Failed · Failure
A United States attempt at lunar orbit that ended when the launch vehicle's third stage failed to ignite.
- Destinations
- Launch vehicle
- Thor-Able
- Launch site
- Cape Canaveral, United States
- Countries
- United States
- Mission types
- Orbiter
Chronology
Mission timeline
Launch
Pioneer 2 launched
NASA lists 07:30:20 UT; the original NASA/USAF final report gives 02:30:21 EST, or 07:30:21 on the report’s UT clock conversion. The event is stored at minute precision because the printed estimates differ by one second.
EarthMission end
Reentered Earth’s atmosphere
NASA Science reports reentry 42 minutes 10 seconds after its 07:30:20 UT launch (08:12:30 UT). The final report gives 42.4 minutes after a 07:30:21 UT launch (08:12:45 UT). Both round to 08:13 UT at minute precision. Reentry coordinates and maximum-altitude values differ between these sources and remain unadjudicated.
Earth
Mission architecture
Vehicles
Pioneer 2 · 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?
- The final report burnout parameter set is an estimated constraint, not yet a fully specified inertial Cartesian state.
- Earth ellipsoid, local velocity azimuth convention, Earth rotation and the exact state boundary around stage separation remain unresolved.
- NASA Science and the final report differ in launch by one second, reentry elapsed time by 14 seconds, and reentry coordinates; no apogee epoch is published in the final table.
- No state covariance is supplied, and the actual-versus-computed tracking plots need calibrated digitization before quantitative validation.
- The Figure 4-24 map appears to support swapping the final report’s reentry coordinate values, but this is an inference from a coarse plotted trajectory and not a confirmed correction.
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
- Pioneer 2 - NASA NSSDCA Spacecraft Details — NSSDCAArchive · Supports: mission claims
- 1958 NASA/USAF Space Probes (ABLE-1), final engineering report, volumes1–3 — NASATechnical document · Supports: mission claims · event claims
- Pioneer 2 - NASA Science mission page — NASAMission page · Supports: mission claims · event 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