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Wow 2cm is still huge if it rams into the ISS at 10km/s. It's like a 20mm bullet with at least 5 times the speed of a gun round (not sure how fast guns are actu

Wow 2cm is still huge if it rams into the ISS at 10km/s. It's like a 20mm bullet with at least 5 times the speed of a gun round (not sure how fast guns are actually :) What are those 'whipple shields'? Are those the foil sheets that basically vaporise the object (and part of the shield) so it won't penetrate the inner hull? I assume they have better tracking than 2cm for the orbit the ISS is in? Does the ISS have its own radar warning? Though I guess if it sees it coming it's already too late for avoidance.

Alupis 6y ago
> It's like a 20mm bullet with at least 5 times the speed of a gun round (not sure how fast guns are actually :) For some perspective, 20mm is 0.787402 inches, so that would be approximately a .79 Caliber projectile. For comparison, a .50 BMG round exits the muzzle of a rifle anywhere between 2,895 ft/s up to 3,044 ft/s[1]. 3,044 ft/s == 927.81 m/s == 0.92781 km/s. So yes, this 20mm piece of space junk is travelling a lot faster than a bullet, and consequently would carry a lot more energy. [1] https://en.wikipedia.org/wiki/.50_BMG https://en.wikipedia.org/wiki/.50_BMG
jccooper 6y ago
> Are those the foil sheets that basically vaporise the object (and part of the shield) so it won't penetrate the inner hull? Yes. Orbital hypervelocity impacts basically vaporize immediately on hitting anything, so you can offset a thin material in front of what you want to protect and cause any incoming object to turn into a cone of many much smaller objects which are less likely to penetrate the main hull.
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