This is fascinating. I just finished reading some of their blog posts and they really make me want to get a career in space-related technology. This is insanely cool.
It's a "Non-Reimbursable Space Act Agreement (NRSAA)".
"The NRSAA details the technical, safety, legal and proprietary issues that will be addressed before any attempts are made to communicate with or control the 1970’s-era spacecraft as it nears the Earth in August."