I landed at a local airport today and was met by the FBO manager. He was somewhat "miffed". He told me I had just landed at a closed airport. I was informed the airport was closed from 7:00 am to 2:00 pm local and that a NOTAM had been filed. There was a group of kids from local schools doing a rocket launch. Fortunately I'm on the FAA NOTAM automatic email system and I'd also checked for TFR's and NOTAM's before I had left the house-nothing noted for our area. It turned out the NOTAM system was "down", or so the feds told the FBO manager. I then (jokingly of course) informed the FBO manager he was allowing kids to launch rockets from an active airport ramp into the airport traffic area! I still can't find record of a NOTAM being filed though. Don't you have to activate a NOTAM after filing it? Anyhow, no harm, no foul. In the end the kids were quite taken by my plane (I've got Jake Jaks Pober Junior Ace) and my dog "Lucky"-yep, "dog" is my copilot. We all had a great time despite the breakdown in communication. After watching the kids do their thing Lucky and I departed for home with an invitation to return any time. Lots of pictures of my plane and pooch with the kids. I might have inspired a few prospective pilots too. Anyway, just a heads up for the future, I think we might be seeing more "system failures" relating to the airspace system.