PRINCIPAL INVESTIGATOR(S ): W. Zachary Osborne, Lawrence S. Pinsky, and J. 



Vernon Bailey 



EXPERIMENT TITLE/NUMBER : Apollo Light Flash Investigations 



PROGRAM/MISSION : Apollo 15, 16, 17 



CLASSIFICATION : Human 



DISCIPLINE(S) : Radiobiology 



OBJECTIVES : To investigate the light flash phenomenon, and to obtain a direct 

 physical record of incident cosmic ray particles. 



PROTOCOL : There were 3 one-hour observation sessions for light flashes on 

 Apollo 15, and 2 one-hour sessions on Apollo 16 and 17. On Apollo 16 and 17, 

 the astronauts wore the ALFMED device during the mission while observing light 

 flashes. Postf light analysis included: location scan, trajectory measurement, 

 translation scan, correlation between observances and tracks, and charge and 

 energy measurements. 



EQUIPMENT : The ALFMED was an electromechanical helmet-like device that 

 supported cosmic radiation-sensitive emulsions. A direct physical record was 

 made of cosmic ray particles that passed through the emulsion plates and the 

 subject's head. 



RESULTS : On Apollo 7-10, no light flashes were detected. On Apollo 11, dark 

 adapted crewmen "saw" light flashes with eyes open or closed. Subjective 

 experience was 66% spot, 25% streak, and 8% cloud type flash. ALFMED result 

 indicated cosmic radiation interaction with retina. Apollo 12-14 continued 

 observations by all crewmen of light flashes. There was a correlation of 

 light flashes with cosmic radiation of 50-300 MeV/nucleon. 



CONCLUSIONS : Evidence shows that, at least in part, the flashes seen by 

 astronauts are correlated with charged particles transversing the retina. 

 Further, since the flux of these particles is sufficient to explain the entire 

 phenomenon, it is likely that all of the flashes originate in this manner. 

 The ALFMED technique has been demonstrated to be effective as a procedure for 

 study of the light flash phenomenon. 



PUBLICATIONS : 35, 111, 385, 412, 413, 426, 427, 428, 429 



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