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.

A member of the United States Naval Academy freshman class wears body armor, helmet and carries a rifle through a mud-filled ditch as part of the “Wet and Sandy” challenge during the rigorous Sea Trials May 17, 2011 in Annapolis, MD. Under strict safety supervision, about 900 freshmen, or “Plebes”, faced 14 hours of 32 rigorous physical and mental challenges during the trials, a daylong, action-oriented event modeled after the Marine Corps 54-hour Crucible and the Navy's Battle Stations. (Photo by Chip Somodevilla/Getty Images)

An employee of the British Museum examines a silver coin dating from 900 AD which is part of the Silverdale Viking Hoard on December 14, 2011 in London, England. The hoard, which was discovered by local metal-detectorist Darren Webster in North Lancashire, comprises of 201 silver objects including arm-rings, coins, finger-rings, ingots, brooch fragments and fine wire braid. (Photo by Oli Scarff/Getty Images)

Toyota Motor unveils a concept car the “PM”, is on display at a press preview for the Tokyo Motor Show in Makuhari, east of Tokyo October 23, 2003. PM is a single seater personal vehicle whose cabin posture changes from upright to reclined as speed increases. (Photo by Koichi Kamoshida/Getty Images)

A Russian trenchmortar crew run to take up a new firing position in the Stalingrad area during the Great Patriotic War. (Photo by Keystone/Getty Images). October 1942

A Japanese girl poses in a costume at a Chara Fes (character festival) event on October 26, 2003 in Tokyo. Cosplay (costume play) is becoming popular among Japanese youths, whereby participants dress up as their favourite characters from comics, computer games and animation. (Photo by Junko Kimura/Getty Images)

Apple's Senior Vice President of Worldwide product marketing Phil Schiller speaks about the new iPhone 4s at the company's headquarters October 4, 2011 in Cupertino, California. (Photo by Kevork Djansezian/Getty Images)

Flowers and an iPad showing a picture of Steve Jobs are placed at a makeshift memorial for Steve Jobs at the Apple headquarters on October 5, 2011 in Cupertino, California. Jobs, 56, passed away after a long battle with pancreatic cancer... (Photo by Kevork Djansezian/Getty Images)