The Prediction Graveyard
Made with ❤️ by Aniruddh JangidLinkedIn
The Graveyard / Japan Aerospace Exploration Agency

early · Unscored / disputed

Mission schedule: Hayabusa would rendezvous with Itokawa in 2005 and return to Earth in June 2007.

Source-backed summary; not presented as a verbatim quotation.

Japan Aerospace Exploration Agency
Space agency and mission operator · Japan

Made: 2004-05-26Resolved: 2010-06-13
Original conceptual trajectory diagram illustrating Right direction, wrong timing
Right direction, wrong timing. Original illustration for The Prediction Graveyard. Aniruddh Jangid, 2026. Original digital diagram. CC BY 4.0. Changes: none. This is a conceptual diagram, not an archival image.

The world at the time.

JAXA's May 2004 mission briefing retained a June 2007 Earth-return schedule after a successful gravity assist. The mission was also testing ion propulsion, autonomous navigation and asteroid sampling, making success more uncertain than a routine return flight.

Hayabusa Earth swing-by implementation and results

What happened.

Hayabusa's capsule returned to Earth on June 13, 2010, three years after the original schedule. JAXA subsequently identified Itokawa particles in the returned container, establishing that the scientific direction eventually succeeded.

Hayabusa ReentryIdentification of origin of particles brought back by Hayabusa

Predicted vs actual.

MetricPredictedActualVariance / caveat
Earth return dateJune 2007June 13, 2010Approximately three years late
Hayabusa ReentryIdentification of origin of particles brought back by Hayabusa

The counter-signal.

In December 2005, JAXA reported lost ground contact after fuel leakage and said the June 2007 return was no longer feasible. It shifted into rescue operations and adopted a June 2010 return plan conditional on recovery.

Status of Hayabusa

Verdict.

Reasoning: sound · Outcome: partial

The original date was wrong, while the mission's return and sample-recovery direction was vindicated later. Labelled early rather than resurrected because JAXA did not conclusively declare the mission dead.

Return event occurred June 13 JST; announcement was June 14. Early means too-early forecast timing, not arrival ahead of schedule; loss of communication was recoverable, so no unverified death-to-resurrection claim is made.

Cause of death / explanatory lens.

Right direction, wrong timing

The lesson.

When recovery succeeds, should you preserve the original missed date alongside the eventual achievement?

Sources.

  1. Hayabusa Earth swing-by implementation and resultsprimary mission briefing · 2004-05-26 · claim and context
  2. Hayabusa Reentryprimary mission announcement · 2010-06-14 · outcome
  3. Status of Hayabusaprimary mission status · 2005-12-14 · counter_signal
  4. Identification of origin of particles brought back by Hayabusaprimary scientific result · 2010-11-16 · eventual sample outcome

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