They're working on four additional radar installations for tracking space debris. Their current installations can track objects down to about a 10 cm diameter, but with their new installations they'll theoretically be able to track objects as small as 2 cm. In general, current radar systems tend to be limited on the lower end to objects in the 5-10 cm range. Systems like LeoLabs’ and the US Air Force’s upcoming Marshall Islands-based Space Fence will improve coverage, but still won’t see the 128 million objects from 1 mm to 1 cm. For perspective, a collision with a 10 cm object will likely completely destroy a satellite, a 1 cm object will likely disable it, and a 1 mm object may disable a subsystem. At closing velocities around 10 km/s, the kinetic energy of even an untrackable chip of paint is greater than the destructive power of an equivalent mass of stationary TNT. Whipple shields around the ISS’s crewed areas are built to absorb impacts with objects of up to around 1 cm. For anything bigger, an avoidance maneuver is used (if we see it coming).
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.
> 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.
They're working on four additional radar installations for tracking space debris. Their current installations can track objects down to about a 10 cm diameter, but with their new installations they'll theoretically be able to track objects as small as 2 cm. In general, current radar systems tend to be limited on the lower end to objects in the 5-10 cm range. Systems like LeoLabs’ and the US Air Force’s upcoming Marshall Islands-based Space Fence will improve coverage, but still won’t see the 128 million objects from 1 mm to 1 cm. For perspective, a collision with a 10 cm object will likely completely destroy a satellite, a 1 cm object will likely disable it, and a 1 mm object may disable a subsystem. At closing velocities around 10 km/s, the kinetic energy of even an untrackable chip of paint is greater than the destructive power of an equivalent mass of stationary TNT. Whipple shields around the ISS’s crewed areas are built to absorb impacts with objects of up to around 1 cm. For anything bigger, an avoidance maneuver is used (if we see it coming).