Pioneer Venus Orbiter spacecraft

Pioneer Venus Orbiter spacecraft

Courtesy of NASA

http://heasarc.nasa.gov/docs/heasarc/missions/pvo.html



Overview
The Pioneer Venus mission consisted of two spacecraft, launched separately: an orbiter and a five-part multiprobe (one part to transport the other four parts). The orbiter orbited Venus much longer than planned, finally crashing into Venus in August, 1992. The multiprobes were released and sent down to the Venusian surface, sending back data about the atmosphere as they descended.


Launch
May 20, 1978(orbiter); August 8, 1978(multiprobe)


Arrival
December 4, 1978 (orbiter); November 16 and 20, 1978 (multiprobe parts)


End of Mission
October 8, 1992 (orbiter); December 9, 1978 (multiprobe parts)


Goals
Mission goals were to study the composition of the atmosphere, to investigate the solar wind near Venus, to map Venus’ surface through a radar imaging system, and to study the characteristics of Venus’ upper atmosphere and ionosphere.


Findings
The highly elliptical orbit of Pioneer Venus around the planet allowed the craft to use radar to map the clouds, atmosphere, ionosphere, and Venus’ surface. During the flight, the craft was able to make observations of several comets. Even with no heat shield or parachute, the craft was able to make measurements to about 110 km altitude before burning up. The multiprobe separated into five separate probes. All the probes entered the atmosphere of Venus within 11 minutes of each other. The probes descended toward the surface over approximately an hour long period sending back data to Earth. Gamma Ray detector detected 217 new cosmic gamma ray bursts and 126 solar flares.