Stars and Heavy Primaries Recorded during a V-2 Rocket Flight

Plates flown to an altitude of 150.7 km in a V-2 rocket exhibit a differential star population of 5000±800 per cc per day and a flux of heavy primaries of about 0.03 per ${\mathrm{cm}}^2$ per min. above the stratosphere. The star intensity is about 3.6 times greater than that recorded by plates exposed in the stratosphere, the increment being attributable to secondary star forming radiations created by interaction of cosmic-ray primaries with the massive projectile. The flux of heavy primaries is essentially of the same order of magnitude as reported for elevations of 28 km.