December 16, 2016

— The death of John Glenn, the first American to orbit the Earth, has led a historian who wrote a biography of the astronaut to share a new look at one of Glenn's most harrowing moments.

"It is one of the most gut-wrenching moments in the history of space exploration," writes author Andrew Chaikin, "and it was all captured on film: John Glenn guiding his Mercury capsule, Friendship 7, through its fiery re-entry into Earth's atmosphere, not knowing if he is about to be burned to a cinder."

As recounted — and now presented anew — by Chaikin, a movie camera that was aimed at Glenn aboard Friendship 7 ran for the length of the flight. Chaikin synchronized this film with audio from the craft's onboard tape recorder.

Click to enlarge and view in new window. (Andrew Chaikin/NASA)

As the retrorockets fired, Glenn happily remarked on the sudden acceleration he felt after being weightless for four and a half hours.

But then came a message from the flight controllers on the ground. On telemetry, they saw indications the spacecraft's landing bag, meant to cushion the impact of splashdown, had prematurely deployed. If so, Glenn's heat shield could be loose, held only by the straps securing the retrorockets to the base of the capsule.

"In Mercury control, astronaut Alan Shepard tells Glenn he must re-enter with the retropack still attached," describes Chaikin, "until aerodynamic forces can build up to hold it in place. It's an untried configuration that no one is sure will be stable. But Glenn had no other option."

Chaikin posted his newly-synchronized film-and-audio clip online in memory of Glenn, who died one week ago (Dec. 9) at the age of 95. The pioneering astronaut's body laid in repose at the Ohio Statehouse on Friday (Dec. 16).

A public memorial service in celebration of Glenn's life is scheduled for 2:00 p.m. EST (1900 GMT) on Saturday at Ohio State University in Columbus.

John Glenn lies in repose, under a U.S. Marine honor guard, in the Rotunda of the Ohio Statehouse, Dec. 16, 2016. (NASA/Bill Ingalls)

Excerpted from a full 10-minute video that was included in Chaikin's 2014 e-book, "John Glenn: America's Astronaut," the re-entry film captures just one example that defined the astronaut-turned-senator as a national hero.

"Glenn's face is bathed in the light of the glowing plasma beyond Friendship 7's window," writes Chaikin, describing the Feb. 20, 1962 scene. "His gaze alternates between the instruments — throughout the re-entry he must maintain the craft's prescribed attitude — and the window, where he sees flaming chunks flying past. Are they the pieces of his heat shield?"

"'A real fireball outside,' Glenn says, but no one can hear him. There is no hint in Glenn's eyes of what is going on inside him, every nerve charged with dreadful anticipation, wondering if he is about to feel the heat of re-entry building up at his back," observes Chaikin.

But then Glenn is through the radio blackout, and the heat shield held. The flaming chunks he saw had been pieces of the retropack. "And as it turns out, the landing bag was not deployed prematurely after all; the telemetry had been the result of a faulty sensor," Chaikin wrote.

"When an orange-and-white parachute blooms above the descending capsule, there's relief and exultation in Glenn's voice as he prepares for the splashdown — and the hero's welcome for a newly minted space legend," writes Chaikin.