The BOREALIS program is a high altitude scientific
balloon program at Montana State University. In this activity students will
construct a model of the BOREALIS system which will help them understand what
components comprise the balloon vehicle. This model is approximately 1/12 scale.
Visit the BOREALIS Image Archive for launch
and recovery pictures of the actual BOREALIS system.
Materials
Construction of this model will require the following materials:
1 helium party balloon
1 plastic ring from a small soda bottle
1 twist tie
plastic wrap (3 in. x 6 in.)
thread (approx. 25 in.)
aluminum foil (1/2 in. x 1/2 in.)
2 payload modules (template included)
1 orange marker or crayon
1 large paper clip or binder clip
glue
scissors
The BOREALIS Vehicle
We will call the balloon vehicle everything that the balloon will
carry into the air. The BOREALIS vehicle consists of
The Leader Line
The Anchor Line Guide Rings
The Parachute Recovery System
The Parachute Shroud Lines
The Shroud Ring
The Capsule Suspension Lines
The Payload Capsule
The Capsule Harness Lines
The Command Capsule
The Primary Antenna
Vehicle Construction
We will start by making the Payload Capsule and the Command
Capsule. The BOREALIS capsules are bright ORANGE in color so that they
are easy to find when the flight is over and the vehicle has landed.
You can print this capsule template on
orange paper, or you can print it on white paper and color the capsules
orange with a marker or crayon.
Once the capsules are colored orange, cut them out. Fold each
paper capsule and glue along the areas marked to form a box with a
lid. Use as little glue as you can. Just enough glue to make the
paper stick will do the job without adding unnecessary weight. Set
the capsules aside, we'll attach them later.
Next let's make the Anchor Line Guide Rings from the twist tie.
Leaving a straight section at the beginning and end, wrap the twist
tie around a pencil or similar object four times to create four
circular rings. Slide the twist tie off the pencil and manipulate the
four circles until they lie flat, next to each other, like a four leaf
clover. Twist the ends together to secure the four ring shape and cut
off any extra twist tie. The finished Anchor Line Guide Rings should
look like the picture at right.
The Parachute will be made from a 3 inch x 6 inch piece of
plastic wrap. The actual BOREALIS Parachute is blue and purple. You
could use colored Saran wrap if you want, but clear will also work
just fine.
Once you have the Parachute piece, cut five pieces of thread. Four of
the pieces should be 15 inches in length, the fifth piece should be 5
inches in length. Tie a piece of 15 inch thread to each corner of the
Parachute, leave the other end of each corner thread free. You can bunch
the corner of the Parachute and tie the thread around it as shown in the
image to the left.
Next, find the center of the Parachute and tie the 5 inch piece
of thread to the center. You can bunch the center, just as you did
the corners to tie the thread around it. Tie the other end of this 5
inch thread to one ring of the Anchor Line Guide Rings.
At this point it will be easiest to complete the model if you
can hang it in front of you. Find some way to temporarily secure the
Anchor Line Guide Rings, such that the Parachute and the 15 inch
threads are hanging in front of you at a height you can easily reach.
Once the Parachute assembly is hanging in front of you, attach
the Shroud Ring. To do this take one of the 15 inch pieces of thread
and wrap it around the soda bottle ring (Shroud Ring) about 3 inches
from the parachute corner. Wrap the thread a couple of times and then
tie it to the ring. Repeat this process with all four 15 inch
threads, spacing them evenly around the Shroud Ring.
When the Shroud Ring is secure attach the Payload Capsule. To do this glue
two pieces of thread to one side of the Payload Capsule approximately 3 inches
from the Shroud Ring. Glue the remaining two pieces of thread to the opposite
side of the Payload Capsule.
Attach the Command Capsule in the same manner as the Payload Capsule,
allowing for 1 inch of space between the two.
Once the glue has dried and the two capsules are secure, gather the four
threads below the Command Capsule and wrap a 1/2 inch x 1/2 inch piece of
aluminum around them to make the Primary Antenna. Clip off the excess thread
such that the Primary Antenna is the final component to the vehicle, as shown
here.
The Balloon
The vehicle portion of your BOREALIS model is now complete. All that
remains is to attach it to the helium balloon.
Attach a large paper clip or binder clip to the helium balloon
to keep it from floating to the ceiling.
Remove any ribbon or string that might have come with the
balloon. Also remove any tape or clips that attached the ribbon or
string to the balloon itself.
Cut a 5 inch piece of thread. Tie or glue one end of the thread
to the bottom of the helium balloon, where the previous string or
ribbon was attached.
Tie the other end of the thread to the ring in the Anchor Line
Guide Ring which is opposite the ring the Parachute is tied to.
The BOREALIS Model
Your model of the BOREALIS system is now complete. Remove the clip on
the balloon and watch it ascend. Be careful not to let it get away.
The completed system should look like the one shown to the right.
You may want to fill the Payload or Command Capsule with a few light
weight objects to make the entire system close to neutral buoyancy, so
that it will not escape so rapidly. Paper punch pieces, rice grains or
paper clips work well for this.
See the BOREALIS classroom for an activity which uses this model to study
buoyancy and issues related to choosing a proper payload weight.
