Gears & Stars
Interactive explanations of machines, the sky and history. Turn them, take them apart, change the numbers and watch what happens.
Engineering
V-2 Rocket
Engineering
The V-2 Rocket
Take apart the first ballistic missile: warhead, tanks, turbopump, guidance and engine.
Open the explainer →EngineeringThe V-2 Turbopump
How hydrogen peroxide steam spun the pumps that fed the engine its alcohol and liquid oxygen.
Open the explainer →EngineeringGyros and Guidance
How spinning gyroscopes kept the V-2 on course, and how their readings steered it.
Open the explainer →Astronomy
Astronomy
The Transit of Venus
Why a black dot crossing the Sun let astronomers measure the solar system.
Coming soon