From Earth to Orbit

How can we think clearly about distances and speeds that are far outside everyday experience?

Why does the same person weigh differently on Earth and the Moon without losing mass?

What must happen to change the speed or direction of a spacecraft?

Can the same force explain a falling object and the Moon's orbit?

Why can an asteroid be irregular while a large planet becomes nearly spherical?

How can worlds of similar size hide radically different amounts of matter?

If gravity is pulling a spacecraft toward Earth, why does it not hit the surface?

Why does a low spacecraft circle Earth faster than a distant satellite?

What changes when a spacecraft has enough energy for its path to stop closing?

Why is reaching orbit more about building sideways speed than only climbing upward?

When a vehicle is far away, how do engineers decide whether the vehicle or the data needs attention?

Can you operate a full mission replay, resolve uncertain telemetry, and prove that the vehicle reached orbit?