“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)

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

A vehicle lies on a road in Adairsville. (Photo by David Goldman/Associated Press)

In this November 30, 2017 photo, Douglas scoops up mud from the bottom of the polluted Guaire River, in search of gold and anything valuable he can sell, in Caracas, Venezuela. Some stretches of the river smell of sewer while others emit a toxic odor of fuel, a stench that stays in ones nose for hours after leaving the water. (Photo by Ariana Cubillos/AP Photo)

In this photo taken on Saturday, March 9, 2019, a visitor dances in front of a sculpture burning at the Maslenitsa (Shrovetide) festival at the Nikola-Lenivets art park in Nikola-Lenivets village, about 200 kilometers (125 miles) south-west of Moscow, Russia. As part of the celebrations of Maslenitsa (Shrovetide) Holiday in Russian, a folk holiday which heralds the beginning of spring, contemporary artist and park founder Nikolay Polissky built a giant sculpture made of wood and hay which was burnt to ashes during a traditional bonfire. (Photo by Alexander Zemlianichenko Jr./AP Photo)

A communal worker removes the snow from steps next people dressed as pandas near the center of the Ukrainian capital Kiev, on November 14, 2018, during an heavy snowfall, the first one of this autumn season. (Photo by Sergei Supinsky/AFP Photo)

Statuettes in various forms of the lost-wax casting process are seen, including the wax figure, wax mold, shell mold, and patina coated statute of “The Actor” during a media event on the production of the statuettes for the 21th annual Screen Actors Guild (SAG) Awards at American Fine Arts Foundry in Burbank, California January 13, 2015. (Photo by Patrick T. Fallon/Reuters)

Competitors Taisto Miettinen and Katja Kovanen fron Finland participate in the annual Wife Carrying World Championships in Sonkajarvi, Finland on July 6, 2019. People from all over the world took part in the event that was founded in 1992. (Photo by Mauri Ratilaine/EPA/EFE/Rex Features/Shutterstock)