Skip navigation
2015

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. 

 

sears_tower.jpg

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.) 

 

ballooning.jpg

 

The sky behind us was getting pretty dark. 

 

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

 

rsz_balloon_payload.jpg

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. 

 

frame0411.jpg

frame0490.jpg

frame0755.jpg

 

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!