Anti-government protesters take cover during clashes with security forces who are firing tear gas from La Carlota airbase in Caracas, Venezuela, Wednesday, May 1, 2019. Opposition leader Juan Guaidó called for Venezuelans to fill streets around the country Wednesday to demand President Nicolás Maduro's ouster. Maduro is also calling for his supporters to rally. (Photo by Ariana Cubillos/AP Photo)

A Falcon 9 SpaceX rocket, with a payload of 60 satellites for SpaceX's Starlink broadband network, lifts off from Space Launch Complex 40 during a time exposure at the Cape Canaveral Air Force Station in Cape Canaveral, Fla., Thursday, May 23, 2019. (Photo by Malcolm Denemark/Florida Today via AP Photo)

Over 30 Douglas C-47 Skytrains (Dakotas) making final preparations for flight formation practice before the 75th D-Day Anniversary flight to Normandy in Duxford, England on June 4, 2019. (Photo by UK Air Force Images)

A Palestinian woman argues with an Israeli border policewoman over the Israeli demolition of a building housing an apartment and a restaurant as the building owners said they were informed by the forces that they did not obtain a construction permit, in Beit Jala in the Israeli-occupied West Bank on August 26, 2019. (Photo by Mussa Qawasma/Reuters)

Armed man stand at entrance of the naval headquarters in Sevastopol, March 19, 2014. Around a dozen Ukrainian servicemen, unarmed and in civilian clothes, walked out of the Ukrainian naval headquarters in the Crimean port of Sevastopol on Wednesday after it was taken over by pro-Russian forces, a Reuters witness said. (Photo by Baz Ratner/Reuters)

U.S. Army soldiers with the 1st Battalion, 501st Infantry Regiment deployed to Combat Outpost Sabari, Afghanistan scan their area as they begin a multi-day air assault mission near the Pakistani border of eastern Afghanistan's Khost province May 2, 2012. (Photo by Staff Sgt. Joshua L. DeMotts/U.S. Air Force)

Rebels of the Revolutionary Armed Forces of Colombia (FARC) visit as they wait to have lunch in El Diamante, Colombia, Friday, September 16, 2016. FARC rebels are gathering for a congress were delegates will debate and vote on the accord reached last month with the Colombian government to end five decades of war. (Photo by Ricardo Mazalan/AP Photo)

Members of the Bavarian police and the Bundeswehr, the German armed forces, guard a vehicle checkpoint as they demonstrate a dynamic operation as part of the GETEX anti-terror exercises during a media event on March 9, 2017 in Murnau, Germany. (Photo by Philipp Guelland/Getty Images)