By MIKE SCHNEIDER

CAPE CANAVERAL, Fla. – She traveled around the world almost three times and was harnessed to a treadmill so she wouldn’t float away.

NASA astronaut Sunita “Suni” Williams completed her version of the Boston Marathon on Monday _ more than 210 miles above Earth.

“I’m done! Woo hoo!” Williams told Mission Control after running 26.2 miles on a treadmill at the international space station.

Already traveling at 17,500 mph, Williams started the race on time at 10 a.m. EDT with race No. 14,000 taped to the front of the treadmill as the space station passed over the Pacific Ocean. She finished, unofficially, 4 hours, 23 minutes and 46 seconds later as the station traveled over Russia.

The 41-year-old astronaut, who grew up in the Boston area, had kind words for the temperamental treadmill, which has had its share of breakdowns.

“No problems. No flaws. No nothing,” said Williams, who wore Boston Red Sox socks for her run. “It did everything I wanted it to do.”

Two laptop computers were on either side so she could watch past Boston Marathons on a DVD and keep track of where the space station was flying. Periodically, she asked Mission Control for an update on the times of friends, including NASA astronaut Karen Nyberg, and her sister, Dina Pandya, who were running the marathon on the ground.

Nyberg finished in 3:32:9 and Pandya in 4:14:30 on a day when the Boston runners faced the remnants of a chilly, soaking nor’easter. The space station was a balmy 78 degrees.

“Those guys are kicking butt even though it’s cold,” William said when told of the times of her friends and sister.

Williams woke up several hours earlier than her crew mates because of the marathon. Also at the space station were U.S. astronaut Michael Lopez-Alegria, Russian cosmonauts Mikhail Tyurin, Fyodor Yurchikhin and Oleg Kotov and space tourist Charles Simonyi.

Williams qualified for the Boston race by finishing the Houston Marathon in January in 3:29:57. On Monday, she ran at a pace of more than 6 mph through most of her race. Like many of her counterparts on the ground, she took a couple of short breaks of a minute or two to stretch her legs or adjust her harness. Her crew mates tossed snacks of orange pieces at her in the weightlessness of space.

She also got plenty of encouragement from Mission Control in Houston.

“Keep it up. I think you’re over Heartbreak Hill,” Mission Control radioed Williams after she reached the 20-mile mark, referring to the race’s final hill whose summit has a view of Boston’s Prudential Tower.

“It’s all downhill … and into the Prudential,” Williams radioed back. “We’re going to make it.”