Saturn IB

The Saturn IB (pronounced "one B", alternatively known as the Uprated Saturn I) was an American launch vehicle commissioned by the National Aeronautics and Space Administration (NASA) for use in the Apollo program. It was an uprated version of the Saturn I rocket, which replaced its S-IV second stage with the much more powerful S-IVB, which gave it enough payload capability to allow it be used for early testing of the Apollo spacecraft while the larger Saturn V needed to send Apollo to the Moon was still being developed. Unlike the earlier Saturn I, it could launch either the partially fueled Apollo Command/Service Module (CSM), or the fully fueled Lunar Module (LM) into low Earth orbit.

The Saturn IB was used for two unmanned CSM suborbital flights, one unmanned LM orbital flight, and for the first manned CSM orbital mission (first planned for Apollo 1, later Apollo 7). It was also used for one orbital mission, AS-203, in which it carried neither a CSM nor a LM, so that the S-IVB would have unburned liquid hydrogen fuel remaining in its tank in orbit. The purpose of this mission was to support design of the restartable version of the S-IVB used in the Saturn V, by observing the behavior of the liquid hydrogen in weightlessness.

After completion of the Apollo Moon landing program, the Saturn IB was used to launch the Apollo CSM on three crew missions to the Skylab space station, and a joint US-USSR space mission, the Apollo Soyuz Test Project.

Specifications

NASA defines the term launch vehicle to refer to all rocket stages and guidance system used to launch a spacecraft, and the term space vehicle for the entire launch stack (launch vehicle plus spacecraft, including any shrouds or adapters.)

Launch vehicle

Payload configurations

S-IB stage

The S-IB stage was built by the Chrysler corporation at the Michoud Assembly Facility, New Orleans.^[3] It was powered by eight H-1 rocket engines burning RP-1 fuel with liquid oxygen (LOX). Eight Redstone tanks (four holding fuel and four holding LOX) were clustered around a Jupiter rocket LOX tank. The four outboard engines were mounted on gimbals, allowing them to be steered to control the rocket. Eight fins surrounding the base thrust structure provided aerodynamic stability and control.

• Height: 80.17 ft (24.44 m)
• Diameter: 21.42 ft (6.53 m)
• Number of fins: 8
• Finspan: 39.42 ft (12.02 m)
• Engines: 8 H-1
• Thrust: 1,600,000 lbf (7,100 kN)
• Fuel: RP-1 (Refined kerosene) 41,000 US gal (155 m³)
• Oxidizer: Liquid oxygen (LOX) 66,000 US gal (250 m³)
• Burn time: 2.5 min
• Burnout altitude: 37 nmi (69 km)

S-IVB-200 stage

The S-IVB was built by the Douglas Aircraft Company at Huntington Beach, California. The S-IVB-200 model was similar to the S-IVB-500 third stage used on the Saturn V, with the exception of the interstage adapter, smaller auxiliary propulsion control modules, and lack of on-orbit engine restart capability. It was powered by a single J-2 engine. The propellant and oxidizer tanks shared a common bulkhead, which saved about ten tons of weight and reduced vehicle length over ten feet.

• Height: 58.42 ft (17.81 m)
• Diameter: 21.67 ft (6.61 m)
• Engines: 1 J-2
• Thrust: 200,000 lbf (890 kN)
• Fuel: Liquid hydrogen (LH2) 64,000 US gal (242 m³)
• Oxidizer: Liquid oxygen (LOX) 20,000 US gal (76 m³)
• Burn time: approx. 7 min
• Burnout altitude (for Saturn IB): orbit

Instrument Unit

The Instrument Unit was built by IBM and rode atop the S-IVB stage. It was constructed at the Space Systems Center in Huntsville. This computer controlled the operations of the rocket from just before liftoff until the S-IVB was discarded. It included guidance and telemetry systems for the rocket. By measuring the acceleration and vehicle attitude, it continuously calculated the position and velocity of the rocket and corrected for any deviations.

Launch sequence events

Saturn IB vehicles and launches

The original Saturn IBs for Apollo were launched from LC-34 and LC-37, Cape Canaveral Air Force Station.

The Saturn IB was used between 1973 and 1975 for three manned Skylab flights, and one Apollo-Soyuz Test Project flight. This final production run did not have alternating black and white S-IB stage tanks, or vertical stripes on the S-IVB aft tank skirt, which were present on the earlier vehicles. Since LC-34 had been dismantled by then, these launches were made from Kennedy Space Center's LC-39B, using a "milkstool" apparatus attached to the Mobile Launcher Platform to raise the rocket up to a height at which the Apollo Command Module's hatch reached the Launch Umbillical Tower's crew access arm.

For earlier launches of vehicles in the Saturn I series, see the list in the Saturn I article.

Saturn IB rockets on display

Currently there are three locations where Saturn IB vehicles (or parts thereof) are on display:

• SA-209 is on display at the Kennedy Space Center Visitor Complex, with the Apollo Facilities Verification Vehicle. Due to severe corrosion, the first stage engines and Service Module were replaced with fabricated duplicates in 1993–1994.
• The SA-211 first stage is on display with the S-IVB-S "Battleship" static test stage stacked in a launch-ready condition at the Alabama Welcome Center on I-65 in Ardmore, Alabama.
• The SA-211 S-IVB stage was converted to a Skylab mockup and is on display at the U.S. Space and Rocket Center in Huntsville, Alabama.

Cost

In 1972, the cost of a Saturn IB including launch was $55 million USD (inflation adjusted US$ 288.7 million in 2012).^[4]

References

External links

• http://www.apollosaturn.com/
• http://www.spaceline.org/rocketsum/saturn-Ib.html
• NASA Marshall Spaceflight Center, Skylab Saturn IB Flight ManualPDF (19.8 MB), 30 September 1972
• Saturn launch vehiclesPDF (61.2 MB)