically reduce the flight time between here and Mars.
The rockets would use a nuclear reactor to heat propellant to high temperatures, providing higher performance than today's chemical propulsion rockets. Programs to develop the technology were terminated in the early 1970s.
Foremost among the obstacles to a manned mission to Mars is the debilitating, and perhaps fatal, effects of prolonged exposure to zero gravity. The report said that the average mission to Mars would be about 1,000 days. At its closest point to Earth, Mars is 35-million miles away, meaning that it would take about 230 days to get there. The moon, by comparison, is a quarter-million miles away _ a three-day journey.
The panel also endorsed NASA's proposed $30-billion space station, which won House support last week only after an all-out lobbying campaign by the Bush administration. Quayle on Tuesday called the space station "the next step" to manned exploration of space.
The space station is critical for research on the way humans react to zero gravity, Stafford said.
_ Information from Scripps Howard News Service, the Associated Press, the Washington Post, the Los Angeles Times and Reuters was used in this report.