3xgood start...then nothing. continuoosly

The craziest thing.... my 2002 sat will go with no probs for 3 times in a 12 hour period. Then when I try to start...nothing. I come back the next day it firews right up... rhree times. anyone got a clue? michaelknopoff@comcast.net...I'm a delivery guy so would appreciate any info asp. thanks

What happens in a no start situation?
Does not crank?
Cranks but does not start?
Security light on?