High-Altitude Balloon Launch from Davis

The SF-HAB group got together in the beginning of August to do another high-altitude balloon launch. The purpose was to test out a new 3D GoPro camera to see how well it would perform at altitude. We also had a LoRA transciever onboard, which we are thinking about using as a remote cutdown device that we would fly on future launches.

The jet stream in July was really unsettled, so we delayed for a few weeks while the winds picked up a bit and shifted heading. Watching the predictions from HABHUB gave us a good idea when to launch. This was one of our predictions before launch.

Prediction from Dixon

Unfortunately, I really goofed up when doing the launch predictions. As you can see in the above screenshot, I used the default ascent rate of 3.5 m/s, which is about 680 ft/min. We normally target 1000 ft/min, so this prediction has the balloon going much further than what we were looking for.

I realized my mistake and ran some more predictions, plus the winds changed slightly overnight, so we decided to launch from Davis. I picked up Ian KO6YQ and met everyone at the launch site at 10am. It took about an hour to get the balloon filled and payloads ready for launch.

Filling the balloon

Here's the last picture before launch. From the top: Kaymont 1kg balloon, parachute, 2m APRS beacon, LoRA radio, and GoPro 3D camera attached to the silver ball. We had lots of line between the payloads, after learning our lesson on the previous launch.

Balloon train

On this launch we actually overfilled the balloon a bit so the actual ascent rate was 1330 ft/min. We did this because the predicted flight path was over the Sacramento airport, and we didn't want the balloon to be anywhere near the ground near the airport.

Here is the 3D YouTube video of the first 53 minutes. Click and drag within the video to change the view:

This flight went up to 100,131 ft, which was not as high as our previous launch. Overfilled balloons rise quicker, but burst at a lower altitude.

W6MRR-11 balloon maximum altitude

As the flight progressed, the tracking team staged at Knights Landing, but when it was clear that we would land well short of that location, we backtracked along Highway 113 and Road 102.

W6MRR-11 balloon maximum altitude

We were parked at the edge of the field where it landed, and we saw the balloon fall from the sky, so the recovery was extremely easy. Mathison KJ6DZB walked out into the field of unripe tomatoes and picked the balloon up from the ground.

Recovery in a tomato field

Here's the recovery team, including Ted K5KZ, myself, and Ian KO6YQ, with Mathison's kids holding the balloon.

Recovery team

Afterwards we had lunch in Woodland and plotted our next launch.