The HAB team members in NARS have created a five-session curriculum to teach physics, atmospheric science, and radio technology that we use as part of our HAB launches. The last session is the most fun of all – analyzing the telemetry data from our HAB’s flight to see what the students can learn from it.

Our students at Bishop-Guertin High School that participated in our High-Altitude Balloon 2  launch this past weekend got together to analyze HAB-2’s flight data.  All of our students tracked HAB-2 using APRS.fi and were excited about the HAB’s flight and final altitude of almost 118,000 ft!

Flight Path

We began by reviewing our flight predictions and expectations for atmospheric conditions that we covered in our previous classroom sessions. You can see the materials that the students worked from via the preceding link. Also, the full set of data from HAB-2’s flight computer can be viewed as well.

We began by comparing the predicted flight path with the actual data from the APRS system on HAB-2.

The students concluded that the shape and direction of the predicted and actual paths matched quite well giving us confidence in the path modeling software.

Balloon Performance

They also noted the HAB-2’s ascent took longer and went much higher than the Balloon Calculator we had used predicted. After some thought, one of the students observed: “maybe we did not put enough helium in the balloon”.  This tuned out to be correct. We checked the scale that we used to set HAB-2’s lift with calibrated weights and we found an error in the scale’s calibration that led us to put about 200 g less lift (less Helium) in the balloon than our model required. We also used the same scale to weight the flight platform. These errors would certainly account for the higher altitude and long ascent times that we experienced.

Temperature and Pressure

The students also looked at the pressure and temperature data from the flight. The pressure was about what was expected but the students noticed that HAB-2 had flown through some temperatures as low as -70° F! The discussion turned to the question of why our video cameras had stopped recording at almost exactly the same time – 53 mins into the flight. An examination of our temperature data gave as a probable answer: the temperature took a dip to -50°F about the time that the GoPro video cameras shut off! Their LiPo batteries are only rated to about -40°F. We concluded that we’d need to find a way to keep the camera batteries warm during our next flight.

Other Questions

The students discussed some additional questions and previewed some raw video from the flight and the recovery included a flight path simulation created by Wayne, AG1A.

HAB-2 Open House

We are planning an open house for the students at our QTH to wrap up the project and to preview the final light video. Members of NARS are welcome to join us for the open house. You can find more information about it here.

I especially want to thank all of the NARS members who worked to prepare for and assist the students with HAB-2:

• Curtis Dude, N1CMD
• Jamey Finchum, KC1ENX
• Abby Finchum, AB1BY
• Anita Kemmerer, AB1QB
• Josi and Anthony Rizzolo, KC1DXL
• Brian Smigielski, AB1ZO

Without our HAB team, HAB-2 and the STEM learning experience that it provided would not have been possible. Thank you all for helping us to create a positive STEM learning experience through Amateur Radio.

Fred, AB1OC