Labourers stack dried bricks inside a kiln, where they will be fired, at a brick factory on the outskirt of Sanaa, Yemen, June 1, 2016. Traditional mud brick tower houses have always been a source of pride to Yemenis, and over a year into a devastating civil war, they are also providing some much-needed jobs in the ancient capital Sanaa. (Photo by Mohamed al-Sayaghi/Reuters)

Fire fighters attend a drill session during the Jilin Fire Fighting Emergency Rescue Drill On Setpember 28, 2011 in Changchun, Jilin Province of China. (Photo by ChinaFotoPress/Getty Images)

An Israeli soldier leaves the battlefield after an army exercise on at the Shizafon army base, in the Negev Desert north of the southern city of Eilat on January 31, 2012 in Shizafon, Israel. (Photo by Uriel Sinai/Getty Images)

Members of the 2013 “Jarl Squad” take part in the annual Up Helly Aa festival which culminates in the burning of a Viking Galley in Lerwick, Shetland Islands on January 29, 2013. Up Helly Aa celebrates the influence of the Scandinavian Vikings in the Shetland Islands and has employed this theme in the festival since 1870. The event culminates with up to 1,000 “guizers” (men in costume) throwing flaming torches into their Viking longboat. (Photo by Andy Buchanan/AFP Photo)

Hooded torch bearers lead the winter procession through the snow on February 4, 2012 in Huddersfield, England. Imbolc is a pagan festival that marks the half way point between the winter solstice and the spring equinox. Imbolc festivals celebrates the awakening of the land and the growing power of the Sun. (Photo by Bethany Clarke/Getty Images)

A recently rescued grey seal pup looks up from its indoor kennel at the RSPCA West Hatch Wildlife Centre on January 9, 2012 in Taunton, England. The centre is currently dealing with a number of mainly grey seals that have been rescued from the coast due to the recent storms. Staff at the centre hope to release all the seals back into the wild by the spring. (Photo by Matt Cardy/Getty Images)

A Colombian air force helicopter retrieves the bodies of victims from the wreckage of a plane that crashed into the Colombian jungle with Brazilian soccer team Chapecoense onboard near Medellin, Colombia, November 29, 2016. The chartered plane was carrying a Brazilian soccer team to the biggest match of its history when it crashed into a Colombian hillside and broke into pieces, killing 75 people and leaving six survivors, Colombian officials said Tuesday. (Photo by Jaime Saldarriaga/Reuters)

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.