Saturn V-B

Infobox rocket
name = Saturn V-B
function = Manned/unmanned LEO and Lunar launch vehicle
manufacturer = Von Braun
country-origin = United States
height = 50.00 m
alt-height = 164 ft
diameter = 10.06 m
alt-diameter = 33 ft
mass = 2,313,320 kg
alt-mass = 5,099,990 lb
stages = 1.5
LEO-payload =22,600 kg
alt-LEO =49,800 lb
status = Concept/study
sites = N/A
launches = N/A
stage1name = S-ID Booster
stage1engines = 4 Rocketdyne F-1
stage1thrust = 30,962.500 kN
alt-stage1thrust = 6,960,647 lb_f
stage1time = 154 seconds
stage1fuel = RP-1/LOX
stage2name = S-ID Sustainer
stage2engines = 1 Rocketdyne F-1
stage2thrust = 7,740.300 kN
alt-stage2thrust = 1,740,089 lb_f
stage2time = 315 seconds
stage2fuel = LH2/LOX

Studied in 1968 by Marshall Space Flight Center, the Saturn V-B was considered an interesting vehicle concept because it nearly represents a single-stage to orbit booster, but is actually a stage and a half booster just like the Atlas. The booster would achieve liftoff via five regular F-1 engines; four of the five engines on the Saturn V-B would be jettisoned and could be fully recoverable, with the sustainer stage on the rocket continuing the flight into orbit. The rocket could have had a good launch capability similar to that of the Space Shuttle if it was constructed, but it never flew.