The Saturn MLV was a proposed concept family of

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely f ...

s, intended as a follow-on to the Saturn V. MLV stands for "Modified Launch Vehicle". Vehicle configurations representative of several alternative uprating methods were specified by the

Marshall Space Flight Center The George C. Marshall Space Flight Center (MSFC), located in Redstone Arsenal, Alabama ( Huntsville postal address), is the U.S. government's civilian rocketry and spacecraft propulsion research center. As the largest NASA center, MSFC's fi ...

for initial studies.

Proposed modifications

# Thrust uprating and modifying of the five F-1 rocket engines used in the first

S-IC The S-IC (pronounced S-one-C) was the first stage of the American Saturn V rocket. The S-IC stage was manufactured by the Boeing Company. Like the first stages of most rockets, most of its mass of more than at launch was propellant, in this cas ...

stage, and corresponding increases in propellant tank capacities. # Addition of a sixth F-1 engine in the

stage, as an alternative to engine uprating, plus increased propellant capacities. # Use of

solid rocket boosters A solid rocket booster (SRB) is a large solid propellant motor used to provide thrust in spacecraft launches from initial launch through the first ascent. Many launch vehicles, including the Atlas V, SLS and space shuttle, have used SRBs to giv ...

derived from the

Titan IIIC The Titan IIIC was an expendable launch system used by the United States Air Force from 1965 until 1982. It was the first Titan booster to feature large solid rocket motors and was planned to be used as a launcher for the Dyna-Soar, though the s ...

vehicle. # Additional

J-2 engine The J-2 is a liquid-fuel cryogenic rocket engine used on NASA's Saturn IB and Saturn V launch vehicles. Built in the U.S. by Rocketdyne, the J-2 burned cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX) propellants, with each engine produc ...

s in the S-II stage, ~131 s increased upper stage propellant capacities. # Improved or advanced upper stage engines, such as the HG-3, plus increased propellant capacities. The baseline Saturn MLV would incorporate these changes from the Saturn V vehicle. The Saturn IC first stage would have been stretched with of propellant and five new F-1A engines; the S-II second stage would have been stretched with of propellant and five J-2 engines; the

S-IVB The S-IVB (pronounced "S-four-B") was the third stage on the Saturn V and second stage on the Saturn IB launch vehicles. Built by the Douglas Aircraft Company, it had one J-2 rocket engine. For lunar missions it was fired twice: first for Earth ...

third stage would have been strengthened, but with a standard of propellant, and one J-2 engine.

Nuclear propulsion Nuclear propulsion includes a wide variety of propulsion methods that use some form of nuclear reaction as their primary power source. The idea of using nuclear material for propulsion dates back to the beginning of the 20th century. In 1903 it was ...

in the third stage and toroidal J-2 engines in the second and third stages were also investigated.

MS-IC first stage

height growth would have been limited to , because of enclosed barge limits. If this was solved, height growth would have been limited to , because of vertical assembly crane limits. The MS-IC-1 first stage would have been strengthened, because of higher structural loads. It would also have been stretched . The propellant pressurization system would have had 15% higher flow rates to account for the differences between the F-1 and UF-1 engines. The stage would have weighed more than the

while empty. The MS-IC-1A would have been a variant of the MS-IC-1 with 6 engines individually weaker than the MS-IC-1's engines. The total amount of thrust would have been about 1.46% higher than the MS-IC-1. Because of the additional engine, inboard gimbal is limited to 2.5°, while outboard is restricted to 7.8°. This would have not posed large control issues. Additional supply lines would have been needed for the MS-IC-1A. The stage would have weighed more than the MS-IC-1 and more than the

, while empty. Manufacturing would remain largely similar, while testing and vehicle assembly equipment would see major changes.

MS-II second stage

The MS-II-1 variant would have been almost unchanged from the S-II stage, except for it being strengthened to handle increased flight loads. Manufacturing and GSE would not have had major changes. The MS-II-1A variant would have had seven J-2 engines. Major changes would have been in the propulsion and thrust structure. The variant would have been extended to account for the of propellant. The MS-II-2 variant would have had to have the thrust structure redesigned, because of the switch to the HG-3 engine. Propellant load would be increased up to a maximum of and stage length would have been extended less than or equal to , without major facility changes. Because of the HG-3 engine, the interface between the stage and engines would have needed changes. Electrical, propellant management and propellant dispersion systems would also have required changes. Manufacturing changes for the MS-II-2 variant from the MS-II-1 variant would have been small, except for the increased diameter of the HG-3 engine's feedlines's increased diameter causing changes to the

LH2 Liquid hydrogen (LH2 or LH2) is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecular H2 form. To exist as a liquid, H2 must be cooled below its critical point of 33 K. However, for it to be in a fully liq ...

tank's feedline fittings. Changes to the

LOX Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an applic ...

tank and thrust structure would also have required changes. GSE changes would also have required changes for handling, transportation. New equipment for propulsion systems would also have been required. Changes would have been required to facilities, in order to have space for duplicate tooling. Testing would only have required minor changes to facilities.

MS-IVB third stage

The MS-IVB-1 third stage would have had the same size and shape as the unmodified

stage, but it would have been strengthened because of the larger payload capacity and flight stresses. The J-2

pump would have been modified. The MS-IVB-1 would have weighed more than the

. Manufacturing for the MS-IVB-1 would only have required minor changes. The helium repressurization system would have replaced ambient helium bottles with cold ones and a heater. The MS-IVB-2 would have been a stretched version of the

using the HG-3 engine. The MS-IVB-2 would also have required strengthening. The thrust structure would have been replaced, because of the higher thrust of the HG-3 engine. The

tank would have received an additional cylindrical segment. The propulsion system's helium system would have been modified in a similar way as the MS-IVB-1, but with an additional heater. The common bulkhead would have been flatter. Because of the switch to the HG-3 engine, the

and

chilldown pumps would have been removed. Manufacturing would have required major changes, with under half of the 52 major tools unchanged. GSE models would also have to be largely modified, with again under half remaining unchanged. The MS-IVB-1A is similar to the MS-IVB-2, but with a J-2 engine and thrust structure. It also has heavier tank walls and other less notable changes. An MS-IVB-3 stage was also investigated.

Nuclear propulsion

In the MS-IVB stages, the use of

nuclear propulsion Nuclear propulsion includes a wide variety of propulsion methods that use some form of nuclear reaction as their primary power source. The idea of using nuclear material for propulsion dates back to the beginning of the 20th century. In 1903 it was ...

could have been used to achieve higher

Trans-lunar injection A trans-lunar injection (TLI) is a propulsive maneuver used to set a spacecraft on a trajectory that will cause it to arrive at the Moon. History The first space probe to attempt TLI was the Soviet Union's Luna 1 on January 2, 1959 which w ...

performance. Because of the lower density of

, the vehicle would have been taller. This would have caused higher structural loads and sometimes would have exceeded facility height limitations. The higher structural loads are believed to be solvable without major changes. Both V-3 vehicles and the V-1/NERVA would have had exceeded the height limit by up to . Limiting nuclear engine propellant to reduce the height to would have caused payload to TLI being reduced by up to approximately . This could have been solved by: # Using diameter stages. # Shortening off-loaded chemical boost stage propellant tanks. # Assembling the uppermost stages outside the VAB. # Using hammerhead nuclear stages. # Increasing the height of one VAB cell's hook height. Crawler-related changes and issues are road load limits, and location of service arms and checkout equipment.

References

External links

astronautix.com
Apollo program MLV {{Saturns