[Sharlin]

Micrometer-scale specks of dust would hit you like they were armor piercing tank gun rounds. The usual shielding proposed is ice. Lots of ice.

[folli]

Why ice?

[Sharlin]

Mostly that it's plentiful, ablative, expendable, plus good radiation shielding (yeah, cosmic ray protons are really going to mess things up at relativistic speeds too unless there's enough mass to stop them).