Exploring Space
It’s not just billions of pounds that sent Bezos, Branson and Musk’s car into space, there was actually a lot of complex physics to work out!
Let’s break down why space exploration helps us down on Earth, as well as the challenges and risks of venturing up into the void.
Imagine Brian Cox’s voice serenading these facts to you for a more elegant Physics learning experience.
Satellites
A satellite is an object in space that orbits around a larger object.
Satellites orbit the Earth when their speed is balanced by the gravitational pull on Earth. Their horizontal speed can therefore beat the downward pull of gravity, allowing it to continuously “fall” towards the Earth while circling it. This is how the moon naturally orbits the Earth.
Uses of satellites include:
Telescopes and detectors for space exploration
Global positioning systems (GPS)
Satellite television, allowing broadcasting to reach homes around the world
Weather forecasting
The period of a geostationary satellite is 24 hours.
The altitude of a geostationary satellite is 36,000km.
The higher the altitude of a satellite, the longer the period of the satellite, as it will have a further distance to travel within one orbit of the Earth.
Challenges of Space Travel
Problem
Sufficient energy is required to power life support system for space travel.
Solution
Energy can be generated on a spacecraft using solar cells.
Problem 2
Travelling long distances in space is very difficult and requires a very fast speed, while maintaining energy and fuel.
Solutions
Energy can be preserved and high velocities can be reached by ‘catapulting’ a space craft utilising the gravity of a large object, such as a moon or asteroid.
Large distances can be travelled using ion drive, where a small unbalanced force over an extended period of time allows a high velocity to be attained.
Risks of Space Travel
Risks include:
Exposure to radiation.
Re-entry into the atmosphere is very dangerous.
Fuel load on take-off has a risk of ignition and explosion.
Pressure differential between the vacuum of space and the atmospheric pressure maintained in the spacecraft poses a risk to astronauts.
Newton’s Laws in Space
A rocket can launch into space with thanks to Newton’s third law.
“Every action has an equal and opposite reaction.”
When a rocket burns fuel, thrust is generated, propelling the rocket upwards. An equal and opposite push is created by the exhaust gas downwards, allowing the rocket to overcome the force of gravity and to be propelled upward.
Key Points!
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Satellites
Describes how satellites orbit the Earth.
Give uses of satellites.
Know the altitude and period of a geostationary satellite.
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Challenges in Space Travel
Describe some challenges in space travel and ways we can overcome these challenges. These are especially good to know for open-ended questions.
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Risk of Space Exploration
Know some risks of manned space exploration.
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Applying Newton's Laws in Space
Be able to describe how a rocket launches into space using Newton’s Laws.