Monday, April 29: High Altitude Balloon Launch

Introduction:

Today’s exercise is the culmination of the previous several weeks spent working on balloon mapping and aerial rigs, etc.  Today, we will fly.  We will soar.  We will launch the University of Wisconsin- Eau Claire into space.  Having finally perfected our camera apparatus and being that the weather appears cooperative, on Friday, April 26 of 2013 the class rigged our space platform to our weather balloon and said our prayers as we floated our helium-powered remote sensor 60,000 feet into the stratosphere.  Hopefully, the camera will parachute safely back to us and we can recover some interesting imagery from our High Altitude Balloon Launch.

 

fig 1: Launch

Methodology:

As can be found in previous posts, this project is something that the Field Methods class has been preparing some time for.  More information can be found in the post for Monday, Feb 11 but I will recap the section that pertains to the HABL.  This activity will take a camera into the upper section of the Earth’s atmosphere, so if we desire to recover any data from the activity we will need to take precautions that combat certain elements of that region of the planet.  Our camera rig will need to

1)      remain attached to the balloon

2)      hold a camera, parachute, and GPS tracking device

3)      deploy the parachute effectively when falling

4)      be light enough that the balloon can rise with it

5)      be stable enough that the camera it contains will capture serviceable imagery

6)      insulate the electronic components enough that the extreme cold, heat, and low pressure of the upper atmosphere does not do any damage to them nor will impact with the earth

7)      be waterproof

  

The rig was based around a Styrofoam outer shell built from a modified tackle container.  A hole was cut in the bottom and plexiglass cover fitted so that the camera could take images through it.  The camera itself was set to take video from this porthole, it was expected that the camera would support an hour of video recording and that the launch would require about forty five minutes to reach its maximum height.  Also included in the rig was a GPS tracking device that Prof. Hupy had effectively rigged to his iPad.  During the launch, this would quickly stop being tracked as its distance from eath’s surface expanded, however it did send out a couple of locations (one every ten minutes to preserve battery life) so that we could see its immediate eastward movement from Eau Claire.  For insulation, some fiberglass and activated (shaken) hothandz hand warmers were used inside the Styrofoam rig once the GPS and camera had been strapped in place.  The top of the box was then taped on with more than enough duct and packing tape.

fig 2: the (rough) general idea for the parachute: let the balloon pop and the parachute should open up as air is forced into the opening under the canvass on the trip down

The Styrofoam camera rig was attached with carbineers to the parachute that would hopefully land the apparatus safely upon the balloon’s popping.  The parachute was then attached to the balloon itself at the center of the canopy, so that it would be held taught as the balloon rose but once the balloon was gone it could catch on the trip back to earth (fig).  The balloon itself was a helium weather balloon which was filled large enough that, as one classmate put it, one could easily roll up and fit a person inside (roughly 8 feet in diameter).  It could have been filled further, but as the balloon rises and the pressure outside of it expands, the gas inside the balloon will not be pushed in as forcefully from the outside atmosphere and the balloon itself will expand.  Obviously, it is undesirable for the balloon to expand beyond failure too quickly, so space was left inside the balloon that the Helium gas could expand while maintaining the buoyancy required to lift the apparatus and parachute through the stratosphere.



fig 3: in the dangerous job of transporting Hydrogen, much care is needed. Good thing we're using Helium.

fig 4: Thank you, professor, for recovering the data!

 The final crucial step in completing a High Altitude Balloon Launch is the recovery of the apparatus itself, accomplished in our case by Professor Hupy and a small cadre of students able to drive to the far side of Clark County where the balloon landed in the canopy of the Wisconsin Woods.  The balloon had to land before the GPS unit was sending its signal to the iPad, and Hupy had to saw some branches in order to get at the balloon, but the rig was successfully recovered and with it, the data (fig 4).

Results:

the Curvature of the Earth

The ultimate result was a sweet video of the earth!  The parachute was successful, and out apparatus was found safely dangling thirty feet up a tree in Clark county, just under 80 miles from the launch site.  If you did not know, this is an exciting accomplishment in and of itself.  Several images were collected from the video (given below) and nearing the top of the ascent, the camera apparatus began swaying enough to clearly show the curvature of the atmosphere.  The earth is ROUND, people!!!  More could be done in further projects by attaching some IR cameras to the rig, I personally would like to be able to collect some imagery that would fall under the Landsat 7 band 6 range of data (heat) or perhaps do a night launch and see the lights from the night sky.  Another addition that should have been considered would be an altimeter that recorded the altitude of the apparatus over time, this way we could have an easy tool to determine the height of each image.

the mighty Chippewa River from high above.