# Space Flashcards

1
Q

Explain why the angle of re-entry poses a challenge.

A

The angle of re-entry to the atmosphere is important

• too steep and the change in kinetic energy being transferred to heat is too fast resulting in overheating and possible rocket break-up
• If the angle is too shallow you will skip off the atmosphere.
2
Q

What is meant by a light year?

A

The distance that light could travel in one year.

3
Q

Explain why re-entering the atmosphere poses a challenge.

A
• When a space craft is in space there is 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 the atmosphere).
• 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 vehicle requires thermal shielding.
4
Q

What information can be extracted from the spectral lines from a star?

A

The elements present in the star.

5
Q

What is a geostationary satellite?

A

Satellites with a period of 24 hours and orbit at a height of 36000km.

6
Q

State two challenges of space exploration.

A
• Travelling the large distances
• Manoeuvring
• Maintaining energy
7
Q

How can you calculate the distance that is one light year?

A
• d=vt
• d = 3 x 108 x (365.25 x 24 x 60 x 60)
8
Q

Explain how a satellite stays in orbit.

A

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.

9
Q

What are the issues of pressure differential?

A

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 conciousness and suffocate or their blood could boil.

10
Q

What is the estimated age of the universe?

A

14 billion years

11
Q

What are the issues of potential exposure to radiation?

A

Can cause

• cataracts
• increased risk of cancer
• damage to DNA and genetic material
12
Q

What is an exoplanet?

A

A planet orbiting a sun outside our solar system.

13
Q

State one way that travelling the large distance in space could be overcome.

A
• Use an ion drive
• Gravity assist (catapult) from a planet, moon or fast moving asteroid
14
Q

Using Newton’s 3rd Law explain how a space rocket takes off.

A

Engines push exhaust gases downwards. Exhaust gases push engines upwards.

15
Q

What are the two main challenges of re-entry?

A
• Angle of re-entry
• High temperatures / heating effect
16
Q

How does the observable universe let us estimate the age of the universe?

A

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 teh age of the universe.

17
Q

What is a planet?

A

A ball of mass 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 the orbit
18
Q

Why is maintaining energy such a big issue in space exploration?

A

Energy is required to maintain life support systems. It would be difficult to carry enough fuel so energy must be generated in space.

19
Q

What are the issues with fuel load on take-off?

A

There is a massive amount of fuel being carried and a huge amount of heat is produced. This could lead to an explosion.

20
Q

What is a galaxy?

A

A galaxy is a gravitationally bound system of stars, stellar remnants, gas, dust and dark matter.

21
Q

An astronaut has a mass of 50kg. What will happen to the astronauts weight on the Moon?

A

The weight will decrease as there is a lower gravitaional field strength on the Moon.

22
Q

An astronaut has a mass of 50kg. What will happen to the astronauts mass on the Moon?

A

It stays at 50kg. Mass does not change.

23
Q

How can a space rocket be slowed down in space?

A

Reverse the thrusters to provide an unbalanced force backwards to slow you down.

24
Q

What is a dwarf planet?

A

A dwarf planet is a ball of mass that

• Orbits a sun
• has enough mass to be almost round
• is not a moon of another object
• HAS NOT removed debris around area of the orbit
25
Q

What is a moon?

A

A natural satellite

26
Q

What is Newton’s 3rd Law?

A

For every action force there is an equal but opposite reaction force

27
Q

How can you work out the resultant force acting on a space rocket at launch?

A

Resultant force = Engine thrust - (Weight + frictional forces)

28
Q

Why is manoeuvring in space such an issue?

A

There is no friction to slow down.

29
Q

List some benefits of space exploration.

A
• Satellite communications
• GPS and SatNav technologies
• Weather forecasting / storm tracking
• Improved mapping
• Spin off technologies - hand held drills, portable DVD players, memory foam
• Space exploration e.g Hubble telescope, International space station
30
Q

What is a solar system?

A

It is a system bound by gravity, made up of a sun and the objects that orbit it.

31
Q

Why is travelling large distance in space such an issue?

A

Carrying the fuel required would be impossible.

32
Q

What is an asteroid?

A

An asteroid is a small rocky and airless object that orbit the sun. They are too small to be planets.

33
Q

What is meant by gravitational field strength?

A

Force per unit mass

34
Q

How can the issue of manoeuvring in space be overcome?

A

Use of reverse thrusters.

35
Q

What type of spectrum is this?

A

Continuous spectrum

36
Q

What is meant by the Big Bang?

A

It suggests that all the matter in the universe was in an infinitely small, hot and dense state which then expanded.

37
Q

How can the issue in maintaining energy in space be overcome?

A

Use solar cells angled towards the Sun.

38
Q

What is a sun?

A

A star is called a sun if it is the centre of a planetary system.

39
Q

What are the possible dangers of space exploration?

A
• pressure differential
• re-entry through atmosphere
40
Q

What is the ‘observable universe’?

A

The observable universe is the furthest point that we can ‘see’ or detect.

41
Q

What is a star?

A

A ball of gas undergoing fusion that gives off heat and light.

42
Q

What are the forces acting on a space rocket at launch?

A
• Weight - downwards
• Friction/air resistance - downwards
• Engine thrust upwards
43
Q

What is the difference between mass and weight?

A

Mass is a measure of the partcles that make an object up. Weight is a force caused by the gravitational field strength of a planet.

44
Q

How can the electromagnetic spectrum be used to obtain information about objects in space?

A

Different objects in space emit different signals that we can detect to get information about the object.

Different frequencies require different detectors.

45
Q

How is the period of a satellite effected by the orbiting altitude/height?

A

The bigger the orbiting altitude / height the longer the period orbit.

46
Q

What is meant by the universe?

A

The universe is all of time and space and its contents.

47
Q

Should the engine force or the resultant force be used when calculating the acceleration of a space rocket on take off?

A

Resultant force

48
Q

What type of spectrum is this?

A

Line Spectrum