Neighborhood Youth Association

Neighborhood Youth Association
Building a better future one kid at a time

Monday, April 4, 2011

Week 9-Test Stand

To separate this class from a typical hobby rocket building class we decided to incorporate some elements that dive a bit deeper into the engineering that goes on in the rocket industry.  One of the biggest steps in manufacturing a rocket is the testing process.  This allows an engine to be qualified and characterized before it is integrated onto the vehicle and flown.  During the test, millions of pieces of data are recorded and analyzed to fully understand how the particular rocket will perform in flight.  We wanted to bring a scaled down version of this to the NYA rocket class.

A test-stand was built fit for the types of rockets we were using.  This test stand had a load cell to measure the thrust output of the engine.  A thrust vs. time plot was generated, which gave the students a real understanding of how these rockets perform.  After testing an A, B, and C engine we went inside and gave them each a thrust plot and they had to figure out which engine it was based on the average thrust, burn time, and delay time.  This was an interesting project that all of the students really got into. 

The students were asked to find the thrust at each division of the graph and average them all together to get an average thrust.  Next, they had to find the burn time, multiply it by the average thrust to come up with a specific impulse.  Finally, they had to find the delay time.  Once all of these three elements were found they could figure out the engine designation.

Week 8-Looking into a Bigger Rocket

This week was all about preparation.  We had to prepare the students for their adventure into building a bigger more powerful rocket.  These types of rockets have more parts to deal with, less instructions, and greater potential for dangerous situations.  We had the students pull out all of the parts and accurately label each one to make sure we had everything we needed.  In addition, this gave them some familiarity with the different vocabulary and an idea of each parts functionality.  After that, we had each student read a step of the instructions and had the entire class attempt to pull out the necessary parts and simulate what would be done.  This class didn't have the excitement of launching a rocket but was extremely necessary for the weeks to come.

Week 7-Launch Day!

After two weeks of consecutive building the students were excited to finally launch their rockets.  We were planning on using the hand-held altimeters to measure the height of the rocket, however they went too high and we did not give ourselves enough distance.  We started at 50 m from the pad and ended up 150 m from the pad, but, even at that distance, the rockets went too high.  In addition, the fact that we couldn't launch straight up in into the air was a problem for height measurements. 

In any case, all of the rockets launched perfectly.  We equipped some with B engines and some with C engines giving the students a taste of how different each of the engines are.  They were all very excited to see the intense speed and power these little engines provided, and were thrilled that all of the parachutes worked and their rockets were recovered.  Now it is on to bigger and more powerful rockets!