The BBC News article Hayabusa-2: Japanese probe set to 'bomb' an asteroid says:

The charge is carried on the Small Carry-On Impactor (SCI) device.

This is a 14kg conical container attached to Hayabusa-2 and packed with plastic explosive.

The SCI is due to separate from Hayabusa-2 at 01:56 GMT on Friday at an altitude of 500m above the surface of Ryugu. That will kick off a 40-minute countdown to detonation. When the device explodes, it is expected to punch a 10m-wide hole in the asteroid.

In the meantime, Hayabusa-2 should have manoeuvred itself to hide away on the other side of the asteroid, shielding the spacecraft from any flying debris.

I don't know how much of the 14 kg is the explosive, but the video shows the explosion to at least not be trivial.

Still, I'm wondering if explosives have been used on other bodies beyond Earth orbit. Thus the question Was Hayabusa-2's plastic explosive charge the largest explosive charge to detonate in beyond LEO? Why "beyond LEO"? Starfish Prime.

I suppose answers will have to be revised again in several years, when space-prospectors start blowing things up regularly. which may happen in the the non-too-distant future on the south pole of the Moon.


See also related items:

  • $\begingroup$ Wow, 40 minutes does not seem like very long to retreat to safety! $\endgroup$
    – Jack
    Apr 5, 2019 at 6:34
  • 4
    $\begingroup$ While it's on the large side as an explosive charge, it's way low in terms of energy. Deep Impact hit Tempel 1 at 10.3 km/s relative speed, releasing energy equivalent of 4.8 metric tons of TNT. $\endgroup$
    – SF.
    Apr 5, 2019 at 14:29

1 Answer 1


The Active Seismic Experiment of the Apollo Lunar Surface Experiments Package carried four grenades. They weighed 2.67, 2.19, 1.70, and 1.52 pounds each.

Like Hayabusa-2's numbers, I'm not sure how much of that weight was explosive, but it does give something to compare to.

Source: ALSEP Flight System Familiarization Manual, p. 2-166.

  • $\begingroup$ But they weren't actually detonated (see the first linked question). $\endgroup$ Sep 18, 2019 at 20:06
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    $\begingroup$ @CamilleGoudeseune: The Active Seismic Experiment was carried on both Apollo 14 and 16. The linked question is about 14, which did not fire any of its grenades because it was deployed too close to the central station. Three of the four grenades on 16 were indeed detonated. The mortar pitch sensor failed after the 3rd firing, and the experiment's objectives had been met, so the last firing was cancelled. $\endgroup$
    – DrSheldon
    Sep 18, 2019 at 21:25
  • $\begingroup$ So, Was Hayabusa-2's plastic explosive charge the largest charge detonated beyond LEO? $\endgroup$
    – uhoh
    Mar 4 at 5:31

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