In this handout provided by the National Aeronautics and Space Administration (NASA), SpaceX's Falcon 9 is moved to the launch pad prior to the rocket's Thales Alenia Space launch attempt on April 26, 2015 in Cape Canaveral, Florida. (Photo by NASA via Getty Images)

In this March 7, 1991 file photo, a U.S. Marine patrol walks across the charred oil landscape near a burning well during perimeter security patrol near Kuwait City. Twenty five years after the first U.S. Marines swept across the border into Kuwait in the 1991 Gulf War, American forces find themselves battling the extremist Islamic State group, born out of al-Qaida, in the splintered territories of Iraq and Syria. The Arab allies that joined the 1991 coalition are fighting their own conflicts both at home and abroad, as Iran vies for greater regional power following a nuclear deal with world powers. (Photo by John Gaps III/AP Photo)

The Thufa hill in Reykjavik, Friday, October 28, 2016. Parliamentary elections will be held in Iceland on October 29, 2016, more than 250,000 voters are called to elect the new parliament, 63 members of the Althing parliament. (Photo by Frank Augstein/AP Photo)

A woman poses for pictures with skulls made of cardboard placed on an altar next to the San Francisco church in Mexico City during the celebration of All Souls Day on November 2, 2015. (Photo by Yuri Cortez/AFP Photo)

In this October 15, 2014 file photo, Katsu Nakamura, sky division manager for Yamaha USA, moves the RMax unmanned helicopter into position before a demonstration of its aerial application capabilities at the University of California, Davis' Oakville Station test vineyard in Oakville, Calif. Researchers at UC Davis have been studying the effectiveness of the drone's ability for spraying pest control and nutritional materials on the test vineyard in California's Napa Valley. (Photo by Rich Pedroncelli/AP Photo)

A woman shields her face from the sun as she rides her scooter in Ahmedabad, India May 20, 2016. (Photo by Amit Dave/Reuters)

The nearly four-week-old Tapir cub bathes on June 28, 2016 in Gondwanaland at the zoo in Leipzig, Saxony. (Photo by Jan Woitas/DPA)

Women breastfeed their babies at an event promoting the freedom of mothers to breastfeed in public, during World Breastfeeding Week, at the Village Museum in Bucharest Romania, Saturday, August 6, 2016. (Photo by Andreea Alexandru/AP Photo)