N.A.S.A. / Boeing Comp. CLV-ATK CLV-ESAS Ares I Ares I
Overall
Vehicle		 Operational from        
  to        
Orbital flights   concept 2005 concept 2005 concept 2007 concept 2008
Payload weight t   20.86   29.35   30.40   30.40
Gross liftoff weight t 735.30 805.50 908.80 923.70
Gross propellant weight t 614.76 667.16 756.46 766.61
Total length m 81.30 88.50 97.75 99.67
Max. diameter (span) m        
Total liftoff thrust (s.l.) kN 12,504 12,504 14,356 14,#.356
Total impulse (vac) MN*s 1,802.8 2,052.6 2,236.8 2,276.5

Fairing

 Total length (+LAS) m 16.05 15.90 21.24 21.24
Diameter m 5.10 5.00 5.00 5.50
Total weight (+LAS) t 5.90 5.90 6.00 6.35

Stage 2

 Name          
  Length m 23.60 32.00 23.60 25.51
Diameter m 5.10 5.00 5.50 5.50
Liftoff weight t 122.02 183.94 144.02 155.36
Propellant weight t 111.13 163.53 126.93 137.08
Engines   J-2S SSME-II J-2X J-2X
Propellant  

LH2/LOX

LH2/LOX

LH2/LOX

LH2/LOX
Total thrust (vac) kN 1,178.8 2,088.2 1,306.0 1,307.5
Specific impulse (vac) N*s/kg 4276 4434 4393 4393
Burn time s   347.2 430.7 460.7
Total impulse (vac) MN*s 475.2 725.0 562.6 602.3

Stage 1

 Name   RSRM RSRM RSRM-5 RSRM-5
  Length (+interstage) m 41.66 40.60 52.91 52.91
Diameter m 3.71 - 5.10 3.71 - 5.00 3.71 - 5.50 3.71 - 5.50
Liftoff weight (+interstage) t 586.50 586.35 728.35 731.58
Propellant weight t 503.63 503.63 629.53 629.53
Engines   ATK ATK ATK ATK
Propellant   solid PBAN solid PBAN solid PBAN solid PBAN
Total thrust (s.l.) kN 12,504 12,504 14,356 14,356
Specific impulse (s.l.) N*s/kg 2360 2360 2400 2400
Burn time s (126) (126) (140) (140)
Total impulse (vac) MN*s 1,327.6 1,327.6 1,674.2 1,674.2