13 August, 2015

TARC Update

It is well past time for an update on my TARC projects and general rocket related activities. 

I will start by saying that Southern Thunder was not kind to me or my rockets.

A test flight of the PMR-TARC15-EMS vehicle was conducted on 20 June, 2015 at the Southern Thunder Launch in Manchester,TN.  The result was a total loss of the vehicle due to failure of the upper gas block.
Before Flight
After "Flight"
The objective of this test was to verify stability of the vehicle and to gather data to estimate the Drag Coefficient of the vehicle.  Simulations of the vehicle in Rocksim indicated that a stable flight was likely and that a delay of 5 seconds would deploy the recovery system at apogee.  The selected motor was an Aerotech E18-7 with the delay adjusted according to Aerotechs instructions to be approximately 5 seconds.
Launch conditions were less than ideal with strong gusting winds.  The Launch rod was angled into the wind to aid in recovery and was not adjustable. The rocket achieved a stable flight, but there was significant weather cocking due to the high winds, this in combination with the launch angle resulted in a very low apogee altitude. The rocket impacted the ground without the recovery system being deployed.  Post flight inspection on the range suggests that the ejection gases may have been blocked from entering the recovery chamber, as indicated by a lack of soot, but given the design of the baffle system it is possible that no soot would have been present at that location had things worked as intended.  An additional potential failure mode would be operator error in adjustment of the delay.
After returning from the range it was determined that the ejection gases over pressured the space directly above the motor and blew out the Gas block at the top of the motor mount tube. 
This pressurized the area around the air-brake linkage assemblies and vented through the holes under the air-brakes.  The end result was the total loss of the vehicle and significant delay of the program.
In the future a full ground test of the recovery deployment system will be conducted and all components investigated for damage.
The PMR-TARC14-002 had a  parachute separate at deployment which resulted int he parachute being lost and a fin breaking on contact with the ground.  The damage is repairable but at this point I am canceling the program and redirecting resources to Geezer TARC Coming up in  just over a week.

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