Why did the parachute not get deployed?

[LWeissbrot]

Hi dear Rocketryforum,



As already described in this thread we are a group of students from the Technical University of Berlin. On 11.4.2022 our hot-water-rocket was launched. We used the Altus Telemtrum v2.0 board to record and transmit the telemetry of the flight. Unfortunately, the recovery system was not triggered during launch, so we are now trying to find the cause of this error.

In this post, I would like to share with you our investigation to date so that perhaps we can work together to find the root cause of the problem. We have characterized the causes of the error and investigated them one by one. So far, we have been able to rule out almost all of the probable causes of the provisioning error, which puzzles us. Unfortunately, we have not yet been able to contact the "Telemetrum" manufacturer.

Attached you will find a few slides in which we have summarized our findings as well as the on-board data of the referenced flight. The video included on the slides can be played if you download the .pptx version here.

I am looking forward to your input! If you have any questions or need more info, just write me.

 

[dhbarr]

A very easy way to test the Telemetrum itself would be to use a d9, d12, or similar.

Multiple runs could eliminate several possibilities at a smallish field with low cost and low risk.

 

[cerving]

Is the Telemetrum dead? If not, download the data and graph it, and also look at the raw data... that will usually tell you why it didn't fire, assuming a sufficient understanding of the device's triggering algorithm.

 

[les]

Question - how is the Teletrum vented to the outside air? How many/size of the vent holes?

 

[Ez2cDave]

https://altusmetrum.org

Contact "Bdale" - [email protected]

Dave F.

 

[dhbarr]

@bdale is the forum handle

Feel free to subscribe to our mailing list. We also hang out on IRC channel #altusmetrum on irc.oftc.net if you have questions that aren't answered here. You can also find us on Facebook, though note we don't check Facebook very often.

 

[LWeissbrot]

Is the Telemetrum dead? If not, download the data and graph it, and also look at the raw data... that will usually tell you why it didn't fire, assuming a sufficient understanding of the device's triggering algorithm.

Looking at the graph data did not indicate a missfire. We had continuity of the apogee channel for the hole flight, although the drogue state was triggered. I really dont understand why the channel did not fire.

 

[LWeissbrot]

@bdale is the forum handle

Do I just write him a private message?