Looks like all that LEGO isn't going into space after all, at least not today. NASA has announced that it has scrubbed today's Space Shuttle Endeavour launch"because of an issue associated with Auxiliary Power Unit 1 heaters." Engineers will assess the issue, but NASA warns that the process will take at least 48-hours and likely more.
According to NASA Spaceflight, the APU issue is only the latest in a number of issues to plague the shuttle on this, its final flight. Issues observed during fuel tank filing and problems with the fuel cells were observed, together with pressure issues in the right tank.
NASA had been working on interconnecting the crossfeed lines between the two tanks, so as to try to equalize the pressure, when the APU problem was caught and the launch cancelled. NASA intends to hold a press conference later today to further detail the scrapped flight.