Microsoft co-founder Paul Allen has spent the last six years working on a giant aircraft capable of launching rockets to space. Today, his company Stratolaunch Systems literally rolled that plane out of its hangar in the Mojave Desert for the first time ever.

This is the hilarious moment a terrified baby hippo ran screaming for its mum when a flock of bird landed on its back in South Luangwa National Park in Zambia. The hippo was seen screaming, running and twisting from side to side in a desperate bid to shake off the red and yellow ox-pecker birds. Ox-peckers and hippos usually have a mutually beneficial relationship where the birds help free hippos of ticks and other parasites by feeding on them. (Photo by Marc Mol/Caters News/SIPA Press)

Dynam employees say a greeting message as they receive customer-care training ahead of the grand opening of the company's pachinko parlour in Fukaya, north of Tokyo July 29, 2014. Japan's once-booming pachinko industry, grappling with a greying customer base and the threat of new competition from casinos, is adopting a softer touch and smoke-free zones to lure a new generation of players, particularly women. Pachinko, a modified version of pinball, is a fading national obsession, with about 12,000 parlours nation-wide and one in thirteen people playing the game. But that figure is declining as the population shrinks and younger people prefer games on their mobile phones. (Photo by Issei Kato/Reuters)

Chinese woman Zhang Jing, known as the “Ugly Girl” smiles after doctors removed the stitches from her fourth session of cosmetic surgery at a hospital on March 23, 2005 in Shanghai, China. Zhang Jing, 26 years old, from Tianjin Municipality, was forced to leave school because her classmates sneered at her appearance during her teenage years. After leaving junior high school, Zhang found herself still unacceptable by society, she struggled to look for a job, but was turned down by one thousand job applications in ten years. Zhang's story was widely reported by the media in 2003, this helped her find a job and get three chances of free plastic surgery. (Photo by China Photos/Getty Images)

Pakistan girls make selfies holding a Pakistan-made weapon displayed at the four-day International Defence Exhibition and Seminar (IDEAS) 2016 in Karachi, Pakistan, Wednesday, November 23, 2016. (Photo by Shakil Adil/AP Photo)

The Eiffel Tour-the body language of balance. I came across this group of young adults from Sarajevo, Bosnia, having fun testing their balance two nights ago in on the Esplanade de Trocadero. (Photo and comment by Peter Turnley)

A Brazilian Navy member ejects spent cartridges while shooting rubber bullets during an exhibition of their operational capacity to combat terrorist attacks and riots ahead of the FIFA Confederations Cup and World Youth Day in Rio de Janeiro on May 27, 2013. (Photo by Ricardo Moraes/Reuters)

French actress Roxane Mesquida (L) and Josephine De La Baume exchange a kiss on the red carpet prior the screening of “The company you keep” during the 69th Venice Film Festival on September 6, 2012 at Venice Lido. “The company you keep” is presented out of competition. (Photos by Tiziana Fabi/Gabriel Bouys/Christine Pettinger/AFP Photo)