Passengers pose for a selfie as they wait for the Night Tube train service at Oxford Circus on the London underground system in London, Britain August 20, 2016. The London Underground is starting its first-ever overnight service, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Photo by Paul Hackett/Reuters)

Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

A visitor relaxes in a sleeping module at Tokyo's tube Hotel “Capsule Inn Akihabara” on February 6, 2007 in Tokyo, Japan. The two-square-meter sleep modules are equipped with a TV, Radio and Wireless LAN and are priced at 3500 yen per night. Uptil recently it has mainly been the office workers who stay at such tube hotels when they cannot go home, but recently they are attracting many foreign travellers due to their Japanese style. (Photo by Koichi Kamoshida/Getty Images)

Casey Stoner of Australia and Repsol Honda Team rounds the bend during the third day of MotoGP testing at Sepang Circuit on February 2, 2012 in Kuala Lumpur, Malaysia. (Photo by Mirco Lazzari gp/Getty Images)

“Pantsir-S1 (NATO reporting name SA-22 Greyhound) is a combined short to medium range surface-to-air missile and anti-aircraft artillery weapon system produced by KBP of Tula, Russia. The system is a further development of SA-19/SA-N-11 and represents the latest air defence technology by using phased-array radars for both target acquisition and tracking”. – Wikipedia

Photo: Test of the surface-to-air missile Pantsir-S rocket and gun system in the conditions of the Polar region on the range “Pemba” near Vorkuta, approximately on October 20 2012. According to the statement of military, during doctrines five cruise missiles from five were destroyed. (Photo by Alexey Reznichenko)

The second and final qualification motor (QM-2) test for the Space Launch System's booster, June 28, 2016, at Orbital ATK Propulsion Systems test facilities in Promontory, Utah. During the Space Launch System flight the boosters will provide more than 75 percent of the thrust needed to escape the gravitational pull of the Earth, the first step on NASA's Journey to Mars. (Photo by Bill Ingalls/NASA)