Aug 28 2009
The Apollo Saturn Third Stage
Welcome to the 26th installment in our series on rocketry and the development of America’s space program. We have had a large concentration on the Apollo spacecraft and we are about finished with the construction of the might Apollo Saturn vehicle. This week, we look at the third stage.
The third stage of the spacecraft was built by the Douglas Aircraft Company at its facility in Huntington Beach, California. The stage measures 58 feet 7 inches tall and is 21 feet 8 inches in diameter. One J-2 engine powers the stage and it uses the same fueling mix as the second stage. Two tanks for the propellant make up the bulk of this stage and the tanks are separated by a common bulkhead in the central part of the assembly.
The third stage weighed in at 25,000 pounds dry and 262,000 pounds when it was fueled. This stage performed two duties during the mission. It was first fired for 2 minutes following the second stage cut off and separation, this place the Apollo spacecraft into Earth orbit. The second firing was a six minute burn to take the spacecraft from Earth orbit and to trans-lunar injection.
In the next post, we will have a look at the engines that powered this mighty beast!
