ISP and the clock

Propulsion System ISP (Hours) based on data from Project Orion
and Project Rho

AM-Beam MAX                        2,834 
H->Fe Fusion MAX                   1,417 
H->He Fusion MAX                     850 
IC-Fusion MAX                        283 
ORION MAX                            278 
NSWR 90% UTB MAX                     133 
AIM                                   17 
VASIMR (high gear)                     8 
Mini-Mag Orion                         6 
ORION Low Altitude                     4 
1959 ORION 2nd Gen                     3 
ORION Fusion                           2 
ORION Fission                          1 
1959 ORION 1st Gen                     1 
Space Shuttle x3 SSME                  0 
Saturn-V first stage x5 F-1            0 
Single Saturn-V F-1                    0 
Space Shuttle x2 SRB                   0