Week 5-Start Building!

We started the class with a 10 minute review of the engine name designations, the current US launch vehicles, and the definition of thrust and total impulse.  Given a table with the total impulse ranges for each letter the students could pick a total impulse and subsequently find the average thrust, total burn time and engine delay time.  For example:

Total Impulse Table

A	1.26-2.50 N·s	0.29-0.56 lbf·s
B	2.51-5.00 N·s	0.57-1.12 lbf·s
C	5.01-10.00 N·s	1.13-2.24 lbf·s
D	10.01-20.00 N·s	2.25-4.48 lbf·s
E	20.01-40.00 N·s	4.49-8.96 lbf·s
F	40.01-80.00 N·s	8.97-17.92 lbf·s
G	80.01-160.00 N·s	17.93-35.96 lbf·s

If we were given a rocket with the designation C8-6 this would be its specifications:

Total Impulse: 7 Ns (it could be anywhere from 5.01-10.00 as stated in the table above)

Thrust: 6 N (the second digit)

Burn Time: 7/6 seconds (Total Impulse/Thrust)


Delay Time: 6 seconds (the last digit)

Then it was time to start building the hobby rockets.  The students each got to choose their own designs because the kit gave enough parts to have 64 different combinations.  Each advisor helped out one student and guided them through the building process.  It was interesting to see how the students mind sets had to change a bit to understand the sequence of steps given in the instructions.  They all seemed to be very interested overall, but definitely needed a lot of help.  They are each about half way through the building process and will hopefully finish up next week.