Editor's Note: This article originally appeared on Business Insider.
Benjamin Franklin nailed it when he said, "Fatigue is the best pillow." True story, Benny. There's nothing like pushing your body so far past exhaustion that you'd willingly, even longingly, take a nap on a concrete slab.
And no one knows that better than military service members and we have the pictures to prove it.
Russia announced earlier this month that the Su-57, its proposed entry into the world of fifth-generation stealth fighter aircraft, would not see mass production.
Videos on social media appear to show Russia's Su-57, a prototype of a new, fifth-generation fighter jet, operating in Syria — and it could be a direct threat to U.S. stealth aircraft like the F-22.