The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)

Dancers perform at a Carnival parade in Les Cayes, Haiti, Tuesday, February 28, 2017. Haiti's three-day Carnival festivities have brought rum-fueled parties, imaginative costumes and high-energy dance music to a southern city that's still recovering from last year's punishing Hurricane Matthew. (Photo by Dieu Nalio Chery/AP Photo)

Revellers attend the 25th edition of the Sziget Festival on August 9, 2017 in Budapest, Hungary. The Sziget Festival, one of the largest music and cultural festivals in Europe, celebrates its 25th anniversary in 2017, taking place from August 9-16 on the Hajogyari Sziget in Budapest. (Photo by Laszlo Mudra/Rockstar Photographers)

A person enter in sauna on the peak of Mount Lagazuoi in Cortina D'Ampezzo, Italy January 16, 2018. Picture taken January 16, 2017. (Photo by Stefano Rellandini/Reuters)

Tour de France hostess wear face masks prior to the start of the first stage of the Tour de France cycling race over 156 kilometers (97 miles) with start and finish in Nice, southern France, Saturday, August 29, 2020. (Photo by Christophe Ena/AP Photo)

Pedestrians look at the wreckage of a vehicle lodged in a storm drain on a street in Abidjan on June 19, 2018, in which a man was reportedly found dead after floodwaters receded following an overnight downpour in the city. Fifteen people have died in Abidjan, Ivory Coast' s economic capital, during flooding caused by torrential rain overnight, Interior Minister Sidiki Diakite said. Rain poured down overnight on June 19, causing flash floods up to 2.5 metres (more than eight feet) deep, he said. (Photo by Sia Kambou/AFP Photo)

People gather on a hill near the Chopin Airport to watch aeroplanes taking off, in Warsaw, Poland, Sunday, September 9, 2018. (Photo by Alik Keplicz/AP Photo)

North Korean girls in similar bathing suits stand under a shower at the Songdowon International Children's Camp, Tuesday, July 29, 2014, in Wonsan, North Korea. The camp, which has been operating for nearly 30 years, was originally intended mainly to deepen relations with friendly countries in the Communist or non-aligned world. But officials say they are willing to accept youth from anywhere – even the United States. (Photo by Wong Maye-E/AP Photo)