Tethered Balloon Experiment
The National Scientific Balloon Facility graciously invited us to be guest investigators at their launch facility. Although working with a smaller balloon at lower altitudes, we had their full support in performing our own tethered balloon investigation. What a neat experience!

Data Analysis & Graphs

Experimental Protocol

A teachers guide for tethered balloon experiments (WORD 36 KB)

Our Data (Excel 1 MB)

 We test inflated our "8-foot" weather balloon. We expected a loud bang but surprisingly it really did inflate to at least 6 feet and about 6 lbs of lift.
Mark, the NSBF Flight Operations Manager helps us equip our test flight with a parachute. Just in case.
Did we mention that we needed a little helium?
At the NSBF you get a truck full.
Such a little balloon.
Getting bigger...
and bigger.
Rigging the payload and recovery equipment.
The LabPro data logger and probes were securely wrapped in bubble pack and suspended from a parachute. Just in case...

Starting the flight.
Our experimental protocol called for recording pressure, temperature, relative humidity, & electric potential every second while we let out line, pausing every 100 feet to get steady readings. Problems developed immediately when the wire for the electric potential got tangled and disconnected. We had to cut it loose.

1000 feet of cord was already strung along the ground from the center of the same launch field that had been used two days earlier for the high altitude BFEM launch.
We simply walked back toward the center of the field, letting the balloon rise above us.
We stopped every 100 ft to allow the probes to stabilize and accumulate data. In addition, we measured the angle that the air movement had deflected the balloon so that we could calculate the balloon altitude.
Being near an airport, we had to obtain FAA clearance and we had to tie a red ribbon every 100 ft so that aircraft could see our cord.
1000 feet up. Here we are at the center of the field.

Flight Profile

This is a graph of altitude vs time.
After recovering the data logger and anxiously checking our data, we launch the balloon for a second flight. This time we launch Stu's digital camera set to take pictures every minute.
Just getting started. Already, how small we look.

Which way is up. I'm dizzy.

The paved circle is 1000 feet in diameter.

Safe and sound. Stu is glad to recover his precious camera.