STS-87 "Columbia" (November 19, 1997 – December 5, 1997) was the fourth US microgravity payload flight, and focused on experiments designed to study how the weightless environment of space affects various physical processes, and on observations of the Sun's outer atmospheric layers. Scott performed two spacewalks; the first, a 7-hour 43 minute EVA, featured the manual capture of a Spartan satellite, in addition to testing EVA tools and procedures for future Space Station assembly. The second spacewalk lasted five hours and also featured space station assembly tests. Testing of the AERCam Sprint was conducted during his EVA. The mission was accomplished in 252 Earth orbits, traveling 6.5 million miles in 376 hours and 34 minutes.