In this handout image provided by NASA, the space shuttle Endeavour is seen on launch pad 39a as a storm passes by prior to the rollback of the Rotating Service Structure (RSS) April 28, 2011, at Kennedy Space Center in Cape Canaveral, Florida. During the 14-day mission, Endeavour and the STS-134 crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts, including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre. Launch is targeted for April 29 at 3:47 p.m. EDT.

South Korean police officers show their martial arts' skills during the official launch ceremony of the 2012 Seoul Nuclear Security Summit on February 15, 2012 in Seoul, South Korea. The Korean National Police Agency launched a security squad, exclusively established for the successful hosting of the 2012 Seoul Nuclear Security Summit. The 2012 Seoul Nuclear Security Summit will be held in Seoul from March 26-27, 2012. (Photo by Chung Sung-Jun/Getty Images)

Mike “The Bedfordshire Bull Botteley” (left) takes on Chris “The General” Levy during a Chessboxing bout at the Scala nightclub on March 10, 2012 in London, England. A new hybrid sport combining chess and boxing in alternate 3 minute rounds, the winner is the one who knocks out or checkmates their opponent first. (Photo by Matthew Lloyd/Getty Images)

Huellas, a paraplegic dog in a wheelchair, walks at Pescadores beach in Chorrillos, Lima, September 7, 2015. Sara Moran has an animal shelter called Milagros Perrunos where she cares for stray dogs and shelters dogs injured from traffic accidents or domestic abuses. With donations and raffle, Moran purchases wheelchairs, food and medical treatment for the dogs at her shelter. (Photo by Mariana Bazo/Reuters)

Participants re-enact the “Battle of Five Armies” from J.R.R. Tolkien's novel “The Hobbit” in a forest near the town of Doksy, Czech Republic June 6, 2015. According to event organizers, hundreds of enthusiasts dressed as characters such as elves, dwarves, goblins and orcs from the book “The Hobbit” re-enacted the clash. (Photo by David W. Cerny/Reuters)

NFL player Rob Gronkowski, of the New England Patriots, from second left, accepts the best comeback athlete award with his brothers, NFL free agent Chris Gronkowski and former NFL player Dan Gronkowski at the ESPY Awards at the Microsoft Theater on Wednesday, July 15, 2015, in Los Angeles. (Photo by Chris Pizzello/Invision/AP Photo)

A retired man (L) looks toward two girls wearing miniskirts, July 13, 1969 in Nice, France. (Photo by AFP Photo)

A woman takes a picture of people posing in front of “Zinzow”, a “Transformers-inspired” sculpture constructed from scrap metal in Podgorica, July 22, 2014. Danilo Baletic, 22, makes sculptures of his childhood cartoon heroes, “Transformers”, from scrap metal. In the last two years he has made seven “Transformers” sculptures that are placed on the streets of Montenegro's capital Podgorica as part of an exhibition called “Transformers defending Podgorica”. (Photo by Stevo Vasiljevic/Reuters)