# Explain why the gravitational field strength decreases as a spacecraft travels away from the Earth's surface, and describe what happens to the weight of an astronaut inside the spacecraft during this journey.

> AQA A-Level Physics (7408) — 3.7.2 Gravitational Fields · Explain · 5 marks

> A spacecraft launches from Earth and travels in a straight line away from the planet into deep space.

## Mark scheme (5 marks)

1. Gravitational field strength decreases as distance from the centre of the Earth increases
2. Because the gravitational force exerted by the Earth on the spacecraft/astronaut decreases with distance
3. Weight is the force due to gravity acting on the astronaut (W = mg)
4. As gravitational field strength decreases, the astronaut's weight decreases
5. The astronaut's mass remains constant throughout the journey

## Key terms

- [gravitational field strength](https://www.gradenine.co.uk/glossary/gravitational-field-strength)
- [weight](https://www.gradenine.co.uk/glossary/weight)

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-the-gravitational-field-strength-36ff19bd) · Published by Druglandscape Ltd.