Competitors ride a home-made vehicle without an engine on a downhill track in the Red Bull Soapbox Race in Santiago, Chile, November 27, 2016. (Photo by Jonathan Faus/Reuters)

Number 10. BELL H-13 SIOUX was a two-bladed, single engine, light helicopter built by Bell Helicopter. Westland Aircraft manufactured the Sioux under license for the British military as the Sioux AH.1 and HT. In 1947, the United States Air Force ordered the improved Bell Model 47A. Most were designated YR-13 and three winterized versions were designated YR-13A. The United States Army first ordered Bell 47s in 1948 under the designation H-13. These would later receive the name Sioux. The Bell-built H-13 B is seen airborne in this April 29, 1951 photo. The helicopter is equipped with a 173 horsepower engine, cruises at 85 miles per hour, climbs 900 feet in a minute and has a service ceiling of 11,500 feet. (Photo by AP Photo)

These eye-catching photographs capture the special relationship between a group of farmers and elephants – with a gorgeous sunset in the background. Vithun Khamsong, a civil engineer, shot the images earlier this year while visiting Surin, Thailand. (Photo by Vithun Khamsong/Caters News Agency)

Expedition 44 flight engineer and NASA astronaut Scott Kelly seen inside the Cupola, a special module which provides a 360-degree viewing of the Earth and the International Space Station. Kelly is one of two crew members spending an entire year in space. (Photo by Scott Kelly/NASA)

A man photographs the main engines of the space shuttle orbiter Discovery on display at the Udvar-Hazy Smithsonian National Air and Space Annex Museum in Chantilly, Virginia August 28, 2015. Shuttle Discovery had 27 years of service and flew 39 times before being retired in 2011. (Photo by Gary Cameron/Reuters)

Thor, Virginia Tech College of Engineering, Robotics and Mechanisms Laboratory, tries to connect the hose to a firehose connection during the hose task at the Homestead-Miami Speedway, Friday, December 20, 2013, in Homestead, Fla. (Photo by Alan Diaz/AP Photo)

In this January 24, 2017 photo, boxer Idamerys Moreno wraps a bandage on her hand before a training session at a sports center in Havana, Cuba. Boxing has long been an athletic engine for Cuba, which has won 72 Olympic medals in that category but women are not allowed to box. (Photo by Ramon Espinosa/AP Photo)

The cruise ship Viking Sky as it drifts after sending a Mayday signal because of engine failure in windy conditions near Hustadvika, off the west coast of Norway, Saturday March 23, 2019. The Viking Sky is forced to evacuate its estimated 1,300 passengers. (Photo by Odd Roar Lange/NTB Scanpix via AP Photo)