Making spacecraft bleed

When you cut yourself, you bleed, and that blood forms a scab to seal the wound and help it heal. It's possible that a similar process could be used to protect spacecraft.

From Tariq Malik of Space.com:

[Ian] Bond [of England's University of Bristol] and his colleague developed a similar system, but replacing blood with resin and veins with tiny glass tubes, to fill in cracks or small holes in satellite "skin" as part of a European Space Agency (ESA) program to study technology for self-healing spacecraft. By closing small cracks or micrometeorite punctures themselves, satellites could stave off more serious structural problems the initial damage may lead to, researchers said.

The future is upon us. Bleeding satellites.