Rockets and landing

A rocket is the only machine that can push itself through empty space. This topic starts with a balloon whizzing across a room and climbs to Newton's laws, momentum, the rocket equation and staging, then to the hardest part of any Mars trip: getting down through air too thin for parachutes alone, from 20,000 km/h to a gentle touch on the ground.

8 levels, 48 lessons. The ages are only a rough guide for parents and teachers; anyone can start at any level.

Level	Rough age	Lessons
Level 1: Push and go	5-6	Pushes make things go; The balloon rocket; Fast and slow; Up into the sky; Coming down gently; Parachutes and legs
Level 2: Action and reaction	7-8	Push back; The skateboard and the ball; No air needed; Fuel and oxygen; The water rocket; The parts of a rocket
Level 3: Forces on a rocket	9-10	Forces in newtons; Thrust and weight; Drag; Speeding up; Stages; Heat shields
Level 4: Into space and down to Mars	11-12	Where space begins; Orbit is speed; The trip to Mars; Seven minutes; Parachutes in thin air; Landing on rockets
Level 5: Newton's laws for rockets	12-13	F = ma; Thrust-to-weight ratio; Momentum; Impulse; Exhaust speed; Drag and speed
Level 6: The rocket equation	13-14	Conservation of momentum; Recoil; Specific impulse; Mass ratio; Tsiolkovsky's rocket equation; Staging, worked out
Level 7: Landing on Mars	15-16	The drag equation; Thin air; Parachutes and terminal speed; Entry heating; Supersonic retropropulsion; Flying on Mars
Level 8: Mission design	17 and beyond	Delta-v to the surface; Propellant from Mars; Gravity losses; Aerobraking and aerocapture; Nuclear and electric propulsion; Landing precision

Numbers for the missions come from NASA's mission pages, linked in each lesson; Mars and Earth figures from NASA's Mars fact sheet.