Space Exploration: Achievements and Challenges (C1)

SPACE SERIES · LESSON 6

Space Exploration:

Achievements

and Challenges

Famous explorers

• Leif Erikson

• Xuanzang

• Marco Polo

• Ibn Battuta

• Zheng He

• Ferdinand Magellan

• James Cook

• Roald Amundsen

• Tenzing Norgay and Edmund Hillary

• Jacques Piccard and Don Walsh

• Yuri Gagarin

• Valentina Tereshkova

How many of the names do you recognise?

Do you know what they discovered?

Does your country have any famous explorers?

Where are we exploring?

Which parts of space do you think humanity is exploring?

Your answers

the moon

Mars

the Milky Way

asteroids

other planets (but not Mercury)

black holes

From Sputnik to Phobos

Task Read the timeline.

1957 The USSR launches Sputnik 1, the first artificial satellite, into orbit around Earth.

2010 Japan's IKAROS unfolds a thin solar sail and becomes the first spacecraft to sail between planets on sunlight.

1965 Soviet cosmonaut Alexei Leonov makes the first spacewalk, floating outside his spacecraft on a cable.

2014 India's Mangalyaan reaches Mars orbit, making India the first country to do so at its first attempt.

1969 Apollo 11: the American astronauts Neil Armstrong and Buzz Aldrin become the first people on the Moon.

2015 NASA's New Horizons flies past Pluto and sends back the first close-up pictures of the dwarf planet.

1970 The Soviet probe Venera 7 lands on Venus, the first craft to send data from another planet's surface.

2020 SpaceX becomes the first private company to fly astronauts to the International Space Station.

1986 Europe's Giotto flies about 600 km from Halley's Comet and takes the first close-up photographs of a comet's core.

2021 China lands its Zhurong rover on Mars and launches the first module of its space station, Tiangong.

1990 NASA and ESA launch the Hubble Space Telescope, which will photograph galaxies billions of light years away.

2021 The James Webb Space Telescope, built by NASA, ESA and Canada, sets off to study the earliest galaxies.

2000 The first crew moves into the International Space Station; people have lived in orbit ever since.

2024 NASA's Parker Solar Probe passes about 6 million km from the Sun's surface, closer than any spacecraft before.

2003 Yang Liwei orbits Earth 14 times, making China the third country to launch a person into space.

2026 Japan's MMX sets off for Mars's moon Phobos, aiming to bring samples home around 2031.

Talking about the timeline

1. Were any of your ideas mentioned?

2. Which things on the list are you most familiar with?

3. Is there anything on the list that surprises you?

4. Are there any noticeable omissions?

5. Which do you think have made the most interesting discoveries?

Student A

Task Read your two texts. You'll summarise them for your partner.

The Voyagers: beyond the Sun's bubble

Cassini–Huygens: hidden seas

In 1977 NASA launched two small probes, Voyager 1 and Voyager 2, to take advantage of a rare line-up of the outer planets. Between them they flew past Jupiter, Saturn, Uranus and Neptune. Voyager 1 found active volcanoes on Jupiter's moon Io, the first seen anywhere beyond Earth, and Voyager 2 is still the only spacecraft to have visited Uranus and Neptune. Each probe carries a Golden Record, a gold-plated disc of sounds, music and pictures from Earth, with greetings in 55 languages, in case anyone ever finds it. The Sun blows out a constant stream of particles, the solar wind, which inflates a huge bubble around the planets. Its edge, where the solar wind meets the thin gas between the stars, is the heliopause. Voyager 1 crossed it in 2012 and Voyager 2 in 2018: the first human-made objects in interstellar space. In November 2026 Voyager 1 reaches one light-day from Earth: a radio signal takes a whole day to get there. Its power is fading, and only two of its instruments are still switched on.

Cassini–Huygens, a joint mission of NASA, the European Space Agency and the Italian Space Agency, was launched in 1997 and reached Saturn in 2004. It carried a European probe, Huygens, which parachuted onto Saturn's largest moon, Titan, in January 2005: still the most distant landing ever made. Beneath Titan's thick orange haze, Cassini mapped rivers, lakes and seas, filled not with water but with liquid methane, a natural gas. The biggest surprise was Enceladus, a small, bright, icy moon. In 2005 Cassini spotted plumes, jets of water vapour and ice grains shooting into space from cracks near its south pole. Later measurements showed that the jets are fed by a salty ocean beneath the ice, covering the whole moon. Flying through the plumes, Cassini detected organic molecules and signs of warm water reacting with rock on the ocean floor. In September 2017, with its fuel almost gone, Cassini was steered into Saturn, so that it could never crash onto, and contaminate, a moon that might support life.

Student B

Task Read your two texts. You'll summarise them for your partner.

Rosetta: catching a comet

Hayabusa2: a handful of asteroid

Comets are lumps of ice and dust left over from the birth of the Solar System, about 4.6 billion years ago. To study one up close, the European Space Agency launched Rosetta in 2004. After a ten-year chase, in August 2014 it became the first spacecraft to orbit a comet: 67P/Churyumov–Gerasimenko, a dark, duck-shaped body about four kilometres across. In November 2014 Rosetta released a small lander, Philae. Its harpoons failed to fire, so it bounced twice and came to rest in the shadow of a cliff. Even so, it was the first landing on a comet, and it sent back data for nearly 60 hours before its battery ran out. Rosetta stayed with the comet for two years. It found that the comet's water holds about three times as much deuterium, a heavy form of hydrogen, as Earth's oceans, so comets like this one probably did not bring most of Earth's water. In 2016 Rosetta ended its mission by landing on the comet too.

Japan's space agency, JAXA, launched Hayabusa2 in December 2014 to bring back pieces of Ryugu, a dark asteroid about 900 metres wide. It arrived in June 2018 and touched down twice in 2019, each time firing a small bullet into the ground and catching the grit that flew up. Between the two touchdowns, it fired a copper projectile into the surface to blast out a crater, so that the second sample would include material from underneath, protected from sunlight. In December 2020 a capsule landed in Australia with 5.4 grams of asteroid. This is a sample return: material brought home, so that scientists can study it with every instrument on Earth, not just the few a probe can carry. The samples are some of the least changed material from the early Solar System ever studied. They contain some of the chemical building blocks of life, and one tiny crystal even held a droplet of liquid, salty water. Hayabusa2 is now on its way to another, much smaller asteroid, due in 2031.

Summarise your two texts for your partner. No comments or opinions yet: just tell the story.

discussion

1. Which of the four did you find the most interesting?

2. Do you ever feel that it's literally unbelievable that humanity is doing this?

3. Can you imagine any practical use coming from any of these missions?

4. What do you think the future of space exploration will look like? (in 50 years, in 500 years, in 5,000 years and in 50,000 years)

What will the future of space exploration look like?

Task Read the four boxes. For each one, compare it with the class's predictions for that time. Which box comes closest to what you said?

IN 50 YEARS By the 2070s, the first crews may already have walked on Mars. China has named 2033 for its first crewed Mars mission, and NASA has spoken of the late 2030s, though such dates often slip. The International Space Station is due to retire around 2030, with private stations planned to replace it, and a proposed NASA telescope may be searching nearby planets for signs of life.

IN 500 YEARS Some people imagine permanent towns on the Moon and Mars, and mines on asteroids that are rich in metals or water ice. More ambitious still is terraforming: changing a whole planet's climate so that it is warm enough, with thick enough air, for people to live outside without a spacesuit. Mars is the usual candidate, but a NASA-funded study in 2018 found that it lacks enough carbon dioxide to thicken its air with any technology we have today.

IN 5,000 YEARS The nearest stars, the Alpha Centauri system, are about 4.4 light years away: some 41 trillion kilometres. At Parker Solar Probe's record speed, the trip would take nearly 7,000 years. Proposals to go faster include light sails, very thin sheets pushed by light; one 2016 plan imagined tiny probes reaching the star in about 20 years. Others imagine generation ships, on which only the travellers' distant descendants would arrive.

IN 50,000 YEARS Voyager 1 will still be travelling, long silent. By then, it will have passed within two light years of Gliese 445, a small star that is moving towards us. It will still carry the Golden Record, its disc of sounds and pictures from Earth. Whether humans will have followed it to the stars, and whether anyone, anywhere, will ever play that record, nobody can say.

discussion

1. Are you excited about any of the things that we'll (hopefully) see in our lifetimes?

2. How realistic do you find the longer term predictions?

3. Who should pay for exploring space: governments, private companies, or the whole world together?

4. Should humanity try to live beyond Earth at all?