Libyan rebel soldiers watch as they fire rockets (background) toward Libyan government troops near front-line positions April 6, 2011 outside of Brega, Libya. Rebel militias fighting against Libyan government loyalist soldiers continued their stand-off in the eastern Libyan desert today, regaining ground toward a key oil port while awaiting further NATO airstrikes in their quest to unseat longtime Libyan ruler Muammar Gaddafi. (Photo by Chris Hondros/Getty Images)

“A small British company with a dream of building a re-usable space plane has won an important endorsement from the European Space Agency (ESA) after completing key tests on its novel engine technology. Reaction Engines Ltd believes its Sabre engine, which would operate like a jet engine in the atmosphere and a rocket in space, could displace rockets for space access and transform air travel by bringing any destination on Earth to no more than four hours away”. – Chris Wickham via Reuters. Photo: Artist's impression of Skylon. (Photo by Reaction Engines Ltd)

Riders pray before competing at a rodeo event in Monte Negro, south of the Amazon basin, Rondonia state, Brazil on August 30, 2019. In recent years, Monte Negro has expanded as a key cattle town with a strong cowboy culture. (Photo by Carl De Souza/AFP Photo)

A cat dressed in a traditional outfit takes part during the Orthodox Christmas celebration in Kiev, Ukraine on January 7, 2020. Orthodox Christians celebrate Christmas Day on December 25 of the older Julian calendar, which currently corresponds to January 7 in the Gregorian calendar. (Photo by Pavlo Gonchar/SOPA Images/LightRocket via Getty Images)

U.S. Marines, left, and South Korean Marines, wearing blue headbands on their helmets, take positions after landing on the beach during the joint military combined amphibious exercise, called Ssangyong, part of the Key Resolve and Foal Eagle military exercises, in Pohang, South Korea, Saturday, March 12, 2016. North Korea said Saturday its military is ready to pre-emptively attack and “liberate” the South in its latest outburst against the annual joint military drills by the United States and South Korea. (Photo by Kim Jun-bum/Yonhap via AP Photo)

A reveler gets ready to perform at a carnival parade in Havana, Cuba August 7, 2015. (Photo by Alexandre Meneghini/Reuters)

Dancers perform during La Paz Fashion Week in La Paz, Bolivia, February 7, 2019. (Photo by David Mercado/Reuters)

Kazakh troops march during a parade of the armed forces to mark the Defender of the Fatherland Day in Astana, May 7, 2014. (Photo by Mukhtar Kholdorbekov/Reuters)