In article ,
Jeff Findley wrote:
How would you reduce such a risk for a next generation spacecraft?
Certainly better micrometeorite protection would help against smaller
objects, but how do you protect a heat shield on something as big as the
envisioned CEV?

The fast answer is that you build the heatshield out of something more
durable. In particular, a Mercury/Gemini/Apollo/Soyuz-style ablative
heatshield is tough and can have large safety margins. The heatshield
itself is good for only one use, but the rest of the spacecraft can be
reusable.

If you're really concerned, you can supplement this by putting an
expendable cover on the rear, so the part of the heatshield that really
matters is protected during most of the time spent in orbit.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |