20k feet drogue deployment, any experiences?

[Sig]

Considering a Mongoose 54 project with potential nearing up to 20k according to RockSim.

Of course everyone wants a safe deployment.

Looking for thoughts on deployment devices, charges and/or methods for a drogue chute at the upper reaches.

There is a great CO2 system from Rouse-Tech but think this would be difficult or maybe impossible to fit in the minimum diameter bay along with altimeter(s).

Some test results (http://www.spacewarptechnology.com/SWT/High%20Altitude%20Tests/TABLE_CONTNETS.htm) Compares and tests FFFF and CD3 system, which leads me to believe careful preparation of the charge(s) should be successful.

Any other products, techniques, or tricks?

Main is easy as it would low altitude.

[hognutz63]

http://www.wimpyrockets.com/page16.html

Cheap and easy. So easy I use this method for all flights.

[Sig]

Ah yes I remember reading about this now.
Much thanks for digging that up for me.
That will work just fine.

[bobkrech]

Back in 2003 I advised the FIT JAMSTAR group http://projects.fit.edu/jamstar/index.html on high altitude recovery and deployment methods. It has been known for more than 6 decades that black powder and other pyrotechnic charges must be hermetically sealed in order to function at high altitudes or space. (That's how the BP is ignited in the CD-3 pyrovalve.)

Below are pages from their website on testing barometric apogee detectors to 130 kft and vacuum testing of lithium batteries and BP charges.

http://projects.fit.edu/jamstar/html/adept_apogee.html

http://projects.fit.edu/jamstar/html/hazard_chamber.html

Their project documentation is available here. http://projects.fit.edu/jamstar/html/publications.html

Bob

[Rocketjunkie]

Standard procedures work to at least 25k feet. The failures occur at higher altitudes. In 1990-1992 I saw several motor ejection flights work although the delays were not accurate. I had a successful motor ejection at 25k feet (AGL at Black Rock) but a second rocket projected to reach 36k did not eject. (I don't know the cause, the rocket was never found.)

[uwish]

our club launched the upper stage of a two stage BBX to over 29K feet with standard deployment BP. We also have CO2, with the booster N apogee isn't until the 58K range.

So, no worries up to the 25K.

[cjl]

Standard methods become somewhat weak by ~20k MSL. I've had good luck with the surgical tubing method - I've personally used it up to ~23k MSL, and I've seen it used up to 40k MSL without problems.