The space suits used by the astronauts on Gemini 7, known as grasshopper suits, were designed for comfort. But after two weeks inside them, that was the last thing on the crew’s minds.

There's a Limit to the Comfort Level of NASA Space Suits (3:32)

In 1942, the Japanese were bearing down on the Philippines, where General Douglas MacArthur was based. To help him escape, the Navy relied on a small but heavily armed class of ships: the PT boat.

How PT Boats Helped General MacArthur Escape Capture (3:39)

Greg Spriggs and Jim Moye are on a mission: to declassify all valuable film footage that exists of every U.S. nuclear test ever conducted.

Bringing Classified Nuclear Test Footage to the Public (1:47)

The Vikings had dreams of exploration and conquest, and the longship was ideal for that purpose. Soon, they were able to venture as far as the Mediterranean and the Middle East.

What Made the Viking Longship So Terrifyingly Effective (3:52)

In the 19th century, there was a watermill almost every mile of the river, such was the huge demand for flour and bread. Today, Eastnor castle’s own mill is still operational–an important piece of local history.

This British Castle Still Has a Functioning Flour Mill (3:39)

Henry Ford was a genius who virtually created the automobile industry as we know it. But what's less lauded was his talent for publicity—and his ability to partner with other pioneers such as Ohio's Harvey Firestone.

How Henry Ford Found the Right Tires for Model T Cars (1:46)

The two-wheel chariot was also a two-crew chariot: a driver handling the reins, and an archer unleashing a volley of arrows. Its speed and maneuverability made it the scourge of ancient battlefields.

Why the Two-Wheel Chariot Was So Effective in Ancient Battles (1:55)

A contemporary weapons expert is about to test a medieval war hammer on a steel breastplate from that era. The aim is to find out how much damage this fearsome instrument of death could deal.

What Kind of Damage Can a Medieval War Hammer Do? (2:09)

The smart tool gives users step-by-step instructions based on WHO’s handwashing protocol