Gears & Stars
Interactive explanations of machines, the sky and history. Turn them, take them apart, change the numbers and watch what happens.
Engineering
Vā2 Rocket
Engineering
The Vā2 Rocket
Take apart the first ballistic missile: warhead, tanks, turbopump, guidance and engine.
Open the explainer āEngineeringThe Vā2 Turbopump
How hydrogen peroxide steam spun the pumps that fed the engine its alcohol and liquid oxygen.
Open the explainer āEngineeringGyros and Guidance
How spinning gyroscopes kept the Vā2 on course, and how their readings steered it.
Open the explainer āAstronomy
Astronomy
The Transit of Venus
Why a black dot crossing the Sun let astronomers measure the solar system.
Coming soon