Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

A visitor passes behind the sculpture “Puma-Dentist” made with plastic, wax and original heads of a puma and a hind by Austrian artist Deborah Sengl during an exhibition at the art gallery Deschler in Berlin April 15, 2008. (Photo by Fabrizio Bensch/Reuters)

People run away as a building is toppled during a controlled demolition as part of an urban transformation in Ankara, Turkey, February 3, 2014. (Photo by Serap Doganyigit/Reuters)

“Life-size humanoid robot BERTI (Bristol EluMotion Robotic Torso number 1 or RT-1) is a self contained, fully automated Robotic Torso, designed and built by Elumotion to provide a robotic platform based on human anatomy. RT-1 is a highly articulated manipulating platform and includes novel dexterous hands that allow emulation of human gesturing”. – Elumotion.com

Photo: BERTI the robot interacts with a Sony AIBO robot dog at The Science Museum's Antenna Gallery on February 17, 2009 in London. (Photo by Peter Macdiarmid/Getty Images)

“A prototype lunar lander was destroyed on August 9, 2012, at Kennedy Space Center during its first free flight”. – James Dean via Florida Today

Photo: Morpheus Ground Level Hot Fire. Photo Date: April 2nd 2012. Location: VTB Flight Complex; Photographer: Joe Bibby

Jesinta Campbell arrives at “Bridesmaids” Celebrity Girls Night Out to celebrate the Australian premiere at Event Cinemas George Street on June 14, 2011 in Sydney, Australia. (Photo by Lisa Maree Williams)

Comic Con fans in costume arrive for the 2nd day of the 2016 New York Comic Con at the Jacob Javits Center on October 7, 2016. The four- day event which runs October 6-9 is the largest pop culture event on the East Coast. (Photo by Timothy A. Clary/AFP Photo)

In this Saturday, June 24, 2017 file photo, Zeid Ali, 12, left, and Hodayfa Ali, 11, comfort each other after their house was hit and collapsed during fighting between Iraqi forces and Islamic State militants in Mosul, Iraq. The Ali cousins said some of their family members are still under the rubble. (Photo by Felipe Dana/AP Photo/File)