For a period of almost one and one-half years, amplitude recordings of the 20 Mc/s signals from Sputnik III (1958 Delta II) were made at the Sagamore Hill Radio Observatory in Massachusetts. A vertical whip antenna was used for most of the measurments but, during some time periods, additional data for both the signal and its 40 Mc harmonic were obtained from Yagi antennas pointing north. An interesting feature of the recordings was the presence of dropouts; i.e., sudden decreases of the signal either to noise level or close to noise level. This phenomenon is illustrated in Figure 1, a recording taken on July 26, 1959, in which the signal is seen to decrease to noise level at 2309 30″ and to return to normal signal level at 2310. The position of the satellite is noted above the chart. Two different types of events responsible for these dropouts are postulated in this letter.