Week 6-Keep on Building

We started off this week with another review of the rocket designations bringing each student to the board to fill in the rocket's total impulse, thrust, burn time, and delay time.  This week went a lot faster than last and we could tell their confidence was building! 

After going through this review we gave the students a little taste ofwhat was going on in the  rocket industry.  It was a busy week in terms of launches. On Friday, March 4th a Taurus rocket carrying a NASA payload failed due to the inability of the payload fairing to jettison.  The students were asking a lot of questions about exactly what happened, who was responsible, and how much money was actually lost.  The satellite cost almost $500 million!  The next night an Atlas V launched an Air Force Space Plane successfully and the Friday after class (March 11) there was a Delta IV launch of a secret NRO satellite.  More details can be found at www.spaceflightnow.com

Finally, it was time to continue building the hobby rockets.  The students all picked up from where they left off last week and didn't miss a beat.  All of the rockets were finished up and we actually tried to launch one.  We decided to go with the weakest engine, an A-engine, just to get a feel for how powerful it was going to be.  Unfortunately, the rocket was too heavy for the engine and it only went up about 15 ft. in the air.  It was a good lesson, however, and the students are looking forward to putting in a more appropriate size next week.

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.