Am headed over to Brussels tomorrow (return Friday) but for the first time and departing on 929 (BRU-LHR-ORD). Get the bummer of no chance to upgrade as C and F are both full on the LHR leg, but even worse is the 0615 departure out of BRU.

What I'm trying to figure out is how early do I need to be at the airport. My international standard is 2-3 hours early, but that would have me at the airport between 0315 and 0415. I'm not even sure the airport is open that early (looks like they aren't a 24/7 terminal). Anyone know what time BRU opens for check-ins? What time is recommended to get there to make that 0615 UA flight to LHR?