Update: The balloon burst prematurely and we were unable to get all the way to the ocean like we had hoped Still though, this was an excellent launch and we were able to prove that our numbers worked, even if the balloon had other plans.
Hi there. It’s me, Eric, and I’ve been pressing my eyes to my computer screen for the last four hours anxiously watching our balloon ascend. To be honest, I’m thrilled beyond belief! We’ve reached neutral buoyancy after a very long, slow ascent at around 123,500 feet. It could keep rising though, so if you want the latest location data, check it out at http://aprs.fi/n9var-1.
Let’s start with some basic info about the balloon:
We filled the balloon with 61.5 standard cubic feet of hydrogen gas. The balloon weighed in at 1616 grams of mass, and the payload and all attached string and duct tape came in at 189 grams. Needless to say, this was a really light launch. We released the balloon at 9:29 AM Pacific Time (even though we were technically in Arizona at the time, my watch wasn’t at Mountain. Sorry.) just across the NV-AZ border around Mesquite, Nevada:
The balloon rose slowly. Very slowly. It was still visible from the launch point when we packed up and drove away.
The balloon has been drifting for a while now. Here’s a screenshot from the APRS feed on my computer at the time of writing this post:
I took the location data from APRS and ran it through MATLAB to calculate the balloon’s altitude over time. The result: a beautiful sine-like graph that looks almost too mathematically perfect to be true:
Then, I decided to take the “derivative” of this data by using the MATLAB gradient function to determine the balloon’s velocity and plot it against its altitude. The result was more erratic than I expected, but definitely has a defined curve-like shape:
As the balloon neared neutral buoyancy, its altitude fluctuated a bit, and the result is a altitude vs. time plot that looks, according to Dr. Maxham, a lot like a spring establishing a load balance:
I’m sure as the flight progresses and the balloon travels further, we’ll have a lot more to share with you. Before we go, though, I’d like to say a few things:
- Thanks to Edward and Amanda for taking me along today. This has perhaps been the most exciting launch to date, and today was a blast, even if the heat was a little… beating.
- Special special SPECIAL thanks to Alicat, who supplied our awesome mass flowmeter. Without them, we wouldn’t be able to even come close to achieving such an amazing flight.
- Thanks for all those who are following along at home and / or couldn’t make the flight today. Your continued support rocks.
- Thanks to all those who’s math we’ve based our calculations on. We truly stand on the shoulders of giants.
Wow. This has been exciting. Look forward to more data and info as we get it, and until then, HAPPY NEUTRAL BUOYANCY!