PORTLAND, Ore. (AP) -- A Portland man was sentenced to six months in federal prison for breaking into a NASA computer systems in 2001 and causing more than $200,000 in damage.

Gregory Aaron Herns, 21, was a 17-year-old computer whiz at an alternative high school in southeast Portland when he hacked into the computer system at NASA's Goddard Space Flight Center.

Herns told federal agents he was looking for computer space to store movies he'd downloaded. It took hours for technicians to find the problem, fix it and patch the system's security holes, officials said.

"It would be like clearing a sidewalk full of spectators with a fire hose so you can walk through it," said Assistant U.S. Attorney Greg Nyhus.

Herns, now a computer science student at Mt. Hood Community College, apologized to the space agency and federal law enforcement officials on Friday.

"These actions took place years ago and are behind me," he told U.S. District Judge Anna Brown. "I've moved on since."

His attorney, Michael R. Levine, said his client was just a kid when the crime took place: "He was a computer geek - with all due respect."

But Nyhus said Herns' activities were much more than a teenager playing around on the computer.

"When you knock a system off line, you have to start it back up again," Nyhus said. "It's not like firing up your Macintosh or your Apple where you push a button and wait six minutes for the thing to boot."

Herns was ordered to pay restitution for the damage he caused and will have limited access to computers for the next three years. After the judge outlined the terms of Herns' restricted computer use, Levine pointed out how hard those conditions will be for a man who does everything online, including paying his bills.

"He's going to get to learn,'' Brown said. "There are other ways to live."