1,fail to inject into orbit,
2,insufficient power,1
3,insufficient fuel,2
4,weight constraint,3
5,excess flameouts,2
6,engine control failure,5
7,radiation level high,6
8,no protection on some inputs,6
9,design mistake,8
10,incorrect assembly,8
11,lack of testing,8
12,no watchdog on flameout,5
13,lack of design review,9
14,no redundancy on controls,6
15,lack of training,10 9