A view of Worker and Kolkhoz Woman, a sculpture by Vera Mukhina, at the main entrance to Moscow's VDNKh exhibition center in Moscow, Russia on September 27, 2017. (Photo by Dmitry Serebryakov/TASS/Barcroft Images)

SpaceX’s Dragon spacecraft, March 6, 2014. SpaceX's Falcon 9 rocket and Dragon spacecraft launched from Launch Complex 40 at the Cape Canaveral Air Force Station, Florida, for their third official Commercial Resupply (CRS) mission to the orbiting lab on April 18, 2014. Dragon returned to Earth with a parachute-assisted splashdown off the coast of southern California on May 14, 2014. Dragon is the only operational spacecraft capable of returning a significant amount of supplies back to Earth, including experiments. (Photo by Ron Lin/SpaceX Photos)

Rooftops of solar powered houses are pictured in Ota, 80 km northwest of Tokyo in this October 28, 2008 file photo. One by one, Japan is turning off the lights at the giant oil-fired power plants that propelled it to the ranks of the world's top industrialised nations. With nuclear power in the doldrums after the Fukushima disaster, it's solar energy that is becoming the alternative. Solar power is set to become profitable in Japan as early as this quarter, according to the Japan Renewable Energy Foundation (JREF), freeing it from the need for government subsidies and making it the last of the G7 economies where the technology has become economically viable. (Photo by Yuriko Nakao/Reuters)

The first autonomous and electric shuttle of PostAuto Schweiz in the old village of Sion, Switzerland, June 2016. (Photo by Ruben Sprich/Reuters)

A videographer uses a drone as he takes a video of a model presenting a lingerie creation at the rehearsal for Eve's Temptation collection during China Fashion Week in Beijing, October 26, 2014. (Photo by Kim Kyung-Hoon/Reuters)

Parade Marshall Captain Gary Tomlin gives a command during a Remembrance Sunday parade through Fulham in West London, Britain November 8, 2009. Every year in November, villages, towns and cities across Britain honour those who have lost their lives in war on Remembrance Sunday. While Queen Elizabeth leads tributes at a national service of remembrance at The Cenotaph war memorial in central London, various neighbourhoods also hold their own local marches and memorials. (Photo by Kevin Coombs/Reuters)

An aerial view of the new Panama Canal expansion project on the Atlantic side of the Panama Canal during an organized media tour by Italy's Salini Impregilo, one of the main sub contractors of the Panama Canal Expansion project, in Panama City May 11, 2016. The newly expanded Panama Canal will be inaugurated on June 26, 2016. (Photo by Carlos Jasso/Reuters)

Palestinian children warm themselves by a fire on a stormy day at Shati (beach) refugee camp in Gaza City January 18, 2016. (Photo by Mohammed Salem/Reuters)