In orbit, a spacecraft is continuously falling under gravity while moving sideways fast enough to keep missing Earth. Astronauts float because they and their spacecraft fall together, not because gravity has vanished. The needed speed depends on the orbit. A gravity assist exchanges momentum with a moving planet; it is not free energy from nowhere. Safety: No moving-body demonstration, compressed air, fuels, flames or thrown objects. Stop: Stop at paper diagrams and the ideal table. No cannon, launcher, tether swing or rocket construction.

Materials: Paper; Pencil 1. Draw Earth as a circle. At its top draw three sideways path starts: a short arc ending on Earth, a longer arc ending on Earth, and a closed curved path around Earth. Add inward gravity arrows. Label this a thought diagram, not calculated trajectories; do not throw anything. 2. Draw a spacecraft and astronaut on the closed path. Add matching motion arrows and write: both in freefall together. Explain why simply going high is not enough for orbit. 3. For an illustrative Sun-frame flyby, draw a planet moving right. Draw a spacecraft path bending behind it. Label spacecraft gains orbital energy; planet loses a tiny amount. Add: a different flyby can slow a spacecraft; the planet-frame far-away speeds can be equal. 4. Copy an ideal rocket table with fixed exhaust speed and final mass: required velocity change 1 unit—initial/final mass ratio 2; 2 units—ratio 4; 3 units—ratio 8. Units are deliberately chosen for this model, not km/s. Write propellant/final mass as 1, 3, 7 respectively. 5. Explain why each added equal velocity-change unit doubles the initial/final ratio in this model. Name the limit: real missions also have gravity losses, drag and staging. Done: Finish the orbit sketch, shared-freefall explanation, energy-exchange labels and three table rows. Proof: Keep all three panels. Note if adult supplied orbit arrows, frame labels or propellant differences. Stop: Stop at paper diagrams and the ideal table. No cannon, launcher, tether swing or rocket construction.