A humanoid robot named “Yangyang” shows a facial expression during its demonstration at the Global Mobile Internet Conference (GMIC) 2015 in Beijing, China, April 29, 20155. The android was produced jointly by China's Shanghai Yangyang Intellegent Robot Science Service center and Japanese professor Hiroshi Ishiguro, with the aim of popularising robotics among the young. (Photo by Kim Kyung-Hoon/Reuters)

A man photographs the main engines of the space shuttle orbiter Discovery on display at the Udvar-Hazy Smithsonian National Air and Space Annex Museum in Chantilly, Virginia August 28, 2015. Shuttle Discovery had 27 years of service and flew 39 times before being retired in 2011. (Photo by Gary Cameron/Reuters)

An exhibitor takes a photo with a Huawei Mate 10 Pro during the 2018 CES in Las Vegas, Nevada, U.S. January 9, 2018. CES, the world's largest annual consumer technology trade show, runs through January 12 and features about 3,900 exhibitors showing off their latest products and services to more than 170,000 attendees. (Photo by Steve Marcus/Reuters)

A traditional Russian nesting doll painted with the likeness of President of Donald Trump and his family is displayed for sale at a Moscow store on March 5, 2017 in Moscow, Russia. Relations between the United States and Russia are at their lowest point in years as evidence mounts about the complex relationship between President Donald Trump's administration and the Russian government. (Photo by Spencer Platt/Getty Images)

A Syrian refugee girl cries as she walks through a rainstorm towards Greece's border with Macedonia, near the Greek village of Idomeni, September 10, 2015. Most of the people flooding into Europe are refes fleeing violence and persecution in their home countries who have a legal right to seek asylum, the United Nations said on Tuesday. (Photo by Yannis Behrakis/Reuters)

A reveller covered in tomato pulp takes part in the annual “Tomatina” festival in the eastern town of Bunol, on August 30, 2017. The iconic fiesta – which celebrates its 72nd anniversary and is billed at “the world's biggest food fight” – has become a major draw for foreigners, in particular from Britain, Japan and the United States. (Photo by Jaime Reina/AFP Photo)

Cuban Daymara A., 20, poses for a photograph after she crossed the border from Colombia through the jungle into La Miel, in the province of Guna Yala, Panama December 2, 2015. According to local authorities in La Miel, some 100 to 150 Cubans have been entering Panama from Colombia every day for the last three months. Scores of Cubans have come to Panama as they seek overland passage towards the United States fearing a recent detente between Washington and Havana could end their preferential treatment. (Photo by Carlos Jasso/Reuters)

Pete McLeod of Canada flies in formation with Nigel Lamb of Great Britain, Martin Sonka of the Czech Republic and Kirby Chambliss of the United States during a Recon flight prior to the seventh stage of the Red Bull Air Race World Championship over the Hoover Dam on October 09, 2014 on the border between the U.S. states of Arizona and Nevada. (Photo by Joerg Mitter/Red Bull via Getty Images)