Stefan Dobrovolny of Austria and Inigo Munoz Elorza of Spain (R) stand in front of a quad bike during a simulated Mars mission on Tyrolean glaciers in Kaunertal, Austria, August 7, 2015. The Austrian Space Forum is sending some of its researchers to practice weight-less walking in spacesuits on a glacier which resembles the terrain on Mars. (Photo by Dominic Ebenbichler/Reuters)

People look at a downhill rider during the Urban Bike Inder Medellin race final at the Comuna 1 shantytown in Medellin, Antioquia department, Colombia on November 19, 2017. (Photo by Joaquin Sarmiento/AFP Photo)

A worker piles salvaged e-bikes and scooters on the back of his three wheeler before taking them to be recycled on August 31, 2021 in Beijing, China. (Photo by Kevin Frayer/Getty Images)

Emma White, of Team Cyclocrossworld, hits the dirt hard during the USA Cycling Cyclo-cross National Championship Elite Women's race at the Valmont Bike Park in Boulder, Colorado, on January 12, 2014. (Photo by Jeremy Papasso/The Daily Camera)

Bronze medalist Carlos Coloma Nicolas of Spain celebrates after finishing third in the cross-country cycling mountain bike race at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Saturday, August 20, 2016. (Photo by Patrick Semansky/AP Photo)

A displaced Iraqi boy leads his animals to safety after escaping from Islamic State controlled village of Abu Jarboa during clashes with IS militants near Mosul, Iraq November 1, 2016. (Photo by Ahmed Jadallah/Reuters)

A Palestinian man waves from his home as a clown and a man in a costume perform to entertain people amid concerns about the spread of the coronavirus disease (COVID-19), in Khan Younis in the southern Gaza Strip on April 19, 2020. (Photo by Ibraheem Abu Mustafa/Reuters)

Green Bay Packers' Johnathan Calvin rides a bike to NFL football training camp on July 27, 2017, in Green Bay, Wis. (Photo by Morry Gash/AP Photo)