Flight This Weekend?
With a much more promising early prediction, we’re going to try and fly this Saturday, November 10th. The track is throwing us ENE, landing southwest of La Porte, IN. We’ll see if this prediction holds. The greatest concern is ground winds. We have an informal 15mph cutoff for reliably safe launch conditions. Predictions are presently at 16mph with 23mph gusts. This could be enough to mean this Saturday’s flight may have to be put on hold. We’ll monitor the situation. Assume the flight is a go unless we hear otherwise. A determination will be made by 5pm on Wednesday. If there is any decision to scrap this attempt, I’ll send out a notification to everyone who signed up and post a blog entry as well. If you want to join us for the flight please sign up in the lab or send me a notification no later than 5 PM on Wednesday.
If we do get off the ground, here are our mission objectives in brief:
- Test ballast ascent control system
- Collect data from miniature GPS unit
- Monitor voltage of Lithium Thionyl Chloride batteries over duration of flight
- Capture HD imagery of balloon burst
The Altitude Control System is taking shape. The first draft test device has gone through some modifications and we plan on final pre-flight tests this Wednesday. The basics of the design consist of a hopper that holds 2kg of sand, a stepper motor driven by an Arduino, and a flow valve that is opened by the motor. The motor rotates a ~ 1cm aperture on a wheel set beneath the hopper to vent the ballast. We had it set to rotate 45° clockwise to open the valve then back 45º to close. The only problem was that if the motor slipped at all, the aperture could get out of alignment. To fix this problem, we decided to use a limiter switch to tell the motor how far to rotate to reach the closed and opened positions. This Saturday, Andrew modified the code to use the switch signal. Jeff helped wire up the switch and connect it to the Arduino. I began installed the switch and ran a test.
Stay tuned to this page for the latest flight update.