Failed · Failure
A United States lunar flyby attempt that fell short of escape velocity but returned data revealing a second radiation belt around Earth.
- Destinations
- Launch vehicle
- Juno II (AM-11)
- Launch site
- Cape Canaveral Launch Complex 5
- Countries
- United States
- Mission types
- Flyby
Chronology
Mission timeline
Launch
Pioneer 3 launched
NASA Science gives launch at 05:44:52 UT from Cape Canaveral Launch Complex 5 aboard Juno II vehicle AM-11.
EarthMission end
Reentered Earth’s atmosphere over Africa
NASA reports reentry on Dec. 7, about 38 h 6 min after launch. Adding that rounded elapsed duration to the NASA launch epoch (1958-12-06T05:44:52Z) gives 19:50:52Z, represented as approximately 19:51Z at minute precision; this is a derived time, not a separately published telemetry timestamp.
Earth
Mission architecture
Vehicles
Pioneer 3 · Spacecraft
Destinations: Moon
Trajectory record
Trajectory dataset not yet available
Known dates and encounters do not uniquely determine a flight path. This mission’s sourced timeline is available above; no verified trajectory is currently published here.
What is needed to reconstruct this path?
- Mission-specific Pioneer III time-tagged angular, Doppler/range, or telemetry observations, or an authoritative fitted state history.
- A powered-flight cutoff epoch and frame-qualified Cartesian state for the subsequent ballistic arc.
- Exact apogee epoch, reentry interface, reentry coordinates, and uncertainty bounds.
- Published maximum altitude and elapsed flight time do not provide a complete state vector, an apogee epoch, orbital orientation, or the trajectory through powered ascent.
- Direct access to the JPL EP 649 scan or another complete copy so Table 2 values and their definitions can be visually verified.
- Reconcile the indexed values (108,051 km from center; 37.65 h) with NASA’s later values (102,322 km maximum altitude; 38 h 6 min after launch).
Provenance
Sources
Each source is listed once and labeled with the mission, event, trajectory, or destination/body context it supports.
Data verified through October 12, 2026
- Scientific Results from the Explorer Satellites and the Pioneer Space Probes, JPL External Publication No. 649 — NASATechnical document · Supports: mission claims
- Evaluation of Pioneer IV Orbit-Determination Program, Eimer and Hiroshige; Tracking Programs and Orbit Determination seminar proceedings (23–26 February1960) — NASATechnical document · Supports: mission claims
- Siddiqi (2018): Beyond Earth, a chronicle of deep space exploration 1958–2016 — NASAMission page · Supports: mission claims · event claims
- Pioneer 3 - NASA Science mission page — NASAMission page · Supports: mission claims · event claims
- Tracking and data handling for the Pioneer III and Pioneer IV firings, NASA-CR-57647 / JPL-EP-701 — NASATechnical document · Supports: mission claims
- Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958–2000 — NASATechnical document · Supports: mission claims
- Pioneer 3 - NASA NSSDCA Spacecraft Details — NSSDCAArchive · Supports: mission claims
- NASA Historical Data Book, Volume II, Tables 3-142–3-145: Pioneer 1–4 Characteristics — NASATechnical document · Supports: mission claims
- DE421 lunar mean-Earth and principal-axes frame specification — NAIFTechnical document · Supports: destination/body context
- DE440 lunar mean-Earth and principal-axes frame specification — NAIFSpice · Supports: destination/body context
- IAU rotational elements and body radii (PCK 00011) — NAIFSpice · Supports: destination/body context
- LOLA global lunar height maps, LDEM_4 V3 original PDS source label — NASATechnical document · Supports: destination/body context
- LOLA 2023 south-polar elevation, uncertainty and effective-resolution maps — NASATechnical document · Supports: destination/body context
- Blue Ghost Lunar Lander Seen From Above: LROC site and terrain context — NASATechnical document · Supports: destination/body context
- Moon Facts — NASAOther · Supports: destination/body context
- SLDEM2015 Blue Ghost region: original PDS elevation-grid label — NASATechnical document · Supports: destination/body context
- JPL Solar System Dynamics Astrodynamic Parameters — JPLOther · Supports: destination/body context
- Planet Sizes and Locations in Our Solar System — NASAOther · Supports: destination/body context