Skip navigation

With the school year behind me, I finally have some time to work on projects that I have been dreaming up all year.  The abundance of free time also means that I am saying 'yes' to a lot of things, and I will soon start to run out of time again.  Regardless, I will complete at least one project this summer!


One thing I wanted to do was re-create Ken Murphy's beautiful 'Year of the Sky on Earth'. In this project, he put camera on top of the Exploratorium in San Francisco.  He took a picture of the sky every 10 seconds for a year, and they put all of the time lapse movies together in one panel.




What I love about this project is that it really captures how sunrise/sunset changes with the seasons.  This gives teachers an opportunity to talk about the seasons from a planetary perspective.  It turns out that people have some very strongly held misconceptions when it comes to the reason for the seasons.


Now that I have a little practice with the Raspberry Pi and cron, I can see how something like this might work.  I would need:


  • A program to start my camera every day at the same time, and let it run until a certain time.
  • A program to turn those pictures into a movie file, and put that into a Dropbox account.
  • A program to remove the pictures each night, and start again.


I would like to recreate this in Chicago with a clear view of the skyline, facing east.  I have a school that is ready to participate, and I (more or less) have the code necessary to do it.  As I am doing this, I am running into some predictable problems.  I think I see solutions to them, which is encouraging.  My hope is to start my project by June 1st, and of course, I will keep the community posted with what is going on.


If there is anything you'd all suggest, I would be more than happy to hear from you!

My college recently received a grant from NASA that allows us to pursue high altitude balloon projects.  I have written about this before, and asked about some potential ideas for experiments and sensors.


Today, in Lexington, IL we launched a balloon with some payloads on it.  This was our first launch, so our payload consisted of a pair of Raspberry Pi cameras, and an Arduino with the BMP Pressure/Temperature/Altitude Sensor.  Prior to the launch I tested the BMP sensor by taking it for a ride to the top of the Sears Tower. 



The sensor worked.  The shape of the curve is what I would expect, though the actual altitude values surprised me.  I am going to have to look in to how that is calculated.  At any rate, the circuit worked, and one of my students built in a red light / green light system to let us know if things are working.  After one test, everything looked great.


A storm was brewing in Lexington, so we had to hustle to get our balloon out in front of it.  We used a 1600g balloon with about 14 pounds of lift for roughly 8 pounds of payload.  (The FAA limits us to 12 pounds overall.) 




The sky behind us was getting pretty dark. 


Our materials were packed into a foam box, held in place with cable ties.



Once we did the pre-flight check, and we were convinced everything was working, we let the balloon fly.  The pictures below are just a few of the more than 2000 that our two Pi Cameras took at 10 second intervals. 






The balloon burst at an altitude of about 90,000.  In later pictures I can see the turbulence with a brief free fall before our parachute deployed.  Shortly after that, both cameras failed.  I think it might have something to do with the fact that the cameras were on the outside of the payload box, and it descended through a storm.  When it landed, both RPis were still on, but the cameras weren't taking pictures.


This was a tremendously fun project.  I have about six more planned over the summer, and we have more experiments to do.  We have some things to revise, but this was a great start.  Any guidance or suggestions from the community would be most welcome!