Pioneer Venus Orbiter

At present the 7-ray detectors in operation are those aboard the Solar Maximum Mission (SMM) and Pioneer Venus Orbiter (PVO). We estimate the typical detection limit of the counter of SMM to be 0.1 2 2... 

One of the most intriguing hits of data about vulcanism on Venus has been reported by Larry Esposito, at the University of Colorado s Laboratory for Atmospheric and Space Physics. Using data obtained from the Hubble Space Telescope, Esposito found that the abundance of sulfur dioxide at the top of the Venusian cloud layer in 1995 was about 20 times less than it had been when measured during the 1978 visit by the Pioneer Venus Orbiter spacecraft. He compared these results with some of the earliest measurements of sulfur dioxide made on the planet dating to the early 1970s. At that point, the abundance... 

FIGURE 14 Ion densities measured by the ion mass spectrometer during one orbit of the Pioneer Venus orbiter spacecraft. [Bauer, S. J., Donahue, T. M., Hartle, R. E., and Taylor, H. A. (1979). Science 205,109.]... 

Fig. 9.2.10 Venus atmospheric temperatures. The results shown are brightness temperatures obtained with the infrared radiometer carried on the Pioneer Venus Orbiter. They are representative of temperatures at the indicated atmospheric levels corresponding to weighting function peaks (Elson, 1979).

Fig. 3.3 Ultraviolet image of Venus clouds as seen by the Pioneer Venus Orbiter (February 26, 1979). NSSDC, NASA...

Several Soviet Venera and Vega spacecraft landed on the surface of Venus in the early 1980s, and survived for a few minutes before succumbing to the stifling heat. X-ray fluorescence chemical analyses for a number of major elements in surface samples were reported. Chemical and isotopic analyses of the Venus atmosphere were made by Pioneer Venus, Venera, and other orbiters. 

The Pioneer Venus mission provided the first radar imaging and altimetry of Venus surface from synthetic aperture radar on an orbiting spacecraft. Subsequently, the Venera 15 and 16 orbiters also carried out radar imaging and altimetry of part of Venus northern hemisphere. Orbital spacecraft radar observations of Venus culminated with the very successful Magellan mission in the early 1990s. 

May 20, 1978 Pioneer Venus 1, orbiter Orbit insertion Dec. 4, 1978, first radar mapping of another planetary surface, Venus atm. entry Aug. 1992... 

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