Journal · 2013 – 2018

Build notes and flight reports

Written while the balloon was being built: the hardware, the Android software, the near-fire, the launch, and what came after.

2018

• January 6, 2018 Cold temperatures + Lithium-ion = performance suck Well, most of us knew this anyway, and there are datasheets that say this too, so I went with a two battery design for the aircraft: (1) a small 9volt Lithium energizer battery (the silver kind you can buy in stores) and
• January 6, 2018 I'm painting the fuselage black I'm struggling with the right answer on this one. I can't afford the circuitry to get too cold, there's not much room for insulation, and the circuitboard is long and thin, which doesn't help with heat retention. So, I'm

2017

• February 2, 2017 Brand new hardware design After a long hiatus, I've realized that my old design using Android phones will be too heavy for my next flight attempt, so I've been busy working for a year or so on a new design using some embedded chips. Bottom line,

2016

• January 26, 2016 Dialing it to 11 (again) It's been a long while since I updated the blog post, but I've spent the 14 months since the last launch completely rebuilding the hardware, and refactoring code for reliability and fallback modes. Upgrading all the phon

2015

• March 26, 2015 Building a satellite in Android is hard. 3 years and counting now Folks - after a long hiatus and a partially successful launch (more later), I thought i'd update the blog for tech minded folks. About two years ago, I posted a diagram of what i thought the code should be on the Android

2014

• November 23, 2014 Pre-launch pictures It's highly overdue, but here are some pictures of the capsule. The first is the innards of the polystyrene box (1.5 inch thick walls!). You can see the main robot circuit board to the left. On that there's a GPS chip wi
• November 21, 2014 Scheduling the launch for Sunday November 23! After 2.5 years of work, hundreds of hours of work, and countless bugs, distractions and such, I'm happy to announce that the balloon capsule is finally ready for launch! There's some dependency on the jetstream and the

2013

• December 13, 2013 Thermal runaway and fire averted Well, I'm getting close to the last ground tests needed, so I wanted to calculate how much heating or cooling I need for the long, cold journey. Heating or cooling satellites turns out to be very difficult, as even thoug
• November 25, 2013 Why predicting where you're going to land is important I made a script so I could click on a potential launch site on the map, then call up a script at the University of Wyoming's high altitude balloon trajectory forecasting tool. It works great, but here's a great example o
• November 14, 2013 Expected balloon trajectory So, what's the mission then? I've kept it hush until this point, but the idea is to take a mini-satellite up as high into near space as it can go, then release paper airplanes. Below is the approximate mission time and p
• September 19, 2013 Near final hardware selected Finally got everything to work - nearly. Below is a picture of the complete robot - an android phone and app, an IOIO board with an additional board on top, a battery pack, and a servo. There's a lot on the board in a sm
• August 8, 2013 Android software - 8000 lines of code and counting I'm finally getting close to a final version of the code. Given this is my first ever Java program for Android, it's taken me a long time to get here. Below is the schematic for how the software modules link together and
• August 6, 2013 Figured out the hardware for the balloon Geek alert. This took a long time to figure out because there's not a lot of documentation out there. I am using an IOIO board bought from Sparkfun to control the robot, servos etc. I was hoping to use an Arduino, but it
• February 3, 2013 What is Black Sky Robotics? The plan is to send a robot to near-space, attached to a helium balloon. Others have done this before, and have taken cameras up there, done science experiments, etc., and then typically the folks doing this have to retr
• February 3, 2013 How the BSR site works T he BSR site has been designed to let users see articles, pictures of the construction of the balloon and capsule, and to let visitors see either live or historical photos, maps with tracks, stats etc. taken by the caps