Sprint 400m Test Flight, Live in a few hours! (Patreon)

Okay, take two...

For those who did not see the last attempt at this flight a few days back, the vehicle called an in-flight abort while on the pad. Not a great thing to do, especially while I was right next to it. Nobody was hurt, and the charge wasn't as loud as you would think, thankfully!

We had the material and daylight to go for another attempt after repacking the chutes and charges, but it just wasn't the right call. With a computer/procedural failure like that, the best thing to do is pack it up, eat some ice cream, and spend the time to fully diagnose why it happened.

The failure, like most failures, was a combination of several small things which added up. It's never a single point. I'd like to make a full video where I break it down at some point, but here's the TLDR: A rouge accelerometer calibration function was in the NAV computer's startup function, and that set the initial bias incorrectly. It would have been corrected for in the pad-idle loop, but we got a GNSS fix so fast that there was no time to null out the problem. I also had poor error checking in the state transition logic from "NAV Converging" to "Ready For Launch", so we moved to the launch ready state while the kalman filter was still figuring things out. 

There's a lot more nuance here, and again I'd like to do a video where we break it down at some point. I think it's good to continue showing what I don't get right on the channel, and this is a great example.

Anyway, the point is that since the vehicle is barely damaged, and the code is fixed, we're GO at attempt number 2 for the 400m test flight(was 500, but then I wanted onboard video). We're aiming for sunset in Central Time, which is around 8pm CT / 9pm ET / 6pm PT. The stream will go live a little bit before then, and is linked above!

Hope to see you there, and thank you again for your support :)

Joe