The LUT, the Shuttle, and the Saturn V S-IC Stage (1969)

Before NASA settled on the Shuttle's makeshift Solid Rocket Boosters and External Tank, it planned a fully reusable winged manned Booster. It even had a backup plan for a temporary Booster stand-in if the Shuttle Program budget grew tight. Space historian David S. F. Portree describes this fascinating might-have-been from 1969.

Cape Kennedy, August 1967: the Apollo 4 Saturn V rocket framed by two LUTs as it leaves the cavernous VAB (left). Image: NASA.
A red-painted Launch Umbilical Tower (LUT) was the Saturn V rocket’s constant companion from the moment technicians lowered the rocket’s 138-foot-tall S-IC first stage into place beside it within a Vertical Assembly Building (VAB) high bay until shortly after the the S-IC’s engines ignited on one of the twin Launch Complex (LC) 39 pads. The nine servicing arms linking the 398-foot-tall LUT to the 363-foot-tall Saturn V would retract or swing out of the way; then, between 1.4 and 9.4 seconds after liftoff, the rocket would perform a LUT clearance yaw maneuver, its five F-1 engines bathing the launch pad in flame. After that, the LUT would stand alone, awaiting transport back to the VAB and the arrival of a new Saturn V.
By late 1969, ...