An astronaut who was determined not to lose her place in the Boston marathon will run next month's race in space, and circle the world twice before the winner crosses the finish line.

Sunita Williams will be tethered to a treadmill aboard the international space station 210 miles above Earth when the starting gun fires on April 16. At an orbiting speed of 17,500 mph, she will travel the race distance of 26 miles and 385 yards every 5.4 seconds.