“The Lockheed Martin X-33 is an unmanned, sub-scale technology demonstrator suborbital spaceplane developed in the 1990s under the U.S. government-funded Space Launch Initiative program”. – Wikipedia

Photo: An Artist's Rendering Shows How Nasa's X-33 Technology Demonstrator, A Cost-Cutting Fully Reusable Single-Stage-To-Orbit Space Vehicle, Will Look Upon Completion. The 67 Foot-Long, 278,600 Pound, Twin Engine Space Vehicle, Capable Of Reaching Speeds In Excess Of Mach 15, Will Lead To The Construction Of A 127 Foot-Long, 2,186,000 Pound Version With Seven Engines And A 50,000 Pound Payload Capacity Called The “Venturestar”. (Photo By Nasa/Getty Images)

A women wearing a mask to protect from extreme smog visits the Tiananmen Gate in Beijing December 8, 2015 as China's capital issues its first ever "red alert" for pollution. (Photo by Damir Sagolj/Reuters)

Anti-pollution protesters wearing traditional costumes and contemporary gas masks ride bicycles in the Qingming Grand river park in Kaifeng, Henan Province, China on January 1, 2017. The Beijing Municipal Environmental Protection Bureau extended an “orange alert” for heavy air pollution for three more days. (Photo by SIPA Asia/Rex Features/Shutterstock)

A cat stretches on top of dried seafood in a shop in the Sheung Wan district of Hong Kong on August 7, 2020. International Cat Day, celebrated on August 8, is a day to raise awareness for cats and learn about ways to help and protect them. (Photo by Isaac Lawrence/AFP Photo)

A medical worker in protective gear sprays mist on her colleague during a hot day at an outdoor clinic for coronavirus tests at a public health facility in the southwestern city of Gwangju, South Korea, 05 June 2020. (Photo by Yonhap/EPA/EFE)

A citizen wearing protective suit shops at a market in Santiago, Chile, April 16, 2020 Chile has taken stringent measures to contain the virus, including imposing a night time curfew, suspending classes, closing non-essential businesses, and mandating the use of face masks on all public transit. (Photo by Jorge Villegas/Xinhua News Agency)

A health worker wearing a protective suit is disinfected inside a portable tent outisee the Gat Andres Bonifacio Memorial Medical Center during an enhanced community quarantine to prevent the spread of the new coronavirus in Manila, Philippines, Monday April 27, 2020. (Photo by Aaron Favila/AP Photo)

An exotic dancer wears personal protective equipment while taking a tip in a drive-through go-go dance tent offered by the Lucky Devil Lounge strip club in the wake of the coronavirus disease (COVID-19) restrictions in Portland, Oregon, U.S. April 24, 2020. (Photo by Terray Sylvester/Reuters)