Two builds: a straw air rocket, and a balloon on a folded paper fin.
2
Builds
3–4 m
Flight (est.)
9
Step panels
11
Materials named
What it is
Two small rockets, built at a table and launched from it. Both sit on the Nature
in Motion station, alongside the wind tunnel and the
junk modelling vehicles.
The pair is the point. A balloon carries what
pushes it. An air rocket does not: the air that throws it stays behind in the straw, so the rocket is
a projectile and the straw is the launcher. That is why the straw needs no preparation at all.
Method
Straw air rocket
A fat straw, a thin straw and one paper rectangle.Cut the paper in two.Wrap the strip round the bottom and fold the ends out.Slide it over the thin straw and blow.
Fins
Three or four, about an inch long, evenly round the base. They keep it pointing the way it was
aimed. Trim them to a shape.
A closed top
Fold the top over and tape it shut. An open tube lets the puff straight through and nothing
flies.
Aim
A little under 45 degrees from the horizontal, and one sharp puff rather than a long blow.
Balloon rocket
One paper square and one balloon.Fold it corner to corner, open it out, then fold it the other way.Trim a small hole where the creases cross.Press the folds down into a four-point fin.Feed the neck through the hole and blow it up.
Sizing the fin
A square about as wide as the balloon. One that wobbles wants a bigger square; one that will not
lift wants a smaller one.
The hole
Big enough for the neck, small enough not to pinch it shut. Too tight and the air cannot get
out.
A tired balloon
A balloon that has stopped shrinking back to its own size has stopped pushing. Change it.
Materials
Pick
paper straws, narrowpaper straws, widepapermasking tapescissorsballoonsclay, optional
Make
cut paper squaresexample rockets
Print
step strip, straw air rocketstep strip, balloon rocket
Quantities and basis are not set on any row. See DECISIONS.md,
19 August 2026.
Safety
Children
Scissors. Paper, tape, straws and balloons. A child blows only their own straw and their own balloon.
Adults
Nothing is adult-only. An adult hands straws and balloons out and does not take them back.
First aid
Cleaning wipes and plasters, for cuts.
This is the only activity at the fair that throws something.
A straw air rocket carries three to four metres indoors, at head height if it is aimed
there. Fire in one direction only, along a clear lane away from the aisle, at a wall or a board,
never across a table and never towards a face. Nobody stands in the lane while a rocket is on the
straw. A balloon rocket cannot be aimed at all, so it wants open air above the table rather than a
lane. The wind tunnel is on the same station and a rocket is not fired into it.
In the mouth
Straws and balloons are one per child. They are not passed on and not put back in the box.
Balloons
Latex. A burst or uninflated balloon is a choking hazard for a small child, so pieces are picked
up rather than left on the floor.
The clay nose
Clay makes a hard nose, which is a heavier thing to be hit by. The nose is paper and tape unless
someone decides otherwise.
The floor-space figure and the one-direction rule are proposed, derived from how
far the rocket flies. Nothing on file describes the room at East London Mosque.
Notes
Written from two prototypes and a rocketry book, 19 August 2026. The book is third-party copyright and is reference only: the steps and materials here are derived and rewritten, and nothing from it is reproduced. The provenance is in activity.md.
The wide straw is the body, the thin straw is the launcher. One prototype instead rolls a paper tube and tapes it along its length. The two are alternatives.
Tape fins or paper fins. Both prototypes use masking tape; the step strip uses paper. Either works.
The station it joins is the fast one. Moving air and a ramp already, and this is the only one of the three that leaves the table.
The name now fits. Plural, because the folder holds two builds. It was flagged as provisional on 18 August for naming the object and not the method.
What this record still needs
A lead and a build time. It is not on the Monday board: no item, no subitems, no owner and no prep tasks. Everything else at this event came off the board first.
Quantities and a basis on every material row, so a pick list can be calculated rather than read.
A type and a duration. How long one child takes on one rocket sets how many can be made in a session.
Themes and tags. Only space is set.
A decision on which builds run, and on tape fins against paper fins.
The room. Nothing on file describes the floor at East London Mosque, which is what the launch lane depends on.
A first delivery. Written before the day, this is a proposal. The notes from the day are what turn it into a record.