Explorer 3 mission
E349081
The Explorer 3 mission was an early U.S. satellite flight in 1958 that helped confirm the existence of the Van Allen radiation belts through its onboard scientific instruments.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Explorer 3 | 2 |
| Explorer 3 mission canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T3339418 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Explorer 3 mission Context triple: [James A. Van Allen, participatedIn, Explorer 3 mission]
-
A.
Magellan spacecraft
The Magellan spacecraft was a NASA robotic probe launched in 1989 that used radar mapping to produce the first detailed global images of the surface of Venus.
-
B.
Nomad space probe
The Nomad space probe is a fictional, highly advanced robotic spacecraft from the Star Trek universe that becomes a powerful and dangerous hybrid entity after merging with an alien probe.
-
C.
Cassini–Huygens
Cassini–Huygens was a joint NASA/ESA/ASI mission consisting of an orbiter and a lander that studied Saturn and its moons in unprecedented detail, including landing on Titan.
-
D.
Luna spacecraft
The Luna spacecraft were a series of Soviet robotic probes launched between the late 1950s and 1970s that achieved many lunar exploration firsts, including the first human-made object to reach the Moon and the first soft landing on its surface.
-
E.
Moon Impact Probe
The Moon Impact Probe was a small Indian lunar probe designed to detach from the Chandrayaan-1 spacecraft and intentionally crash onto the Moon’s surface to conduct scientific measurements and demonstrate landing technologies.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Explorer 3 mission Target entity description: The Explorer 3 mission was an early U.S. satellite flight in 1958 that helped confirm the existence of the Van Allen radiation belts through its onboard scientific instruments.
-
A.
Magellan spacecraft
The Magellan spacecraft was a NASA robotic probe launched in 1989 that used radar mapping to produce the first detailed global images of the surface of Venus.
-
B.
Nomad space probe
The Nomad space probe is a fictional, highly advanced robotic spacecraft from the Star Trek universe that becomes a powerful and dangerous hybrid entity after merging with an alien probe.
-
C.
Cassini–Huygens
Cassini–Huygens was a joint NASA/ESA/ASI mission consisting of an orbiter and a lander that studied Saturn and its moons in unprecedented detail, including landing on Titan.
-
D.
Luna spacecraft
The Luna spacecraft were a series of Soviet robotic probes launched between the late 1950s and 1970s that achieved many lunar exploration firsts, including the first human-made object to reach the Moon and the first soft landing on its surface.
-
E.
Moon Impact Probe
The Moon Impact Probe was a small Indian lunar probe designed to detach from the Chandrayaan-1 spacecraft and intentionally crash onto the Moon’s surface to conduct scientific measurements and demonstrate landing technologies.
- F. None of above. chosen
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
NASA space mission
ⓘ
artificial satellite ⓘ scientific satellite ⓘ |
| countryOfOrigin |
United States of America
ⓘ
surface form:
United States
|
| decayDate | 1958-06-16 ⓘ |
| discovererOf |
Earth’s radiation belts
ⓘ
surface form:
Van Allen radiation belts
|
| epoch |
International Geophysical Year activities
ⓘ
surface form:
International Geophysical Year
|
| historicalSignificance |
early confirmation of Earth’s radiation belts
ⓘ
one of the first successful U.S. scientific satellites ⓘ |
| instrument |
Geiger–Müller tube
ⓘ
cosmic ray detector ⓘ micrometeorite detector ⓘ telemetry system ⓘ temperature sensors ⓘ |
| launchContractor | Army Ballistic Missile Agency ⓘ |
| launchDate | 1958-03-26 ⓘ |
| launchSite |
Cape Canaveral Missile Annex Launch Complex 26A
ⓘ
Cape Canaveral ⓘ
surface form:
Cape Canaveral, Florida
|
| launchVehicle |
Jupiter-C rocket
ⓘ
surface form:
Juno I
|
| launchYear | 1958 ⓘ |
| mass | 14 kg ⓘ |
| missionEnd | 1958-06-16 ⓘ |
| missionType |
Earth science
ⓘ
radiation belt research ⓘ |
| onboardComputer | none ⓘ |
| operator |
Jet Propulsion Laboratory
ⓘ
United States Army ⓘ |
| orbitApogee | about 2,650 km ⓘ |
| orbitInclination | about 33.4 degrees ⓘ |
| orbitPerigee | about 186 km ⓘ |
| orbitPeriod | about 115 minutes ⓘ |
| orbitType | low Earth orbit ⓘ |
| partOf |
NASA Explorer Program
ⓘ
surface form:
Explorer program
|
| powerSource | battery ⓘ |
| predecessor | Explorer 1 ⓘ |
| primaryObjective |
confirm existence of Van Allen radiation belts
ⓘ
study Earth’s radiation environment ⓘ |
| principalInvestigator |
James A. Van Allen
ⓘ
surface form:
James Van Allen
|
| programGoal | demonstrate U.S. satellite capability during early Space Age ⓘ |
| shape | cylindrical ⓘ |
| spaceAgency | National Aeronautics and Space Administration precursor organizations ⓘ |
| spacecraftBus | Explorer 1-type bus ⓘ |
| status | deorbited ⓘ |
| successor |
Explorer 4 spacecraft
ⓘ
surface form:
Explorer 4
|
| telemetryFrequency |
108.00 MHz
ⓘ
108.03 MHz ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Explorer 3 mission Description of subject: The Explorer 3 mission was an early U.S. satellite flight in 1958 that helped confirm the existence of the Van Allen radiation belts through its onboard scientific instruments.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Explorer 3
this entity surface form:
Explorer 3