Science Fun

Last week we started a review of the power behind the Saturn V and started a look at the design of the F-1 engine that was used in the spacecraft. There were five of these monsters in the first stage and boy did they have a ferocious appetite for fuel!

Just the mechanics of one of these mighty engines was a marvelous invention for the time it was created. Fuel and oxidizer were forced into the combustion chamber by pumps that were driven by a gas generator and a turbine. The turbine was driven at 5500 RPM to produce 55,000 horsepower to run the pumps. The fuel pump produced 15,471 gallons of RP-1 fuel per minute and the oxidizer pump 24,811 gallons of liquid oxygen per minute. Fuel traveled through tubing to cool the turbine.

The F-1 engine burned 3,945 pounds of liquid oxygen and 1,738 pounds of RP-1 per second, producing 1,500,000 pounds of thrust. This consumption equaled a flow rate of 413.5 gallons of liquid oxygen, and 257.9 gallons of RP-1 per second – now, that was just one engine, remember there are five of these in the first stage.

The first stage fired for 2.5 minutes, at which it carried the vehicle to an altitude of 42 miles at a speed of 6,164 miles per hour. The combined propellant flow of all five engines was 3,357 gallons per second, which would empty a 30,000 gallon swimming pool in 8.9 seconds. Each F-1 engine had more thrust power than all three main space shuttle engines combined.

The Saturn V Rocket was a very powerful and mighty machine that carried our astronauts into space and to the moon and home again. We have explored the various components that make up this beast and now we will explore the power behind this rocket.

Five F-1 engines in the first stage of the Saturn V was what was needed to start the mission. A large mass had to be moved and moved very quickly to escape the gravitational pull of Earth. Rocketdyne originally developed the F-1 engine for an Air Force program. After development began, the Air Force suspended the program as it did not have the need for such a large engine. However, the newly created space agency, NASA, saw a need for it and contracted with Rocketdyne to continue the development.

The F-1 engine first ‘static’ test firing was done in 1957 and a full test firing was performed in 1959. Thus, this piece of the Apollo spacecraft was designed and developed before Apollo was even conceived. The engine initially had combustion problems that resulted in continued refinements and development tests through the early 60s.

This engine was the most powerful, single nozzle, liquid-fueled rocket ever used in service. One other engine was designed that would have been more powerful, the M-1; which was ground tested, however, was not put into service. The engine burned RP-1 (kerosene) rocket fuel and used liquid oxygen as the oxidizer. A turbo pump was used to inject fuel and oxidizer into the combustion chamber.

In our post next week, we will continue our review of the F-1 engine and we will give you some ‘numbers’ to have fun with.

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!

Well, here we are again, another week has past and it is time for the second act in our Apollo Saturn V rocket, that is, this week we will examine the second stage of this mighty machine.

The second stage of the Saturn V rocket, also known as S-II, was built by North American Aviation at Seal Beach, California. This stage was fueled with liquid hydrogen and liquid oxygen. This stage had five J-2 engines and were arranged the same as the first stage, with the outer engines being able to move to control the direction of flight.

The second stage was 81 feet 7 inches tall and a diameter of 33 feet, which is identical to the first stage. The weight was 88,000 pounds dry and when fully fueled, it tilted the scales at 1.06 million pounds. Over 90 percent of the weight of this stage was in propellant, during testing, there were several structural failures due to the weight of the propellant in the tanks and not enough support. A redesign of the two tanks, allowing them to rest on top of each other with a honey comb resin sandwiched between two sheets of aluminum created a bulkhead between the two tanks, thus adding additional support.

Next up is the third stage of the Saturn V – join us next week as we continue our adventure.

Welcome to the first stage of the Saturn V rocket! This is the largest and most powerful stage of the three stages that make up the power phase of the spacecraft. It is these three stages that are responsible for getting the rest of the Apollo spacecraft into Earth orbit and then to begin its journey to the moon. All starts with the first stage – let’s explore….

The Saturn V first stage was built by the Boeing Company at the Michoud Assembly Facility in New Orleans, which happens to be the location where the Space Shuttle external fuel tanks are built. The completed first stage weighed in at 2,000 tons, which the largest portion of this weight being in the propellants. The dry weight was 288,000 pounds.

This stage stood at 138 feet tall, was 33 feet in diameter. It had five engines arranged in a cross pattern with the center engine fixed and the outer four engines could be directionally controlled by hydraulics to guide the spacecraft. The center engine was cut off 26 seconds earlier than the out four engines to help reduce acceleration in preparation for stage separation and ignition of the second stage.

Total burn time for the engines was 168 seconds, with 7 seconds being prior to lift off. At engine cutoff, the space craft was at an altitude of 42 miles, was down range from the launch site at 58 miles and was traveling at more than 5,352 MPH. The F-1 engines consumed RP-1 Rocket Fuel and liquid oxygen oxidizer to produce 7.64 million pounds of force. Next week, we will continue with the second stage of the Saturn V rocket.

For the last two weeks, our series on Rocketry and the Apollo spacecraft was place on hold while we focused on the 40th anniversary of the Apollo 11 moon landing. This entire series of posts on rocketry and the focus of the Apollo Saturn V rocket were enhanced by the occurrence of the anniversary of this historic event. We now resume our regular mission of the study of the systems of the Apollo Saturn V, which we were previously about to begin.

Development on the Saturn V rocket was started in 1962 at the Marshall Spaceflight Center with the development and testing of the C1 – C4 rockets. The C-1 rocket became the Saturn 1 vehicle, the C-2 was dropped from production, the C-3 rocket was designed to use two F-1 engines in the first stage, four J-2 engines in the second stage and six RL-10 engines in the third. The C-3 rocket was originally going to be used by NASA in Earth Rendezvous missions. NASA soon began development on a larger and more powerful rocket, the C-4, which would use 4 F-1 engines on the first stage, and a modified C-3 as the second stage, and a third stage with a single J-2 engine.

As further developments and testing occurred, NASA realized that it was still in need of more power to move men and equipment to Earth orbit and beyond. Testing and development began on the C-5 rocket to provide the increased power and lifting capability needed for the Apollo missions. The C-5 rocket was designed as a three stage rocket that used 5 F-1 engines in the first stage, five J-2 engines for the second stage, and a third stage with a single J-2 engine. (We will look at the engines in a future post).

In 1963, NASA selected the C-5 rocket to be the one that would work for Apollo. It was renamed to the Saturn V and is the most powerful rocket built to carry man and equipment into space and beyond. The Apollo Saturn V rocket stood 363 feet tall, it had a base diameter of 33 feet without the fins and when fully fueled, it weighed in at 6.5 million pounds and had a payload capacity of 260,000 pounds. Join us next time as we explore the first stage of this mighty rocket!