BOSTON -

Astronaut Sunita "Suni" Williams started her version of the Boston Marathon on Monday, running on a treadmill 210 miles above Earth undeterred by the wind and rain lashing her Massachusetts counterparts.

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. Two laptop computers were on either side of the treadmill so she could watch a live feed of the race from Boston and keep track of where the international space station was flying.

Restrained to the treadmill in a harness so she wouldn't float away and wearing Boston Red Sox socks, Williams ran at a brisk pace at the start of the 26.2-mile race. Williams' sister, Dina Pandya, and NASA astronaut Karen Nyberg were running in the race on the ground.

"Just want to let you know the team here is cheering for her and by our calculations she already has completed her 26 miles," Mission Control told her crew mate, Michael Lopez-Alegria, a few minutes into the race.

While racers in Boston bundled up on a raw day, the space station was balmy enough that Williams needed only a navy T-shirt and shorts.

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

The 41-year-old Williams qualified for the Boston race by finishing the Houston Marathon in January in 3 hours, 29 minutes, 57 seconds.

About 45 minutes into the start of the race, or a trip halfway around the world in the space station, Lopez-Alegria reported to Mission Control: "Suni's still smiling. That's a good sign."

Like many of her counterparts on the ground, Williams took a short break of a minute or two about an hour into the marathon to stretch her legs and type on the laptop computer. She resumed the race at the same pace as before of more than six miles per hour.

More than a half hour later, after the space station had circled Earth once since the start of the race, Williams radioed down to Mission Control: "It's coming up on 9.5 miles now and it looks like we've gone around the world. Nice statistic."

In an interview with The Associated Press last week, Williams joked that she was hoping the station's treadmill would hold up since it has had its share of breakdowns.

"Marathons are hard on the body," she said. "It's hard on the machine. I hope both of us survive."