STS-134 Mission Specialists Mike Fincke, left, chats with STS-134 Assistant Launch Director Pete Nickolenko following the successful return of space shuttle Endeavour to NASA's Kennedy Space Center in Florida. Endeavour's final return from space completed the 16-day, 6.5-million-mile STS-134 mission. Main gear touchdown on the Shuttle Landing Facility's Runway 15 was at 2:34:51 a.m. EDT, followed by nose gear touchdown at 2:35:04 a.m., and wheelstop at 2:35:36 a.m. STS-134 delivered the Alpha Magnetic Spectrometer-2 (AMS) and the Express Logistics Carrier-3 (ELC-3) to the International Space Station. AMS will help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter from the station. ELC-3 carried spare parts that will sustain station operations once the shuttles are retired from service. STS-134 was the 25th and final flight for Endeavour, which spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles. Photo credit: NASA/Kim Shiflett