|
| power = 241 watts | launch_date = UTC | launch_rocket = Atlas SLV-3D Centaur-D1AR | launch_site = Cape Canaveral LC-36A | last_contact = December 9, 1978, 20:22:55 UTC (bus) UTC (day probe) | orbit_epoch = | orbit_reference = Heliocentric | orbit_periapsis = | orbit_apoapsis = | orbit_inclination = | orbit_period = | apsis = helion |interplanetary = }} The Pioneer Venus Multiprobe, also known as Pioneer Venus 2 or Pioneer 13 was a spacecraft launched in 1978 to explore Venus as part of NASA's Pioneer program. ==Spacecraft== The Pioneer Venus Multiprobe bus was constructed by the Hughes Aircraft Company, built around the HS-507 bus. It was cylindrical in shape, with a diameter of and a mass of . Unlike the probes, which did not begin making direct measurements until they had decelerated lower in the atmosphere, the bus returned data on Venus' upper atmosphere. The bus was targeted to enter the Venusian atmosphere at a shallow entry angle and transmit data until destruction by the heat of atmospheric friction. The objective was to study the structure and composition of the atmosphere down to the surface, the nature and composition of the clouds, the radiation field and energy exchange in the lower atmosphere, and local information on the atmospheric circulation pattern. With no heat shield or parachute, the bus made upper atmospheric measurements with two instruments, an Ion Mass Spectrometer (BIMS) and a Neutral Mass Spectrometer (BNMS), down to an altitude of about 110 km before disintegrating on December 9, 1978. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pioneer Venus Multiprobe」の詳細全文を読む スポンサード リンク
|