Hacker News Reader

Comment by andrewflnr | Hacker News Reader

If you're a satellite, could it ever be effective to use active radar to detect small, fast incoming debris and smack it with a laser? There's obviously a question of power, but do we even have good enough sensors and weapons? Can you get enough warning to react in time, without making it worse?

View on HN

That's a neat idea, but it misses an important step: after the laser hits the debris, what's changed? Now instead of a small piece of cold metal coming at you, you have a very hot blob of molten metal moving at roughly the same direction and speed.

With high enough power, the debris might eject some material (pushing it into a different orbit).

https://en.wikipedia.org/wiki/Kessler_syndrome#Avoidance_and...

https://en.wikipedia.org/wiki/Laser_broom

I guess it isn't something that would be on lots of satellites. But it wouldn't need to be.

My idea was that you get a rapidly spreading cloud of metallic vapor coming your way. Again, though, power. Also what maxerickson said, but then you need to be even more precise, at least if it's coming right at you.

Satellites can currently move out of the way. Cheaper and less energy to move 2 meters one way and then back again.

That does require it to expend precious propellent though. Perhaps what we need are satellites built in shapes that allow them to turn and dodge debris using only gyroscopic attitude control

That's quite a clever idea.

Maybe along those lines you could have a clean up satellite with a nuclear reactor and high powered laser to gradually vapourize the junk?

Reply on news.ycombinator.com