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)

Kristina Elekes, 23, races on her ski during the Bikini Race contest held at Arena Platos Paltinis winter resort, near Sibiu city, 275 Km north from Bucharest, Romania, 06 March 2016. Bikini Race is a timed show on the slopes, at the fourth edition, for women dressed only in swimmsuits and some winter accessories. (Photo by Mihaela Bobar/EPA)

Pinky Ghelani and Suzzy Wokabi watch a TV broadcast of Britain's Prince Harry and Meghan Markle's royal wedding at the Windsor golf and country club in Nairobi, Kenya May 19, 2018. (Photo by Thomas Mukoya/Reuters)

This time exposure photo provided by the Santa Barbara County Fire Department shows a series of lightning strikes over Santa Barbara, Calif., seen from Stearns Wharf in the city's harbor, Tuesday evening, March 5, 2019. A storm soaking California on Wednesday could trigger mudslides in wildfire burn areas where thousands of residents are under evacuation orders, authorities warned. (Photo by Mike Eliason/Santa Barbara County Fire Department via AP Photo)

Rian Johnson, left, director of the upcoming film “Knives Out”, takes a picture of cast member Ana de Armas as they are introduced onstage during the Lionsgate presentation at CinemaCon 2019, the official convention of the National Association of Theatre Owners (NATO) at Caesars Palace, Thursday, April 4, 2019, in Las Vegas. (Photo by Chris Pizzello/Invision/AP Photo)

Demonstrators take part in a protest against U.S. President Donald Trump in Glasgow, Britain February 20, 2017. (Photo by Russell Cheyne/Reuters)

Civil security aircrafts parade during the inauguration of the Nimes-Garons civil security air force base on March 10, 2017 in Nimes, southern France. (Photo by Pascal Guyot/AFP Photo)

A protestor gestures toward the White House on the Ellipse near the South Lawn of the White House during the Women's March on Washington January 21, 2017 in Washington, DC. Large crowds are attending the anti-Trump rally a day after U.S. President Donald Trump was sworn in as the 45th U.S. president. (Photo by Drew Angerer/Getty Images)