Hayabusa Day

What Is Hayabusa Day?

Every June 13th is "Hayabusa Day" (はやぶさの日, Hayabusa no Hi) in Japan. On June 13, 2010, JAXA's asteroid explorer "Hayabusa" (はやぶさ, "Peregrine Falcon") returned to Earth after a seven-year, 6-billion-kilometer journey — successfully delivering samples collected from the surface of asteroid Itokawa (イトカワ) to Earth's surface. The return capsule, which safely parachuted to the Australian Outback, contained the first samples ever successfully returned from an asteroid to Earth — a landmark achievement in planetary science and a milestone in Japan's space program. The day was established by the "Ginga Renpo" (Galaxy Federation), an association of municipalities that host JAXA facilities, headquartered in Sagamihara, Kanagawa Prefecture.

Hayabusa's Extraordinary Journey

JAXA's Hayabusa mission (launched 2003) was intended to travel to asteroid Itokawa, collect samples, and return them to Earth by 2007. The mission encountered severe difficulties: a large solar flare degraded the spacecraft's solar cells; its ion engines suffered repeated failures; the probe malfunctioned during its first landing attempt; the sample collection mechanism may not have operated correctly; and after a fuel leak the spacecraft lost contact with Earth for about seven weeks (December 2005 to January 2006). Despite all these setbacks, Hayabusa's mission team never gave up — repeatedly finding workarounds that extended the mission three years and finally returned the capsule to Earth in 2010.

Scientific Achievement

When scientists opened the Hayabusa sample capsule, they found approximately 1,500 tiny particles of asteroid material — the first samples ever returned from the surface of an asteroid. Analysis of the Itokawa samples provided unprecedented insights into the composition of primitive asteroids and the early solar system. The mission's scientific success validated the extraordinary effort of Japan's mission team and opened a new era of asteroid sample return science.

Hayabusa's Cultural Impact

Hayabusa's story — its perseverance through crisis after crisis — resonated deeply with Japanese audiences. The spacecraft was anthropomorphized in media coverage as a brave, determined traveler who refused to give up despite adversity. Several feature films, a planetarium film, books, and merchandise about Hayabusa appeared around the return, and the mission became one of Japan's most beloved space achievements. The sequel mission Hayabusa2 (2014-2020) successfully returned samples from asteroid Ryugu — continuing and extending Hayabusa's legacy.

Fun Facts

• MINERVA: Hayabusa released a small hopping robot called "MINERVA" near Itokawa, but it failed to land and drifted into space. Hayabusa2 later carried the "MINERVA-II" rovers, which successfully landed on asteroid Ryugu, along with the German-French lander "MASCOT."
• Ryugu samples: Hayabusa2's Ryugu samples — collected in 2019 and returned to Earth in December 2020 — contained organic compounds and water-bearing minerals that provide evidence about the chemistry of the early solar system and the possible delivery of life's building blocks to Earth by asteroids.