Space Flashcards
How can a space rocket be slowed down in space?
Reverse the thrusters to provide an unbalanced force backwards to slow you down
What is Newton’s 3rd Law
For every action force there is an equal but opposite reaction force
Using Newton’s 3rd Law, explain how a space rocket takes off
Engines/rocket pushes exhaust gases downwards. Exhaust gases push engines/rocket upwards
Explain how a satellite stays in orbit
- Satellite has a constant horizontal velocity
- Satellite has a constant vertical acceleration due to the gravitational field strength of the planet
- This gives a curved trajectory
- The planet is curved so the satellite remains in orbit
What are the possible dangers of space exploration?
- Pressure differential
- Exposure to radiation
- Fuel load on take-off
- Re-entry through atmosphere
What are the 2 main challenges of re-entry?
- Angle of re-entry
- High temperatures / heating effect due to frictional forces
Explain why the angle of re-entry poses a challenge
- Too steep and the change in kinetic energy being transferred to heat is too fast resulting in overheating and possible rocket break-up
- Too shallow and you will skip off the atmosphere
Explain why re-entering the atmosphere poses a challenge
- When the spacecraft is in space there in no friction as space is a vacuum
- When you re-enter the Earth’s atmosphere you go from no friction to lots of friction caused by gas particles in the air
- The result is that the space craft loses kinetic energy and slows down
- However, due to conservation of energy, the energy is not lost but is converted to heat
- The outside of the space craft becomes incredibly hot
- This means that the space craft requires thermal shielding
List some benefits of space exploration
- Satellite communications
- GPS and satNav technologies
- Weather forecasting and storm tracking
- Improved mapping
- Spin-off technologies - hand held drills, space blankets, freeze-dried food, memory foam…
- Space exploration e.g. Hubble telescope, International Space Station
What is meant by a light year?
The distance that light can travel in one year
What is the ‘observable universe’
The furthest point in space that we can ‘see’ or detect
How can the electromagnetic spectrum be used to obtain information about space?
Different objects in space emit different signals that we can detect to get information about the object. Different frequencies require different detectors.
What type of spectrum is this?
Continuous spectrum
What type of spectrum is this?
Line spectrum
What information can be extracted from the spectral lines from a star?
The elements present in the star
How can you calculate the distance that is one light year?
- d = vt
- d = 3x108 x (365.25 x 24 x 60 x 60)
- d = 9.46x1015 m
What is the difference between mass and weight?
Mass is a measure of the particles that make up an object. Weight is a force caused by the gravitational field strength of a planet.
What is meant by gravitational field strength?
Force per unit mass
An astronaut has a mass of 50kg. What will happen to the astronaut’s mass on the Moon?
It stays at 50kg. Mass does not change
An astronaut has a mass of 50kg. What will happen to the astronaut’s weight on the Moon?
The weight will decrease as there is a lower gravitational field strength on the Moon
What is a sun?
A star is called a sun if it is the centre of a planetary system
What is a planet?
- An object that orbits a sun
- Has enough mass to be almost round
- Is not a moon of another object
- Has removed debris from the area round its orbit
What is a dwarf planet?
- A dwarf planet orbits a sun
- Has enough mass to be almost round
- Is not a moon of another planet
- HAS NOT removed debris around the area of its orbit
What is a moon?
An object that orbits a planet
What is an asteroid?
A small rocky and airless object that orbits the sun. They are too small to be planets.
What is a solar system?
A system bound by gravity, made up of a sun and the objects that orbit it.
What is a star?
A ball of gas undergoing fusion that gives off heat and light.
What is an exoplanet?
A planet orbiting a sun outside of our solar system.
What is a galaxy?
A gravitationally bound system of stars, stellar remnants, gas, dust and dark matter.
What is meant by the universe?
All of time and space and its contents
What is geostationary satellite?
A satellite with a period of 24 hours and an orbital height of 36,000 km.
What is the estimated age of the universe?
13.8 billion years
How is the period of a satellite affected by the orbiting altitude/height?
The bigger the orbiting altitude / height, the longer the orbital period
What are the issues with fuel load on take-off?
There is a massive amount of fuel being carried and a huge amount of heat energy is produced. This could lead to an explosion.
What are the issues of pressure differential?
Pressure in space is so low, it is almost zero. Space suits and pressurised space craft are required to protect astronauts otherwise they would lose consciousness and suffocate or their blood could boil.
What are the issues of potential exposure to radiation?
- Can cause cataracts
- Increased risk of cancer
- Damage to DNA and genetic material
State 2 challenges of space exploration
- Travelling the large distances
- Manoeuvring
- Maintaining energy
What is meant by the Big Bang?
It suggests that all the matter in the universe was in an infinitely small, hot and dense state which then expanded
How does the observable universe let us estimate the age of the universe?
The furthest point that we can detect is the distance which light must have travelled for the whole age of the universe. This allows us to work out the approximate time of travel and so the age of the universe
State one way that travelling the large distance in space could be overcome
- Use an ion drive
- Gravity assist (catapult) from a planet, moon or fast moving asteroid
Why is travelling large distances in space such an issue?
Carrying the fuel required would be impossible
Why is manoeuvring in space such an issue?
There is no friction to slow you down.
Why is maintaining energy such a big issue in space exploration?
Energy is required to maintain life support systems. It would be difficult to carry enough fuel so energy must be generated in space.
How can the issue of maintaining energy in space be overcome?
Use solar cells angled towards the Sun
How can the issue of manoeuvring in space be overcome?
Use of reverse thrusters.
What are the forces acting on a space rocket at launch?
- Weight - downwards
- Friction/air resistance - downwards
- Engine thrust - upwards
How can you work out the resultant force acting on a space rocket at launch?
Resultant force = engine thrust - (weight + frictional forces)
Should the engine force or the resultant force be used when calculating the acceleration of a space rocket on take off?
Resultant force
