Sprint Flight 10 Raw Footage (Patreon)

Hi Patrons! Here's all the raw footage from Sprint's 10th flight yesterday!

WOW. What a flight... So many things worked, and so many things did not. This might be one of the most valuable flights I've had to date. I'm still putting together the pieces of the puzzle, but here's what we know so far.

Through the entire flight, we had a slight wiggle on the Z axis. This is bizarre already, as I used the same exact TVC mount for Flight 9, which was fine. It could have been damaged in the last flight, but still odd. The wiggle became a big problem near the end of the burn, where we eventually flipped out of control.

Right around the start of the major wiggle, we began dropping packets from the rocket's telemetry radio. As far as I can tell, everything on the flight computer was still fine, but the distance and orientation of the antenna made it hard to keep a connection.

Shortly after burnout, we lose all recorded data on the vehicle. This is a really similar failure to what happened in Sprint Flight 9, but it seems I didn't fix it all the way. It'll take more debugging, but I think this computer has a flash chip with a bad page. If you aren't familiar with NOR Flash chips, basically, each time we log data, we use a new "page" or column on on the chip. It looks like one or more of these is dead and unable to be written to, and my logging code does not properly account for that.

Right before we lose data recording, two things happen. 1. The data error register gets set high(from a 0 to a 1). This is a variable that represents whether datalogging is working - if we have a bad write to the flash chip, it goes high. 2. More confusingly, the avionics voltage spikes from roughly 11.5v to 15v. That's huge, and it's indication of an electrical failure somewhere.

Somewhere around apogee(I'm guessing), the navigation subcontroller dies. Just gone. Maybe we had a short on the I2C bus, maybe we had a short on the processor, but it's almost certainly a short somewhere. Prior to launch we were experiencing problems that I assume were related to the ~95% humidity in the air, and AVA did not have a protective conformal coat. Condensation could have formed, which shorted the NAV, causing it to reboot.

Because the NAV died, we had no altitude data, and did not fire the first pyro charge. Thankfully, I spent a few hours earlier this week setting up a link between the ground station and flight computer to manually trigger a 2x backup charge in the vehicle. That work paid off, as we would not have deployed the chute otherwise.

The chute did deploy, but was tangled a bit on the way down. That was fine, as I was aiming for a sporty recovery speed anyway. Very glad I got the vehicle back, and it has only minimal damage. 

I'm still trying to construct a timeline of what failed when, but there's SO much to learn from this flight, that it may take a few days. That's all for the Sprint V1 program, I'd love to do Sprint V2 though - maybe early next year? We could set the goal higher too. 5km? 10km? 10,000,000km?

Anyway, next up for BPS is a model of LauncherOne, and Scout E, the landing rocket! There will be a few weeks of down time before we launch again, but thank you as always for the support!

May your skies be blue, and your wind be low :)

Joe