NASA astronaut Scott Kelly is seen floating during a spacewalk on Dec. 21, 2015. NASA astronauts Scott Kelly and Tim Kopra released brake handles on crew equipment carts on either side of the space station’s mobile transporter rail car so it could be latched in place ahead of Wednesday’s docking of a Russian cargo resupply spacecraft. Kelly and Kopra also tackled several get-ahead tasks during their three hour, 16 minute spacewalk.