Space

Question 1

Planet

Answer 1

An object that does not undergo nuclear fusion but orbits a star/sun.

Question 2

Dwarf planet

Answer 2

An object that orbits a star and is similar to a planet but is not large enough to clear its orbital path of debris.

Question 3

Moon

Answer 3

A natural satellite that orbits a planet

Question 4

Star

Answer 4

A large ball of hot gases that is undergoing nuclear fusion and emitting electromagnetic radiation.

Question 5

Sun

Answer 5

A star at the centre of a solar system

Question 6

Asteroid

Answer 6

An object that orbits the sun that does not fulfil planetary criteria

Question 6

Solar system

Answer 6

A central star orbited by planets

Question 7

Exoplanet

Answer 7

A planet outside our solar system that orbits a star

Question 8

Galaxy

Answer 8

A cluster of gravitationally bound stars, gas and dust clouds.

Question 9

Universe

Answer 9

Consists of many galaxies separated by empty space.

Question 10

how do satellites orbit planets?

Answer 10

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.

Question 11

period + altitude of a geostationary satellite

Answer 11

The period of a geostationary satellite is 24 hours.

The altitude of a geostationary satellite is 36,000km.

Question 12

what effect does altitude have on a geostationary satellite?

Answer 12

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.

Question 13

Challenges of space travel 1

Answer 13

Sufficient energy is required to power life support system for space travel.

Solution:

Energy can be generated on a spacecraft using solar cells.

Question 14

Challenges of space travel 2

Answer 14

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.

Question 15

Risks of space exploration

Answer 15

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.

Question 16

How Newton’s third law works w a rocket

Answer 16

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.

Question 17

How old is the universe?

Answer 17

13.8 billion years

Question 18

What is the big bang theory

Answer 18

The Big Bang Theory states that all current and past matter in the Universe came into existence at the same time from a small point of energy that exploded with extreme force.

Question 18

what is a light year

Answer 18

A light year is the distance that light travels in a year.

(365.25 X 24 X 60 X 60)

Question 19

Three types of line spectra

Answer 19

Continuous spectrum, Absorption line spectrum and Emission line spectrum

Question 20

Benefits of space exploration

Answer 20

Weather forecasting

Environmental monitoring

Detail of the oceans

Climate monitoring

Question 21

The Hubble space telescope

Answer 21

The HST placed a visible light telescope in orbit, to avoid the blurring effect of the Earth’s atmosphere

Question 22

Ion drive

Answer 22

Ion drives are a form of rocket which use Newtons’s third law to propel spacecrafts. Instead of sending out hot gases like a chemical rocket an ion drive sends out ionised gas particles.

They create a small unbalanced force over an extended period of time.

Ion drives produce low levels of thrust but are very efficient, and if fired for long periods of time can make a significant difference to a craft’s velocity.

Question 22

Maintaining sufficient energy to operate life support systems

Answer 22

We need food, water, air (oxygen), heat and light. Space does not have these things. Electrical energy is used to operate the equipment of the spacecraft to meet these requirements.

The main electrical power source used on spacecraft in photovoltaic solar cells (they convert the sun’s light energy into electricity). Problem is, they were heavy and inefficient. Space exploration I has made developments into making them thinner, more efficient and cheaper.

Problem with this, what are you going to do when the spacecraft is not able to be near the sun?

Question 23

Travelling large distances using a ‘catapult’

Answer 23

Spacecraft catapult or slingshot around a planet by entering and leaving the gravitational field of a planet. The spacecraft’s speed increases as it approaches the planet but decreases while escaping its gravitational pull. However, as the planet is orbiting the Sun, and the spacecraft is affected by this motion during the manoeuvre. To increase speed, the spacecraft flies with the movement of the planet, taking a small amount of the planet’s orbital energy. The slingshot manoeuvre can change the spaceship’s trajectory and speed relative to the Sun.

Question 24

Manoeuvring a spacecraft in a zero friction environment

Answer 24

In the vacuum and micro-gravity of Earth orbits means there is a near friction free environment. Ion drives and rocket engines must allow craft to accelerate, but to stop or slow that motion the spacecraft must produce the opposing force itself. This is done using secondary manoeuvring thrusters, either to provide the opposing thrust directly or to turn the craft so it can fire its main engines in the desired direction.

When Soyuz craft are docking with the ISS, they must match their speed with that of Space Station and get the docking hatches to meet up to within ten centimetres. That level of precision requires the flight commander to be able to make fine adjustments to the speed, angle, and height of the approach.

Question 25

Fuel load on take-off

Answer 25

Rocket engines use Newton’s 3rd Law to propel spacecraft. The engine burns fuel to produce hot gases which are ejected from the engine, the hot gases push back on the spacecraft body sending it forward.

At take off these rockets contain incredible amounts of highly combustible fuel. An Ariane rocket contains around 400 000kg of fuel at take off to get objects into a low Earth orbit, considerably more for a geostationary satellite.

Question 25

Potential exposure to radiation

Answer 25

The Earth’s atmosphere provides us with much more than the air we breathe. It does a fantastic job of protecting us from harmful radiations from the sun and other stars.

While in space, astronauts are exposed to radiation mostly composed of high-energy protons, alpha particles, and high-atomic-number ions. They are also exposed to radiation from nuclear reactions in some spacecraft. Galactic cosmic rays from outside the Milky Way galaxy consist mostly of highly energetic protons.

Astronauts are exposed to between 50-2,000 millisieverts (mSv) while on six-month-duration missions to the International Space Station. The risk of cancer caused by ionizing radiation is well documented at radiation doses beginning at 50 mSv and above.

Question 26

Pressure differential

Answer 26

However, during spacewalks and when travelling in capsules to and from the station, the astronaut’s spacesuits provide that pressurised environment. It is part of the reason that spacesuits look so bulky.

Micrometeorites are tiny pieces of meteorite that travel through space. Though they are very small the speeds they travel at can mean they can cause a lot of damage, potentially puncturing a spacesuit. To prevent this, spacesuits are made from layers of Kevlar.

The multiple layers and pressurised suits reduce the mobility of astronauts. Engineers from the space programs are continually working on how to make the suits easier to move in.

Question 27

Re-entry through an atmosphere

Answer 27

Re-entering the Earth’s atmosphere at high speed is very dangerous, and if a craft is not properly shielded against re-entry heat and/or enters at an incorrect angle, it can break up and burn up in the atmosphere

Question 28

How many metres are in a light year

Answer 28

9.46x10^15 metres in a light year

Question 29

Continuous spectrum

Answer 29

Complete colours blended together

Question 30

Line absorption spectra

Answer 30

Looks like the continuous spectrum except a few lines of black are there

Question 31

Line emission spectra

Answer 31

Completely black except for a few lines of colour (the complete opposite of line absorbtion)

Question 32

How are radio waves detected

Answer 32

Detected using a curved reflector using antenna/aerial

Question 32

How are microwaves detected

Answer 32

Detected using a curved reflector using antenna/aerial