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Hayabusa2 threads a close pass by asteroid Torifune

Hayabusa2 threads a close pass by asteroid Torifune

New Capabilities

Japan's probe tests pinpoint asteroid navigation on its long road to a tiny space rock in 2031

July 5th, 2026: Hayabusa2 flies past Torifune

Overview

Updated Jul 5

On July 5, 2026, a Japanese spacecraft flew about 1 kilometer past an asteroid the size of a skyscraper, moving at roughly 5 kilometers per second. JAXA confirmed Hayabusa2 pulled off the pass and gathered data on 98943 Torifune, a 450-meter rock no probe had ever visited.

The flyby was a navigation test as much as a science run. Steering that precisely at that speed is the same skill needed to slam a spacecraft into an asteroid on purpose. That is the core move in planetary defense, and Hayabusa2 just rehearsed it.

Why it matters

The same pinpoint steering Hayabusa2 tested is what a future mission would need to nudge a dangerous asteroid off a collision course with Earth.

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Key Indicators

1 km
Closest approach
How near Hayabusa2 aimed to pass Torifune's surface.
5 km/s
Flyby speed
Relative velocity during the pass, about 18,000 km/h.
450 m
Asteroid width
Torifune is an elongated, rocky S-type near-Earth object.
5
Onboard instruments
Cameras and sensors used to read Torifune's shape and surface.
2031
Final target
Planned rendezvous with the tiny asteroid 1998 KY26.

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People Involved

Satoshi Tanaka
Satoshi Tanaka
JAXA mission team member, Hayabusa2 extended mission
Presented the flyby plan to international peers
 Patrick Michel
Patrick Michel
Planetary scientist on the Hayabusa2 science team
Awaiting flyby data on a never-before-seen asteroid
 Makoto Yoshikawa
Makoto Yoshikawa
Hayabusa2 mission manager
Overseeing the extended mission

Organizations Involved

Japan Aerospace Exploration Agency (JAXA)
Japan Aerospace Exploration Agency (JAXA)
Space agency
Operates Hayabusa2

Japan's space agency, which built and flies the Hayabusa2 asteroid probe.

Timeline

December 2014 July 2026

5 events Latest: July 5th, 2026 · 2 months ago
Tap a bar to jump to that date

  1. Hayabusa2 flies past Torifune

    Latest Milestone

    The probe passes roughly 1 kilometer from the 450-meter asteroid at about 5 km/s, gathering data and testing close-range autonomous guidance.

  2. Plan briefed to asteroid scientists

    Statement

    JAXA's Satoshi Tanaka details the flyby at a NASA Small Bodies Assessment Group meeting.

  3. JAXA sets the flyby date

    Statement

    JAXA announces the July 5 Torifune flyby and the plan to pass as close as 1 kilometer.

  4. Ryugu samples come home

    Milestone

    A capsule with Ryugu material lands in Australia. JAXA extends the mission and points the probe at new targets.

  5. Hayabusa2 launches

    Milestone

    JAXA sends Hayabusa2 from Tanegashima toward the near-Earth asteroid Ryugu.

Scenarios

1

JAXA publishes clean Torifune imagery and shape data

Likely Resolves by Jul 5, 2027

Discussed by: JAXA, Hayabusa2 science team (Patrick Michel)

The instruments hold their aim through the fast pass and return usable images and surface data on Torifune. JAXA and its science partners release results describing the asteroid's shape, spin, and composition, adding a new object to the studied catalog. This is the outcome the team framed as the science payoff of the flyby.

2

Hayabusa2 nails its 2027 Earth swingby

Likely Resolves by Q2 2028

Discussed by: JAXA extended mission team

The trajectory to 1998 KY26 runs through two Earth gravity assists, in 2027 and 2028. If the probe completes the first swingby on course, the plan to reach KY26 in 2031 stays alive. A miss or major thruster problem would force a redesign of the route or end the extended run early.

3

Hayabusa2 reaches 1998 KY26 in 2031

Possible Resolves by End of 2031

Discussed by: JAXA, planetary-science community

The mission's endpoint is a rendezvous with 1998 KY26, an object only about 10 meters across that spins once every 10 minutes. Reaching and studying it up close would be a first for such a tiny, fast-rotating asteroid. Getting there depends on years of flawless navigation on aging hardware.

4

Spacecraft fault ends the mission before KY26

Unlikely Resolves by End of 2031

Discussed by: Space press covering aging-probe risk

Hayabusa2 launched in 2014 and relies on a small ion engine, worn thrusters, and limited fuel. A critical failure during the long cruise or an Earth swingby would strand the probe short of its 2031 target. Extended missions run this hardware risk in exchange for cheap bonus science.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

July 2005

Deep Impact hits comet Tempel 1 (2005)

NASA's Deep Impact released a washing-machine-sized copper slug that smashed into comet Tempel 1 while the main craft watched. The goal was to study what lay beneath a comet's surface. The impactor had to steer itself into a target moving at more than 10 km/s.

Then

The collision blasted out a bright plume, revealing the comet's dusty, loosely packed makeup.

Now

It showed spacecraft can autonomously guide themselves into small, fast bodies, a building block for later impact missions.

Why this matters now

Like Hayabusa2's flyby, it hinged on hitting a precise point near a small body at high closing speed.

June 2010

Original Hayabusa returns Itokawa dust (2010)

Japan's first Hayabusa probe reached the asteroid Itokawa, survived thruster and communication failures, and limped home with the first samples ever taken from an asteroid. The mission nearly failed several times over seven years.

Then

A capsule with tiny Itokawa grains landed in Australia, a world first despite the spacecraft's damage.

Now

It established Japan's asteroid program and the playbook of pushing aging probes through risky extended operations.

Why this matters now

The current extended mission repeats that bet: squeeze more firsts out of tired hardware rather than retire it.

September 2022

NASA's DART impact (2022)

NASA flew a 570-kilogram spacecraft, DART, straight into the small asteroid Dimorphos at about 6 km/s. It was the first test of deflecting an asteroid by hitting it. The craft steered itself into the target using onboard cameras in the final hour.

Then

The impact shortened Dimorphos's orbit around its larger companion by about 32 minutes, more than expected.

Now

DART proved a kinetic impactor can measurably move an asteroid, making it the leading planetary-defense method on the table.

Why this matters now

Hayabusa2's close, high-speed pass tests the same precise autonomous guidance a DART-style deflection needs.

Sources

(5)
JAXA ISAS JAXA Space.com The Japan Times Wikipedia