After planting his boots on the moon, the first thing Neil Armstrong did was scoop up some pebbles and stuff them in a pocket, just in case he had to make a quick getaway. Retrieval of lunar soil was the chief scientific aim of the Apollo program, which mobilized an army of engineers and scientists, enlisted America's industrial might and, at its peak, consumed 1 percent of the nation's gross national product.
Today, two scientists are trying to persuade NASA to let them retrieve rocks from another extraterrestrial object. But their mission would lack some of the drama of Apollo 11.
They're designing a golf-cart-size robot that would fly to an asteroid called Nereus. The boxy craft would bounce six times across the surface like a pogo stick, each time shooting sample-collecting tubes into the rock. Then it would return to Earth orbit and jettison the sample package, which would land by parachute.
The price tag: a mere $150 million, not including the cost of the rocket needed for liftoff.
Call it Space-Probes-R-Us. Call it NASA Lite. Whatever it is called, it may typify the next decade of American space exploration.
One of the scientists, Andrew F. Cheng of Johns Hopkins' Applied Physics Laboratory, said five years ago his colleagues might have disparaged his low-cost mission, called NEARS for Near Earth Asteroid Return Samples. Instead, NASA gave Dr. Cheng and his partner, Eugene Shoemaker of the Lowell Observatory in Arizona, $100,000 for a feasibility study.
"People generally would have thought that any [extraterrestrial rock] sample return mission would have to cost billions of dollars," Dr. Cheng said. "The last sample return mission was the Apollo program.
"The ground rules have changed," he said. "The big missions are not going to be undertaken in the near future."
The Apollo program, Skylab, the space shuttle, the Hubble space telescope, the Jupiter-bound Galileo and Mars Observer were massive undertakings. Just planning for the space station has so far cost $11.2 billion.
But the agency's era of living large may be over.
First, Washington is in a penny-pinching mood. As part of efforts to curb the federal deficit, the Clinton administration asked Congress to cut NASA's budget by about $300 million, to $14 billion, in 1995.
Second, some key NASA officials seem to have concluded that big, instrument-packed, expensive vehicles carry correspondingly big risks: They can be crippled or destroyed by the failure of a single part.
Witness Challenger's failed O-ring seal that caused an explosion that killed the seven on board, the Hubble telescope's subtly misshapen mirror, Galileo's jammed antenna and the Mars Observer's suspected fuel line leak, which may have caused it to explode.
Third, taxpayer support for mammoth space programs seems to have been swept away, like the Berlin Wall, in the meltwater of the Cold War. Gallup polls found that the proportion of Americans who believe the United States ought to be first to Mars dropped from 51 percent to 35 percent from 1989 to 1991 -- a period of reduced tensions between the West and the tottering Soviet empire.
To save the space station, National Aeronautics and Space Administration had to shrink the project, recruit the Russians as partners and lobby Congress hard. NASA has given up efforts to add another space shuttle to its aging fleet. The agency is saddled with operating costs for active spacecraft. And some previously planned, billion-dollar-plus space robots may still get snagged by the talons of congressional budget hawks: the Cassini Saturn probe, scheduled for launch in 1997, and an orbiting X-ray telescope.
"NASA is going to continue to do one big thing, which is develop and operate the space station," said John M. Logsdon, director of the Space Policy Institute at George Washington University. "That is going to take a large share of the available money for the next 'X' number of years. . . . With the rest of the money, it is almost certain that there will be smaller, more numerous missions, rather than the focus on long-duration, large, expensive missions that we've followed for the last 20 years."
For the past decade, various advisory groups prodded NASA to mount smaller, less complex and less costly missions, but were ignored. The latest, and loudest, call for change came in December 1990, with the Augustine Commission report. There is "a natural tendency for projects to grow in scope, complexity and cost," the panel found. "Deliberate steps must be taken to guard against this phenomenon if programs are not to collapse under their own weight . . ."
Finally, Washington seemed to listen.
In 1991, NASA got a new administrator, Daniel S. Goldin. At a ceremony honoring the $50 million, 570-pound Pioneer 10 spacecraft that conducted a grand tour of the solar system, he said the agency should learn from its past triumphs and seek "better, faster and cheaper" missions.
The phrase, sometimes rendered, "smaller, faster, cheaper" has become NASA's unofficial motto.
Not everyone inside NASA embraces the small-is-beautiful philosophy. "If you really want to do cutting-edge science, it is often difficult to do that without making a significant technical investment," said one agency official.
Critics outside the agency doubt NASA is capable of reinventing itself.
In his book "Hubble Wars," Eric J. Chaisson, a former senior scientist at Baltimore's Space Telescope Science Institute, blamed the Hubble telescope's problems on NASA's management, saying the agency "needs to be thoroughly reformed or replaced."
In an interview, Dr. Chaisson faulted Mr. Goldin for "championing slower, more expensive and probably worse" projects by fighting to save the space station.
There are signs the agency is struggling to alter its course.
Over the next decade or so, NASA plans to spend $7.1 billion on Mission to Planet Earth. The project, based at Goddard Space Flight Center in Greenbelt, will aim 18 satellites at the atmosphere, oceans, glaciers, forests and deserts to gather crucial environmental data.
This research could have direct practical benefits -- something few recent NASA programs can boast. James A. Van Allen, discoverer of the Earth's radiation belts and a prominent NASA critic, said Mission to Planet Earth "should be kind of the centerpiece of NASA's efforts."
Others think the agency should stay in the human space flight business.
John Pike of the Federation of American Scientists thinks that, by collaborating on a manned mission to Mars, for example, the world's industrial powers could learn to set aside their differences. "In the 21st century, we're going to have a tremendous number of problems with population, poverty, peacekeeping and pollution," he said. "In the absence of a global community cooperating in space, we're going to have a much harder time cooperating on those problems."
Many think that, eventually, humankind is fated to explore other worlds -- whether the motive is competition, cooperation or simple curiosity.
Roald Z. Sagdeev, once head of the Soviet space science program and now director of East-West Space Science Center at the University of Maryland, is cheerfully pessimistic.
"We are doomed to undertake such an enterprise," he said.