The first X-47B prototype is in development since 2007, during the US Navys UCAS-D program. The first roll-out was on 16th December 2008. First Ground testing on the X-47B was in 2009 on the United States Air Force Base 42 in Palmdale, California. The X-47B was first flown on 4th February 2011, the second prototype was flown on 22nd November 2011. The US Air Force plans to test the X-47B in the next three years on the Edwards Air Force Base, California and on the Naval Air Station Patuxent River, Maryland. Even if no weapon tests are planned the X-47B has internal weapon bays, to simulate being an operational aircraft. Carrier tests are planned to begin in this year.