A few of us (too few) traveled to the National Pike Park launch site on Saturday, November 17, 2007.  It was a cold windy day, but we were ready. 

Objectives:

• Try the timer ejection system along with the crimson ejection charge.
• Get more altimeter data from the Team 2 V2 rocket.

To launch the timer and ejection system, we used an old rocket from last year and an E9-8 engine.  The E9 had it's own ejection charge which would go off at around 8 seconds after burnout.  We tried it twice and both seem to work. We angled the launch tower into the wind, which reduced altitude, but helped get the rocket down away from the trees. We launched with a 60gram wooden egg in the nose cone, and used a old altimeter (version 1).

We decided not to launch the V2 that afternoon because of the wind.  There was too much risk in getting caught in the trees. Team 2 went out the next weekend, November 24, and launched the V2 with a G64.  It reached an apogee of 881 feet (altimeter data).  We need more flights to see if the G64s are consistent.

Lessons

• The timer did signal the ejection charge at the specified delay time following the launch acceleration.
• The crimson ejection charge went off, but may have been too small to separate a large nose cone.
• The ejection charge socket needs to be firm in the wall between the ejection pressure area and the electronics area.
• The comparison of the flight data for the E9 engines gives some cause for concern with regard to the consistency of the engines.
• It is good to avoid the trees, and fly another day.
   

To set the ejection timer delay time to release the chute before apogee, you need to know the burn time of the engine and the ejection time from the engine ejection system.  For the Estes E9-8, it was somewhere between 3 seconds and 11 seconds after launch.  We chose 5.6 and 4.3 seconds for the timer to eject the chute.
 

Launches

Excel File

Pictures

The launch site

Composite rocket