Astronaut Scientific Debriefings, 1962-1963
- Date
- 1962 to 1963
- Place
- Low Earth Orbit
- Record
- Pentagon file
- Assessment
- Not assessed
- Evidence strength
What was reported
A 216-page compilation of post-flight scientific debriefings for the Mercury program (Glenn, Schirra, Cooper and others) with NASA and outside scientists (Dr. O'Keefe, Dr. Voas, Dr. Nordberg, Dr. Liddel and others), the great majority devoted to exhaustively analyzing the 'fireflies' phenomenon first reported by John Glenn on Mercury-Atlas 6. Detailed technical discussion (particle color, velocity field relative to the spacecraft, behavior across three orbits, charge repulsion, thruster-firing correlation) concludes the particles are frost/ice condensate from spacecraft outgassing and thruster exhaust, not extraterrestrial in origin. Schirra's MA-8 debrief adds direct confirmation that the particles are the same substance fogging his window after retrofire.
What officials concluded
Resolved
Detailed scientific analysis concludes the particles are frost/ice condensate produced by spacecraft outgassing (hydrogen peroxide byproduct gas, water coolers) and thruster firings, not extraterrestrial particles, consistent across three…
- Agency
- NASA
- Released in
- 123456
Evidence profile
- Yes: Visual
- No: Infrared
- No: Radar
- No: Video
- No: Photo
- No: Film
- No: Audio
- No: Night vision
- No: Other sensor
- No: Civilian
- No: Military aircrew
- No: Military ground
- No: Airline crew
- No: Sensor operator
- No: Law enforcement
- Yes: Scientist
- No: Astronaut
- No: Intelligence official
- No: Other
- Yes: Light only
- No: Orb or sphere
- No: Disc
- No: Triangle
- No: Cylinder
- No: Cube
- No: Other shape
- No: Physiological
- No: Physical trace
- No: Electromagnetic
- No: Sound
- No: Silent
Why this rating This document is itself the detailed scientific resolution of the 'fireflies' phenomenon reported across the batch's other Mercury/Gemini/Apollo files: technical analysis conclusively attributes the particles to spacecraft outgassing, thruster exhaust and frost, with a plausible physical mechanism and consistent orbit-to-orbit behavior.
As described in the file
- Witnesses
- John Glenn (MA-6), Walter Schirra (MA-8), Gordon Cooper (MA-9), debriefed by NASA and outside scientists
- Sensors
- Visual, physical/spectroscopic instrument discussion (post-flight analysis)
- Shape
- Flat, frost-like or blob-like particles; color affects apparent edge sharpness
- Size
- Small, dust/frost-flake scale
- Lights and colour
- White to yellow-green/chartreuse, fluorescing in sunlight
- Motion
- Moved with, and radially away from, the spacecraft; consistent velocity/direction per orbit, with variation attributed to electrostatic repulsion near the craft
- Duration
- Observed repeatedly across every orbit of each flight
- Altitude or range
- Immediately adjacent to spacecraft
Pentagon files
Astronaut Scientific Debriefings, 1962-1963
Open the original on war.gov
What the file claims
- Unverified
A scientific panel concluded Glenn's 'fireflies' were spacecraft-associated particles, not extraterrestrial, based on consistent velocity and direction across three orbits.
- Unverified
Schirra directly attributed the 'firefly'/frost particles to hydrogen peroxide byproduct gas and water-cooler outgassing forming an environment around the spacecraft, matching window fogging he separately observed after retrofire.
- Unverified
Cooper described the particles as luminous streams appearing to originate from thruster firings, moving in the direction opposite the spacecraft's flight path.