You're sealed inside the nose cone of your homemade rocket ship, Earthstar One, wearing a used Russian space suit, staring wide-eyed at the digital clock on the instrument panel. Outside, in the middle of the Alvord Desert in Southeastern Oregon, maybe a quarter of a million people have gathered to watch you blast into space at four times the speed of sound.

At T minus one minute, you key the microphone in your bubble helmet and explain to your friends at Mission Control (a van parked a prudent distance away) that you've made a mistake. A big mistake. Go ahead and stop the countdown, OK, and let's all just go home and have a beer. On me. Ha-ha. Guys?

But when they strapped you into the capsule's chair you told them that no matter what you said during the last few seconds of the countdown, the launch was to proceed as planned. So at zero, they push the red button.

And you wake up, sweating. Just another dream--except for the rocket.

Actually, Earthstar One is a dream, an all-too-real dream, a dream that's presently in multiple pieces, strewn about the floor of Brian Walker's garage in Bend. A few weeks ago, Gordon Cooper, one of the original Mercury Seven, dropped by to have a look for himself. Cooper was the last American to fly solo into space. Brian Walker intends to be the next. Even though he barely managed to graduate from high school, never went to college and has never piloted anything more substantial than a motor-powered paraglider.

But he's really good at building toys. At 45, he's still a bachelor, living off the royalties from inventions like the Alien Orbiter (a gyroscopic flying saucer), the Celestial Seeker (a hand-held planetarium), and the Pop-it Rocket (a piston-powered foam rocket that flies 80 feet into the air with a single pump).

This inventive track record gives Walker some credibility as a DIY astronaut. Earthstar One, you see, is one hell of a toy: a 26-foot-tall, 10,000-pound plastic missile capable (in theory, at least) of hefting one 200-pound toymaker 30 miles into the heavens.

Here's how it works: Two giant air pistons push Earthstar One off the launch pad like a real-life Pop-it Rocket, then hydrogen peroxide inside the main fuel tank mixes with a reactive metal and expands exponentially, creating 12,000 pounds of thrust, venting a pillar of vapor like a toy water rocket. Once the fuel is spent, the capsule separates from the booster, is weightless for a few seconds as it leaves the outer reaches of the stratosphere, then floats back to Earth on a parachute.

"When most people think of extreme sports, they picture bungee-jumping," says Walker, scheduled for a liftoff in May 2002. "But this is the most extreme outdoor thing a person can do. Blasting off the planet."

Not that he's much of a risk taker, mind you. There are some things he just won't do. Like ride a Harley.

"Pete Conrad landed on the moon, then
he came home and got himself killed on a motor-sickle," Walker says. "Now that's just foolish."

To track Brian Walker's progress on Earthstar One and view a computer- animated rendition of his proposed sub-orbital flight, check out .