Base jumpers leap from the 300-metre high skydeck of Malaysia's landmark Kuala Lumpur Tower against the backdrop of the city's skyline in Kuala Lumpur on September 30, 2018 during the annual International KL Tower Base-Jump event. (Photo by Manan Vatsyayana/AFP Photo)

Swiss police officers stand beside of mock gates of the NEAT Gotthard Base Tunnel inside the event hall for the upcoming opening ceremony near the town of Erstfeld, Switzerland May 31, 2016. The celebrations of the opening of the Gotthard Base Tunnel will start on June 1, 2016. With a length of 57 km (35 miles) crossing the Alps, the Gotthard Base tunnel is the world's longest train tunnel. (Photo by Arnd Wiegmann/Reuters)

Rotterdam based SMIT and Livorno based NERI salvage workers start their work of diesel recovery on a pontoon from the the cruise ship Costa Concordia that lies stricken off the shore of the island of Giglio on January 24, 2012 in Giglio Porto, Italy. (Photo by Laura Lezza/Getty Images)

A man in a mock space suit experiences walking in space at “Mars Base 1 Camp” on May 15, 2023 in Jinchang, Gansu Province of China. The simulated Mars base allows visitors to immerse themselves in the Mars experience. (Photo by Li Yalong/China News Service/VCG via Getty Images)

A breeder puts a giant panda cub into a crib at Chengdu Research Base of Giant Panda Breeding in Chengdu, Sichuan province, September 23, 2013. Fourteen new joiners to the 128-giant-panda-family at the base were shown to the public on Monday, according to local media. (Photo by Reuters/China Daily)

Civilians are led by members of pro-Russian self-defence units as they run outside a military base during an assault in the Crimean town of Belbek near Sevastopol March 22, 2014. Russian troops forced their way into a Ukrainian airbase in Crimea with armored vehicles, automatic fire and stun grenades on Saturday, injuring a Ukrainian serviceman and detaining the base's commander for talks. (Photo by Vasily Fedosenko/Reuters)

Britain's BASE jumper Sam Hardy lives up to his name after throwing himself off the top of the 335m-high Kuala Lumpur Tower during the KL Tower International Jump in Kuala Lumpur, Malaysia, Saturday, September 27, 2014. BASE stands for the places such jumpers usually jump from: buildings, antennas, spans (bridges) and earth (cliffs). (Photo by Lai Seng Sin/AP Photo)

A female Kurdistan Workers Party (PKK) fighter works on her laptop while watching a Kurdish TV station at a base in the Sinjar mountains, March 11, 2015. Women fighters at a Kurdistan Workers Party (PKK) base on Mount Sinjar in northwest Iraq, just like their male counterparts, have to be ready for action at any time. Smoke from the front line, marking their battle against Islamic State, which launched an assault on northern Iraq last summer, is visible from the base. Many of the women have cut links with their families back home; the fighters come from all corners of the Kurdish region. (Photo by Asmaa Waguih/Reuters)