Saving Hubble, First Primates, Iraqibacter - S3.E3

Saving Hubble - Two teams of spacewalkers take on the risky mission of reviving the ailing Space Telescope.

First Primates - Our most distant primate ancestors, which lived about 55 million years ago, were tree-dwellers the size of mice.

Profile: Alfredo Quiñones-Hinojosa -

He jumped the fence from Mexico to work as a farmhand and ended up a leading brain surgeon.

Killer Microbe - A relatively benign bug becomes a highly lethal pathogen, known to U.S. soldiers as Iraqibacter.