
Former South Carolina Gov. Mark Sanford, right, speaks with voter Travis Holt, a mechanic with the U.S. Air Force, at Orlando's Pizza in Daniel Island, S.C., on Monday, May 6, 2013. Server Kevin Caughman works at rear. Sanford is making his last campaign push against his Democratic opponent, Elizabeth Colbert Busch, before Tuesday's special election. (AP Photo/Mic Smith)

Former South Carolina Gov. Mark Sanford, right, speaks with voter Travis Holt, a mechanic with the U.S. Air Force, at Orlando's Pizza in Daniel Island, S.C., on Monday, May 6, 2013. Server Kevin Caughman works at rear. Sanford is making his last campaign push against his Democratic opponent, Elizabeth Colbert Busch, before Tuesday's special election. (AP Photo/Mic Smith)

In this Wednesday, May 1, 2013 photo released by the U.S. Air Force, the X-51A Waverider, carried under the wing of a B-52H Stratofortress bomber, prepares to launch for its fourth and final flight over the Pacific Ocean. The X-51A, an experimental, unmanned aircraft developed for the U.S. Air Force, went hypersonic during a test off the Southern California coast, traveling at more than 3,000 mph, the Air Force said Friday. (Associated Press)

In this Wednesday, May 1, 2013 photo released by the U.S. Air Force, the X-51A Waverider, carried under the wing of a B-52H Stratofortress bomber, prepares to launch for its fourth and final flight over the Pacific Ocean. The X-51A, an experimental, unmanned aircraft developed for the U.S. Air Force, went hypersonic during a test off the Southern California coast, traveling at more than 3,000 mph, the Air Force said Friday. (Associated Press)

** FILE ** In this undated handout file photo provided by the U.S. Air Force, an MQ-9 Reaper, armed with GBU-12 Paveway II laser guided munitions and AGM-114 Hellfire missiles, is piloted by Col. Lex Turner during a combat mission over southern Afghanistan. An instruction on camouflaging cars is one of 22 tips on how to avoid drones, listed on a document left behind by the Islamic extremists as they fled northern Mali from a French military intervention in January. (AP Photo/Lt. Col.. Leslie Pratt, US Air Force, File)

** FILE ** In this undated handout file photo provided by the U.S. Air Force, an MQ-9 Reaper, armed with GBU-12 Paveway II laser guided munitions and AGM-114 Hellfire missiles, is piloted by Col. Lex Turner during a combat mission over southern Afghanistan. An instruction on camouflaging cars is one of 22 tips on how to avoid drones, listed on a document left behind by the Islamic extremists as they fled northern Mali from a French military intervention in January. (AP Photo/Lt. Col.. Leslie Pratt, US Air Force, File)

** FILE ** In this undated handout file photo provided by the U.S. Air Force, an MQ-9 Reaper, armed with GBU-12 Paveway II laser guided munitions and AGM-114 Hellfire missiles, is piloted by Col. Lex Turner during a combat mission over southern Afghanistan. An instruction on camouflaging cars is one of 22 tips on how to avoid drones, listed on a document left behind by the Islamic extremists as they fled northern Mali from a French military intervention in January. (AP Photo/Lt. Col.. Leslie Pratt, US Air Force, File)

** FILE ** In this undated handout file photo provided by the U.S. Air Force, an MQ-9 Reaper, armed with GBU-12 Paveway II laser guided munitions and AGM-114 Hellfire missiles, is piloted by Col. Lex Turner during a combat mission over southern Afghanistan. An instruction on camouflaging cars is one of 22 tips on how to avoid drones, listed on a document left behind by the Islamic extremists as they fled northern Mali from a French military intervention in January. (AP Photo/Lt. Col.. Leslie Pratt, US Air Force, File)

U.S. Air Force Explosive Ordnance Disposal (EOD) technician Staff Sgt. Salvatore DiGiacomo from the 514th Civil Engineer Squadron, Joint Base McGuire-Dix-Lakehurst, NJ., Demonstrates the EOD 9 bomb suit and helmet ensemble operational equipment on August 21, 2012 during Air Force Week in New York City, New York. (U.S. Air Force photo by Tech. Sgt. Jeremy T. Lock)