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.

Wind turbines stand in the Baltic 1 offshore wind farm on April 29, 2011 in the Baltic Sea near Zingst, Germany. Baltic 1, a project of German energy utility EnBW that includes 21 turbines rated at 2.3 megawatts each, will be Germany's first commercial offshore wind farm once it officially begins operation on May 2. Germany has thus far lagged in offshore wind farm construction when compared to neighbors like Great Britain and Denmark, though German Chancellor Angela Merkel has vowed to invest heavily into offshore wind farms as part of an overall policy to encourage renewable energy production. (Photo by Joern Pollex/Getty Images)

An unmanned Falcon 9 SpaceX rocket lifts off from launch complex 40 at the Cape Canaveral Air Force Station, Wednesday, February 11, 2015, in Cape Canaveral, Fla. On board is the Deep Space Climate Observatory, which will head toward a solar-storm lookout point a million miles away. (Photo by John Raoux/AP Photo)

A helicopter pours water over a wildfire with the Space Shuttle Endeavour seen through heavy smoke in the background April 27, 2011 in Cape Canaveral, Florida. (Photo by Roberto Gonzalez/Getty Images)

NASA space shuttle Atlantis is prepared on the Vehicle Assembly Building floor at the Kennedy Space Center May 18, 2011 in Cape Canaveral, Florida. The space shuttle program ends with Atlantis mission STS-135 scheduled for early July. Space shuttle Atlantis will carry the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. Atlantis also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module. (Photo by Roberto Gonzalez/Getty Images)

Actress Charlize Theron attends the launch of DIOR VIII hosted by Charlize Theron at Dior Boutique on June 8, 2011 in New York City. (Photo by Jason Kempin/Getty Images)

3D interactive artist Joe Hill poses with one of his works as part of the VisitBritain tourism campaign at Circular Quay on September 6, 2011 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)

Fan Bingbing attends the new High Jewellery Collection “Sortilege de Cartier” launch dinner at Villa Aurelia on September 17, 2011 in Rome, Italy. (Photo by Pascal Le Segretain/Getty Images for Cartier)