© Mark Ollig
Project Mercury, announced by the National Aeronautics and Space Administration (NASA) Dec. 17, 1958, aimed to put the first Americans in space.
The Soviet Union’s growing technological prowess following their launch of the first artificial satellite to orbit the Earth, Sputnik 1, Oct. 4, 1957, was among the reasons for Project Mercury.
The US participation in the “space race” was also inspired by national pride and fear of falling behind.
On April 12, 1961, the space race heated up when Soviet cosmonaut Yuri Gagarin became the first human in space, completing one orbit around the Earth aboard the Vostok 3KA space vehicle.
The US responded May 5, 1961, when Alan Shepard, navigating the Mercury Freedom 7 spacecraft, became the first American in space.
His 15-minute suborbital flight reached an altitude of 116 miles and ended with a safe splash down in the Atlantic Ocean.
NASA’s Mercury spacecraft, measuring six feet, 10 inches long, and six feet, 2.5 inches in diameter, was mainly constructed using titanium and cost $5.5 million, approximately $56.6 million today.
Its heat shield originated from existing ballistic-missile warhead technology and measured six feet and eight inches in diameter, with a radius curvature of 10 feet. It comprised a fiberglass/phenolic resin composite, with an inner structural laminate providing stability.
On Feb. 20, 1962, as 40-year-old John Glenn was settled into his Mercury spacecraft Friendship 7 seat, his friend and backup pilot, Scott Carpenter, radioed these memorable words: “Godspeed, John Glenn.”
John Glenn became the first American to orbit our planet aboard Friendship 7, launched by the Mercury-Atlas LV-3B booster rocket.
The Atlas booster stage detached about two minutes after launch, with the smaller engine thrusting Glenn’s spacecraft into orbit.
During his first orbit of Earth, astronaut John Glenn radioed Mercury Control Center in Cape Canaveral, FL, declaring, “Zero-G and I feel fine.”
He would later report seeing “very bright little particles” drifting by the spacecraft’s observation window as “small, glowing fireflies” that worried the folks in the Mercury Control Center.
“They do have a different motion from me because they swirl around the capsule and then depart back the way I am looking,” Glenn reported.
During Friendship 7’s second orbit, the Mercury Control Center received a signal indicating the spacecraft’s heat shield was loose and was concerned the illuminated “fireflies” Glenn saw were related.
If the heat shield detaches during re-entry, the spacecraft will burn up due to the extreme temperatures.
As a safety measure, Glenn was instructed not to detach the retropack (a metal structure holding the three retrorockets attached to the heat shield) after initiating the retrofire during the spacecraft’s re-entry.
It was hoped that the retropack, typically detached before re-entry, would keep the heat shield in place if it was loosened.
A clogged side-to-side movement steering thruster interrupted the automatic control system at the end of the first orbit.
John Glenn quickly switched to the manual fly-by-wire system. He maintained the spacecraft’s attitude, ensuring it stayed on course while working with systems regulating the thrusters and retrorockets.
After three orbits, the Mercury spacecraft gradually slowed for the fiery re-entry into Earth’s atmosphere.
During the four minutes and 56 seconds of re-entry, Friendship 7’s heat shield ablated (charred and evaporated) the extreme fiery heat by dissipating it through erosion and vaporization away from the spacecraft, thus protecting Glenn from temperatures reaching 5,432 degrees Fahrenheit.
Friendship 7’s drogue parachute deployed, followed by the main chute, ending with a safe splash down in the Atlantic Ocean.
After a five-hour mission, John Glenn was recovered by the US Navy ship USS Noa (DD-841) and then transferred by helicopter to the USS Randolph (CV-15), the primary recovery ship.
Upon inspecting the spacecraft, officials discovered a faulty operating switch in the heat shield circuit, indicating that the shield’s clamp had been prematurely released.
The fireflies Glenn saw were ice crystals formed from condensation on Friendship 7’s exterior and shaken loose by various movements while in orbit; the sun illuminated them, and the weightlessness of space allowed them to drift around the spacecraft.
In 1964, John Glenn left NASA, becoming a US Senator for his home state of Ohio ten years later.
Six Mercury spaceflights, launched between 1961 and 1963, were the foundation for the following Gemini and Apollo space programs.
At 77 years and 103 days old, John Glenn proved he still had the right stuff by becoming the oldest person to orbit the Earth (134 orbits) during a nine-day mission aboard the space shuttle Discovery from Oct. 29 to Nov. 7, 1998.
As a payload specialist, Glenn performed experiments and underwent tests to study aging during spaceflight.
After leaving the US Senate in 1999, he founded the John Glenn Institute for Public Service and Public Policy.
“Star Trek” actor William Shatner became the oldest to travel into space Oct. 13, 2021, at 90 years and 205 days, during his 11-minute, 66-mile-high suborbital flight.
However, he did not orbit the Earth as Glenn had aboard Discovery.
John Herschel Glenn Jr. was born in Cambridge, OH, July 18, 1921, and died Dec. 8, 2016, at 95 in Columbus, OH.
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| The front page of the Feb. 21, 1962, edition of the Minneapolis Morning Tribune. This edition featured John Glenn, the first American to orbit the planet. It includes photos of him and his wife, Annie Glenn. (photo of this newspaper from my collection) |