Home › Breakup events › Thor Ablestar (1961 breakup)
EXPLOSION · 1961-06-29
The Ablestar upper stage from the June 1961 Transit 4A launch exploded shortly after deployment — the first known orbital breakup in history, which more than tripled the tracked-object count at the time. Fragments still circle Earth over sixty years later.
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Isolate this debris field on the live globe →Opens Space Junk View, hides everything else, and frames the surviving tracked fragments of Thor Ablestar (1961 breakup) as they orbit.
Breakup events like this are why low Earth orbit is now crowded with debris. Space Junk View tracks all 31,328 cataloged objects — including roughly 10,229 pieces of debris — and lets you isolate a single event's fragment cloud to see exactly where its wreckage went. See the full breakup-events hub and our space-debris statistics.
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