Hot- Air Balloons
Instructional information adapted from PITSCO Hot Air Ballooning Teacher's Guide.
Objective:
Students will have the opportunity to practice science as inquiry and develop
their team building skills as they construct and launch a hot-air balloon.
Materials:
Items per team for balloon:
Colored tissue paper (10 sheets per team)
5 Glue sticks
3 Scissors
Balloon Gore pattern
30” of Drywall tape (per team)
Stapler
6” kite string (per team)
Standards:
STANDARD A: Teachers of science plan an inquiry-based science program for their students.
STANDARD C: Teachers of science engage in ongoing assessment of their teaching and of
student learning.
STANDARD D: Teachers of science design and manage learning environments that provide
students with the time, space, and resources needed for learning science.
Introduction:
The balloon has played an important role in the history of flight. For centuries, humans have searched
for the secret of flight and dreamed of leaving Earth to fly through the air. In the 15th century,
Leonardo da Vinci devoted years of study to find a way to achieve this. He drew up the first known
sketches of parachutes and helicopters.
The French Montgolfier brothers completed the first known flight of a hot air balloon in 1783. Joseph
and Jacques noticed a shirt hung out to dry over a fire billowing upward and inflated. They studied the
ascending force of the smoke and came up with the idea that if they enclosed the heat in an “envelope,”
the bag would rise from the ground. They experimented with paper bags from their mill. On
September 19, 1783, the brothers put a sheep, a duck, and a rooster in a tethered balloon to determine
if animals could survive at heights. The experiment occurred at the Palace of Versailles. King Louis
VI, his court, and 130,000 astonished spectators witnessed the event. The no doubt terrified
“passengers” were in flight for 8 minutes, traveled almost two miles and were 1700 feet up in the sky.
On November 21, 1783 Pilatre de Rozier (a physician) and Marquis d’ Arlandes (an infantry
officer) became the first humans to fly in a Montgolfier balloon. It was made of cotton and paper.
Their flight lasted twenty-five minutes and covered a distance of five miles. They reached a height of
3,000 feet. When they finally landed in a field the farmers were quite shocked to see a balloon landing
in their field, so they attacked it with pitchforks until the passengers were able to convince them they
were legitimate. The King sent out a declaration to the country that it would be illegal to attack
balloonists. To this day, balloonist will carry a bottle of champagne to give to the property owner, so to
prevent getting attacked by pitchforks.
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Hot- Air Balloons
Activity:
But what makes a balloon rise and fall so gently? As the air is heated in the balloon, it rises. As the air
inside the balloon cools (or equals the outside temperature) it will slowly fall. Let’s look at few
examples:
A helium balloon vs. an air balloon – What is the difference between these two balloons? What
makes one rise and the other not? The helium in the Mylar balloon is lighter than the air around it, so it
floats. It is less dense. What happens to the balloon after a couple of days? It starts to sag, because the
helium is diffused. This same thing happens with a hot air balloon. The warm air helps it stay afloat
and as the warm air is diffused it starts to sag.
Spiral Up Draft – The energy from the light heats the air above it. The air molecules move
faster and farther apart as they absorb energy. The separation of the molecules makes the air lighter
(less dense) and it rises upwards. Cooler air rushes in to take the place of the warmer air rising. As long
as the lamp is on, warm air rises and cooler air moves in to takes its place producing air movements
called convection currents (which is the movement of air due to differences in temperature.) This is
what happens to hot air balloons when they are floating through the countryside. The constant flow of
warm air as produced by the flame and the burner with the cooler surrounding air keep the balloon
afloat.
Mover- Cold water is denser than warm water. This difference in density occurs because cold
water contracts (gets closer together, more dense) and warm water expands (moves father apart, less
dense). This makes a drop of cold water heavier because there are more molecules of water in it than in
a drop of warm water. Dense cold water settles in the bottom of the bottle, and the less dense warm
water rises. This same things happens with air.
Building the Balloon:
Arrange the students in groups of no more than four people. (If the numbers don’t work out
right, go with three people instead of with five in a group.) Before passing out equipment baskets, go
over what they will be getting and how they are used.
Gore – pattern of the balloon. We use a pattern developed by Pitsco.
Scissors – Safety issues
String – about 6 inches in length
Drywall tape – about 30 inches
Glue sticks – If you run out of glue raise your hand and we will bring you more.
Stapler
Making the Balloon:
1. Take two sheets of tissue paper and glue them longwise. The glued seam should be about ½
inch. After gluing all the sheets, you should have 5 sheets that are each about 5 feet long.
2. Stack all 5 sheets on top of each other with the center seam lined up. Don’t worry if the edges
don’t line up, that part will be cut away.
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Hot- Air Balloons
3. Place the pattern on top left of the 5 sheets of tissue paper, lining up the center seams together.
Trace the pattern with a pencil. Remove pattern.
4. Place the pattern on the top right of the 5 sheets of tissue paper, lining up the center seams.
Make sure you aren’t overlapping the first traced pattern. Trace the pattern with a pencil.
5. Use the scissors and cut the patterns out. Be sure to cut through all 5 sheets at once. Pull the
scraps away and save for decorating later on.
6. Stack the two sets of patterns on top of each other, lining up the edges. Gore 1 will be on the
top of the stack.
7. Slide Gore 1 back off of Gore 2, so that ½ inch of Gore 2 is showing. Starting in the middle
section of Gore 2, fold the exposed edge ½ inch over the middle section of Gore 1 and crease
the fold. Using the glue stick, place a thin line of glue on the edge and glue the edge of Gore 2
to Gore 1. After the middle has been glued, glue the top and bottom sections, following with
the edges in between.
8. Gore 1 & 2 should be connected and there should be only one edge. To reinforce the seam,
fold that edge ½ inch again to reinforce that seam. Glue along the fold as in step 2. Make sure
there is a double seam from top to bottom. (This is called a French seam in sewing.)
9. Next, take Gore 2 and slide it away so that ½ inch of Gore 3 is exposed. Starting in the middle
section of Gore 3, fold the exposed edge ½ inch over Gore 2 and crease the fold. Place a thin
line of glue on the edge of Gore 3 and glue it to the edge of the Gore 2. After the middle has
been glued, glue the top and bottom sections, following with the edges in between.
10. Make sure all sections (middle, top, bottom) of Gore 2 are glued to Gore 3. Finish by folding
and gluing the seam a second time as in step 3.
11. Continue this until 9 gores are connected. The connected gores should resemble an accordion
pattern.
12. Last, connect Gore 10 to Gore 1. Fold the inner gores out of the way. Fold the middle section
of Gore 10 about ½ inch. Place a line of glue on the fold of Gore 10 and glue it to Gore 1.
Finish by folding and gluing a second seam.
13. All gores should now be connected. Check all seams for any holes or tears and patch any with
the extra tissue paper.
Finishing the Envelope:
1. About three inches from the top opening of the envelope tie the 6” piece of string around the
opening to close the hole.
2. Next, turn the balloon inside out. Be careful not to tear the balloon.
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Hot- Air Balloons
3. Take the drywall tape and fold it in the middle. Place the edge of the mouth (bottom) of the
envelope into the groove of the drywall tape and staple the tape to the mouth of the envelope.
4. The balloon is now complete. Inspect the balloon for any tears and patch or repair if necessary.
Balloon Launch:
1. Time to launch the balloon! For this purpose, use the PITSCO Balloon launcher. Attach the
propane tank to the hose and clamp at the bottom of the launcher. Turn on the propane, slide
the igniter into the hole near the bottom of the pipe, and squeeze the trigger until the propane
ignites with a steady roar.
2. It will take two people to help launch the balloon. Hold the envelope carefully above the pipe,
leaving approximately a 1-2 inch gap. Each person should hold the mouth of the balloon as
well as the top of the envelope. This will help steady the balloon. BE VERY CAREFUL-THE AIR IS VERY HOT!
3. As the envelope fills, check it for any tears, holes, or seams that may have become partially
unglued. Glue small pieces of tissue over any holes. Be sure tissue patches are as small as
possible to avoid adding extra weight to one side that may cause the balloon to tilt during flight
or allow some of the hot air to escape.
Helpful hints when making the balloon:
1. Give one piece of the instructions and then have them complete that part before moving on. I
found it was easier to get the group started as one and then for the subsequent directions, I did
them individually at each table. It cut down on questions and everyone was able to see what I
was doing.
2. This is a great project because there is a lot of room for error. I have watched balloons being
made that I thought would never fly and they did! The main trick is to remember to double glue
each seam, and to tie a tight knot at the top. Other than that anything goes.
3. The gluing of the gores, is done in a zig zag fashion. Alternating between sides. It will look like
an accordion before you glue the top gore to the bottom gore.
4. Save the extra pieces of tissue paper to patch holes and tears.
5. If there is extra time, they can personalize their balloon with the scraps.
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Hot- Air Balloons
Common Questions regarding real hot air balloons:
Can a hot air balloon go “pop” like a child’s toy?
No, it is impossible. There is a hole about the size of a house door at the base that prevents a
pin size hole or a peck from a bird from causing any problems.
How many people can ride in a hot air balloon?
It depends on the weight of the balloon, the number of the people, the weight of the people, the
height you want to travel and the air temperature. But an average balloon under normal
circumstances will hold four people.
What time of day is the best time to launch?
Morning, the wind is clam and it is also the coolest part of the day. It is not recommended to
take a balloon up in the rain. It adds a significant amount of weight to the balloon.
What kind of fabric is a balloon made form?
Rip-stop nylon prevents tearing. The area near the flame is made with a special fire resistant
material Nomex. That is what race car drivers wear.
Where is the fuel stored that is used to heat the burner?
The fuel cylinders tanks of propane are stored in each corner of the basket.
The most popular size is a ‘77’. It is called a ‘77’ because the envelope (main part of the
balloon) holds 77,000 cubic feet of air. In warmer conditions, you might need and ‘84’ or a ‘90’ to
carry four people.
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Hot- Air Balloons
KEY TERMS
Aloft: high or higher up
Approach: final part of a hot air balloon’s flight path before it lands
Balloonist: person who enjoys flying a balloon
Basket: part of a balloon that holds the passengers
Cold Inflation: process of using fans to fill the envelope of a hot air balloon with cold air to prepare
for takeoff
Cooling Vent: a panel in the side or top of a balloon that can be opened to release hot air
Dense: crowded closely together; heavy
Displace: to move something from its usual position
Envelope: the fabric portion of a balloon system that contains the hot air or gas
Gondola: basket that carries the passengers of a hot air balloon
Gore: section of fabric, which is sewn together with other gores to make the envelope of a balloon
Hydrogen: a lighter-than-air gas sometimes used to fill gas balloons
Using hydrogen can be dangerous because it is very flammable.
Helium: a lighter-than-air gas commonly used to fill gas balloons
Hot Inflation: process of applying heat to raise the balloon upright prior to launch
Molecules: tiny particles that make up air, gases, liquids, and solid objects
Pilot Light: a small flame on the burner that is always lit when the balloon is flying
Propane: fuel used to heat the air in hot air balloons
Vent: an opening that lets air escape
WEBSITE TO PURCHASE SUPPLIES
1. Pitsco Ideas and Soutions:
http://catalog.pitsco.com
800-835-0686
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