Russian marines take on more than 30 obstacles in a course that exceeds 10 kilometers.
Russia's Stealth Fighter Makes First Flight with New Engine
The Sukhoi Su-57, also known as the T-50 and previously known as the PAK FA, completed a 17-minute test flight with a new engine, the Saturn izdeliye 30, on Dec. 5, 2017, at the Gromov Flight Research Institute. The aircraft is designed to eventually replace Russia's fleet of MiG-29s and Su-27s. (United Aircraft Corp. video)