Bear with me, I'm not a MatE, so I'm positing a material that definitely exists, I'm just not sure quite which one.

One of the problems with any sort of orbital broom idea is that the impact of the sweeper is likely to scatter as much material as it collects. However, if your energy absorbing material is something that, in orbit, will sublimate into a gas, you have some alternatives.

You launch a satellite with a large supply of gas, the material in liquid form, and a small mixer/temperature chamber. Once in orbit, this chamber foams the material, freezes it into a solid, and extrudes the solid into (through the miracle of printer technology) a giant, thick, sheet.

This foam acts as an energy absorbing layer which allows any impacters to slow to a stop still inside the foam. Any particulate that is sprayed from the foam sublimates quickly into harmless gas. As the main foam sublimates, the material remains adhered in the remaining surface. Even better, dark debris should melt its way deeper into the material over time from solar heating. Eventually the entire thing sublimates, returning debris to the satellite/mixing chamber, which retains enough fuel to de- orbit with all attached materials.

Specific properties that the material must have. Liquid (or possibly gas, but I like liquid) at launch temperatures. Below it's triple point in orbit. Somewhat-to-highly adhesive in solid form. Ideally light or white colored in foamed form in order to slow sublimation.

As far as the ideal material, I'm thinking plain foamed water ice would work, as might dry ice (C02). If not, a search of various organic compounds should turn up something.
-- MechE, Oct 22 2012

An older and somewhat similar Idea Vacuum_20Cleaner
The main problem with putting a cleaning system IN ORBIT is that it tends to stay in orbit. I prefer a system that reaches orbital height, but has no significant orbital velocity. After colliding with space junk, the junk slows and the "cleaner" speeds up, but neither is moving fast enough for an orbit. [Vernon, Oct 22 2012]

It's mine, I saw it first! Near_20Earth_20Orbi...ation_20Corporation
Okay, maybe second... [normzone, Oct 22 2012]

You leave my recyclables alone (link) (+).
-- normzone, Oct 22 2012



random, halfbakery