365DaysDate: February 20, 2009


Title: John Glenn’s Fireflies and the Astronauts’ Constellation

Podcaster: Robert Pearlman

Link: www.collectSPACE.com

Description: February 20, 2009 marks the 47th anniversary of the first American in orbit. Astronaut John Glenn circled the Earth three times and in the process, discovered a new stellar phenomena… or did he? collectSPACE.com recounts the tale of  John Glenn’s “fireflies” and shares the history behind their infamous scatological cousin.

Bio: Robert Pearlman is the editor and founder of collectSPACE.com, the leading online resource and community for space history enthusiasts including historians, authors, former and current space program workers and museum conservators.

Today’s Sponsor: This episode of “365 Days of Astronomy” is sponsored by Mark Jones in honor of the Ecumenical Center for Religion and Health, providing counseling services to the children and families of the San Antonio area. Learn more about the Ecumenical Center at www.ecrh.org.


Hi, I’m Robert Pearlman, editor of collectSPACE.com. Forty seven years ago today, the United States launched its first astronaut into orbit. Two Americans had preceded John Glenn into space the year before, but their flights followed a roller-coaster like sub-orbital trajectory, going up and down in a matter of just 15 minutes. Glenn’s mission would bring the U.S. up to par with the Soviets, who had already launched two cosmonauts on planet-rounding flights.

More than just to race the Russians, Glenn’s five hour mission would collect data for the National Aeronautics and Space Administration — more commonly known as NASA — as to the ability of an astronaut to function in weightlessness. He would eat in space, consuming food from toothpaste-like tubes, and report back his condition in zero-gravity.

GLENN: “Roger. Zero-G and I feel fine. Capsule is turning around. Oh! That view is tremendous!”

Glenn would also describe his surroundings to the ground, looking out his window. Entering the shadow of the Earth — sunrise and sunset came every 45 minutes in orbit — Glenn described his vision of the night sky. He had been trained to recognize constellations and what unfolded before him was the darkest of skies.

GLENN: “The sky above is absolutely black, completely black. I can see stars though up above. I do not have any of the constellations identified as yet. Over.”

Glenn would soon start picking out the familiar patterns in the starry sky. He reported seeing Aries and Triangulum. Ground controllers, positioned at communication stations spread across the globe, also advised him of what constellations would next come into view. The ability for an astronaut to pick out the stars and constellations would be important, as just like the explorers who crossed the oceans in ships, astronauts would use the stars to guide and orient their spacecraft.

During his first of three orbits, as night became day and the sun rose from behind him, Glenn again peered out his window, only this time, the field of stars were far more numerous and they were… moving! Glenn radioed down from his spacecraft, which he had named Friendship 7, to whoever was in range to listen.

GLENN: “This is Friendship Seven. I’ll try to describe what I’m in here. I am in a big mass of some very small particles, that are brilliantly lit up like they’re luminescent. I never saw anything like it. They round a little: they’re coming by the capsule, and they look like little stars. A whole shower of them coming by.”

“They swirl around the capsule and go in front of the window and they’re all brilliantly lighted. They probably average maybe 7 or 8 feet apart., but I can see them all down below me, also.”

Glenn was clearly taken by this new constellation of mini-stars, at which he was at the center. Ground controllers were concerned these new traveling partners were impacting his capsule, but he said they weren’t. They were moving slowly — at least relative to his own orbital speed — just enough that they were trailing his spacecraft.

A few minutes later, just as quickly as they had come, they were gone.

GLENN: “And just as the, as I looked back up out the window, I had literally thousands of small, luminous particles swirling around the capsule and going away from me at maybe 3 to 5 miles per hour. Now that I am out in the bright sun, they seem to have disappeared.”

What were these “fireflies” — as Glenn would refer to them — that had circled his spacecraft? Were they a new astronomical phenomenon? Were they pieces of his capsule?  Or maybe his imagination?

There were theories but the answer wasn’t confirmed until the next Mercury spacecraft, dubbed Aurora 7, launched astronaut Scott Carpenter into orbit in May 1962.

Carpenter had been specifically tasked with trying to observe and photograph the particles reported by Glenn. And though he had earlier sightings — “I have the fireflies,” he affirmed —  the proof he needed came during his third orbit, again just after sunrise.

“Ah, beautiful lighted fireflies that time,” reported Carpenter to the ground. “I have the fireflies they are very bright. They are capsule-emanating. I can rap the hatch and stir

off hundreds of them. Rap the side of the capsule, huge streams come out. They — some appear to glow.”

“Some appear to glow but I don’t believe they really do, it’s just the light of the sun,” he continued.

Carpenter soon identified the source of his and Glenn’s traveling partners.  “They are little tiny white pieces of frost. I judge from this that the whole side of the capsule must  have frost on it.”

Glenn’s “fireflies” became Carpenter’s “frost-flies” or snowflakes. Condensation gathered on the outside of their spacecraft as they passed from the cold night into the warm day and then froze again, creating a layer of frost. As the spacecraft passed through sunrise, the flakes would liberate from the spacecraft, sometimes assisted by the motion of the astronaut inside.

The mystery solved, that might have been the end of any talk of floating flakes of frost were it not for another Mercury astronaut.

Walter “Wally” Schirra flew the second to last Mercury mission but it was aboard Gemini VI together with astronaut Thomas Stafford did the subject of fireflies present itself again. “They appeared to John Glenn as fireflies. To others taking a quick look, as Tom Stafford did at the moment of rendezvous, they resembled a star field,” Schirra recalled years later. “As I said before, their source was water released in the heat exchange process that cooled our space suits. Another source was urine. ‘We peed all over the world,’ I’m fond of saying, despite the groans that come from the audience.”

Taking advantage of some free time, Schirra and Stafford photographed their ejected, frozen urine, which glinted in the sunlight. “We logged each shot with a label — urine drops at sunrise, urine drops at sunset, etc. When the photos were processed at the cape, they were beautiful, and I ordered a set of prints,” said Schirra, who passed away in 2007.

After the flight, a NASA astronomer noticed the photos during the astronauts’ astronomy debriefing, which had become mixed with other celestial photos taken during the mission. “Wally, what constellation is this?”, asked Dr. Jocelyn Gill of Schirra’s firefly photos.

“Jocelyn,” he replied, “that’s the constellation Urion.”

And so began a long history of astronauts admiring the constellation they created. That is, until late last year, when the space shuttle delivered a new device to the International Space Station. It’s purpose? To recycle “constellation Urion” back into useable water.

If you enjoyed this story from space history, then I invite you to collectSPACE.com. Celebrating our tenth year online, collectSPACE brings together the people, artifacts and stories that tell of humanity’s space exploration efforts.

End of podcast:

365 Days of Astronomy
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