Iraqi troops fire artillery towards Islamic State (IS) group jihadists' positions in west Mosul on March 11, 2017 during the ongoing battle to retake the city from the group. (Photo by Aris Messinis/AFP Photo)

Lady Gaga performs on ABC's “Good Morning America” at Rumsey Playfield, Central Park on May 27, 2011 in New York, United States. (Photo by Andrew H. Walker/Getty Images)

Singer/rapper Nicki Minaj performs on ABC's “Good Morning America” at Rumsey Playfield, Central Park on August 5, 2011 in New York City. (Photo by Jemal Countess/Getty Images)

The last of the summer roses are dusted with a coating of frost as the first freezing temperatures descend on Britain on November 7, 2011 in Knutsford, England. The roses are the last blooms to survive the Summer at Curbishleys specialist rose nursery in Cheshire. (Photo by Christopher Furlong/Getty Images)

A pug dressed as Yoda from the movie Star Wars walks along the runway at the 9th Annual Pug Parade on February 25, 2006 in Bradenton, Florida. 117 pugs competed for 10 prizes in 6 categories. Proceeds from the event benefit the Sarasota County Humane Society. (Photo by Phillippe Diederich/Getty Images)

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.

A customer buys a box of bullits and a target of Osama Bin Laden October 3, 2001 at Blue Ridge Arsenal in Chantilly, VA. Guns sales have risen across America since the September 11th terrorist attacks. (Photo by Mark Wilson/Getty Images)