A SpaceX Falcon Heavy rocket lifts off from historic launch pad 39-A at the Kennedy Space Center in Cape Canaveral, Florida, February 6, 2018. The world' s most powerful rocket, SpaceX' s Falcon Heavy, blasted off Tuesday on its highly anticipated maiden test flight, carrying CEO Elon Musk' s cherry red Tesla roadster to an orbit near Mars. Screams and cheers erupted at Cape Canaveral, Florida as the massive rocket fired its 27 engines and rumbled into the blue sky over the same NASA launchpad that served as a base for the US missions to Moon four decades ago. (Photo by Thom Baur/Reuters)

Paris Jackson arrives at the Calvin Klein Collection fashion show during New York Fashion Week at New York Stock Exchange on February 13, 2018. (Photo by Ouzounova/Splash News and Pictures)

Artist German Vinogradov acts in the performance of the burning of installation, devoted to Maslenitsa, or Pancake Week, a pagan holiday marking the end of winter, in the village of Nikola-Lenivets, Kaluga region, Russia, February 17, 2018. (Photo by Maxim Shemetov/Reuters)

On the second straight day of record-setting temperatures, Maddy Hacker is hoisted up by friend Jasmine Harper, both of McLean, Virgnia, as they attempt an acrobatic stunt in front of the U.S. Capitol in Washington, U.S., February 21, 2018. (Photo by Kevin Lamarque/Reuters)

Members of the SubCielo company perform during the fifth annual Puerto Rico Circo Fest in San Juan, Puerto Rico, Saturday, March 10, 2018. The festival is held simultaneously in several spots on the streets of the Old San Juan city on March 10–11. (Photo by Ricardo Arduengo/AFP Photo)

A group of people are seen on a Victoria line train in London, England during the first night of the Night Tube service on August 19 2016. The Central line and Victoria line are the first to operate a Night service with further lines expected to be running by the end of the year. (Photo by SWNS.com)

Robot inventor Wu Yulu sits on a rickshaw driven by a robot which he invented in his village in rural Beijing's Tongzhou district, China, 17 November 2016. The 54-year-old Chinese farmer living in rural Beijing's Tongzhou district invented 63 robots in the past 30 years. Wu, who only received primary school education, plans to give up the agricultural work for his robot products. He regularly participates in exhibitions, transfers patent rights and teaches at the university to earn money. (Photo by Wu Hong/EPA)

Immigrants from the West Indies at Victoria Station in London, 1956. (Photo by Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images)