Their tail numbers are AV-073 and AV-080 and they are two of the Atlas V rockets expected to make history when they launch Boeing’s CST-100 on a pair of flight tests to set the stage for operational flights in the future carrying astronauts to the International Space Station. The first flight will not carry anyone but will perform orbital checkouts to prove the CST-100 systems. The second flight is to have people aboard and run a mission profile similar to the ones NASA will ask for when it begins regular Commercial Crew missions to the orbiting laboratory. Read the full story at http://go.nasa.gov/1bk4ifJ