Documents / Official release
This NASA file of astronaut scientific debriefing papers from 1962 collects internal Office of Space Sciences material on the science observations made on early Mercury flights. A February 1962 memo from Maurice Dubin asks for more detail on John Glenn's report of luminous particles and the atmospheric horizon layer. A draft memo concludes that the particles were tied to the spacecraft and were not extraterrestrial. The file also holds a Los Alamos letter that attributes the high haze layer to nitrogen peroxide, and notes on Carpenter's airglow observations.
From the source:Release of 2026-06-12 This file contains memoranda, correspondence, reports, and other materials relating to contemporary scientific interest in investigating the nature of luminous phenomena reported by astronauts John Glenn and Walter Schirra during spaceflight. This collection includes transcripts from NASA interviews and debriefings with both astronauts regarding those observations. It also contains details relating to scientific observations of atmospheric phenomena, including brief descriptions of luminous particles, experiences while aboard spacecraft, and circa 1955 theoretical analysis of meteoric particles entering the atmosphere. Pages 34-35, 55-56, 57-63, 64-113, and 122-127 feature content relevant to the PURSUE initiative.
“Nevers”23 pages
Il4 MAURICE DUDIN consideration oflong-duration meteor echoe it ha been suggested that the electron density in the trail is greater than the critical density for the radio wavelengths employed in probing meteors, and has led to a revision of the Herlofson ratios for the production of heat, light, and ionization. GREENHOW and HAWKINS (1952) thereby found that a mete.or of visual magnitude +6 would produce approxi mately 1012 electrons per centimetre of path. This is one hundred times greater than HERLOFSON's estimates, and leads to a discrepancy of roughly five stellar magnitudes between his theoretical estimate and the experimental determination of electron-line density in meteor trail . GREENHOW and HAWKINS conclude that meteors produce more· ionization than was originally estimated. Instead of the kinetic energy of the meteor being divided between heat, light, and ionization in the ratio 104 : 102 : 1, the ratios are probably 104 : 102 : 10 for bright meteors, and 10 4 : 10 : 10 for faint meteors. These revised estimates imply that the visual magnitudes corresponding to ap echo of given characteristics is about five magni tudes fainter than given by HEBLOFSON. This means that the majority of echoes of short duration must arise from meteors which are below the limits of naked-eye visibility, and conversely, that all visible meteors must produce radio echoes of long duration-a well-known ob ervational fact . A further consideration in the model of HEBLOFSON is the fact that unmelted meteorites hav been found on the smface of the earth. WHIPPLE (1950, 1951) has shown that the micrometeorite, if below a certain size, can dissipate the energy gained sufficiently rapidly to permit the ·e particles to be stopped by the atmosphere without melting. Recalling that the Herlofson model required that ablation of the meteorite was the initial step in the production of light and ionization, thi point warrants some discussion. GREE HOW and HAWKINS (1952) have indicated that for radio meteors the amount of light produced is correspondingly reduced for small meteoric particles but the relative ionization is not reduced, but rather is generally larger than indicated by HERLOFSON's treatment. It seems worthwhile to review briefly the physical process involved in the interaction of a micrometeorite with the atmosphere. Since it is not believed that ablation results for these very small particle , one might question whether or not the ionization efficiency would become correspondingly poorer. The physical problem is one of considering a collision of the micrometeorite with a molecule or atom of air, with the relative energy of collision in the range from 10 to 800 eV. The mean free path of the air is much ·greater than the diameter of tho micro meteorite, and thus the problem may be treated by kinetic theory rather than fluid dynamics. • There are everal proces es which might occur: (1) An elastic collision of a molecule of air with the micrometeorite would yield a molecule with a velocity capable of ionizing. (2) An inelastic collision of a molecule of air with the Inicro meteorites such that the air molecule enter the surface of the micrometeorite, and thereby heats the Inicrometeorite and al o forms a "monolayer" on the surface; such molecules if not chemically bonded to the surface might very ,easily evaporate off the surface with the velocity high enough for ionization. (3) Secondary ioniza tion from collisions with a surface. (4) Attachment to oxygen by the collision and the eventual addition of a free electron to the atmosphere; and (5) sputtering of
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Official release, from the pursue collection. The PDF is mirrored here; the original link is under it. 216 pages are in the text index: search them above, or from the library's search.