Education Technology

Journey to the Stratosphere

Activity Overview

When a helium balloon is released it races rapidly towards the sky. Does it continue to travel at this speed? Watch the YouTube video of a weather balloon with included telemetry to help answer the question. Students race the balloon, using regression to make predictions for the elevation at 30 minutes. Students check their answers on the video rather than the back of the book. Enjoy the flight and the view as the balloon journeys into the stratosphere.


Calculate Sx and Sy for a data set with strong correlation and use these values to determine the regression equation y = a + bx. Students use their equation to make prediction (extrapolate) and test the accuracy of these predictions and the limitations of their equation.


  • Linear and statistical calculations: Sx, Sy, R, y = a + bx
  • Correlation
  • Extrapolate
  • Regression

About the Lesson

Maxime Dehaye a French Web Developer and avid photographer released a weather balloon with a range of sensors and video cameras attached. The video can be seen on YouTube, including the on-board telemetry. The data is transcribed and plotted on the calculator whilst the balloon travels skyward towards the stratosphere. Students calculate Sx and Sy using the corresponding formulas and use these results to arrive at the equation y = a + bx. Based on data for the first minute, students make predictions for the altitude of the balloon at 30 minutes generally with surprising accuracy.