||This article's lead section may not adequately summarize key points of its contents. (December 2010)|
|A-101 (Saturn-Apollo 6)|
|Mission name||A-101 (Saturn-Apollo 6)|
|Spacecraft mass||17,000 pounds (7,700 kg)|
|Launch pad||Complex 37B|
|Launch date||May 28, 1964
|Mission duration||~3 days 8 hours|
|Number of orbits||54|
|Apogee||204 kilometers (127 mi)|
|Perigee||179 kilometers (111 mi)|
|Orbital period||88.5 min|
|Distance traveled||2,184,630 kilometers (1,357,470 mi)|
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. Therefore, 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. A flight-weight command module weighed around 12,000 pounds (5,400 kg); the boilerplate command/service module combination weighted 17,000 pounds (7,700 kg).
This allowed it to be instrumented with 116 measuring devices so that engineers could see the strain, pressure, and acceleration experienced by the spacecraft, which they hoped would confirm their calculations.
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 May 28, 1964, from LC-37B. There had been several delays during the count as liquid oxygen vapors obscured 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. Engineers removed this requirement, which was not critical, from the computer, allowing the launch to proceed.
The ascent was normal up to 116.9 seconds after launch. At that point, engine number eight shut off early. This was not planned as on 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 so catastrophic as 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 (1.26 seconds earlier than predicted), with the stage and boilerplate in a 182 kilometers (113 mi) by 227 kilometers (141 mi) orbit. It continued to transmit data for four orbits when the batteries failed. Both stayed in orbit for 54 orbits, re-entering the atmosphere east of Canton Island in the Pacific Ocean 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 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.
|Wikimedia Commons has media related to: Saturn-Apollo 6|
- The Apollo Spacecraft: A Chronology
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- Postlaunch Report for Apollo Mission A-101