AS-101 (also designated SA-6) was the sixth flight of the

Saturn I The Saturn I was a rocket designed as the United States' first medium lift launch vehicle for up to low Earth orbit payloads.Terminology has changed since the 1960s; back then, 20,000 pounds was considered "heavy lift". The rocket's first sta ...

launch vehicle, which carried the first boilerplate

Apollo spacecraft The Apollo spacecraft was composed of three parts designed to accomplish the American Apollo program's goal of landing astronauts on the Moon by the end of the 1960s and returning them safely to Earth. The expendable (single-use) spacecraft ...

into low Earth orbit.NSSDC: ''SA-6''
/ref> The test took place on May 28, 1964, lasting for four orbits (about six hours). The spacecraft and its upper stage completed a total of 54 orbits before reentering the atmosphere and crashing in the Pacific Ocean on June 1, 1964. The flight experienced a single anomaly: one of the eight first-stage Saturn I engines shut down early, but the guidance system compensated by burning the remaining seven engines longer. AS-101 was followed by four more flights to verify the launch aerodynamics of the

Apollo command and service module The Apollo command and service module (CSM) was one of two principal components of the United States Apollo spacecraft, used for the Apollo program, which landed astronauts on the Moon between 1969 and 1972. The CSM functioned as a mother sh ...

(CSM) and its

launch escape system A launch escape system (LES) or launch abort system (LAS) is a crew-safety system connected to a space capsule that can be used to quickly separate the capsule from its launch vehicle in case of an emergency requiring the abort of the launch, suc ...

(LES) tower.

Boilerplate Apollo

The first five launches of the Saturn I had carried

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth t ...

nosecones, a proven design which allowed engineers to focus on development of the rocket. To verify the launch aerodynamics of the CSM, AS-101 carried BP-13, a boilerplate spacecraft that weighed and duplicated the size and shape of the CSM, and a dummy LES tower. A flight-weight command module (CM) weighed around . The boilerplate spacecraft was instrumented with 116 sensors reading strain, pressure, temperature, heat flux, and acceleration.

Flight

It took three attempts to launch the rocket from Cape Kennedy Air Force Station Space Launch Complex 37B. The first attempt was scrubbed after the

liquid oxygen 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 app ...

damaged a wire mesh screen during a test, causing fuel contamination. The second attempt was scrubbed after the rocket's guidance system overheated due to failure of an air conditioning compressor. The vehicle finally lifted off on May 28, 1964. There had been several delays during the countdown as liquid oxygen vapors obscured an optical window in the SA-6's instrument unit, so that a ground-based

theodolite A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building an ...

could not see it. This theodolite was required by the countdown computer in order for launch to proceed. Engineers deemed it non-critical and reprogrammed the computer, allowing the launch to proceed. The ascent was normal up to 116.9 seconds after liftoff, at which point engine number eight shut off early. This was not planned, as it had been on SA-4 as a test, but the rocket compensated perfectly by burning the remaining fuel in the other seven engines for 2.7 seconds longer than planned. The first stage separated and the second stage ignited. Ten seconds later, the launch escape system was jettisoned as planned. Also jettisoned from the first stage were eight film cameras that observed separation of the stages. The second stage cut off at 624.5 seconds after launch (1.26 seconds earlier than predicted), with the stage and boilerplate spacecraft in a by orbit. It continued to transmit data for four orbits, after which the batteries failed. The vehicle made a total of 54 orbits, re-entering the atmosphere east of Kanton Island in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

on June 1.

Engine failure cause

Engineers were quick to find the cause of the failure of engine number eight. The teeth on one of the gears in the

turbopump A turbopump is a propellant pump with two main components: a rotodynamic pump and a driving gas turbine, usually both mounted on the same shaft, or sometimes geared together. They were initially developed in Germany in the early 1940s. The purpo ...

were stripped off. This did not cause any delays in the next launches as engineers had already decided that the gear design was inferior and were planning to change it for the next launch. This was the only problem encountered with an H-1 engine during a flight.

References

External links

The Apollo Spacecraft: A ChronologyNASA Space Science Data Coordinated Archive
*http://science.ksc.nasa.gov/history/apollo/sa-6/sa-6.html
Postlaunch Report for Apollo Mission A-101
{{Use American English, date=January 2014 Apollo program Spacecraft launched in 1964 Spacecraft which reentered in 1964 Test spaceflights Spacecraft launched by Saturn rockets