Extension: Space Exploration, Past, Present and Future

This is an extension lesson. It goes beyond the Stage 4 syllabus dot points for interest and enrichment. There is no new dot point to memorise here. Instead, this lesson takes the space science you have already met in this unit and tells the bigger human story: how people have explored space, what we are doing right now, and where we might go in the future. Enjoy it, ask questions, and notice how often Australia appears in the story.

The story of space exploration really begins in the 1950s. Two powerful countries, the Soviet Union and the United States, competed to be first in space. People called this competition the Space Race, and it pushed science and engineering forward at an amazing speed.

• 1957, the first satellite: The Soviet Union launched Sputnik 1, the first ever artificial satellite to orbit Earth. It was about the size of a beach ball and did little more than send out a steady beep, but it proved that humans could put an object into space.
• 1961, the first human in space: Soviet pilot Yuri Gagarin became the first person to travel into space and orbit the Earth, aboard a spacecraft called Vostok 1. His flight lasted less than two hours, but it showed that humans could survive the journey.
• 1969, the first humans on the Moon: The United States landed Apollo 11 on the Moon. Astronauts Neil Armstrong and Buzz Aldrin walked on the surface while Michael Collins orbited above. People around the world watched it live on television.

Think about the timing. In 1957 we could only send a beeping ball into orbit. Just twelve years later, in 1969, human beings were walking on another world. That is one of the fastest leaps in the whole history of science.

Here is something many Australians are proud of. When Apollo 11 landed on the Moon in 1969, the spacecraft was on the far side of the Earth from the United States for part of the broadcast. To receive the faint signals and pictures from the Moon, NASA needed large radio dishes spread around the world, and several of these were in Australia.

• The Parkes radio telescope in country New South Wales, known today by its Wiradjuri name Murriyang, received much of the live television of the first Moon walk and relayed it to the world.
• Honeysuckle Creek, a tracking station near Canberra, received the very first minutes of the Moon-walk pictures, the famous footage of Neil Armstrong stepping down onto the surface.
• Today the Canberra Deep Space Communication Complex at Tidbinbilla, near Canberra, is still one of only a few stations on Earth that NASA uses to talk to spacecraft far out in the Solar System.

So when you picture those first footprints on the Moon, remember that some of the clearest pictures the world saw came through Australian dishes. Our wide, quiet landscapes make excellent places to listen to faint signals from space.

Space exploration did not stop after the Moon landings. Today there is more activity in space than ever before, and a lot of it is happening right now as you read this.

• The International Space Station (ISS): a large laboratory that orbits the Earth, where astronauts from many countries live and carry out experiments. It has had people living on board continuously for more than twenty years.
• Robotic rovers on Mars: wheeled robots like NASA's Perseverance drive across the surface of Mars, taking photos, testing rocks and searching for signs that tiny life may once have existed there.
• Space telescopes: powerful telescopes placed above the atmosphere take sharp pictures of distant galaxies, far clearer than telescopes on the ground can manage.
• Commercial spaceflight and reusable rockets: private companies now build rockets, and some of these rockets can land back on Earth and be flown again. Reusing a rocket, instead of throwing it away after one flight, helps to lower the cost of reaching space.

Australia is part of this present-day story too. In 2018 the government set up the Australian Space Agency, based in Adelaide, to help grow Australian space science, industry and jobs.

What comes next? Space agencies and companies are already planning the next big steps.

• Returning to the Moon: NASA's Artemis programme aims to send astronauts back to the Moon, this time to stay for longer and learn how to live and work there. Many other countries, including Australia, are helping with parts of these missions.
• Reaching Mars: several groups hope to one day send humans all the way to Mars. This would be the longest crewed journey ever attempted.

Travelling far into space is very hard. Here are some of the reasons:

• Distance: Mars is so far away that, even at its closest, a spacecraft takes many months to get there.
• Radiation: beyond the protection of Earth, astronauts face harmful radiation from the Sun and from space, which can damage the body.
• Time: long missions mean crews are away from home, family and rescue for years.
• Supplies: there are no shops in space, so every breath of air, drop of water and bite of food must be carried, recycled or somehow grown along the way.

Solving these problems is exactly the kind of challenge that drives new science and new technology.

Space exploration brings real benefits, but it also raises fair questions. Good scientists and citizens think about both sides.

Some benefits:

• New technology: inventions made for space, from better cameras to water-cleaning systems, often end up helping people on Earth.
• New knowledge: exploring space teaches us about other worlds and about our own planet.
• Useful satellites: satellites give us weather forecasts, television and internet links, and GPS for finding our way.

Some questions and concerns:

• Cost: space missions are very expensive, and some people argue the money could be spent on problems here on Earth.
• Space junk: old, broken satellites and bits of rocket now orbit the Earth as fast-moving rubbish, which can crash into working spacecraft.

There is no single right answer. The point is to look at the evidence on both sides and make a thoughtful decision, which is exactly how science helps us think about the world.