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Mission record

Pioneer Venus 2

Also known as Pioneer Venus Probe Bus, Pioneer Venus Multiprobe, Pioneer 13, Pioneer Venus 1978, PioneerVenusProbeBus

NASA-Office of Space Science Applications · Launched

Explore trajectory

Completed · Success

One mission carrying four instrumented atmospheric entry probes plus the bus that delivered them. The probes were released in November 1978 and all four entered the Venus atmosphere on 9 December 1978, two Small Probes on the nightside and one Small Probe and the Large Probe on the dayside, studying 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 the local atmospheric circulation pattern. The bus itself carried Ion and Neutral Mass Spectrometers, was targeted to enter at a shallow angle and returned signals until it was destroyed by the heat of atmospheric friction.

Destinations
Launch vehicle
Atlas-Centaur
Launch site
Cape Canaveral, United States
Countries
United States
Mission types
Atmospheric probe

Chronology

Mission timeline

  1. Launch

    Launched on an Atlas-Centaur from Cape Canaveral

    The launch/orbital information page prints 1978-08-08T07:33:00Z, recorded at minute precision because it prints a whole minute with zero seconds, and the bus master catalog gives the same time, 07:33:00 UT.

    Earth

  2. Milestone

    One midcourse correction on 16 August 1978

    The bus master catalog records one midcourse correction on 16 August 1978 and that the trip to Venus took 123 days.

  3. Deployment

    Three Small Probes released on 20 November 1978

    Each of the three small probe pages records that the three small probes were identical, were designated the North Probe (1978-078E), the Night Probe (1978-078F) and the Day Probe (1978-078G), were all mounted on the Multiprobe Bus (1978-078A) and were released on 20 November 1978. The bus master catalog adds that after release the bus was slowed slightly to fall behind the probes.

  4. Milestone

    All four probes enter the Venus atmosphere

    The small probe pages record that the probes were targeted for different entry points in the Venus atmosphere and all entered on 9 December 1978. The bus master catalog records that two Small Probes entered on the nightside and one Small Probe and the Large Probe on the dayside, that the Large Probe took 1-1/2 h to descend through the atmosphere, and that the three smaller probes reached the surface of the planet 75 min after entry. The one probe launch/orbital information page this record cites, the Large Probe's, prints a Lander row whose Epoch start year is 1979 rather than 1978 - Epoch start (UTC): 1979-12-09 19:39:53 - one year after the Decay Date of 1978-12-09 printed at the head of that same page; the record follows 1978, which the master catalog pages print in prose. The three small probes' launch/orbital pages were not fetched and are not committed here, so the same defect is stated of the one page that carries it rather than of all four.

    Venus

  5. Milestone

    Bus enters the dayside atmosphere at 200 km altitude

    The bus master catalog records that at 20:21:52 UT on 9 December 1978 the bus entered the dayside Venus atmosphere at 200 km altitude at 37.9 S, 290.9 E, a full date and time in one sentence. Its launch/orbital information page carries an Atmospheric probe row with the same epoch start, 1978-12-09 20:21:52.

    Venus

  6. Mission end

    Bus signal ends at 110 km altitude one minute after entry

    The bus master catalog records that it returned signals until reaching an altitude of 110 km one minute later at 20:22:55 UT, and its launch/orbital information page prints 1978-12-09 20:22:55 as the epoch stop of the same row, which is where the date beside the time comes from.

    Venus

  7. Deployment

    Large Probe separates from the Bus on 16 November

    The bus master catalog records that the Large Probe separated from the Bus on 16 November and the Small Probes on 20 November. Carried without a timestamp because that sentence prints no year; the Small Probe release below has a year because the small probe pages print one.

  8. Other

    The two enumeration spines disagree on which small probe is Day and which is Night

    NSSDCA titles 1978-078F Pioneer Venus Small Probe (Night) and 1978-078G Pioneer Venus Small Probe (Day), and all three small probe pages print the designation list naming the Night Probe as 1978-078F and the Day Probe as 1978-078G. GCAT reverses the two: the hcocat rows this record cites give Piece 1978-078F the Name Day Probe as D00592 and Piece 1978-078G the Name Night Probe as D00593. hcocat is the only GCAT file cited here and the only one whose committed excerpt carries either row. The two catalogues agree on which piece letter carries which satellite number, 12105 for F and 12106 for G, and disagree only on the label. Recorded rather than resolved; this record follows NSSDCA, whose pages it is written from.

Mission architecture

Vehicles

  • Pioneer Venus Probe Bus · Spacecraft

    Destinations: Venus

    • Pioneer Venus Large Probe · Probe

      Destinations: Venus

    • Pioneer Venus Small Probe (North) · Probe

      Destinations: Venus

    • Pioneer Venus Small Probe (Night) · Probe

      Destinations: Venus

    • Pioneer Venus Small Probe (Day) · Probe

      Destinations: Venus

Trajectory record

Trajectory dataset not yet available

No verified trajectory dataset is committed for this mission, so Mission Atlas renders no path.

Provenance

Sources

Each source is listed once and labeled with the mission, event, trajectory, or destination/body context it supports.

Data verified through September 3, 2026