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SatelliteIndex

Satellite · NORAD 1388 · COSPAR 1965-042A

EXPLORER 28 (IMP-3)

DecayedPayloadHEOUnknown derived

Altitude now

object decayed

Velocity

Inclination

53.61°

Period

5.8 d

8,341.7 min

Perigee

32,289km

Apogee

227,451km

orbit unavailableNo orbital element set on file — decayed 04 Jul 1968.· Metadata updated 12 h ago

Live position

Live position

Live position unavailable — this object re-entered the atmosphere on 04 Jul 1968 and is no longer tracked.

Mission

Mission & classification

Mission type derived
Unknown
Object type
Payload
SATCAT ops status
Decayed [D]
Radar cross-section

CelesTrak groups

Not listed in any CelesTrak group.

Aliases

  • EXPLORER 28 (IMP-3)Celestrak Satcat

Ownership

Operator & country

Operator
SATCAT owner code
US · United States

Launch

Launch

Launch page
Launch date
29 May 1965
COSPAR launch id
1965-042

Objects from the same launch

No other catalogued object is linked to this launch.

Change log

History

No changes recorded since first ingestion on 11 Sept 2026 18:54 UTC. Status, orbit class, name and ownership changes are logged here as sources are re-ingested.

Regulatory

UN registration

UN Register of Objects Launched into Outer Space (UNOOSA) — connector planned, not yet ingested; registration unavailable

Transparency

Sources & provenance

All sources

No source is linked to this record yet — the catalogue row exists but no provenance entry has been written for it.

Field provenance

No field-level provenance recorded.

Timeline

Events

All events

No events detected for this object yet. Launches, decays and orbit changes are generated by the derived-analytics connector.

Reference

Identifiers

NORAD catalogue number
1388
COSPAR / international designator
1965-042A
SatelliteIndex id
sat_01M28X3JJGRANHQWGKWZE60ZGC
Canonical slug
explorer-28-imp-3-1388

Orbit class, mission type and constellation membership are derived by SatelliteIndex (Unknown) — see the methodology. Positions are propagated estimates, not tracking measurements; never use them for conjunction assessment.

EXPLORER 28 (IMP-3) — Live Orbit, NORAD 1388 | SatelliteIndex