National Geographic Entertainment has picked up the rights to Restrepo, the documentary by journalists Sebastian Junger ’84 and Tim Hetherington that follows a platoon of American soldiers in Afghanistan. The film won the Sundance Film Festival grand jury documentary prize and is set for release on June 2. The National Geographic channel, which has worldwide TV rights, will broadcast the film next fall. The film was named after a 15-man outpost in Afghanistan’s Korengal Valley, considered one of the most dangerous postings in the U.S military. “From May 2007 to July 2008, Hetherington and Junger dug in with a platoon of…