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Pioneer 13
Venus Multiprobe
Venus Multiprobe
Credit: NASA
American Venus probe. Launched 1978.08.08 (Pioneer Venus 2) to (Pioneer Venus Probe 4). The Pioneer Venus Multiprobe consisted of a bus which carried one large and three small atmospheric probes.

Status: Operational 1978. First Launch: 1978-08-08. Last Launch: 1978-08-08. Number: 5 . Gross mass: 875 kg (1,929 lb). Height: 2.90 m (9.50 ft).

After release from the carrier vehicle, the probes entered the atmosphere at 41,600 km/hr, followed by the bus. The small probes were each targeted at different parts of the planet and were named accordingly.

The North probe entered the atmosphere at about 60 degrees north latitude on the day side. The night probe entered on the night side. The day probe entered well into the day side, and was the only one of the four probes which continued to send radio signals back after impact, for 67 minutes. The carrier vehicle, not designed for atmospheric re-entry, followed the probes into the Venusian environment and relayed data about the characteristics of the extreme outer atmosphere until it was destroyed by atmospheric heating. Despite their drastically different roles, the Orbiter and Multiprobe were very similar in design. The use of identical systems (including flight hardware, flight software, and ground test equipment) and incorporation of existing designs from previous missions (including OSO and Intelsat) allowed the mission to meet its objectives at minimum cost.

Spacecraft

  • Multiprobe bus (Carrier vehicle) - With no heat shield or parachute, the bus survived and made measurements only to about 110 km altitude before burning up. The bus was a 2.5 m diameter cylinder weighing 290 kg. Spin stabilized. Body mounted solar panels provided 241 W. Payloads: Ion Mass Spectrometer (BIMS) - studied the composition of the upper atmosphere. Neutral Mass Spectrometer (BNMS) - studied the composition of the upper atmosphere.

  • Large probe - Weighed 315 kg. Consisted of 3 parts: a forward heat shield, an aft protective cover and a spherical titanium pressure vessel (73 cm diameter). Total probe diameter was 1.5 m. After deceleration from initial atmospheric entry at about 11.5 km/s near the equator on the Venus night side, the heat shield and protective cover were jettisoned, and a parachute was deployed at 47 km altitude to further slow descent. After parachute deployment, the exposed pressure vessel and its instrument package descended for about 1 1/2 hour before impact. During descent, the instruments were powered by batteries. Nine observation windows (8 sapphire and 1 diamond) were provided for instrument observations.3 pressure vessel penetrations were also provided as inlets for direct atmospheric sampling. Payload: Atmospheric Structure (LAS). Nephelometer (LN) - studied cloud particles. Cloud Particle Size Spectrometer (LCPS) - measured particle size and shape. Gas Chromatograph (LGC) - studied atmospheric composition. Infrared Radiometer (LIR) - monitored the distribution of infrared radiation. Neutral Particle Mass Spectrometer (NPMS) - studied atmospheric composition. Solar Flux Radiometer (LSFR) - examined solar flux penetration into the atmosphere. Differential Long Base Line Interferometer (DLBI). Atmospheric Propagation (MPRO) - temperature, pressure, and acceleration measurements.

  • Small probes - Each probe weighed 75 kg and was 0.8 m in diameter. Consisted of 3 parts: a forward heat shield, an aft protective cover and a spherical titanium pressure vessel. Unlike the large probe, the heat shield and protective cover remained attached to the pressure vessel, and no parachutes were deployed. Prior to atmospheric entry, each probe deployed a yo-yo despin device to reduce its spin rate from 48 to 15 rpm. Batteries provided power during descent (which lasted approx.75 minutes). Payload: Nephelometer. Temperature, pressure, and acceleration sensors. Net flux radiometer - mapped the distribution of sources and sinks of radiative energy in the atmosphere. Radio signals from all four probes were also used to characterize winds, turbulence, and propagation in the atmosphere.

NASA NSSDC Master Catalog Description

Pioneer Venus Small Probe (North) - This spacecraft was the first Small Probe of the Pioneer Venus Multiprobe mission. On this mission four instrumented atmospheric entry probes were carried by a spacecraft Bus to the vicinity of Venus for descent through the atmosphere to the planetary surface. Two Small Probes entered on the nightside, and one Small Probe and one Large Probe entered on the dayside of the planet. The spacecraft Bus entered the atmosphere and obtained atmospheric composition data until burnup. Investigations emphasized the study of the structure composition and nature of the atmosphere down to the surface, and of the clouds, the radiation field and energy exchange in the lower atmosphere, and local information on the atmospheric circulation pattern. A sister mission, Pioneer Venus Orbiter, placed an orbiting spacecraft around Venus 5 days before the Probes entered the atmosphere. Simultaneous measurements by the Probes and Orbiter permitted relating specific local measurements to the general state of the planet and its environment as observed from orbit.

The three small probes were identical and were designated the North Probe (1978-078E), the Night Probe (1978-078F), and the Day Probe (1978-078G). They were all mounted on the Multiprobe Bus (1978-078A) and were released on 20 November 1978. The probes were targeted for different entry points in the Venus atmosphere, all entered on 9 December 1978. The total cost of building and operating the Pioneer Venus probes was $83 million.

Spacecraft and Subsystems

The probe consisted of a spherical pressure vessel surrounded by a forward conical heat shield and an afterbody. The probes had a mass of 90 kg and a diameter of 0.8 m. The pressure vessel held all the scientific instruments and spacecraft systems. It was made of two precisely machined flanged titanium hemispheres joined by bolts with seals between. The seals comprised O-rings and graphoil flat gaskets. The vessel walls were lined on the inside with Kapton blankets and the interior was filled with 102 kPa of Xenon. The instruments were mounted on two beryllium shelves to absorb heat. A small hemispherical antenna protruded from the top of the pressure vessel. The pressure vessel had 7 openings, one for the antenna, three for electrical cables, two for scientific instruments, and one for an access hatch. There were also special diamond and sapphire windows. The probe did not have any thrusters, once released it was on a ballistic trajectory. The aeroshell was a 45 degree blunt cone made of titanium which used a bonded carbon phenolic ablative coating as a heat shield. The aeroshell was permanently attached to the pressure vessel, as was the fiberglass honeycomb afterbody. The small probes did not have parachutes. The small probe carried an atmospheric structure experiment, a nephelometer, a net-flux radiometer, and radio science experiments.

Mission Profile

The North Probe was released from the Multiprobe Bus at 13:06:29 UT on 20 November 1978. (All times are given in spacecraft time, Earth received time was approximately 3 minutes later.) It was targeted for the nightside at high northern latitudes and reached Venus on 9 December 1978. The probe initiated telemetry at 18:32:55 UT and entered the atmosphere (200 km altitude) at 18:49:40 UT. After a 53 minute descent, the probe touched down on the surface (59.3 N, 4.8 E) at 19:42:40 UT. Signals ended at this time.

NASA NSSDC Master Catalog Description

Pioneer Venus Large Probe - This spacecraft was the Large Probe portion of the Pioneer Venus Multiprobe mission. On this mission four instrumented atmospheric entry probes were carried by a spacecraft bus to the vicinity of Venus and released for descent through the atmosphere to the planetary surface. Two Small Probes entered on the nightside and a Small Probe and this Large Probe entered on the dayside of the planet. The spacecraft Bus entered the atmosphere and obtained atmospheric composition data until burnup. Investigations emphasized the study of 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. A sister mission, Pioneer Venus Orbiter, placed an orbiting spacecraft around Venus 5 days before the Probes entered the atmosphere. Simultaneous measurements by the Probes and Orbiter permitted relating specific local measurements to the general state of the planet and its environment as observed from orbit.

Spacecraft and Subsystems

The Large Probe comprised a spherical pressure vessel, a forward aeroshell heat shield, and an aft cover. The probe was 1.5 m in diameter and had a mass of 315 kg. The pressure vessel was built of three machined titanium parts: an aft hemisphere, a flat ring section, and a forward cap. Each section was flanged and bolted together and sealed with O-rings and graphoil gaskets. The interior of the pressure vessel was filled with 102 kPa of nitrogen. A pressure bottle held nitrogen to increase the internal pressure by 41 kPa. Two beryllium shelves held the instruments and spacecraft systems. The interior of the shell was lined with a 2.5 cm thick Kapton blanket. An antenna protruded from the top (aft) of the sphere. Two arms on the outside of the pressure vessel held a prism and an arm on the opposite side held a temperature sensor. There were 14 sealed penetrations in the pressure vessel: one for the antenna, four for electrical cables, two access hatches and seven for instruments. Power was provided by a 40 A-hr silver-zinc battery. Radio transmission at 2.3 GHz was powered by four 10-W amplifiers. The blunt cone-shaped aeroshell had an ablative carbon phenolic coating as a heat-shield. A pilot chute and mortar were mounted on the aeroshell and the main chute, held by the aft cover, was connected to three towers on the pressure vessel. The Large Probe carried a neutral mass spectrometer, a solar flux radiometer, an atmospheric structure experiment, a nephelometer, a cloud particle size spectrometer, a gas chromatograph, an infrared radiometer, and radio science experiments. The total cost of building and operating the probes was $83 million.

Mission Profile

The Large Probe, mounted on the Multiprobe Bus, was launched on the Pioneer Venus 2 mission on 8 August 1978 at 07:33:00 UT from Cape Canaveral. There was one midcourse correction on 16 August 1978. The Large Probe was released from the Multiprobe Bus at 02:37:13 UT on 16 November 1978 and entered the Venus atmosphere (200 km altitude) on 9 December at 18:45:32 UT. Telemetry had been initiated 16 minutes earlier. The heat shield was jettisoned at an altitude of 67 km. The parachute was jettisoned at 19:03:28 UT at an altitude of 47 km, and the probe impacted the surface (4.4 N, 304 E) at 19:39:53 UT, at which point transmissions ended.

NASA NSSDC Master Catalog Description

Pioneer Venus Small Probe (Day) - This spacecraft was the third Small Probe of the Pioneer Venus Multiprobe mission. On this mission four instrumented atmospheric entry Probes were carried by a spacecraft Bus to the vicinity of Venus for descent through the atmosphere to the planetary surface. Two Small Probes entered on the nightside, and one Small Probe and one Large Probe entered on the dayside of the planet. The spacecraft Bus entered the atmosphere and obtained atmospheric composition data until burnup. Investigations emphasize the study of the structural composition and nature of the atmosphere down to the surface, and of the clouds, the radiation field and energy exchange in the lower atmosphere; and local information on the atmospheric circulation pattern. A sister mission, Pioneer Venus Orbiter, placed an orbiting spacecraft around Venus 5 days before the Probes entered the atmosphere. Simultaneous measurements by the Probes and the Orbiter permitted relating specific local measurements to the general state of the planet and its environment as observed from orbit.

The three small probes were identical and were designated the North Probe (1978-078E), the Night Probe (1978-078F), and the Day Probe (1978-078G). They were all mounted on the Multiprobe Bus (1978-078A) and were released on 20 November 1978. The probes were targeted for different entry points in the Venus atmosphere, all entered on 9 December 1978. The total cost of building and operating the Pioneer Venus probes was $83 million.

Spacecraft and Subsystems

The probe consisted of a spherical pressure vessel surrounded by a forward conical heat shield and an afterbody. The probes had a mass of 90 kg and a diameter of 0.8 m. The pressure vessel held all the scientific instruments and spacecraft systems. It was made of two precisely machined flanged titanium hemispheres joined by bolts with seals between. The seals comprised O-rings and graphoil flat gaskets. The vessel walls were lined on the inside with Kapton blankets and the interior was filled with 102 kPa of Xenon. The instruments were mounted on two beryllium shelves to absorb heat. A small hemispherical antenna protruded from the top of the pressure vessel. The pressure vessel had 7 openings, one for the antenna, three for electrical cables, two for scientific instruments, and one for an access hatch. There were also special diamond and sapphire windows. The probe did not have any thrusters, once released it was on a ballistic trajectory. The aeroshell was a 45 degree blunt cone made of titanium which used a bonded carbon phenolic ablative coating as a heat shield. The aeroshell was permanently attached to the pressure vessel, as was the fiberglass honeycomb afterbody. The small probes did not have parachutes. The small probe carried an atmospheric structure experiment, a nephelometer, a net-flux radiometer, and radio science experiments.

Mission Profile

The Day Probe was released from the Multiprobe Bus at 13:06:29 UT on 20 November 1978. (All times are given in spacecraft time, Earth received time was approximately 3 minutes later.) It was targeted for the dayside at midsouthern latitudes and reached Venus on 9 December 1978. The probe initiated telemetry at 18:35:27 UT and entered the atmosphere (200 km altitude) at 18:52:18 UT. After a 56 minute descent, the probe touched down on the surface (31.3 S, 317 E) at 19:47:59 UT. The probe continued to transmit for another 67 minutes, 37 seconds after landing.

NASA NSSDC Master Catalog Description

Pioneer Venus Small Probe (Night) - This spacecraft was the second Small Probe of the Pioneer Venus Multiprobe mission. On this mission four instrumented atmospheric entry probes were carried by a spacecraft Bus to the vicinity of Venus for descent through the atmosphere to the planetary surface. Two Small Probes entered on the nightside, and one Small Probe and one Large Probe entered on the dayside of the planet. The spacecraft Bus entered the atmosphere and obtained atmospheric composition data until burnup. Investigations emphasized the study of the structure composition and nature of the atmosphere down to the surface, and of the clouds, the radiation field and energy exchange in the lower atmosphere, and local information on the atmospheric circulation pattern. A sister mission, Pioneer Venus Orbiter, placed an orbiting spacecraft around Venus 5 days before the Probes entered the atmosphere. Simultaneous measurements by the Probes and Orbiter permitted relating specific local measurements to the general state of the planet and its environment as observed from orbit.

The three small probes were identical and were designated the North Probe (1978-078E), the Night Probe (1978-078F), and the Day Probe (1978-078G). They were all mounted on the Multiprobe Bus (1978-078A) and were released on 20 November 1978. The probes were targeted for different entry points in the Venus atmosphere, all entered on 9 December 1978. The total cost of building and operating the Pioneer Venus probes was $83 million.

Spacecraft and Subsystems

The probe consisted of a spherical pressure vessel surrounded by a forward conical heat shield and an afterbody. The probes had a mass of 90 kg and a diameter of 0.8 m. The pressure vessel held all the scientific instruments and spacecraft systems. It was made of two precisely machined flanged titanium hemispheres joined by bolts with seals between. The seals comprised O-rings and graphoil flat gaskets. The vessel walls were lined on the inside with Kapton blankets and the interior was filled with 102 kPa of Xenon. The instruments were mounted on two beryllium shelves to absorb heat. A small hemispherical antenna protruded from the top of the pressure vessel. The pressure vessel had 7 openings, one for the antenna, three for electrical cables, two for scientific instruments, and one for an access hatch. There were also special diamond and sapphire windows. The probe did not have any thrusters, once released it was on a ballistic trajectory. The aeroshell was a 45 degree blunt cone made of titanium which used a bonded carbon phenolic ablative coating as a heat shield. The aeroshell was permanently attached to the pressure vessel, as was the fiberglass honeycomb afterbody. The small probes did not have parachutes. The small probe carried an atmospheric structure experiment, a nephelometer, a net-flux radiometer, and radio science experiments.

Mission Profile

The Night Probe was released from the Multiprobe Bus at 13:06:29 on 20 November 1978. (All times are given in spacecraft time, Earth received time was approximately 3 minutes later.) It was targeted for the nightside at midsouthern latitudes and reached Venus on 9 December 1978. The probe initiated telemetry at 18:39:08 UT and entered the atmosphere (200 km altitude) at 18:56:13 UT. After a 56 minute descent, the probe touched down on the surface (28.7 S, 56.7 E) at 19:52:05 UT. The probe transmitted for 2 more seconds after impact.

NASA NSSDC Master Catalog Description

Pioneer Venus Probe Bus - The spacecraft was the Bus portion of the Pioneer Venus Multiprobe mission. On this mission four instrumented atmospheric entry Probes were carried by this Bus to the vicinity of Venus and released for descent through the atmosphere to the planetary surface. Investigators emphasized the study of 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. A sister mission, Pioneer Venus Orbiter, placed an orbiting spacecraft around Venus 5 days before the Probes entered the atmosphere. Simultaneous measurements by the probes and orbiter permitted relating specific local measurements to the general state of the planet and its environment as observed from orbit.

Spacecraft and Subsystems

The Multiprobe Bus had a total mass at launch of 875 kg, of which 585 kg were the attached Large Probe and three Small Probes, 32 kg was hydrazine fuel, and 290 kg was the Bus structure itself. The Bus was a 2.5 meter diameter cylinder on top of which were mounted the Large Probe in the center and the three Small Probes spaced 120 degrees apart around the Large Probe. The total height of the unit from the bottom of the Bus to the top of the large probe was 2.9 meters. Power was provided by a solar array around the outside of the cylinder and batteries. Attitude control and knowledge was provided by radial and aft thrusters and star sensors. Communications were via forward and aft omnidirectional antennae and an aft medium gain horn antenna. The bus was not equipped with heat shield or parachutes, it was only designed to survive upper atmospheric entry. The Large Probe was designed to be launched from the Bus by a pyrotechnic spring-separation system. The Small Probes were held by clamps which could be released by firing explosive nuts. The probes would then spin off the bus tangentially due to the 48 rpm rotation. The Bus carried Ion and Neutral Mass Spectrometers to study the upper atmosphere. The total cost of building and operating the probes was $83 million.

Mission Profile

The Probe Bus was launched on the Pioneer Venus 2 mission on 8 August 1978 at 07:33:00 UT from Cape Canaveral. There was one midcourse correction on 16 August 1978. The trip to Venus took 123 days. The Large Probe separated from the Bus on 16 November and the Small Probes on 20 November. After release of the probes the bus was slowed slightly to fall behind the probes as they headed towards Venus. Two Small Probes entered on the nightside, and one Small Probe and the Large Probe entered on the dayside of the planet. The spacecraft was spin-stabilized at about 48 rpm. The Large Probe took 1-1/2 h to descend through the atmosphere, while the three smaller probes reached the surface of the planet 75 min after entry. The Bus portion of the spacecraft was targeted to enter the Venusian atmosphere at a shallow entry angle and transmit data to Earth until the Bus was destroyed by the heat of atmospheric friction during its descent. At 20:21:52 UT on 9 December 1978 the bus entered the dayside Venus atmosphere (200 km altitude) at 37.9 S, 290.9 E. It returned signals until reaching an altitude of 110 km one minute later at 20:22:55 UT.


More at: Pioneer 13.

Family: Venus. Country: USA. Launch Vehicles: Atlas, Atlas SLV-3D Centaur. Projects: Pioneer series. Launch Sites: Cape Canaveral, Cape Canaveral LC36A. Agency: NASA, NASA Ames, Hughes. Bibliography: 2, 278, 296, 6, 6781, 12959.
Photo Gallery

Pioneer 13Pioneer 13
Credit: Manufacturer Image



1978 August 8 - . 07:33 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC36A. LV Family: Atlas. Launch Vehicle: Atlas SLV-3D Centaur.
  • Pioneer Venus 2 - . Payload: Pioneer-Venus 2. Mass: 904 kg (1,992 lb). Nation: USA. Agency: NASA Ames. Program: Pioneer. Class: Venus. Type: Venus probe. Spacecraft: Pioneer 13. Decay Date: 1978-12-09 . USAF Sat Cat: 11001 . COSPAR: 1978-078A.

    The Pioneer Venus Multiprobe consisted of a bus which carried one large and three small `atmospheric probes. The large probe was released on November 16, 1978 and the three small probes on November 20. All four probes entered the Venus atmosphere on December 9, followed by the bus. The small probes were each targeted at different parts of the planet and were named accordingly. The North probe entered the atmosphere at about 60 degrees north latitude on the day side. The night probe entered on the night side. The day probe entered well into the day side, and was the only one of the four probes which continued to send radio signals back after impact, for over an hour. With no heat shield or parachute, the bus survived and made measurements only to about 110 km altitude before burning up. It afforded the only direct view of the upper Venus atmosphere, as the probes did not begin making direct measurements until they had decelerated lower in the atmosphere.

  • Pioneer Venus Probe 4 - . Payload: Pioneer-Venus 2. Mass: 90 kg (198 lb). Nation: USA. Agency: NASA Ames. Program: Pioneer. Class: Venus. Type: Venus probe. Spacecraft: Pioneer 13. Decay Date: 1978-12-09 . USAF Sat Cat: 12106 . COSPAR: 1978-078G.
  • Pioneer Venus Probe 3 - . Payload: Pioneer-Venus 2. Mass: 90 kg (198 lb). Nation: USA. Agency: NASA Ames. Program: Pioneer. Class: Venus. Type: Venus probe. Spacecraft: Pioneer 13. Decay Date: 1978-12-09 . USAF Sat Cat: 12105 . COSPAR: 1978-078F.
  • Pioneer Venus Probe 2 - . Payload: Pioneer-Venus 2. Mass: 90 kg (198 lb). Nation: USA. Agency: NASA Ames. Program: Pioneer. Class: Venus. Type: Venus probe. Spacecraft: Pioneer 13. Decay Date: 1978-12-09 . USAF Sat Cat: 12104 . COSPAR: 1978-078E.
  • Pioneer Venus Probe 1 - . Payload: Pioneer-Venus 2. Mass: 315 kg (694 lb). Nation: USA. Agency: NASA Ames. Program: Pioneer. Class: Venus. Type: Venus probe. Spacecraft: Pioneer 13. Decay Date: 1978-12-09 . USAF Sat Cat: 12103 . COSPAR: 1978-078D.

1978 December 9 - .
  • Pioneer Venus 2, Venus Atmospheric Probes - . Nation: USA. Spacecraft: Pioneer 13.


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