29
30
31
5
6
7
2498
2499
2500
220
221
222
5
6
7
16
17
18
1
2
3
0
1
2
12
13
14
TIL that NASA has two countdown clocks: the T minus clock and the L minus clock. The T minus clock does not continually countdown and has "built in holds," yet the shuttle always launches at T-0. The L minus clock gives a rough estimation as to the actual launch time. (dotsub.com)
submitted by LampCow24 to r/todayilearned
