Four members of the joint STS-135/Expedition 28 crews are able to spend part of their last shared time onboard the International Space Station performing floating exercises that can't be done in Earth's gravity. Inside the Harmony Node 2 module, are NASA astronauts Mike Fossum (top), Expedition 28 flight engineer, and Doug Hurley, STS-135 pilot; and Ron Garan, Expedition 28 flight engineer. The crew member at bottom is partially obscured and is unidentified. ISS028-E-017535 (17 July 2011) -- high res (1.3 M) low res (104 K)
What's that - you don't know what "planking" is?