Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

A Aldabra Tortoise receives a Christmas treat at Taronga Zoo on December 14, 2012 in Sydney, Australia. Taronga Zoo celebrated Christmas early giving Christmas-themed environmental activities to the Zoo's Giraffes, Sun Bears, Meerkats, Aldabra Tortoise and Cockatoos providing a wonderful natural display for Zoo visitors. (Photo by Lisa Maree Williams)

“The Lockheed Martin X-33 is an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program”. – Wikipedia

Photo: An Artist's Rendering Shows How Nasa's X-33 Technology Demonstrator, A Cost-Cutting Fully Reusable Single-Stage-To-Orbit Space Vehicle, Will Look Upon Completion. The 67 Foot-Long, 278,600 Pound, Twin Engine Space Vehicle, Capable Of Reaching Speeds In Excess Of Mach 15, Will Lead To The Construction Of A 127 Foot-Long, 2,186,000 Pound Version With Seven Engines And A 50,000 Pound Payload Capacity Called The “Venturestar”. (Photo By Nasa/Getty Images)

In this photo distributed by the Israeli Defense Forces (IDF) May 23, 2005, woman soldiers wear branches in their helmets as their infantry instructors' course learns about camouflage during the field craft week of their training May 19, 2005 at an army base near Beersheva in Israel's southern desert. It takes the IDF more than 2 months to teach these 18-year-old female recruits the basic arts of warfare before they assigned to pass on their newly-acquired skills to the army's male and female draftees. (Photo by Abir Sultan/IDF via Getty Images)

The public get the first view at the opening of the new miniature model Knuffingen Aiport at Miniatur Wunderland on the airport's opening day on May 4, 2011 in Hamburg, Germany. Miniatur Wunderland is the world's largest model railroad landscape, and the model airport, also the world’s largest, goes into operation following 6 years of development and construction and an investment of EUR 3.5 million. The airport is a reproduction of Hamburg’s international airport and includes 40 aircraft that take off and land and 90 vehicles that autonomously move around the runways on May 4, 2011 in Hamburg, Germany. (Photo by Stuart Franklin/Getty Images)

(L-R) U.S. President Barack Obama, Queen Elizabeth II and First Lady Michelle Obama arrive at Winfield House, the residence of the Ambassador of the United States of America, in Regent's Park, on May 25, 2011 in London, England. The 44th President of the United States, Barack Obama, and First Lady Michelle are in the UK for a two day State Visit at the invitation of HM Queen Elizabeth II. Last night they attended a state banquet at Buckingham Palace and today's events include talks at Downing Street and the President will address both houses of Parliament at Westminster Hall. (Photo by Yui Mok - WPA Pool/Getty Images)

Visitors to Salisbury Cathedral stop to look at Sean Henry's sculpture Standing Man (2007) currently being exhibited in the Cloisters on August 2, 2011 in Salisbury, United Kingdom. The exhibition, “Conflux: A Union of the Sacred and the Anonymous”, features over 20 contemporary sculptures of dramatically different scales occupying vacant plinths and open spaces on both the inside and exterior of the iconic 13th century building. This exhibition brings to the Cathedral the biggest single group of polychrome sculpture since the Reformation and runs until the end of October. (Photo by Matt Cardy/Getty Images)

A protester uses his laptop computer in the “Occupy LSX” camp outside St. Paul's Cathedral ahead of a demonstration against higher tuition fees and privatisation in universities on November 9, 2011 in London, England. Around 4000 police officers are on duty and are to be allowed to deploy baton rounds if needed. The march is expected to finish at London Wall in the heart of the capital's financial district. (Photo by Oli Scarff/Getty Images)