Risks and benefits of space exploration
You check the weather forecast on your phone, and a map app tells you which Luas stop is closest. Both rely on satellites. Space exploration costs billions of euro and puts people at risk, so is it worth it? In this page you learn to weigh up the benefits and risks, as the Junior Cycle asks you to examine and discuss.
Benefits of space exploration
Many everyday technologies began as space technology or depend on it every day.
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Weather forecasting: satellites watch cloud and storms. Met Éireann uses this kind of data to warn us about storms.
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Communications and GPS: satellites relay phone calls, TV and navigation signals.
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Monitoring the Earth: satellites track the melting of ice, forest loss and sea temperature. This gives evidence about climate change.
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Technology and materials: research for space led to better medical scanners, water filters and lightweight materials.
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Science: probes and telescopes tell us about the origin of the universe and the planets, and help in the search for life elsewhere.
Name three benefits that space exploration has brought to everyday life on Earth, for example satellite weather forecasting.
Name three benefits that space exploration has brought to everyday life on Earth, for example satellite weather forecasting.
Risks to astronauts
Space is a hostile place. Astronauts face:
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Radiation: outside the protection of the atmosphere and the magnetic field, cosmic rays and solar radiation can damage cells and raise the risk of cancer (see the mutagens link: radiation damages DNA).
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Weightlessness over a long time: bones become weaker and muscles waste away. Astronauts exercise for about two hours a day to reduce this.
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Isolation and stress: being confined with a small crew for months affects mental health.
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Equipment failure: a leak or fire has no easy rescue.
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Supplies: oxygen, water, food and medicine must be carried or recycled.
A mission this long means weak bones and muscles, high radiation dose and isolation. The crew needs oxygen, water, food and medical supplies, which they must carry or make on the spot.
State two risks to astronauts during a long mission in space.
State two risks to astronauts during a long mission in space.
A mission to Mars would take about $7$ months each way, with about $500$ days on the surface. a) Calculate the total length of the mission in days, taking a month as…
A mission to Mars would take about $7$ months each way, with about $500$ days on the surface.
- a) Calculate the total length of the mission in days, taking a month as $30$ days.
- b) Give two health risks for the astronauts resulting from the length of the journey.
- c) Give two supplies that would have to be carried or produced for the crew.
Space debris and satellites
Space debris is human-made junk in orbit: dead satellites, rocket parts and fragments from collisions. It travels at several km per second, so even a tiny piece can destroy a satellite or damage a spacecraft.
More debris means more collisions, and each collision makes more debris. If satellites stopped working we would lose GPS, phone and internet links, TV and weather forecasts. Planes, ships and emergency services would struggle.
Large satellite networks bring benefits and drawbacks:
| Benefits | Drawbacks |
|---|---|
| Internet in remote rural areas | More debris and collision risk |
| Support for emergency services | Bright satellites streak across telescope images, which harms astronomy |
| Jobs and new technology | Satellites burning up in the atmosphere add pollution |
Explain what is meant by "space debris" and state one problem it can cause.
Explain what is meant by "space debris" and state one problem it can cause.
Satellites used for communications and GPS orbit the Earth. Explain two ways in which our daily lives would be affected if all satellites stopped working, and explain…
Satellites used for communications and GPS orbit the Earth. Explain two ways in which our daily lives would be affected if all satellites stopped working, and explain how an increase in space debris could make this more likely.
Robots or people? Cost and ethics
Space missions cost enormous sums. A probe to Jupiter's moons might cost €2 billion. Should that money go to hospitals instead?
| For space spending | Against space spending |
|---|---|
| Discoveries and new technology, with benefits on Earth | The money could pay for urgent needs like health and housing |
| Satellites help with climate and weather monitoring | Benefits are uncertain and may take decades |
| Inspires young people into science | Risk of failure: a mission can be lost |
Robotic probes carry no people, so there is no risk to human life, and they need no food, water or return journey. They are cheaper but cannot make quick decisions on the spot.
Other ethical and environmental issues:
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Contamination: microorganisms from Earth could spoil other worlds and confuse the search for life.
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Asteroid mining: it could supply metals, but who owns them? It could also create debris.
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Settling Mars: it could be a back-up for humanity, but is it fair to spend so much while problems remain on Earth?
Decisions should include more than scientists. Citizens, politicians and ethicists must be involved because the money comes from taxes and the risks affect everyone.
A space agency spends €2 billion on a robotic probe to study Jupiter's moons. A councillor in Cork argues that the money should be spent on hospitals instead. a) Give…
A space agency spends €2 billion on a robotic probe to study Jupiter's moons. A councillor in Cork argues that the money should be spent on hospitals instead.
- a) Give one argument in favour of the councillor's view.
- b) Give one argument in favour of space exploration spending.
- c) Explain why using a robotic probe rather than a crewed mission reduces some risks.
A company proposes launching $10,000$ small satellites to provide internet access in remote parts of rural Ireland. a) Discuss two benefits of the proposal. b) Discuss…
A company proposes launching $10,000$ small satellites to provide internet access in remote parts of rural Ireland.
- a) Discuss two benefits of the proposal.
- b) Discuss two risks or drawbacks, including one for astronomy and one for the space environment.
- c) Give and justify your own conclusion on whether the project should go ahead.
Some scientists propose mining asteroids for metals and sending humans to settle on Mars. a) Discuss two scientific or technological benefits that could result. b)…
Some scientists propose mining asteroids for metals and sending humans to settle on Mars.
- a) Discuss two scientific or technological benefits that could result.
- b) Discuss two ethical or environmental concerns, for example contaminating other worlds with microorganisms from Earth.
- c) Explain why it is important that decisions about space exploration involve more than scientists.
Weightlessness and radiation on the ISS
The International Space Station (ISS) orbits about 400 km above the Earth. Gravity there is still about 90% of its strength at the surface. Astronauts feel weightless because they and the station are in free fall: they fall towards the Earth all the time but also move sideways so fast that they keep missing it.
Distance = speed $\times$ time. At $7.7\ \text{km/s}$:
Radiation: the atmosphere and the magnetic field of the Earth shield us from cosmic rays and charged particles from the Sun. Outside them, radiation can damage DNA and cause cancer, and it can damage electronics. Ways to reduce it: shielding with dense materials or water, shelters during solar storms, shorter missions and monitoring doses.
The International Space Station orbits the Earth at about $7.7$ km/s. a) Calculate the distance it travels in $90$ minutes (one orbit), in km. b) Explain why astronauts…
The International Space Station orbits the Earth at about $7.7$ km/s.
- a) Calculate the distance it travels in $90$ minutes (one orbit), in km.
- b) Explain why astronauts on the ISS experience apparent weightlessness although gravity there is still about $90\%$ of its strength at the surface.
- c) Explain two radiation risks faced by astronauts outside the protection of the Earth's atmosphere and magnetic field, and suggest one way to reduce them.
Back to the start: satellites give us forecasts and navigation, but the same space has debris, radiation and large costs. A good judgement weighs both.