JOINT'S JUMPING AS JPL BUILDS PACK OF PROBES.

Byline: David R. Baker Daily News Staff Writer

In a checkered smock and paper shoes, Andy Rose circled his handiwork: a silver-and-gold, tinsel-covered box bound for Mars.

Dubbed Deep Space 1, the spacecraft Rose is assembling is just one in an flotilla of about 20 small probes under design or construction at NASA's Jet Propulsion Laboratory. Not since the money-gushing 1960s, when spending on the space race was a national priority, has JPL worked on so many spacecraft at once.

The hectic pace, driven by the National Aeronautics and Space Administration's demand for cheaper vehicles that take less time to build, marks a dramatic change for JPL. Once, the lab's engineers gave whole decades of their lives to a single project. Now machines that will crawl across asteroids, shoot instrument-filled bullets at the Martian soil, land on comets and skim close to the sun's surface share designers and technicians, all working on tight deadlines and budgets.

The revved-up pace pleases Rose, an 18-year JPL veteran who said he's still touched to see one of his spacecraft blast free of Earth.

``I live for this kind of thing,'' he said, as an engineer measured Deep Space 1 for a thermal blanket last week. ``I'm very pleased we've gone to better, cheaper, faster missions. You have a lot more stuff coming through here.''

During last week's national conference of the American Astronautical Society in Pasadena, the new JPL probes - and the innovative technology they will use - dominated the discussion among many of the country's leading spaceflight experts.

To Jupiter and beyond

Three of the probes discussed are under Jan Ludwinski's care. An effusive man who talks at breakneck speed, Ludwinski spent 10 years working on just the Galileo probe to Jupiter. Now he helps design missions for the entire Ice and Fire project, which will examine the solar system's furnace-hot center and cold, dark outer edge.

One Ice and Fire probe will explore Pluto, the only known planet in our solar system that has never been visited by a man-made probe. Another will look for signs of an ocean beneath the smooth, icy surface of Europa, one of Jupiter's moons. A third will fly through the intense heat of the sun's corona, circling closer to its surface than any other mission.

None of these probes will approach Galileo in size, complexity or price. The annual budget for developing all three is about $100 million per year, with each finished probe expected to cost around $180 million, compared to Galileo's $1.4 billion.

The smaller craft, Ludwinski admits, can't do everything. Some questions about the nature of the solar system can be answered only by looking at a lot of information at once and seeing how each piece affects the others. The new breed of small spacecraft, however, carry relatively fewer instruments than their expensive predecessors and gather less data.

Is smaller better?

In a society where bigger often is seen as better, advocates of smaller craft defend their use.

As proof, Ludwinski points to JPL's success with the relatively cheap Mars Pathfinder mission, which last summer explored a field of boulders under the pink Martian sky.

``People ask me, `Is `faster, better, cheaper' really better than the old way - was Galileo bad and Pathfinder good?' '' he said. ``You can't answer that. . . . There are lots and lots of really important questions we can answer with smaller craft, and we're choosing to answer those now.''

In other parts of JPL's sprawling, 170-building campus, the philosophy of small has produced a strange array of machines.

One is an asteroid probe that looks much like a toy car with sharply spiked metal wheels. In 2003, the tiny, 600-gram machine will be dropped onto an asteroid named 4660 Nereus to photograph the surface with a camera that can zoom from wide panoramas to microscopic scale.

Lawn darts to Mars

Another is a set of two probes - each the size of a liter bottle of soda - designed to be fired at the surface of Mars from an orbiting spacecraft. Shooting through the atmosphere without parachutes, braking engines or air bags, they will hit the ground at about 400 miles per hour, burrow into the dirt and study subsurface rocks.

``They just go `ka-wham,' like a lawn dart,'' said Carl Kukkonen, director of JPL's microelectronics center. ``We've dropped them out of airplanes, and they work.''

For all the scientific innovation in the new generation of JPL probes, many of the missions rely on technology that has been used before or is, in some cases, downright old.

The Stardust probe, for example, is constructed to fly within 100 miles of a comet's nucleus in 2004 and bring back to Earth specks of comet dust. But the substance used to catch and trap the dust - a material called aerogel that looks like a solid piece of blue smoke - has been around since the 1930s.

The cost of success

The increased activity at JPL has come as the facility is trying to adjust to layoffs, triggered by the same federal budget belt-tightening that led NASA to insist on cheaper missions. The lab's work force has dropped from 7,600 employees in 1992 to 5,700 today, and director Edward Stone expects to dip just below 5,000 employees in the next two years.

With fewer workers and more work, some engineers say they've run into scheduling problems for people whose skills are needed by several programs. But few criticize the new philosophy that has taken root at JPL or wish for a return to the lab's old pace.

``When you build one mission per decade, your work force rusts,'' said Stacy Weinstein, deputy manager for the asteroid rover project. Weinstein also works on an upcoming Mars mission.

``When you have a lot of missions going on, you're not standing around idle,'' she said. ``A lot of people have been talking about whether, with so much going on, things might fall through the cracks, but it hasn't happened yet.''

CAPTION(S):

3 Photos

PHOTO (1 -- Bulldog edition only) Eric Baumgartner and the Mars 2005 space rover are part of a new stance on more and cheaper space missions.

(2) Ken Pellak works on the Jet Propulsion Laboratory's Deep Space 1 vehicle.

(3) Engineer Andy Rose works on the Jet Propulsion Laboratory's Deep Space 1 vehicle, which is one of 20 current projects.

Myung J. Chun/Daily News