Saturn V Dynamic Test Vehicle


The Saturn V Dynamic Test Vehicle, designated SA-500D, is a prototype Saturn V rocket used by NASA to test the performance of the rocket when vibrated to simulate the shaking which subsequent rockets would experience during launch. It was the first full-scale Saturn V completed by the Marshall Space Flight Center. Though SA-500D never flew, it was instrumental in the development of the Saturn V rocket which propelled the first men to the Moon as part of the Apollo program. Built under the direction of Dr. Wernher von Braun, it served as the test vehicle for all of the Saturn support facilities at MSFC.
SA-500D is the only Saturn V on display that was used for its intended purpose, and the only one to have been assembled prior to museum display. It is on permanent display at the U.S. Space & Rocket Center, Huntsville, Alabama.

Pre-flight configurations

Before a Saturn V could be launched, engineers needed to verify that their design had accounted for everything the rocket would encounter on its journey, from assembly to the launchpad and from Earth to the Moon. To validate the Saturn V design and procedures, they created five pre-flight configurations for testing. These configurations were subjected to tests simulating all aspects of flight preparations and flight itself, and all the tests needed to demonstrate satisfactory results before MSFC would certify the Saturn V to fly.
SA-500D was one of the five pre-flight configurations of the Saturn V. This configuration showed the Saturn V's "bending and vibration characteristics" and verified "the adequacy of guidance and control systems' design." The rocket's of thrust would generate vigorous shaking and it was important to see that the rocket would not shake apart or vibrate itself off-course.
Other pre-flight configurations were:
  • Battleship test model, used for initial engine firing and design improvements
  • Structural test model, to certify the structure for loads during launch at the anticipated temperatures, and to assess the stiffness of each stage
  • SA-500F, the facilities checkout model, verify launch facilities, train launch crews, and develop test and checkout procedures.
  • S-1C-T and S-II-T, all-systems test model of the S-IC first stage and S-II second stage for static firing of engines in the flight configuration
The vehicle designated SA-500D did not include an Apollo spacecraft, but boilerplate parts were used during testing to verify the entire system.

Development of the test article

The Saturn V consisted of three stages and an Instrument Unit. The first stage, S-IC, delivered thrust and delivered the other stages to. Afterwards, it was jettisoned to fall into the Atlantic Ocean and the second stage continued acceleration. The second stage, S-II, was responsible for lifting the remaining parts nearly to Earth orbit. The third stage, S-IVB provided the final push to orbit and the trans-lunar injection burn to set the Apollo spacecraft on a course to the Moon. The IU was the guidance and control computer. SA-500D was the assembly of these components for dynamic testing.
The Saturn V Dynamic Test Stand with "electrodynamic shakers" provided a table capable not only of holding the Saturn V fully assembled and fueled, but also able to simulate the vibrations that would be generated by rocket engines.
The components used for testing were developed from 1964 to 1966, and the tests conducted in 1966–67. Because the Saturn V shared some components with the Saturn IB, some of the components for SA-500D were initially used for dynamic testing with the Saturn IB stack.
In naming the individual stages, MSFC used the stage designation with a suffix indicating its purpose. For example, S-IC-D was the first stage, S-IC, for dynamic testing, and S-IC-1 was the first flight model of the first stage. Suffixes used were "S", for structural, "F" for facilities, "T" for all-systems test, and "D" for dynamic testing.
Following is a history of each component of the dynamic test article in order of appearance.

Apollo boilerplate

Development of the test article started from the top. A boilerplate Apollo spacecraft, BP-27 together with LTA-2, was used for all configurations of dynamic testing. The boilerplate took the place of actual flight hardware. Boilerplate size, shape, mass and center of gravity were the same, but it was not necessary for the entire Apollo spacecraft to be complete to commence dynamic testing. The boilerplate was outfitted with instrumentation to record data for engineering study and evaluation.
BP-27 consisted of hardware specifically built for that configuration and some hardware reassigned from other designations. The command module and launch escape system were unique to BP-27. The service module SM-010 and the spacecraft–lunar module adapter SLA #1 were also assigned to BP-27.
BP-27 was accepted at the Marshall Space Flight Center in late September 1964.
Shortly thereafter, MSFC took delivery of the boilerplate lunar module, called a lunar test article and designated LTA-2. LTA-2 is the only part of SA-500D to fly in space. It was refurbished, designated LTA-2R, and flew on Apollo 6.
BP-27 was used for Saturn IB dynamic testing, shipped to Kennedy Space Center to be a component of SA-500F, and shipped back to MSFC for full-stack testing with SA-500D.

Third stage

The third stage, S-IVB-D arrived at MSFC before any other Saturn V stages because it was destined for dynamic testing in the Saturn IB first. It was assembled by Douglas near Los Angeles. With ceremony and dignitaries for the first Douglas-built S-IVB stage, it set out by barge December 8, 1964, and made its way to New Orleans via the Panama Canal, the Mississippi, Ohio, and Tennessee Rivers to MSFC, where it arrived on January 4, 1965. The same day, MSFC took delivery of the first stage of the Saturn IB for dynamic and facilities checkout testing, S-IB-D/F. The parts were assembled together with the instrument unit designated S-IU-200D/500D and BP-27 for dynamic testing in the Saturn IB configuration from February to September 1965 before it was allocated to the Saturn V configuration.

Instrument unit

The Saturn V instrument unit served as the electronics hub for the first three stages of the rocket, controlling engine firing, guidance, stage separation, and climate for the three stages below. It consisted of two main parts, a rigid ring for structure, and within that, electronics.
Instrument units had a slightly different numbering scheme than the other parts. S-IU-200D/500D was for use with the SA-200D dynamic test article – a Saturn IB, and also for use with SA-500D, the Saturn V.
IBM won the contract to build electronics for the IU, and so, by 1964, constructed a $14 million four-building complex including a manufacturing facility with clean room in Huntsville.
The IU's structural ring had two responsibilities: provide a mounting location for IBM's electronics and hold everything on top of it. It needed to be structurally sound enough to hold the weight of the lunar module, service module, command module, and the three astronauts during the acceleration provided by three mighty stages of rocket beneath. The rings were all fabricated at MSFC.
The IU for SA-500D was not the first built. MSFC built S-IU-200V/500V for vibration testing from September to November 1964. Wyle Labs tested it as part of the Saturn I-B program.
S-IU-200D/500D was the second IU to be built, with the ring completed in January 1965 and electronic components from IBM installed by February 1. It was the last piece necessary for dynamic testing in the Saturn IB program. It was stacked together with S-IVB-D, S-IB-D, and BP-27 for Saturn IB testing through much of 1965. On October 8, 1965, it began dynamic testing for the Saturn V program as part of SA-500D.

First stage

MSFC built the first three S-IC test first stages for the Saturn V: S-IC-T, the S-IC-S, and the S-IC-F. They also built the first two flight stages, S-IC-1 and S-IC-2. S-IC-D was the first to be built by Boeing at the Michoud Assembly Facility, New Orleans using the tooling that had been developed in Huntsville.
S-IC-D, was under construction on September 9, 1965, when Hurricane Betsy struck the Michoud Assembly Facility. The building housing the stage sustained severe damage, but the stage itself was repaired promptly.
S-IC-D set out on the maiden voyage of NASA barge Poseidon to Marshall Space Flight Center on October 6, 1965, and arrived at MSFC October 13. The first stage was lifted into place in the dynamic test stand January 13, 1966 in the picture top right. Said one observer, "Fog and clouds hovered around the top of the tall test stand most of the day while the stage was being lifted from its transporter into place inside the stand, said to be the tallest building in Alabama."

Second stage

The second stage of SA-500D had a complex history. The second stage, S-II-D had been on order, but that part was cancelled February 19, 1965. The plan was to use another test article for dynamic testing as well as its other purpose. Two such test articles were destroyed during testing after having been designated for the dynamic test phase. The actual article used in SA-500D was named in the third re-allocation, when S-II-F, the facilities checkout article, was designated S-II-F/D.
S-II-S, which North American Aviation's Space and Information Systems Division at Seal Beach had completed by January 31, was re-designated as S-II-S/D to be used for dynamic testing. S-II-S/D would not survive its final structural test on September 29, 1965, but the test was exercising considerable margin above the structural integrity required for flight.
In January 1966, the all-systems test S-II-T was re-designated S-II-T/D, so that it might be used for dynamic testing as well as engine firing. S-II-T/D completed integrated checkout of ground support facilities at MTF on February 3, 1966. S-II-T/D's engines were fired five times at MTF from April to May, including a full-duration test. On May 28, 1966, S-II-T/D was undergoing a pressure test to find a hydrogen leak, but the hydrogen pressure sensors and switches had been disconnected unbeknownst to the second-shift crew when they tried to pressurize the tank. Five technicians sustained minor injuries. MSFC convened an investigation that night, and the team completed the report in two days.
After the S-II-T/D destruction, a third article was assigned to dynamic test duties. Facilities checkout article S-II-F became the dynamic test article designated S-II-F/D. S-II-F was shipped from S&ID, Seal Beach, California on February 20, 1966, to Kennedy Space Center where it arrived March 4. It filled in the final part of SA-500F to check out facilities for processing the Saturn V, replacing a dumbbell-shaped temporary stage of the same length and weight as an S-II stage. SA-500F was assembled in the Vehicle Assembly Building where it was mated to S-IC-F on March 28 and S-IVB-F the next day.
SA-500F was completed in the Vehicle Assembly Building, tested for stability against swaying in the wind, and rolled out to the launch pad May 25, 1966, on Mobile Launcher-1.
Hurricane Alma interrupted exercises as SA-500F was rolled back to the VAB on June 8, though the ground crew supposed the rollback was more of an exercise than necessity because winds remained below critical for the entire storm. It was returned to Launch Complex 39A two days later and finally returned to the VAB October 14, 1966 for disassembly.
After facilities checkout at KSC was completed, the remaining components of SA-500F were then transferred to MSFC for inclusion in SA-500D: the Apollo boilerplate BP-27 and S-II-F/D. The second stage was modified for dynamic testing, and shipped by Posideon from KSC on October 29 to arrive at MSFC November 10, 1966.