Catwalks hang over a section of the newly constructed eastern span of the San Francisco-Oakland Bay Bridge during a media tour of the self-anchored suspension span tower on August 29, 2011 in Oakland, California. Contruction crews have erected twelve foot wide catwalks that connect to the San Francisco-Oakland Bay Bridge self-anchored suspension span's tower and crews will begin to lay the nearly one mile of main cable beginning in early 2012. The bridge has been under constrution since 2002 with an estimated price tag of $6.3 billion and will have the world's tallest Self-Anchored Suspension (SAS) tower once completed. (Photo by Justin Sullivan/Getty Images)

“The Space Launch System, or SLS, is a Shuttle-Derived heavy launch vehicle being designed by NASA, following the cancellation of the Constellation Program, to replace the Space Shuttle after its retirement. The NASA Authorization Act of 2010 envisions the transformation of the Ares I and Ares V vehicle designs into a single launch vehicle usable for both crew and cargo. It is to be upgraded over time with more powerful versions. The proposed SLS is visually similar to the legacy Saturn V booster and in particular the proposed, two-stage, Saturn INT-20”. – Wikipedia

Photo: In this illustration provided by NASA, the design for a new space rocket system, the Space Launch System, is seen. NASA's new rocket design will reportedly cost about $35 billion and be ready to for test launch in 2017. According to NASA, the rocket will be used to carry Orion Multi-Purpose Crew Vehicle as well as cargo and science experiments to earth's orbit, as a backup for the space station and possibly destinations beyond that. (Illustration by NASA via Getty Images)

Apple Senior VP of Worldwide Marketing Phil Schiller talks about the display on the new iPad during an Apple product launch event at Yerba Buena Center for the Arts on March 7, 2012 in San Francisco, California. In the first product release following the death of Steve Jobs, Apple Inc. introduced the third version of the iPad (iOS 5.1; Processor is an Apple A5X ARM-based unit; Display 2048 x 1536 pixels; Camera is set at 5 megapixels and has a 5-element lens plus auto face-detection, auto focus lock and image stabilisation for video; Wi-Fi + 4G) and an updated Apple TV. (Photo by Kevork Djansezian/Getty Images)

A student attending a winter military camp reacts during a training session in Ansan, south of Seoul January 3, 2013. Hundreds of students between 11 and 17 years old attend winter boot camp training courses every year. The winter courses range from 4 to 14 days at the Blue Dragon Camp run by retired marines, which also offers summer boot camp for students. (Photo by Kim Hong-Ji/Reuters)

Tech. Sgt. Milo Hinson, 3rd Combat Camera Squadron, uses a flashlight while shooting a Berretta 9mm during the night-fire portion of Advance Weapons, Tactics and Techniques training in San Antonio. During night-fire training, airmen learn how to tactically illuminate targets with flashlights and practice using night vision goggles. (Photo by Staff Sgt. Jonathan Snyder/U.S. Air Force). 2011

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

Lasha Pataraia pulls a truck, which weighs 8,250kg (8 tons), with his ear during an event to break the Guinness Book of World Records in Rustavi, outside Tbilisi November 29, 2012. The 32-year-old broke a Guinness record after he managed to pull the truck with his ear for 21,50 metres (70.5 feet), according to organisers. (Photo by Irakli Gedenidze/Reuters)