Program archive

Explorer program

Explorer 1 turned the first successful U.S. satellite launch into a landmark scientific mission and opened a continuing family of space-science investigations.

Missions: 37
People: 0
Vehicles: 39

Explore this program

Choose a path through the Explorer program archive.

Currently viewing · Timeline

Explorer program timeline

37 flights. One complete program record.

Follow every archived flight from the earliest development test through the program’s latest flown mission, with its defining milestones and mission hardware connected along the way.

Defining milestones

The turning points that shaped this program and its legacy.

1958 · First successful U.S. satelliteExplorer 1Explorer 1 reached orbit and returned the data behind the discovery of the Van Allen belts.Explore milestone →

Every Explorer program program record

All 37 flown and non-flight archive records arranged chronologically.

Launch corridor

37 flights and tests compressed into 2 expandable arcs.

Arc 01Ignition1958–1971 · 18 records
Arc 02Final approach1972–2025 · 19 records

Flight arc 01IgnitionExplorer 1 → IMP-61958–1971 · 18 records1958–1971
18 records

Flight arc 02Final approachIMP-7 → TRACERS1972–2025 · 19 records1972–2025
19 records