U.S. Marines first test against Japanese defenses on Okinawa.

The cockpit voice recorder of Thai Airways Flight 311, which went down on July 31, 1992, reveals an unexpected detail: a palpable level of tension between the pilot and his first officer.

Did tension between this flight crew lead to disaster? (3:53)

As U.S. troops stormed Saipan in 1944, it soon became clear that the enemy was well prepared to inflict a mortal blow.

The deadly surprise that awaited U.S. troops on Saipan (3:31)

When Thai Airways Flight 311 crashed into a remote area of the Himalayas on July 31, 1992, investigators needed to get to the site quickly to pull evidence. But the area was completely inaccessible, even by helicopter.

This crash site was a major challenge for investigators to reach (3:45)

Relive the aerial dogfights and naval clashes of the Battle of the Philippine Sea, thanks to stunning color footage. It is a visual record of the battle that underlined U.S. superiority in the Pacific.

This famous Pacific battle is captured in stunning detail (3:21)

An unmanned test flight was impossible, so the first ever shuttle launch was a high-risk endeavor with two top astronauts on board.

How NASA Crew Members Reacted to the Space Launch (2:56)

Did a previous accident in 2001 cause this aircraft to fatally crash on October 31, 2015? Investigators look closely at the affected part of the plane—the rear fuselage—hoping for a breakthrough.

Did an old accident cause this plane to crash 14 years later? (3:57)

While stars like Jimmy Stewart and Clark Gable enlisted and served during World War II, directors like John Ford would bring military footage of the Pacific conflict straight to American viewers.

How Hollywood encouraged military service during World War II (2:38)

Did a terrorist group bring down Metrojet 9268, on October 31, 2015, from a cruising altitude of 31,000 feet? Investigators focus on the type of weapons they have—and their range.

Did terrorists bring down this Russia-bound flight? (4:00)

In the 1920s, the U.S. was in full thrill-seeking mode, with everything from horse-diving (you have to see it to believe it) to barnstorming. And at the center of many of these activities were a group of daring young women.

The weird thrills that Americans pursued in the 1920s (3:13)