Prison Order, Slowing Equality, Space in Space

There are over ten million people in prison worldwide, and the experiences of those prisoners differ drastically from prison to prison and from country to country. The pay gap between men and women has shrunk a lot since the 1970s, but progress has stalled. NASA’s developed a plan to clean up orbit. Also on today’s show: Alaskan middle schoolers endure an unusual final exam; robot designers borrow a trick from the human body.