WASHINGTON – Space experts outlined their ambitious goal of combing the solar system for signs of life but offered a bleak picture for the future of manned space flights before a congressional committee Wednesday.
Scientists,testifying before the Senate Subcommittee on Science,Technology and Space,praised the National Aeronautics and Space Administration's progress with robotic space exploration but said research on manned space flights has fallen behind.
“The U.S. has no peers in robotic exploration,” said Louis J. Lanzerotti,a scientist at Bell Laboratories and Lucent Technologies. “Our vision for human exploration is surely lacking.”
With little American enthusiasm for space travel,Lanzerotti said,“Our vision for humans in space needs some really hard thinking.”
Sen. Sam Brownback,R-Kan.,questioned the panel of space experts about the practicality of the unfinished international space station that depends on NASA’s manned space shuttles to deliver supplies,equipment and manpower. Shuttle missions have been halted until completion of the investigation into the Columbia disaster.
“The international space station is part of the future,” said Michael J.S. Belton,chair of the Solar System Exploration Survey Committee of the National Research Council.
Belton also warned that the possibility of a cataclysmic asteroid striking the earth's surface is a danger worthy of serious consideration,not simply the product of a Hollywood screenwriter's imagination.
“It will happen sooner or later,” he said in response to questioning by Sen. Bill Nelson,D-Fla.,a former astronaut.
“We don't know if it's going to happen tomorrow or in a 1,000 years or 10,000 years,” Belton told the committee.
He said movements of asteroids in space are random and unpredictable,but scientists could discover more about them in 50 to 100 years if investments in technology are made now.
He referred to a 50-meter asteroid that many scientists believe exploded over Russia in 1908 and destroyed 800 square miles of a remote Siberian forest. Scientists have estimated that the blast was many times more powerful than the atomic bomb dropped on Hiroshima during World War II.
“It needs studying,” he said. “No one's studying it right now.”
Belton and Orlando Figueroa,director of the NASA’s Mars Exploration Program Office,also said that some of the basic questions of human existence are the driving force behind the agency’s exploration plans.
Figueroa said NASA wants to “understand the origins of life” and look for life elsewhere,including on Mars. He said there's strong evidence of water running over the surface at some point in its history,and there's a good possibility Mars once had a wet and warm environment.
Two space probes,Spirit and Opportunity,will join one other NASA probe on Mars next year. They will drive to different locations on the planet and capture “breathtaking views” of the Martian landscape,Figueroa said.
At the turn of the decade,NASA plans to send nuclear-propelled,unmanned space probes to three of Jupiter's ice-covered moons,including the largest one,Ganymede. The three moons NASA will explore have shown signs of water,Figuero said. He also said scientists have found more than 100 planets like Jupiter around other stars similar to the sun.
There are trillions of stars,so Figueroa said he believes chances are good that life is out there.
Brig. Gen. Richard C. Zilmer,director of the Strategy and Plans Division for the Marine Corps,testified that future space technologies could allow Marines to be on the ground anywhere in the world within two hours of deployment.
That assertion immediately drew a “wow” from Brownback,who organized the hearing.
Zilmer said that in 25 to 30 years Marines or special forces could be traveling into low Earth orbit,allowing for faster flights.
It would give the Marines the ability “to react to strategic events” such as weapons of mass destruction disasters or conflicts in remote places such as central Africa,Zilmer said.
“We are not funding anything along these lines right now,” he said. “We believe the technology is going to go that way eventually.”
Lanzerotti also described the importance of understanding the volatile and unpredictable environment that spacecraft face,most notably solar flares.
Solar flares are massive explosions on the sun's surface that release as much energy as a billion megatons of TNT. The energy and radiation are propelled into space,often affecting Earth's atmosphere.
Lanzerotti said the “seahorse flare” detected Aug. 7,1972,in between two manned space flight missions would have been fatal for the crews if it had occurred during the flights. He said scientists did not have much knowledge about solar flares then.
“We have a little more now,but not a lot more,” he said. “We're a long way from very accurate predictions.”