Observations of galactic cosmic-ray intensity at heliocentric radial distances of from 1.0 to 2.0 astronomical units.

From observations with the Jupiter-bound spacecraft Pioneer 10 it is found that the integral intensity of the galactic cosmic radiation (E sub p greater than 80 MeV) varied by less than 3% (either plus or minus) over the heliocentric radial range from 1.0 to 2.0 AU during the epoch 1972 March-July.