Like most engineering or technical operations, NASA generally uses Coordinated Universal Time (UTC, formerly called Greenwich Mean Time) as the standard reference for activities. This is, for convenience, often converted to local time in either Florida or Texas - this report uses Eastern Standard Time (EST) unless other-wise noted. In addition to the normal 24-hour clock, NASA tells time via several other methods, all tied to specific events. The most recognizable of these is "T minus (T-)" time that counts down to every launch in hours, minutes, and seconds. NASA also uses a less precise "L minus" (L-) time that tags events that hap-pens days or weeks prior to launch. Later in this report there are references to "Entry Interface plus (EI+)" time that counts, in seconds, from when an Orbiter begins re-entry. In all cases, if the time is "minus" then the event being counted toward has not happened yet; if the time is "plus" then the event has already occurred.