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 trajectoryCompleted · 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
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.
EarthMilestone
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.
Deployment
Large probe released
NSSDCA reports physical separation; no exact release position or impulse is implied.
SunDeployment
Three small probes released
All three were released from the spinning bus; separate probe timelines retain each identity.
SunMilestone
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.
VenusMilestone
Day probe continued transmitting on surface
Reported duration67minutes37seconds after impact; source end clocks differ by2seconds, so a new exact end clock is not invented.
VenusMilestone
Large probe entered atmosphere
NSSDCA200km entry at spacecraftUT; not the laterCanberra ground reception time.
VenusDeployment
Large-probe parachute deployed (approximate time)
NSSDCA gives approximately18:46:21 spacecraftUT. The0.76m pilot extracts the4.94m main chute; the heat shield separates after inflation near67km. A rounded engineering event time does not establish subsecond dynamics.
VenusMilestone
North probe entered atmosphere
NSSDCA200km entry at spacecraftUT; not the laterCanberra ground reception time.
VenusMilestone
Day probe entered atmosphere
NSSDCA200km entry at spacecraftUT; not the laterCanberra ground reception time.
VenusMilestone
Night probe entered atmosphere
NSSDCA200km entry at spacecraftUT; not the laterCanberra ground reception time.
VenusDeployment
Large probe parachute released
NSSDCA gives the spacecraft clock; source LAS data uses ground reception and sounder-referenced altitude.
VenusLanding
Large probe reached surface
Current NSSDCA mission description. Historic body coordinates are rounded; alternate large-probe clock differs by2seconds. No precise surface pose is established.
VenusLanding
North probe reached surface
Current NSSDCA mission description. Historic body coordinates are rounded; alternate large-probe clock differs by2seconds. No precise surface pose is established.
VenusLanding
Day probe reached surface
Current NSSDCA mission description. Historic body coordinates are rounded; alternate large-probe clock differs by2seconds. No precise surface pose is established.
VenusLanding
Night probe reached surface
Current NSSDCA mission description. Historic body coordinates are rounded; alternate large-probe clock differs by2seconds. No precise surface pose is established.
VenusMilestone
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.
VenusLoss of contact
Probe bus last signal
Bus transmission ended near110km altitude. Day probe surface transmissions continued later; this event ends the bus, not all five vehicles.
VenusOther
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
Trajectory record
Time-dependent navigation trajectory
Source states place the model at the selected time. Reconstructed flight, estimates, predictions and historical mission plans are identified by interval; gaps remain visible.
Source records and sampling assumptions are retained with the repository data. Model attitude and surface appearance are illustrative.
- Pioneer Venus 2 Large Probe lower descent: Physically reconstructed based on publicly available data · approximate lower-atmosphere descent only · December 9, 1978 to December 9, 1978
- Pioneer Venus 2 North Probe lower descent: Physically reconstructed based on publicly available data · approximate lower-atmosphere descent only · December 9, 1978 to December 9, 1978
- Pioneer Venus 2 Night Probe lower descent: Physically reconstructed based on publicly available data · approximate lower-atmosphere descent only · December 9, 1978 to December 9, 1978
- Pioneer Venus 2 Day Probe lower descent: Physically reconstructed based on publicly available data · approximate lower-atmosphere descent only · December 9, 1978 to December 9, 1978
Provenance
Sources
Each source is listed once and labeled with the mission, event, trajectory, or destination/body context it supports.
Data verified through September 14, 2026
- Pioneer Venus Probe Bus - NSSDCA Master Catalog (spacecraft 1978-078A), archived snapshot — NSSDCAArchive · Supports: mission claims · event claims
- Pioneer Venus Probe Bus - NSSDCA launch/orbital information (1978-078A), archived snapshot — NSSDCAArchive · Supports: mission claims · event claims
- Pioneer Venus Large Probe - NSSDCA Master Catalog (spacecraft 1978-078D), archived snapshot — NSSDCAArchive · Supports: mission claims
- Pioneer Venus Large Probe - NSSDCA launch/orbital information (1978-078D), archived snapshot — NSSDCAArchive · Supports: mission claims · event claims
- Pioneer Venus Small Probe (North) - NSSDCA Master Catalog (spacecraft 1978-078E), archived snapshot — NSSDCAArchive · Supports: mission claims · event claims
- Pioneer Venus Small Probe (Night) - NSSDCA Master Catalog (spacecraft 1978-078F), archived snapshot — NSSDCAArchive · Supports: mission claims · event claims
- Pioneer Venus Small Probe (Day) - NSSDCA Master Catalog (spacecraft 1978-078G), archived snapshot — NSSDCAArchive · Supports: mission claims · event claims
- GCAT: General Catalog of Artificial Space Objects (heliocentric catalog), J. McDowell — OTHEROther · Supports: mission claims · event claims
- Pioneer Venus Probe Bus: spacecraft and original data review — NSSDCAMission page · Supports: mission claims · event claims
- Pioneer Venus Large Probe: spacecraft and original data review — NSSDCAMission page · Supports: mission claims · event claims
- Pioneer Venus Small Probe (North): spacecraft and original data review — NSSDCAMission page · Supports: mission claims · event claims
- Pioneer Venus Small Probe (Night): spacecraft and original data review — NSSDCAMission page · Supports: mission claims · event claims
- Pioneer Venus Small Probe (Day): spacecraft and original data review — NSSDCAMission page · Supports: mission claims · event claims
- Pioneer Venus 2 mission history — NASAMission page · Supports: mission claims · event claims
- Pioneer Venus: mission engineering and spacecraft drawings, NASA SP461 — NASATechnical document · Supports: mission claims · event claims
- PDS mission document with NASA SP518 tables and diagrams — NASATechnical document · Supports: mission claims · event claims
- Pioneer Venus multiprobe relative crustal and atmospheric velocities — NASAArchive · Supports: mission claims · event claims
- Pioneer Venus original atmospheric structure and trajectory data — NASAArchive · Supports: mission claims · event claims
- Cruz and Lingard: Aerodynamic Decelerators for Planetary Exploration — NASAPaper · Supports: mission claims · event claims
- Planetary Mission Entry Vehicles Quick Reference Guide V4 — NASATechnical document · Supports: mission claims · event claims
- Lorenz and Allen: recovered Pioneer Venus entry accelerometer data — OTHERArchive · Supports: mission claims
- Planet Sizes and Locations in Our Solar System — NASAOther · Supports: destination/body context
- Our Sun: Facts — NASAOther · Supports: destination/body context