Engineering topics
Phillips, James R.
Publications and source records attributed to Phillips, James R..
Pioneer Venus Orbiter search for Venusian lightning
The results are reported of a search during 1988 and 1990 for optical pulses from lightning on the Venus nightside using the star sensor aboard the Pioneer Venus Orbiter. No optical evidence for lightning activity is found. These searches covered a much larger latitude range than any previous search. The results show that the Beta and Phoebe Regio areas previously identified by Russell et al. (1988) as areas with high rates of lightning activity were not active during the two seasons of the present observations. The results imply that the global flash rate and energy dissipation rate derived by Krasnopol'sky (1983) from observations of a single storm are too high. Experimental measurements performed to determine the amount of scattering occurring in the star scanner optics indicate that a previously determined upper bound to lightning activity is too low.
Observing Halley from Venus
During the 3 mo of perihelion passage of Comet Halley in 1985 and 1986, the Pioneer Venus Orbiter was diverted from its normal role of collecting Venus science, and operated as a platform for ultraviolet and solar-wind observations of the comet. This paper describes the unusal features of the planning, and the special problems encountered in order to observe the comet.