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Pioneer Venus Multiprobe#Small probes

{{short description|NASA atmospheric mission to Venus (1978)}}

{{more footnotes|date=January 2015}}

{{Infobox spaceflight

| name = Pioneer Venus Multiprobe

| names_list = Pioneer Venus 2
Pioneer 13

| image = Pioneer Venus Multiprobe spacecraft.jpg

| image_caption = Artist's impression of the five components of Pioneer 13 approaching Venus

| mission_type = Venus atmospheric probes

| operator = NASA{{\}}Ames

| website = [https://science.nasa.gov/mission/pioneer-venus-2/ science.nasa.gov]

| COSPAR_ID = 1978-078A

| SATCAT = 11001

| mission_duration = {{time interval|8 Aug 1978|9 Dec 1978}}

| spacecraft_bus = HS-507

| manufacturer = Hughes

| dry_mass = {{convert|290|kg|lb}} (bus)
{{convert|315|kg|lb}} (large probe)
{{nowrap|3 x {{convert|90|kg|lb}} (small probes)}}

| launch_mass = {{convert|904|kg|lb}}{{cite web|url=https://solarsystem.nasa.gov/missions/pioneer-venus-2/in-depth/ |title=Pioneer Venus Multiprobe/Pioneer Venus 2/Pioneer 13 |publisher=NASA's Solar System Exploration website |access-date=December 1, 2022}}

| power = 241 W

| launch_date = {{start-date|August 8, 1978, 07:33|timezone=yes}} UTC

| launch_rocket = Atlas SLV-3D Centaur-D1AR (AC-51)

| launch_site = Cape Canaveral LC-36A

| last_contact = December 9, 1978, 20:22:55 UTC
(main bus)
{{end-date|December 9, 1978, 20:55:34|timezone=yes}} UTC
(Day probe)

| orbit_epoch =

| orbit_reference = Heliocentric

| orbit_semimajor = {{convert|0.9|AU|km mi|sp=us}}

| orbit_eccentricity = 0.19

| orbit_periapsis = {{convert|0.69|AU|km mi|sp=us}}

| orbit_apoapsis = {{convert|1.01|AU|km mi|sp=us}}

| orbit_inclination = 2.3 degrees

| orbit_period = 284.0 days

| apsis = helion

|interplanetary =

{{Infobox spaceflight/IP

|type = atmospheric

|object = Venus

|component = Large Probe

|arrival_date = December 9, 1978, 18:45:32 UTC

|departure_date = 19:39:53 UTC

|location = {{Venus coords and quad cat|4.4|N|304.0|E}}

}}

{{Infobox spaceflight/IP

|type = atmospheric

|object = Venus

|component = North Probe

|arrival_date = December 9, 1978, 18:49:40 UTC

|departure_date = 19:42:40 UTC

|location = {{Venus coords and quad cat|59.3|N|4.8|E}}

}}

{{Infobox spaceflight/IP

|type = atmospheric

|object = Venus

|component = Day Probe

|arrival_date = December 9, 1978, 18:52:18 UTC

|departure_date = 19:47:59 UTC

|location = {{Venus coords and quad cat|31.3|S|317.0|E}}

}}

{{Infobox spaceflight/IP

|type = atmospheric

|object = Venus

|component = Night Probe

|arrival_date = December 9, 1978, 18:56:13 UTC

|departure_date = 19:52:05 UTC

|location = {{Venus coords and quad cat|28.7|S|56.7|E}}

}}

{{Infobox spaceflight/IP

|type = atmospheric

|object = Venus

|component = Main bus

|arrival_date = December 9, 1978, 20:21:52 UTC

}}

| programme = Pioneer program

| previous_mission = Pioneer 12

| next_mission =

| programme2 = Pioneer Venus

}}

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. This part of the mission included a spacecraft bus which was launched from Earth. The bus carried one large and three smaller probes, which, after separating, each penetrated the Venusian atmosphere at a different location, returning data as they descended into the planet's thick atmosphere. The entries occurred on December 9, 1978.

In context

There was also an orbiter launched in 1978, part of the overall Pioneer Venus project along with this entry probe mission. Whereas the probes entered the atmosphere in 1978, the Pioneer Venus Orbiter would stay in orbit throughout the 1980s and the early 1990s. The next major mission was the Magellan spacecraft, which was an orbiter capable of mapping Venus by seeing through its opaque clouds with radar.

Spacecraft

File:Pioneer Venus 2 inspection.jpg

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 {{convert|2.5|m|sp=us}} and a mass of {{convert|290|kg}}. 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 atmospheric circulation patterns. With no heat shield or parachute, the bus made upper atmospheric measurements with two instruments:

  • BIMS – an ion mass spectrometer to determine the origin and long-term development of the Venusian atmosphere, the dynamics of the upper atmosphere layers, 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 {{convert|5|kg|lb}}.
  • BNMS – a neutral mass spectrometer. This made measurements of the interaction between the solar wind and Venus, the photochemistry of the upper layers of and heat distribution in the Venusian atmosphere. It had a range of 1 to 60 u, weighed {{convert|1|kg|lb}}, and used ~1 W of power.

The spacecraft operated down to an altitude of about {{convert|110|km}} before disintegrating.

Probes

The spacecraft carried one large and three small atmospheric probes, designed by Senior Scientist and Program Manager Irwin Baker of Hughes Aircraft Company, 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, and another transmitted for 2 seconds after landing.

= Large probe =

File:Pioneer Venus Large Probe.jpg

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 {{convert|11.5|km/s|sp=us}} near the equator on the night side of Venus, a parachute was deployed at {{convert|67|km}} altitude. The large probe was about {{convert|150|cm|sp=us}} in diameter and the pressure vessel itself was {{convert|73.2|cm|in|sp=us}} in diameter.

= Small probes =

File:Smallvenusprobe.gif

File:Entry-points-for-Pioneer-Venus-Atmosphere-probes.png

File:Pioneer-Venus-large-prode-descent-sequence.png

Three identical small probes, around {{convert|0.8|m|sp=us}} 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:{{cite web |url=http://nssdc.gsfc.nasa.gov/planetary/pioneer_venus.html |title=Pioneer Venus Project Information |work=NASA Goddard Space Flight Center |access-date=2016-08-17 }}

  • 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.[http://nssdc.gsfc.nasa.gov/planetary/pvprobes.html Pioneer Venus Probes]. NASA Goddard Space Flight Center, 2005.

  • 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 {{convert|110|km|mi}}.

The four probes transmitted data until they impacted the surface of Venus. The Day Probe survived the impact, returning data from the surface for 67 minutes and 37 seconds after reaching the surface.NASA. [https://solarsystem.nasa.gov/missions/pioneer-venus-2/in-depth/ Pioneer Venus 2], NASA Science: Solar System Exploration, February 3, 2021. Retrieved 24 April 2022.

class="wikitable sortable"

|+Pioneer Venus probes and bus: atmospheric entry and impacts (all times in UT)

! Entry time (200 km)

! Impact time

! Loss of signal

! Impact coordinates

! Solar Zenith Angle

! Local Venus time

Large Probe

| 18:45:32

| 19:39:53

| 19:39:53

| {{Venus coords and quad cat|4.4|N|304.0|E}}

| 65.7

| 7:38

North Probe

| 18:49:40

| 19:42:40

| 19:42:40

| {{Venus coords and quad cat|59.3|N|4.8|E}}

| 108.0

| 3:35

Day Probe

| 18:52:18

| 19:47:59

| 20:55:34

| {{Venus coords and quad cat|31.3|S|317.0|E}}

| 79.9

| 6:46

Night Probe

| 18:56:13

| 19:52:05

| 19:52:07

| {{Venus coords and quad cat|28.7|S|56.7|E}}

| 150.7

| 0:07

Bus

| 20:21:52

| (signal lost at 110 km altitude)

| 20:22:55

| {{Venus coords and quad cat|37.9|S|290.9|E}} (estimated)

| 60.7

| 8:30

Scientific results

Below an altitude of {{convert|50|km}} the temperatures measured by the four probes were identical to within a few degrees, between {{convert|448|and|459|C}} on the surface; the ground pressure, between {{convert|86.2|and|94.5|bar}}. Nephelometers identified three cloud layers with different characteristics. The most remarkable discovery was that the ratio of 36argon / 40argon isotopes was much higher than in the Earth's atmosphere, which seems to indicate that the genesis of the Venusian atmosphere is very different from that of Earth's. The reconstituted trajectory of the atmospheric probes determined that the wind averaged {{convert|200|m/s}} in the middle cloud layer, {{convert|50|m/s}} at the base of these clouds and just {{convert|1|m/s}} on the ground. Overall data from airborne sensors confirmed and refined the data obtained by the Soviet Venera program that preceded the American mission to Venus.Paolo Ulivi et David M. Harland, Robotic Exploration of the Solar System Part 1, The Golden Age 1957–1982, Springer Praxis, 2007 ({{ISBN|978-0-387-49326-8}})

Trajectory

Diagram of the PVM's path to planet Venus from Earth in 1978, and this also notes the launch of the Pioneer Venus Orbiter which took place that year also.

File:Pioneer-Venus-Trajectories.png

{{clear}}

Graphic overview

File:Pioneer Venus Orbiter and Multi-Probe - 1978 01565.jpg

{{clear}}

See also

{{Portal|Spaceflight}}

References

{{reflist|refs}}

= Bibliography =

{{External links|section|date=November 2022}}

{{refbegin|2}}

  • {{cite journal|jstor=1748508|title=Pioneer Venus Results: An Overview|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/41|first=T. M.|last=Donahue|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=41–44|bibcode=1979Sci...205...41D|doi=10.1126/science.205.4401.41|pmid=17778895|s2cid=1600807}}
  • {{cite journal|jstor=1748509|title=Encounter with Venus: An Update|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/44|first=Lawrence|last=Colin|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=44–46|bibcode=1979Sci...205...44C|doi=10.1126/science.205.4401.44|pmid=17778896|s2cid=26297893}}
  • {{cite journal|jstor=1748510|title=Thermal Contrast in the Atmosphere of Venus: Initial Appraisal from Pioneer Venus Probe Data|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/46|first1=Alvin|last1=Seiff|first2=Donn B.|last2=Kirk|first3=Richard E.|last3=Young|first4=Simon C.|last4=Sommer|first5=Robert C.|last5=Blanchard|first6=John T.|last6=Findlay|first7=G. M.|last7=Kelly|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=46–49|bibcode=1979Sci...205...46S|doi=10.1126/science.205.4401.46|pmid=17778897|s2cid=24774892}}
  • {{cite journal|jstor=1748511|title=Composition and Structure of the Venus Atmosphere: Results from Pioneer Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/49|first1=J. H.|last1=Hoffman|first2=R. R.|last2=Hodges|first3=M. B.|last3=McElroy|first4=T. M.|last4=Donahue|first5=M.|last5=Kolpin|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=49–52|pmid=17778898|bibcode=1979Sci...205...49H|doi=10.1126/science.205.4401.49|s2cid=20713222}}
  • {{cite journal|jstor=1748512|title=Laboratory Corroboration of the Pioneer Venus Gas Chromatograph Analyses|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/52|first1=V. I.|last1=Oyama|first2=G. C.|last2=Carle|first3=F.|last3=Woeller|first4=J. B.|last4=Pollack|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=52–54|bibcode=1979Sci...205...52O|doi=10.1126/science.205.4401.52|pmid=17778899|s2cid=40293580}}
  • {{cite journal|jstor=1748513|title=Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/54|first1=H. B.|last1=Niemann|first2=R. E.|last2=Hartle|first3=A. E.|last3=Hedin|first4=W. T.|last4=Kasprzak|first5=N. W.|last5=Spencer|first6=D. M.|last6=Hunten|first7=G. R.|last7=Carignan|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=54–56|bibcode=1979Sci...205...54N|doi=10.1126/science.205.4401.54|pmid=17778900|s2cid=21839920}}
  • {{cite journal|jstor=1748514|title=Implications of the Gas Compositional Measurements of Pioneer Venus for the Origin of Planetary Atmospheres|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/56|first1=James B.|last1=Pollack|first2=David C.|last2=Black|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=56–59|bibcode=1979Sci...205...56P|doi=10.1126/science.205.4401.56|pmid=17778901|s2cid=13281057}}
  • {{cite journal|jstor=1748515|title=Ultraviolet Night Airglow of Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/59|first1=A. Ian|last1=Stewart|first2=Charles A.|last2=Barth|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=59–62|pmid=17778902|bibcode=1979Sci...205...59S|doi=10.1126/science.205.4401.59|s2cid=12841902}}
  • {{cite journal|jstor=1748516|title=Short-Term Cyclic Variations and Diurnal Variations of the Venus Upper Atmosphere|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/62|first1=G. M.|last1=Keating|first2=F. W.|last2=Taylor|first3=J. Y.|last3=Nicholson|first4=E. W.|last4=Hinson|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=62–64|bibcode=1979Sci...205...62K|doi=10.1126/science.205.4401.62|pmid=17778903|s2cid=23057356}}
  • {{cite journal|jstor=1748517|title=Temperature, Cloud Structure, and Dynamics of Venus Middle Atmosphere by Infrared Remote Sensing from Pioneer Orbiter|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/65|first1=F. W.|last1=Taylor|first2=D. J.|last2=Diner|first3=L. S.|last3=Elson|first4=D. J.|last4=McCleese|first5=J. V.|last5=Martonchik|first6=J.|last6=Delderfield|first7=S. P.|last7=Bradley|first8=J. T.|last8=Schofield|first9=J. C.|last9=Gille|first10=M. T.|last10=Coffey|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=65–67|bibcode=1979Sci...205...65T|doi=10.1126/science.205.4401.65|pmid=17778904|s2cid=2023608}}
  • {{cite journal|jstor=1748518|title=Further Results of the Pioneer Venus Nephelometer Experiment|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/67|first1=Jacques|last1=Blamont|first2=Boris|last2=Ragent|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=67–70|pmid=17778905|bibcode=1979Sci...205...67B|doi=10.1126/science.205.4401.67|s2cid=19155512}}
  • {{cite journal|jstor=1748519|title=Clouds of Venus: A Preliminary Assessment of Microstructure|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/70|first1=Robert G.|last1=Knollenberg|first2=D. M.|last2=Hunten|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=70–74|bibcode=1979Sci...205...70K|doi=10.1126/science.205.4401.70|pmid=17778906|s2cid=36125836}}
  • {{cite journal|jstor=1748520|title=Cloud Images from the Pioneer Venus Orbiter|first1=L. D.|last1=Travis|first2=D. L.|last2=Coffeen|first3=A. D.|last3=Del Genio|first4=J. E.|last4=Hansen|first5=K.|last5=Kawabata|first6=A. A.|last6=Lacis|first7=W. A.|last7=Lane|first8=S. S.|last8=Limaye|first9=W. B.|last9=Rossow|first10=P. H.|last10=Stone|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=74–76|bibcode=1979Sci...205...74T|doi=10.1126/science.205.4401.74|pmid=17778907|s2cid=43906539}}
  • {{cite journal|jstor=1748521|title=Nature of the Ultraviolet Absorber in the Venus Clouds: Inferences Based on Pioneer Venus Data|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/76|first1=James B.|last1=Pollack|first2=Boris|last2=Ragent|first3=Robert|last3=Boese|first4=Martin G.|last4=Tomasko|first5=Jacques|last5=Blamont|first6=Robert G.|last6=Knollenberg|first7=Larry W.|last7=Esposito|first8=A. Ian|last8=Stewart|first9=Lawrence|last9=Travis|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=76–79|bibcode=1979Sci...205...76P|doi=10.1126/science.205.4401.76|pmid=17778908|s2cid=28250903}}
  • {{cite journal|jstor=1748522|title=Absorption of Sunlight in the Atmosphere of Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/80|first1=Martin G.|last1=Tomasko|first2=Lyn R.|last2=Doose|first3=Peter H.|last3=Smith|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=80–82|bibcode=1979Sci...205...80T|doi=10.1126/science.205.4401.80|pmid=17778909|hdl=2060/19830010359|s2cid=35649934|hdl-access=free}}
  • {{cite journal|jstor=1748523|title=Preliminary Results of the Pioneer Venus Small Probe Net Flux Radiometer Experiment|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/82|first1=V. E.|last1=Suomi|first2=L. A.|last2=Sromovsky|first3=H. E.|last3=Revercomb|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=82–85|bibcode=1979Sci...205...82S|doi=10.1126/science.205.4401.82|pmid=17778910|s2cid=22181310}}
  • {{cite journal|jstor=1748524|title=Venus Winds Are Zonal and Retrograde Below the Clouds|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/85|first1=C. C.|last1=Counselman|first2=S. A.|last2=Gourevitch|first3=R. W.|last3=King|first4=G. B.|last4=Loriot|first5=R. G.|last5=Prinn|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=85–87|bibcode=1979Sci...205...85C|doi=10.1126/science.205.4401.85|pmid=17778911|s2cid=39737494}}
  • {{cite journal|jstor=1748525|title=Measurements of Turbulence in the Venus Atmosphere Deduced from Pioneer Venus Multiprobe Radio Scintillations|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/87|first1=Richard|last1=Woo|first2=J. W.|last2=Armstrong|first3=William B.|last3=Kendall|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=87–89|bibcode=1979Sci...205...87W|doi=10.1126/science.205.4401.87|pmid=17778912|s2cid=10233431}}
  • {{cite journal|jstor=1748526|title=Venus: Preliminary Topographic and Surface Imaging Results from the Pioneer Orbiter|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/90|first1=Gordon H.|last1=Pettengill|first2=Peter G.|last2=Ford|first3=Walter E.|last3=Brown|first4=William M.|last4=Kaula|first5=Harold|last5=Masursky|first6=Eric|last6=Eliason|first7=George E.|last7=McGill|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=90–93|bibcode=1979Sci...205...90P|doi=10.1126/science.205.4401.90|pmid=17778913|s2cid=12582229}}
  • {{cite journal|jstor=1748527|title=Gravity Field of Venus: A Preliminary Analysis|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/93|first1=Roger J.|last1=Phillips|first2=William L.|last2=Sjogren|first3=Elsa A.|last3=Abbott|first4=John C.|last4=Smith|first5=Ray N.|last5=Wimberly|first6=Cari A.|last6=Wagner|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=93–96|bibcode=1979Sci...205...93P|doi=10.1126/science.205.4401.93|pmid=17778914|s2cid=21557337}}
  • {{cite journal|jstor=1748528|title=Ionosphere of Venus: First Observations of Day-Night Variations of the Ion Composition|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/96|first1=Harry A.|last1=Taylor|first2=Henry C.|last2=Brinton|first3=Siegfried J.|last3=Bauer|first4=Richard E.|last4=Hartle|first5=Paul A.|last5=Cloutier|first6=Robert E.|last6=Daniell|first7=Thomas M.|last7=Donahue|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=96–99|bibcode=1979Sci...205...96T|doi=10.1126/science.205.4401.96|pmid=17778915|s2cid=11269827}}
  • {{cite journal|jstor=1748529|title=Initial Observations of the Nightside Ionosphere of Venus from Pioneer Venus Orbiter Radio Occultations|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/99|first1=A. J.|last1=Kliore|first2=I. R.|last2=Patel|first3=A. F.|last3=Nagy|first4=T. E.|last4=Cravens|first5=T. I.|last5=Gombosi|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=99–102|pmid=17778916|bibcode=1979Sci...205...99K|doi=10.1126/science.205.4401.99|s2cid=10322619}}
  • {{cite journal|jstor=1748530|title=Empirical Models of the Electron Temperature and Density in the Nightside Venus Ionosphere|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/102|first1=L. H.|last1=Brace|first2=R. F.|last2=Theis|first3=H. B.|last3=Niemann|first4=H. G.|last4=Mayr|first5=W. R.|last5=Hoegy|first6=A. F.|last6=Nagy|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=102–105|bibcode=1979Sci...205..102B|doi=10.1126/science.205.4401.102|pmid=17778917|s2cid=25337442}}
  • {{cite journal|jstor=1748531|title=Thermal Structure and Energy Influx to the Day- and Nightside Venus Ionosphere|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/105|first1=W. C.|last1=Knudsen|first2=K.|last2=Spenner|first3=R. C.|last3=Whitten|first4=J. R.|last4=Spreiter|first5=K. L.|last5=Miller|first6=V.|last6=Novak|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=105–107|bibcode=1979Sci...205..105K|doi=10.1126/science.205.4401.105|pmid=17778918|s2cid=26084728}}
  • {{cite journal|jstor=1748532|title=Comparison of Calculated and Measured Ion Densities on the Dayside of Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/107|first1=A. F.|last1=Nagy|first2=T. E.|last2=Cravens|first3=R. H.|last3=Chen|first4=H. A.|last4=Taylor|first5=L. H.|last5=Brace|first6=H. C.|last6=Brinton|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=107–109|bibcode=1979Sci...205..107N|doi=10.1126/science.205.4401.107|pmid=17778919|s2cid=28832064}}
  • {{cite journal|jstor=1748533|title=Venus Ionosphere: Photochemical and Thermal Diffusion Control of Ion Composition|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/109|first1=Siegfried J.|last1=Bauer|first2=Thomas M.|last2=Donahue|first3=Richard E.|last3=Hartle|first4=Harry A.|last4=Taylor|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=109–112|bibcode=1979Sci...205..109B|doi=10.1126/science.205.4401.109|pmid=17778920|s2cid=32579568}}
  • {{cite journal|jstor=1748534|title=Absorption of Whistler Mode Waves in the Ionosphere of Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/112|first1=W. W. L.|last1=Taylor|first2=F. L.|last2=Scarf|first3=C. T.|last3=Russell|first4=L. H.|last4=Brace|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=112–114|bibcode=1979Sci...205..112T|doi=10.1126/science.205.4401.112|pmid=17778921|s2cid=45428203}}
  • {{cite journal|jstor=1748535|title=Initial Pioneer Venus Magnetic Field Results: Nightside Observations|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/114|first1=C. T.|last1=Russell|first2=R. C.|last2=Elphic|first3=J. A.|last3=Slavin|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=114–116|bibcode=1979Sci...205..114R|doi=10.1126/science.205.4401.114|pmid=17778922|s2cid=24494352}}
  • {{cite journal|jstor=1748536|title=Electron Observations and Ion Flows from the Pioneer Venus Orbiter Plasma Analyzer Experiment|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/116|first1=D. S.|last1=Intriligator|first2=H. R.|last2=Collard|first3=J. D.|last3=Mihalov|first4=R. C.|last4=Whitten|first5=J. H.|last5=Wolfe|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=116–119|bibcode=1979Sci...205..116I|doi=10.1126/science.205.4401.116|pmid=17778923|s2cid=42935022}}
  • {{cite journal|jstor=1748537|title=Gamma-Ray Burst Observations by Pioneer Venus Orbiter|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/119|first1=W. D.|last1=Evans|first2=J. P.|last2=Glore|first3=R. W.|last3=Klebesadel|first4=J. G.|last4=Laros|first5=E. R.|last5=Tech|first6=R. E.|last6=Spalding|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=119–121|bibcode=1979Sci...205..119E|doi=10.1126/science.205.4401.119|pmid=17778924|s2cid=38916824}}
  • {{cite journal|jstor=1748508|title=Pioneer Venus Results: An Overview|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/41|first=T. M.|last=Donahue|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=41–44|bibcode=1979Sci...205...41D|doi=10.1126/science.205.4401.41|pmid=17778895|s2cid=1600807}}
  • {{cite journal|jstor=1748509|title=Encounter with Venus: An Update|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/44|first=Lawrence|last=Colin|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=44–46|bibcode=1979Sci...205...44C|doi=10.1126/science.205.4401.44|pmid=17778896|s2cid=26297893}}
  • {{cite journal|jstor=1748510|title=Thermal Contrast in the Atmosphere of Venus: Initial Appraisal from Pioneer Venus Probe Data|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/46|first1=Alvin|last1=Seiff|first2=Donn B.|last2=Kirk|first3=Richard E.|last3=Young|first4=Simon C.|last4=Sommer|first5=Robert C.|last5=Blanchard|first6=John T.|last6=Findlay|first7=G. M.|last7=Kelly|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=46–49|bibcode=1979Sci...205...46S|doi=10.1126/science.205.4401.46|pmid=17778897|s2cid=24774892}}
  • {{cite journal|jstor=1748511|title=Composition and Structure of the Venus Atmosphere: Results from Pioneer Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/49|first1=J. H.|last1=Hoffman|first2=R. R.|last2=Hodges|first3=M. B.|last3=McElroy|first4=T. M.|last4=Donahue|first5=M.|last5=Kolpin|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=49–52|pmid=17778898|bibcode=1979Sci...205...49H|doi=10.1126/science.205.4401.49|s2cid=20713222}}
  • {{cite journal|jstor=1748512|title=Laboratory Corroboration of the Pioneer Venus Gas Chromatograph Analyses|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/52|first1=V. I.|last1=Oyama|first2=G. C.|last2=Carle|first3=F.|last3=Woeller|first4=J. B.|last4=Pollack|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=52–54|bibcode=1979Sci...205...52O|doi=10.1126/science.205.4401.52|pmid=17778899|s2cid=40293580}}
  • {{cite journal|jstor=1748513|title=Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/54|first1=H. B.|last1=Niemann|first2=R. E.|last2=Hartle|first3=A. E.|last3=Hedin|first4=W. T.|last4=Kasprzak|first5=N. W.|last5=Spencer|first6=D. M.|last6=Hunten|first7=G. R.|last7=Carignan|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=54–56|bibcode=1979Sci...205...54N|doi=10.1126/science.205.4401.54|pmid=17778900|s2cid=21839920}}
  • {{cite journal|jstor=1748514|title=Implications of the Gas Compositional Measurements of Pioneer Venus for the Origin of Planetary Atmospheres|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/56|first1=James B.|last1=Pollack|first2=David C.|last2=Black|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=56–59|bibcode=1979Sci...205...56P|doi=10.1126/science.205.4401.56|pmid=17778901|s2cid=13281057}}
  • {{cite journal|jstor=1748515|title=Ultraviolet Night Airglow of Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/59|first1=A. Ian|last1=Stewart|first2=Charles A.|last2=Barth|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=59–62|pmid=17778902|bibcode=1979Sci...205...59S|doi=10.1126/science.205.4401.59|s2cid=12841902}}
  • {{cite journal|jstor=1748516|title=Short-Term Cyclic Variations and Diurnal Variations of the Venus Upper Atmosphere|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/62|first1=G. M.|last1=Keating|first2=F. W.|last2=Taylor|first3=J. Y.|last3=Nicholson|first4=E. W.|last4=Hinson|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=62–64|bibcode=1979Sci...205...62K|doi=10.1126/science.205.4401.62|pmid=17778903|s2cid=23057356}}
  • {{cite journal|jstor=1748517|title=Temperature, Cloud Structure, and Dynamics of Venus Middle Atmosphere by Infrared Remote Sensing from Pioneer Orbiter|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/65|first1=F. W.|last1=Taylor|first2=D. J.|last2=Diner|first3=L. S.|last3=Elson|first4=D. J.|last4=McCleese|first5=J. V.|last5=Martonchik|first6=J.|last6=Delderfield|first7=S. P.|last7=Bradley|first8=J. T.|last8=Schofield|first9=J. C.|last9=Gille|first10=M. T.|last10=Coffey|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=65–67|bibcode=1979Sci...205...65T|doi=10.1126/science.205.4401.65|pmid=17778904|s2cid=2023608}}
  • {{cite journal|jstor=1748518|title=Further Results of the Pioneer Venus Nephelometer Experiment|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/67|first1=Jacques|last1=Blamont|first2=Boris|last2=Ragent|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=67–70|pmid=17778905|bibcode=1979Sci...205...67B|doi=10.1126/science.205.4401.67|s2cid=19155512}}
  • {{cite journal|jstor=1748519|title=Clouds of Venus: A Preliminary Assessment of Microstructure|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/70|first1=Robert G.|last1=Knollenberg|first2=D. M.|last2=Hunten|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=70–74|bibcode=1979Sci...205...70K|doi=10.1126/science.205.4401.70|pmid=17778906|s2cid=36125836}}
  • {{cite journal|jstor=1748520|title=Cloud Images from the Pioneer Venus Orbiter|first1=L. D.|last1=Travis|first2=D. L.|last2=Coffeen|first3=A. D.|last3=Del Genio|first4=J. E.|last4=Hansen|first5=K.|last5=Kawabata|first6=A. A.|last6=Lacis|first7=W. A.|last7=Lane|first8=S. S.|last8=Limaye|first9=W. B.|last9=Rossow|first10=P. H.|last10=Stone|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=74–76|bibcode=1979Sci...205...74T|doi=10.1126/science.205.4401.74|pmid=17778907|s2cid=43906539}}
  • {{cite journal|jstor=1748521|title=Nature of the Ultraviolet Absorber in the Venus Clouds: Inferences Based on Pioneer Venus Data|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/76|first1=James B.|last1=Pollack|first2=Boris|last2=Ragent|first3=Robert|last3=Boese|first4=Martin G.|last4=Tomasko|first5=Jacques|last5=Blamont|first6=Robert G.|last6=Knollenberg|first7=Larry W.|last7=Esposito|first8=A. Ian|last8=Stewart|first9=Lawrence|last9=Travis|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=76–79|bibcode=1979Sci...205...76P|doi=10.1126/science.205.4401.76|pmid=17778908|s2cid=28250903}}
  • {{cite journal|jstor=1748522|title=Absorption of Sunlight in the Atmosphere of Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/80|first1=Martin G.|last1=Tomasko|first2=Lyn R.|last2=Doose|first3=Peter H.|last3=Smith|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=80–82|bibcode=1979Sci...205...80T|doi=10.1126/science.205.4401.80|pmid=17778909|hdl=2060/19830010359|s2cid=35649934|hdl-access=free}}
  • {{cite journal|jstor=1748523|title=Preliminary Results of the Pioneer Venus Small Probe Net Flux Radiometer Experiment|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/82|first1=V. E.|last1=Suomi|first2=L. A.|last2=Sromovsky|first3=H. E.|last3=Revercomb|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=82–85|bibcode=1979Sci...205...82S|doi=10.1126/science.205.4401.82|pmid=17778910|s2cid=22181310}}
  • {{cite journal|jstor=1748524|title=Venus Winds Are Zonal and Retrograde Below the Clouds|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/85|first1=C. C.|last1=Counselman|first2=S. A.|last2=Gourevitch|first3=R. W.|last3=King|first4=G. B.|last4=Loriot|first5=R. G.|last5=Prinn|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=85–87|bibcode=1979Sci...205...85C|doi=10.1126/science.205.4401.85|pmid=17778911|s2cid=39737494}}
  • {{cite journal|jstor=1748525|title=Measurements of Turbulence in the Venus Atmosphere Deduced from Pioneer Venus Multiprobe Radio Scintillations|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/87|first1=Richard|last1=Woo|first2=J. W.|last2=Armstrong|first3=William B.|last3=Kendall|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=87–89|bibcode=1979Sci...205...87W|doi=10.1126/science.205.4401.87|pmid=17778912|s2cid=10233431}}
  • {{cite journal|jstor=1748526|title=Venus: Preliminary Topographic and Surface Imaging Results from the Pioneer Orbiter|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/90|first1=Gordon H.|last1=Pettengill|first2=Peter G.|last2=Ford|first3=Walter E.|last3=Brown|first4=William M.|last4=Kaula|first5=Harold|last5=Masursky|first6=Eric|last6=Eliason|first7=George E.|last7=McGill|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=90–93|bibcode=1979Sci...205...90P|doi=10.1126/science.205.4401.90|pmid=17778913|s2cid=12582229}}
  • {{cite journal|jstor=1748527|title=Gravity Field of Venus: A Preliminary Analysis|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/93|first1=Roger J.|last1=Phillips|first2=William L.|last2=Sjogren|first3=Elsa A.|last3=Abbott|first4=John C.|last4=Smith|first5=Ray N.|last5=Wimberly|first6=Cari A.|last6=Wagner|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=93–96|bibcode=1979Sci...205...93P|doi=10.1126/science.205.4401.93|pmid=17778914|s2cid=21557337}}
  • {{cite journal|jstor=1748528|title=Ionosphere of Venus: First Observations of Day-Night Variations of the Ion Composition|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/96|first1=Harry A.|last1=Taylor|first2=Henry C.|last2=Brinton|first3=Siegfried J.|last3=Bauer|first4=Richard E.|last4=Hartle|first5=Paul A.|last5=Cloutier|first6=Robert E.|last6=Daniell|first7=Thomas M.|last7=Donahue|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=96–99|bibcode=1979Sci...205...96T|doi=10.1126/science.205.4401.96|pmid=17778915|s2cid=11269827}}
  • {{cite journal|jstor=1748529|title=Initial Observations of the Nightside Ionosphere of Venus from Pioneer Venus Orbiter Radio Occultations|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/99|first1=A. J.|last1=Kliore|first2=I. R.|last2=Patel|first3=A. F.|last3=Nagy|first4=T. E.|last4=Cravens|first5=T. I.|last5=Gombosi|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=99–102|pmid=17778916|bibcode=1979Sci...205...99K|doi=10.1126/science.205.4401.99|s2cid=10322619}}
  • {{cite journal|jstor=1748530|title=Empirical Models of the Electron Temperature and Density in the Nightside Venus Ionosphere|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/102|first1=L. H.|last1=Brace|first2=R. F.|last2=Theis|first3=H. B.|last3=Niemann|first4=H. G.|last4=Mayr|first5=W. R.|last5=Hoegy|first6=A. F.|last6=Nagy|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=102–105|bibcode=1979Sci...205..102B|doi=10.1126/science.205.4401.102|pmid=17778917|s2cid=25337442}}
  • {{cite journal|jstor=1748531|title=Thermal Structure and Energy Influx to the Day- and Nightside Venus Ionosphere|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/105|first1=W. C.|last1=Knudsen|first2=K.|last2=Spenner|first3=R. C.|last3=Whitten|first4=J. R.|last4=Spreiter|first5=K. L.|last5=Miller|first6=V.|last6=Novak|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=105–107|bibcode=1979Sci...205..105K|doi=10.1126/science.205.4401.105|pmid=17778918|s2cid=26084728}}
  • {{cite journal|jstor=1748532|title=Comparison of Calculated and Measured Ion Densities on the Dayside of Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/107|first1=A. F.|last1=Nagy|first2=T. E.|last2=Cravens|first3=R. H.|last3=Chen|first4=H. A.|last4=Taylor|first5=L. H.|last5=Brace|first6=H. C.|last6=Brinton|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=107–109|bibcode=1979Sci...205..107N|doi=10.1126/science.205.4401.107|pmid=17778919|s2cid=28832064}}
  • {{cite journal|jstor=1748533|title=Venus Ionosphere: Photochemical and Thermal Diffusion Control of Ion Composition|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/109|first1=Siegfried J.|last1=Bauer|first2=Thomas M.|last2=Donahue|first3=Richard E.|last3=Hartle|first4=Harry A.|last4=Taylor|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=109–112|bibcode=1979Sci...205..109B|doi=10.1126/science.205.4401.109|pmid=17778920|s2cid=32579568}}
  • {{cite journal|jstor=1748534|title=Absorption of Whistler Mode Waves in the Ionosphere of Venus|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/112|first1=W. W. L.|last1=Taylor|first2=F. L.|last2=Scarf|first3=C. T.|last3=Russell|first4=L. H.|last4=Brace|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=112–114|bibcode=1979Sci...205..112T|doi=10.1126/science.205.4401.112|pmid=17778921|s2cid=45428203}}
  • {{cite journal|jstor=1748535|title=Initial Pioneer Venus Magnetic Field Results: Nightside Observations|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/114|first1=C. T.|last1=Russell|first2=R. C.|last2=Elphic|first3=J. A.|last3=Slavin|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=114–116|bibcode=1979Sci...205..114R|doi=10.1126/science.205.4401.114|pmid=17778922|s2cid=24494352}}
  • {{cite journal|jstor=1748536|title=Electron Observations and Ion Flows from the Pioneer Venus Orbiter Plasma Analyzer Experiment|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/116|first1=D. S.|last1=Intriligator|first2=H. R.|last2=Collard|first3=J. D.|last3=Mihalov|first4=R. C.|last4=Whitten|first5=J. H.|last5=Wolfe|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=116–119|bibcode=1979Sci...205..116I|doi=10.1126/science.205.4401.116|pmid=17778923|s2cid=42935022}}
  • {{cite journal|jstor=1748537|title=Gamma-Ray Burst Observations by Pioneer Venus Orbiter|url=https://archive.org/details/sim_science_1979-07-06_205_4401/page/119|first1=W. D.|last1=Evans|first2=J. P.|last2=Glore|first3=R. W.|last3=Klebesadel|first4=J. G.|last4=Laros|first5=E. R.|last5=Tech|first6=R. E.|last6=Spalding|date=6 July 1979|journal=Science|volume=205|issue=4401|pages=119–121|bibcode=1979Sci...205..119E|doi=10.1126/science.205.4401.119|pmid=17778924|s2cid=38916824}}

{{refend}}

{{Pioneer program}}

{{Venus spacecraft}}

{{NASA space program}}

{{Orbital launches in 1978}}

Category:Missions to Venus

Category:Pioneer program

Category:1978 in spaceflight

Category:Spacecraft launched in 1978

Category:Extraterrestrial atmosphere entry

Category:Extraterrestrial aircraft

External links

{{Commons category|Pioneer Venus 2}}

  • [http://nssdc.gsfc.nasa.gov/planetary/pioneer_venus.html NASA: Pioneer Venus Project Information]
  • [https://web.archive.org/web/20080925191131/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Pioneer_Venus Pioneer Venus Program Page] by [http://solarsystem.nasa.gov/ NASA's Solar System Exploration]
  • [https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1978-078A NSSDC Master Catalog: Spacecraft Pioneer Venus Probe Bus]. (Other components of the mission have their own pages at this site too.)