Pioneer Venus Multiprobe

Pioneer Venus Multiprobe

Pioneer Venus Multiprobe
Mission type	Venus atmospheric probes
Operator	NASA / ARC
COSPAR ID	1978-078A
SATCAT no.	11001
Website	National Space Science Data Center (NASA)
Mission duration	4 months, 1 day
Spacecraft properties
Bus	HS-507
Manufacturer	Hughes
Launch mass	904 kilograms (1,993 lb)
Dry mass	290 kilograms (640 lb) (bus) 315 kilograms (694 lb) (large probe) 3 x 90 kilograms (200 lb) (small probes)
Power	241 watts
Start of mission
Launch date	August 8, 1978, 07:33 (1978-08-08UTC07:33Z) UTC
Rocket	Atlas SLV-3D Centaur-D1AR
Launch site	Cape Canaveral LC-36A
End of mission
Last contact	December 9, 1978, 20:22:55 UTC (bus) December 9, 1978, 20:55:34 (1978-12-09UTC20:55:35Z) UTC (day probe)
Orbital parameters
Reference system	Heliocentric
Semi-major axis	0.9 astronomical units (130,000,000 km; 84,000,000 mi)
Eccentricity	0.19
Perihelion	0.69 astronomical units (103,000,000 km; 64,000,000 mi)
Apohelion	1.01 astronomical units (151,000,000 km; 94,000,000 mi)
Inclination	2.3 degrees
Period	284.0 days
Venus atmospheric probe
Spacecraft component	Large Probe
Atmospheric entry	December 9, 1978, 18:45:32 UTC
Impact date	19:39:53 UTC
Impact site	4°24′N 304°00′E / 4.4°N 304.0°E / 4.4; 304.0
Venus atmospheric probe
Spacecraft component	North Probe
Atmospheric entry	December 9, 1978, 18:49:40 UTC
Impact date	19:42:40 UTC
Impact site	59°18′N 4°48′E / 59.3°N 4.8°E / 59.3; 4.8
Venus atmospheric probe
Spacecraft component	Day Probe
Atmospheric entry	December 9, 1978, 18:52:18 UTC
Impact date	19:47:59 UTC
Impact site	31°18′S 317°00′E / 31.3°S 317.0°E / -31.3; 317.0
Venus atmospheric probe
Spacecraft component	Night Probe
Atmospheric entry	December 9, 1978, 18:56:13 UTC
Impact date	19:52:05 UTC
Impact site	28°42′S 56°42′E / 28.7°S 56.7°E / -28.7; 56.7
Venus atmospheric probe
Atmospheric entry	December 9, 1978, 20:21:52 UTC

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

Pioneer Venus Bus with probes attached

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 2.5 metres (8 ft 2 in) and a mass of 290 kilograms (640 lb). 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:

• BIMS - a ion mass spectrometer to determine the origin and long-term development of the Venusian atmosphere, the dynamics of the upper atmosphere layers and its energy balance and the effect of solar radiation and interplanetary space on those layers. This instrument had a range of 1 to 46 u, used 6 W of power and weighed 5 kilograms (11 lb).
• BNMS - a neutral mass spectrometer to the surface to be examined and reflected reflected particles, which could determine the composition. This made measurements about the interaction between the solar wind and Venus, the photochemistry of the upper atmosphere layers and its mass and the heat spread in the Venusian atmosphere. It had a range of 1 to 60 u and took ions in the upper atmosphere layers from passing the arc shock until the mother ship burned into the atmosphere. Weight 1 kilogram (2.2 lb) and power 1 W.

Down to an altitude of about 110 km before disintegrating on December 9, 1978.

Probes

The spacecraft carried one large and three small atmospheric probes, designed to collect data as they descended into the atmosphere of Venus. The probes did not carry photographic instruments, and were not designed to survive landing – the smaller probes were not equipped with parachutes, and the larger probe's parachute was expected to detach as it neared the ground. All four probes continued transmitting data until impact; however, one survived and continued to transmit data from the surface.

Large probe

Pioneer Venus Large Probe opens its parachute (Artist's rendition)

The Large probe carried seven experiments, contained within a sealed spherical pressure vessel. The science experiments were:

• LNMS - neutral mass spectrometer to measure the atmospheric composition
• LGC - gas chromatograph to measure the atmospheric composition
• LSFR - solar flux radiometer to measure solar flux penetration in the atmosphere
• LIR - infrared radiometer to measure distribution of infrared radiation
• LCPS - cloud particle size spectrometer to measure particle size and shape
• LN - nephelometer to search for cloud particles
• temperature, pressure, and acceleration sensors

This pressure vessel was encased in a nose cone and aft protective cover. After deceleration from initial atmospheric entry at about 11.5 kilometres per second (7.1 mi/s) near the equator on the night side of Venus, a parachute was deployed at 67 km altitude. The large probe was about 150 centimetres (59 in) in diameter and the pressure vessel itself was 73.2 centimeters (28.8 in) in diameter.

Small probes

A small probe (1-antenna, 2-temperature sensor, 3-frontal protection, 4-hermetic container, 5-nephelometer, 6-radiometer)

Entry of Pioneer Venus Multiprobe

Pioneer Venus Large Probe descent sequence

Trajectory of Pioneer Venus Multiprobe

Three identical small probes, around 0.8 metres (2 ft 7 in) in diameter, were deployed. These probes consisted of spherical pressure vessels surrounded by an aeroshell, but unlike the large probe, they had no parachutes and the aeroshells did not separate from the probes.

The science experiments were:^[1]

• a neutral mass spectrometer to measure the atmospheric composition
• a gas chromatograph to measure the atmospheric composition
• SNFR - solar flux radiometer to measure solar flux penetration in the atmosphere
• an infrared radiometer to measure distribution of infrared radiation
• MTUR - cloud particle size spectrometer to measure particle size and shape
• SN - nephelometer to search for cloud particles
• SAS - temperature, pressure, and acceleration sensors

The radio signals from all four probes were also used to characterize the winds, turbulence, and propagation in the atmosphere. The small probes were each targeted at different parts of the planet and were named accordingly.^[2]

• 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.

Launch

The Pioneer Venus Multiprobe was launched by an Atlas SLV-3D Centaur-D1AR rocket, which flew from Launch Complex 36A at the Cape Canaveral Air Force Station. The launch occurred at 07:33 on August 8, 1978, and deployed the Multiprobe into heliocentric orbit for its coast to Venus.

Arrival at Venus

Prior to the Multiprobe reaching Venus, the four probes were deployed from the main bus. The large probe was released on November 16, 1978, and the three small probes on November 20.

All four probes and the bus reached Venus on December 9, 1978. The large probe was the first to enter the atmosphere, at 18:45:32 UTC, followed over the next 11 minutes by the other three probes. The bus entered the atmosphere at 20:21:52 UTC, and returned its last signal at 20:22:55 from an altitude of 110 kilometres (68 mi).

The four probes transmitted data until they impacted the surface of Venus. The Day Probe survived impact, returning data from the surface for over an hour.

Scientific results

Below the altitude of 50 km the temperatures measured by the four probes are identical to within a few degrees. They are between 448 °C and 459 °C (838 °F and 858 °F) on the surface. The ground pressure is between 86.2 bar and 94.5 bar. Nephelometers identified three cloud layers with different characteristics. The most remarkable discovery regarding the ratio of ³⁶argon / ⁴⁰argon isotopes much higher than in the atmosphere which seems to indicate that the genesis of the Venusian atmosphere is very different from that of Earth. The reconstituted trajectory of atmospheric probes was determined that the wind averaged a speed of 200 m/s in the middle cloud layer at 50 m/s at the base of these clouds and just 1 m/s at the ground. Overall data from airborne sensors confirmed, while specifying the data obtained by the Soviet space probe Venera program that preceded this mission.^[3]

See also

• Pioneer Venus Orbiter
• List of missions to Venus
• Timeline of artificial satellites and space probes
• Galileo Probe (Jupiter atmospheric probe delivered by Galileo spacecraft)

References

External links

Wikimedia Commons has media related to Pioneer Venus project.

• NASA: Pioneer Venus Project Information
• Pioneer Venus Program Page by NASA's Solar System Exploration
• NSSDC Master Catalog: Spacecraft Pioneer Venus Probe Bus. (Other components of the mission have their own pages at this site too.)

Science Magazine in year 1979 issue 4401

• Donahue, T. M. (6 July 1979). "Pioneer Venus Results: An Overview". Science. 205 (4401): 41–44. JSTOR 1748508. 
• Colin, Lawrence (6 July 1979). "Encounter with Venus: An Update". Science. 205 (4401): 44–46. JSTOR 1748509. 
• Seiff, Alvin; Kirk, Donn B.; Young, Richard E.; Sommer, Simon C.; Blanchard, Robert C.; Findlay, John T.; Kelly, G. M. (6 July 1979). "Thermal Contrast in the Atmosphere of Venus: Initial Appraisal from Pioneer Venus Probe Data". Science. 205 (4401): 46–49. JSTOR 1748510. 
• Hoffman, J. H.; Hodges, R. R.; McElroy, M. B.; Donahue, T. M.; Kolpin, M. (6 July 1979). "Composition and Structure of the Venus Atmosphere: Results from Pioneer Venus". Science. 205 (4401): 49–52. JSTOR 1748511. PMID 17778898. 
• Oyama, V. I.; Carle, G. C.; Woeller, F.; Pollack, J. B. (6 July 1979). "Laboratory Corroboration of the Pioneer Venus Gas Chromatograph Analyses". Science. 205 (4401): 52–54. JSTOR 1748512. 
• Niemann, H. B.; Hartle, R. E.; Hedin, A. E.; Kasprzak, W. T.; Spencer, N. W.; Hunten, D. M.; Carignan, G. R. (6 July 1979). "Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations". Science. 205 (4401): 54–56. JSTOR 1748513. 
• Pollack, James B.; Black, David C. (6 July 1979). "Implications of the Gas Compositional Measurements of Pioneer Venus for the Origin of Planetary Atmospheres". Science. 205 (4401): 56–59. JSTOR 1748514. 
• Stewart, A. Ian; Barth, Charles A. (6 July 1979). "Ultraviolet Night Airglow of Venus". Science. 205 (4401): 59–62. JSTOR 1748515. PMID 17778902. 
• Keating, G. M.; Taylor, F. W.; Nicholson, J. Y.; Hinson, E. W. (6 July 1979). "Short-Term Cyclic Variations and Diurnal Variations of the Venus Upper Atmosphere". Science. 205 (4401): 62–64. JSTOR 1748516. 
• Taylor, F. W.; Diner, D. J.; Elson, L. S.; McCleese, D. J.; Martonchik, J. V.; Delderfield, J.; Bradley, S. P.; Schofield, J. T.; Gille, J. C.; Coffey, M. T. (6 July 1979). "Temperature, Cloud Structure, and Dynamics of Venus Middle Atmosphere by Infrared Remote Sensing from Pioneer Orbiter". Science. 205 (4401): 65–67. JSTOR 1748517. 
• Blamont, Jacques; Ragent, Boris (6 July 1979). "Further Results of the Pioneer Venus Nephelometer Experiment". Science. 205 (4401): 67–70. JSTOR 1748518. PMID 17778905. 
• Knollenberg, Robert G.; Hunten, D. M. (6 July 1979). "Clouds of Venus: A Preliminary Assessment of Microstructure". Science. 205 (4401): 70–74. JSTOR 1748519. 
• Travis, L. D.; Coffeen, D. L.; Del Genio, A. D.; Hansen, J. E.; Kawabata, K.; Lacis, A. A.; Lane, W. A.; Limaye, S. S.; Rossow, W. B.; Stone, P. H. (6 July 1979). "Cloud Images from the Pioneer Venus Orbiter". Science. 205 (4401): 74–76. JSTOR 1748520. 
• Pollack, James B.; Ragent, Boris; Boese, Robert; Tomasko, Martin G.; Blamont, Jacques; Knollenberg, Robert G.; Esposito, Larry W.; Stewart, A. Ian; Travis, Lawrence (6 July 1979). "Nature of the Ultraviolet Absorber in the Venus Clouds: Inferences Based on Pioneer Venus Data". Science. 205 (4401): 76–79. JSTOR 1748521. 
• Tomasko, Martin G.; Doose, Lyn R.; Smith, Peter H. (6 July 1979). "Absorption of Sunlight in the Atmosphere of Venus". Science. 205 (4401): 80–82. JSTOR 1748522. 
• Suomi, V. E.; Sromovsky, L. A.; Revercomb, H. E. (6 July 1979). "Preliminary Results of the Pioneer Venus Small Probe Net Flux Radiometer Experiment". Science. 205 (4401): 82–85. JSTOR 1748523. 
• Counselman, C. C.; Gourevitch, S. A.; King, R. W.; Loriot, G. B.; Prinn, R. G. (6 July 1979). "Venus Winds Are Zonal and Retrograde Below the Clouds". Science. 205 (4401): 85–87. JSTOR 1748524. 
• Woo, Richard; Armstrong, J. W.; Kendall, William B. (6 July 1979). "Measurements of Turbulence in the Venus Atmosphere Deduced from Pioneer Venus Multiprobe Radio Scintillations". Science. 205 (4401): 87–89. JSTOR 1748525. 
• Pettengill, Gordon H.; Ford, Peter G.; Brown, Walter E.; Kaula, William M.; Masursky, Harold; Eliason, Eric; McGill, George E. (6 July 1979). "Venus: Preliminary Topographic and Surface Imaging Results from the Pioneer Orbiter". Science. 205 (4401): 90–93. JSTOR 1748526. 
• Phillips, Roger J.; Sjogren, William L.; Abbott, Elsa A.; Smith, John C.; Wimberly, Ray N.; Wagner, Cari A. (6 July 1979). "Gravity Field of Venus: A Preliminary Analysis". Science. 205 (4401): 93–96. JSTOR 1748527. 
• Taylor, Harry A.; Brinton, Henry C.; Bauer, Siegfried J.; Hartle, Richard E.; Cloutier, Paul A.; Daniell, Robert E.; Donahue, Thomas M. (6 July 1979). "Ionosphere of Venus: First Observations of Day-Night Variations of the Ion Composition". Science. 205 (4401): 96–99. JSTOR 1748528. 
• Kliore, A. J.; Patel, I. R.; Nagy, A. F.; Cravens, T. E.; Gombosi, T. I. (6 July 1979). "Initial Observations of the Nightside Ionosphere of Venus from Pioneer Venus Orbiter Radio Occultations". Science. 205 (4401): 99–102. JSTOR 1748529. PMID 17778916. 
• Brace, L. H.; Theis, R. F.; Niemann, H. B.; Mayr, H. G.; Hoegy, W. R.; Nagy, A. F. (6 July 1979). "Empirical Models of the Electron Temperature and Density in the Nightside Venus Ionosphere". Science. 205 (4401): 102–105. JSTOR 1748530. 
• Knudsen, W. C.; Spenner, K.; Whitten, R. C.; Spreiter, J. R.; Miller, K. L.; Novak, V. (6 July 1979). "Thermal Structure and Energy Influx to the Day- and Nightside Venus Ionosphere". Science. 205 (4401): 105–107. JSTOR 1748531. 
• Nagy, A. F.; Cravens, T. E.; Chen, R. H.; Taylor, H. A.; Brace, L. H.; Brinton, H. C. (6 July 1979). "Comparison of Calculated and Measured Ion Densities on the Dayside of Venus". Science. 205 (4401): 107–109. JSTOR 1748532. 
• Bauer, Siegfried J.; Donahue, Thomas M.; Hartle, Richard E.; Taylor, Harry A. (6 July 1979). "Venus Ionosphere: Photochemical and Thermal Diffusion Control of Ion Composition". Science. 205 (4401): 109–112. JSTOR 1748533. 
• Taylor, W. W. L.; Scarf, F. L.; Russell, C. T.; Brace, L. H. (6 July 1979). "Absorption of Whistler Mode Waves in the Ionosphere of Venus". Science. 205 (4401): 112–114. JSTOR 1748534. 
• Russell, C. T.; Elphic, R. C.; Slavin, J. A. (6 July 1979). "Initial Pioneer Venus Magnetic Field Results: Nightside Observations". Science. 205 (4401): 114–116. JSTOR 1748535. 
• Intriligator, D. S.; Collard, H. R.; Mihalov, J. D.; Whitten, R. C.; Wolfe, J. H. (6 July 1979). "Electron Observations and Ion Flows from the Pioneer Venus Orbiter Plasma Analyzer Experiment". Science. 205 (4401): 116–119. JSTOR 1748536. 
• Evans, W. D.; Glore, J. P.; Klebesadel, R. W.; Laros, J. G.; Tech, E. R.; Spalding, R. E. (6 July 1979). "Gamma-Ray Burst Observations by Pioneer Venus Orbiter". Science. 205 (4401): 119–121. JSTOR 1748537. 
• Donahue, T. M. (6 July 1979). "Pioneer Venus Results: An Overview". Science. 205 (4401): 41–44. JSTOR 1748508. 
• Colin, Lawrence (6 July 1979). "Encounter with Venus: An Update". Science. 205 (4401): 44–46. JSTOR 1748509. 
• Seiff, Alvin; Kirk, Donn B.; Young, Richard E.; Sommer, Simon C.; Blanchard, Robert C.; Findlay, John T.; Kelly, G. M. (6 July 1979). "Thermal Contrast in the Atmosphere of Venus: Initial Appraisal from Pioneer Venus Probe Data". Science. 205 (4401): 46–49. JSTOR 1748510. 
• Hoffman, J. H.; Hodges, R. R.; McElroy, M. B.; Donahue, T. M.; Kolpin, M. (6 July 1979). "Composition and Structure of the Venus Atmosphere: Results from Pioneer Venus". Science. 205 (4401): 49–52. JSTOR 1748511. PMID 17778898. 
• Oyama, V. I.; Carle, G. C.; Woeller, F.; Pollack, J. B. (6 July 1979). "Laboratory Corroboration of the Pioneer Venus Gas Chromatograph Analyses". Science. 205 (4401): 52–54. JSTOR 1748512. 
• Niemann, H. B.; Hartle, R. E.; Hedin, A. E.; Kasprzak, W. T.; Spencer, N. W.; Hunten, D. M.; Carignan, G. R. (6 July 1979). "Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations". Science. 205 (4401): 54–56. JSTOR 1748513. 
• Pollack, James B.; Black, David C. (6 July 1979). "Implications of the Gas Compositional Measurements of Pioneer Venus for the Origin of Planetary Atmospheres". Science. 205 (4401): 56–59. JSTOR 1748514. 
• Stewart, A. Ian; Barth, Charles A. (6 July 1979). "Ultraviolet Night Airglow of Venus". Science. 205 (4401): 59–62. JSTOR 1748515. PMID 17778902. 
• Keating, G. M.; Taylor, F. W.; Nicholson, J. Y.; Hinson, E. W. (6 July 1979). "Short-Term Cyclic Variations and Diurnal Variations of the Venus Upper Atmosphere". Science. 205 (4401): 62–64. JSTOR 1748516. 
• Taylor, F. W.; Diner, D. J.; Elson, L. S.; McCleese, D. J.; Martonchik, J. V.; Delderfield, J.; Bradley, S. P.; Schofield, J. T.; Gille, J. C.; Coffey, M. T. (6 July 1979). "Temperature, Cloud Structure, and Dynamics of Venus Middle Atmosphere by Infrared Remote Sensing from Pioneer Orbiter". Science. 205 (4401): 65–67. JSTOR 1748517. 
• Blamont, Jacques; Ragent, Boris (6 July 1979). "Further Results of the Pioneer Venus Nephelometer Experiment". Science. 205 (4401): 67–70. JSTOR 1748518. PMID 17778905. 
• Knollenberg, Robert G.; Hunten, D. M. (6 July 1979). "Clouds of Venus: A Preliminary Assessment of Microstructure". Science. 205 (4401): 70–74. JSTOR 1748519. 
• Travis, L. D.; Coffeen, D. L.; Del Genio, A. D.; Hansen, J. E.; Kawabata, K.; Lacis, A. A.; Lane, W. A.; Limaye, S. S.; Rossow, W. B.; Stone, P. H. (6 July 1979). "Cloud Images from the Pioneer Venus Orbiter". Science. 205 (4401): 74–76. JSTOR 1748520. 
• Pollack, James B.; Ragent, Boris; Boese, Robert; Tomasko, Martin G.; Blamont, Jacques; Knollenberg, Robert G.; Esposito, Larry W.; Stewart, A. Ian; Travis, Lawrence (6 July 1979). "Nature of the Ultraviolet Absorber in the Venus Clouds: Inferences Based on Pioneer Venus Data". Science. 205 (4401): 76–79. JSTOR 1748521. 
• Tomasko, Martin G.; Doose, Lyn R.; Smith, Peter H. (6 July 1979). "Absorption of Sunlight in the Atmosphere of Venus". Science. 205 (4401): 80–82. JSTOR 1748522. 
• Suomi, V. E.; Sromovsky, L. A.; Revercomb, H. E. (6 July 1979). "Preliminary Results of the Pioneer Venus Small Probe Net Flux Radiometer Experiment". Science. 205 (4401): 82–85. JSTOR 1748523. 
• Counselman, C. C.; Gourevitch, S. A.; King, R. W.; Loriot, G. B.; Prinn, R. G. (6 July 1979). "Venus Winds Are Zonal and Retrograde Below the Clouds". Science. 205 (4401): 85–87. JSTOR 1748524. 
• Woo, Richard; Armstrong, J. W.; Kendall, William B. (6 July 1979). "Measurements of Turbulence in the Venus Atmosphere Deduced from Pioneer Venus Multiprobe Radio Scintillations". Science. 205 (4401): 87–89. JSTOR 1748525. 
• Pettengill, Gordon H.; Ford, Peter G.; Brown, Walter E.; Kaula, William M.; Masursky, Harold; Eliason, Eric; McGill, George E. (6 July 1979). "Venus: Preliminary Topographic and Surface Imaging Results from the Pioneer Orbiter". Science. 205 (4401): 90–93. JSTOR 1748526. 
• Phillips, Roger J.; Sjogren, William L.; Abbott, Elsa A.; Smith, John C.; Wimberly, Ray N.; Wagner, Cari A. (6 July 1979). "Gravity Field of Venus: A Preliminary Analysis". Science. 205 (4401): 93–96. JSTOR 1748527. 
• Taylor, Harry A.; Brinton, Henry C.; Bauer, Siegfried J.; Hartle, Richard E.; Cloutier, Paul A.; Daniell, Robert E.; Donahue, Thomas M. (6 July 1979). "Ionosphere of Venus: First Observations of Day-Night Variations of the Ion Composition". Science. 205 (4401): 96–99. JSTOR 1748528. 
• Kliore, A. J.; Patel, I. R.; Nagy, A. F.; Cravens, T. E.; Gombosi, T. I. (6 July 1979). "Initial Observations of the Nightside Ionosphere of Venus from Pioneer Venus Orbiter Radio Occultations". Science. 205 (4401): 99–102. JSTOR 1748529. PMID 17778916. 
• Brace, L. H.; Theis, R. F.; Niemann, H. B.; Mayr, H. G.; Hoegy, W. R.; Nagy, A. F. (6 July 1979). "Empirical Models of the Electron Temperature and Density in the Nightside Venus Ionosphere". Science. 205 (4401): 102–105. JSTOR 1748530. 
• Knudsen, W. C.; Spenner, K.; Whitten, R. C.; Spreiter, J. R.; Miller, K. L.; Novak, V. (6 July 1979). "Thermal Structure and Energy Influx to the Day- and Nightside Venus Ionosphere". Science. 205 (4401): 105–107. JSTOR 1748531. 
• Nagy, A. F.; Cravens, T. E.; Chen, R. H.; Taylor, H. A.; Brace, L. H.; Brinton, H. C. (6 July 1979). "Comparison of Calculated and Measured Ion Densities on the Dayside of Venus". Science. 205 (4401): 107–109. JSTOR 1748532. 
• Bauer, Siegfried J.; Donahue, Thomas M.; Hartle, Richard E.; Taylor, Harry A. (6 July 1979). "Venus Ionosphere: Photochemical and Thermal Diffusion Control of Ion Composition". Science. 205 (4401): 109–112. JSTOR 1748533. 
• Taylor, W. W. L.; Scarf, F. L.; Russell, C. T.; Brace, L. H. (6 July 1979). "Absorption of Whistler Mode Waves in the Ionosphere of Venus". Science. 205 (4401): 112–114. JSTOR 1748534. 
• Russell, C. T.; Elphic, R. C.; Slavin, J. A. (6 July 1979). "Initial Pioneer Venus Magnetic Field Results: Nightside Observations". Science. 205 (4401): 114–116. JSTOR 1748535. 
• Intriligator, D. S.; Collard, H. R.; Mihalov, J. D.; Whitten, R. C.; Wolfe, J. H. (6 July 1979). "Electron Observations and Ion Flows from the Pioneer Venus Orbiter Plasma Analyzer Experiment". Science. 205 (4401): 116–119. JSTOR 1748536. 
• Evans, W. D.; Glore, J. P.; Klebesadel, R. W.; Laros, J. G.; Tech, E. R.; Spalding, R. E. (6 July 1979). "Gamma-Ray Burst Observations by Pioneer Venus Orbiter". Science. 205 (4401): 119–121. JSTOR 1748537.