Half of the time was a tour of the facility. The other half was the interview. The interview lasted one hour. There was a time after the interview to talk with the interviewer.

I applied online, within a week I got a call to schedule an onsite interview. Onsite I had to check in and wait for my turn, one on one with hiring manager. Didn't ask any technical questions, but he was definitely impressed that I had done some research on the project I was interviewing for. The research also helped me to tailor my responses to what the position would need. They want you to respond with STAR format (they email you details) and don't expect you to know too much because they understand you are fresh out of college.

The interview was almost entirely behavioral. They asked questions in a STAR format so absolutely practice this before interviewing. It was a good experience and the Skunkworks campus is very impressive and requires that you obtain a security badge before beginning the interview so arrive at least 30 minutes before your scheduled time.