I received an offer within two days of my interview, and am currently still in the background check process. So far, the entire process has taken approximately a month.
I was suddenly sent an extremely last-minute email notifying me that I've been invited to interview with the company in two days. In addition, I was invited to an optional complementary dinner the night before. I chose to go to the dinner, as it's nice to get to know some of the hiring managers prior to interviewing and just being able to network with other candidates and Lockheed Martin employees. The HR specialist I was in contact with about the event was very slow to respond, which is probably the only negative part of my experience. She did not book my hotel room (DoubleTree, very nice) until the day of, so I was literally planning my trip the day of. Although it was a hassle getting there, and I'd experienced a near anxiety attack along the way thanks to public transportation never being on time, it was certainly worth it. I had the privilege of meeting and sitting with the three hiring managers I would be interviewing with the next day. The dinner was certainly a little awkward at first -- everyone was standing in little circles and I had no idea what to do, but luckily some other candidates came in and approached me for conversation. We got an informal overview of the Early Career Developmental Program (ECDP) all recent college hires are enrolled in, and we got to ask some questions. I would definitely suggest asking at least one question to set yourself apart from other candidates if you find yourself in a similar situation.
The day of the interview was rather nice. The hotel provided a shuttle bus to and from the event, and LM provided free breakfast and lunch from Panera. Everyone was really so kind and personable. Prior to interviewing, we were given a formal overview of the ECDP, along with some background info on the company. We were also given an itinerary upon arriving which contained our interviewing schedule for the day. There were three interviews, with each one lasting a total of 30 minutes. After each interview was a 30 minute break. While some of us interviewed, others waited. I was primarily asked behavioral questions testing things like: leadership skills, problem-solving skills, interpersonal skills, communication skills, writing skills, etc. I actually went through Glassdoor interview reviews to pick out behavioral questions I thought I would have trouble coming up with a response on the spot, thought about it, wrote down some answers, and practiced them. While I was not asked any of those questions, I was still able to apply some of the examples I had written down in response to other questions. Each interviewer was incredibly kind and easy to talk to. I read so many people say they really make you feel comfortable, and I was unsure if it would be the same for me, as well, but it really was. Trust me, you'll probably be nervous for a total of five minutes at most as long as you prepare responses! Use my interview question tactic, and you'll do great. The questions are worded really oddly, though, and the hiring managers will tell you that if you have the opportunity to network with them prior to the interview day, so try not to get too thrown off by them like I did at first.
Also, here's a tip: you really only have to impress one manager, not all three, as they're all looking to hire someone for their own team. It's possible that you might get hired for a position you didn't apply for, as not all hiring managers you interview with will work within the department the position you applied for belongs to.