INCREASES IN ORBITAL PERIOD OF ABLESTAR ROCKETS WITH PARTICULAR REFERENCE TO 1964-83A

The unusual behaviour of certain Ablestar rockets is discussed. Optical observations of satellite 1964-83A are used to obtain nodal periods for 1966 August and September. These indicate that an increase in period occurred at that time. It is likely that there was a sudden discontinuity, the probable time of which is determined to be 1966 September 8.85 ± 0.02. A warning is given that orbital elements may be affected by activity in liquid-fuel rockets in ways that might mistakenly be interpreted as effects of outside influences such as air-drag. This study also demonstrates the usefulness of close contact between analyst and observer. © 1968.