A-101

A-101 was the first Saturn rocket launch to carry a 'boilerplate' Apollo spacecraft. Space mission |

  insignia = Apollo program insignia.png|
  mission_name = A-101 (Saturn-Apollo 6) |
  sign  = A-101 (SA-6) |

launch_pad = Cape Canaveral | launch = May 28, 1964
17:07:00 UTC
Complex 37B | landing = June 2, 1964
~01:00:00 UTC |

  duration  = ~3 days 8 hours |
  orbits = 54 |
  apogee = 127 mi (204 km) |
  perigee = 111 mi (179 km) |
  period = 88.5 min |
  inclination = 31.8° |

distance = 1,357,466 mi
(2,184,630 km) | mass = 38,900 lb (17,650 kg) |

Boilerplate

The first five launches of the Saturn I had carried Jupiter-C nosecone that were a proven design allowing engineers to focus on the rocket. However in order to get to the Moon, it had to be shown that the rocket could actually launch the Apollo spacecraft shape. So on A-101 the rocket carried a boilerplate spacecraft and a dummy Launch Escape System (LES). The boilerplate (BP-13) duplicated the size, weight, shape, and center of gravity of a manned Apollo command module.

This allowed it to be instrumented with 116 measuring devices so that engineers could see the strain, pressure, and acceleration experienced by the spacecraft, hopefully confirming their calculations.

Flight

It took three attempts to get the rocket off the pad. The first launch attempt was scrubbed after the liquid oxygen damaged a wire mesh screen during a test, causing fuel contamination. The second attempt was scrubbed after the rocket's guidance system overheated when a compressor failed in the air conditioning.

It finally lifted off on 28 May from LC-37B. There had been several delays during the count as liquid oxygen vapours obscured the an optical window in the SA-6's instrument unit, so that a ground based theodolite could not see it. This theodolite was needed for launch to proceed. In the end this requirement was removed from the computer by engineers to allow the launch to proceed as it was not critical. The mission used Apollo boilerplate # 13.

The ascent was nominal up to 76.9 seconds after launch when engine number eight shutoff early. This was not planned like at SA-4 but pleasingly for engineers the rocket compensated perfectly and burned the first stage for 2.7 more seconds than planned. The first stage separated and the second stage ignited. Ten seconds later the LES was jettisoned as planned (any explosion would not be catastrophic to need its ability to pull the spacecraft away at high speed). 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 (l.26 seconds earlier than predicted), with the stage and boilerplate in a 182 km by 227 km orbit. It continued to transmit data for four orbits when the batteries failed. Both stayed in orbit for 54 orbits reentering the atmosphere east of Canton Island in the Pacific Ocean on June 1.

A-101 (SA-6) (NASA)

Engine failure cause

Engineers were quick to find the cause of the engine number eight failure. The teeth on one of gears in the turbopump 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 first and only problem encountered with an H-1 engine during a flight.

External links

*The Apollo Spacecraft: A Chronology
*http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1964-025A
*Moonport: A History of Apollo Launch Facilities and Operations
*http://science.ksc.nasa.gov/history/apollo/sa-6/sa-6.html
*Stages to Saturn