3-3 Travelling into Space

Dreams of Space Travel

In 1902, French filmmaker George Méliès directed a movie called Le voyage dans la lune, which translates to "A Trip to the Moon". Movies had only been around for about a decade by then, and they didn't yet have sound (nor does this one). In the 1800s there were many novels written about space and space travel, such as those by Jules Verne, and Méliès was inspired by them to make what might be the first ever science-fiction movie.

The most iconic scene involves the space travellers' capsule hitting the "man in the Moon" in the eye:

If you want, you can watch the entire 15-minute film here:

It's a little silly, and movies have come a long way since then, but it's fun and interesting to see what people from over 120 years ago thought might be the way to get to space.

If you're interested in reading some of Jules Verne's novels which inspired Méliès, you can get them at the Project Gutenberg website:

• From the Earth to the Moon

• A Journey to the Centre of the Earth

These can be read in a web browser, on a dedicated e-reader (like Kindle), or on a tablet or smartphone using an app like Lithium (for Android) or Apple Books (for iOS).

Crewed vs. Uncrewed Exploration

In the previous section we have already seen Sputnik 1, which the Soviet Union launched into orbit as the Earth's first artificial satellite in 1957. This is an example of uncrewed space exploration: there was nobody on that orbiting object.

(You will likely also see the word "unmanned" when describing this type of space exploration. These days the preferred, gender-neutral word is "uncrewed," as it has no "crew" of people on it.)

On April 12, 1961, the Soviet Union (USSR) launched Vostok 1, which had pilot Yuri Gagarin inside it:

This was the first crewed spaceflight, and Gagarin orbited the Earth once at an altitude of about 170 km above the surface. The flight took less than two hours from start to finish but was an extremely important event in human history.

Consider the following, though:

• Gagarin was in a tiny capsule, which looked like a soup can with a sphere stuck onto the end of it. From one end to the other, it was about 4.5 m long.

• The Vostok capsule was mounted on top of what was, to that point, the world's largest and most powerful rocket.

• Up to that point, only 12 out of the 24 previous rocket launches by the USSR were successful. That means this launch, with Gagarin on it, only had about a 50% chance of succeeding.

• If the launch did not succeed, it was very likely that Gagarin could be killed in the process.

• Nobody knew if humans could survive in orbit, in an environment where gravity was not (directly) experienced. The Soviet Union had sent a couple of animals into orbit and they survived the journey, but no human had ever attempted this before.

With all these unknowns, a crewed spaceflight was extremely risky at the time, and it continues to be so today.

There are many pros and cons to both uncrewed and crewed space travel. You'll think about them in a little more detail later on.

History of Some Major Space Projects

Here's a rough timeline of some major milestones in space exploration, according to Popular Mechanics magazine, along with the country or countries that achieved them.

October, 1957: Sputnik 1 (USSR)

As discussed before, this was the first artificial satellite in orbit.

April, 1961: Vostok 1 (USSR)

As seen above, this was the first human spaceflight.

June, 1963: Vostok 6 (USSR)

Valentina Tereshkova becomes the first woman in space. She completed 48 orbits of Earth, spending almost three days in space.

July, 1965: Mariner 4 (USA)

This uncrewed spacecraft took the first close-up pictures of another planet -- Mars -- and continued orbiting the Sun to study the solar wind.

July, 1969: Apollo 11 (USA)

Various Apollo launches tested out rockets and vehicles to see how well they worked. The eleventh launch in the series was the one that was aiming for a landing on the moon, and it was successful.

April, 1970: Apollo 13 (USA)

This was supposed to be the third moon landing, but on the third day of the mission an explosion in the oxygen tanks forced the crew and engineers to try everything to get everyone home safely. (Yes, this is the one the movie is about. It's a very good movie.)

December, 1970: Venera 7 (USSR)

This was the first spacecraft to "softly" land (i.e., not just crash-land) on another planet. In this case, it was Venus, which is almost 500°C with crushingly high atmospheric pressure and a constant drizzle of sulphuric acid. The picture below is from Venera 13 which could actually send pictures and not just temperature and pressure readings.

August/September, 1977: Voyager 1 and 2 (USA)

These two spacecraft were launched 16 days apart, and travelled to the outer solar system to take close-up pictures of the outer planets for the first time. They are still going and Voyager 1 is the most distant human-made object from Earth, probably leaving the solar system entirely.

January, 1986: Space Shuttle Challenger (USA)

Starting in 1981, the Space Shuttle made many launches to Earth orbit, eventually helping to build the International Space Station. But an accident just after launch of Challenger killed all seven astronauts on board.

April, 1990: Hubble Space Telescope (USA)

As seen before in Telescopes, the Hubble Space Telescope took fantastic pictures that not only looked great, but helped us understand the universe more thoroughly.

December, 1996: Mars Pathfinder/Sojourner (USA)

Launched in 1996 and landing in July, 1997, the Sojourner rover was the first object landed on another planet that could drive around and collect samples for on-board experiments.

October, 1997: Cassini-Huygens (USA, European Space Agency, Italy)

Cassini was an orbiter that studied the planet Saturn in great detail, and Huygens was a lander that touched down on Titan, the largest moon of Saturn. Cassini lasted until 2017, when it was intentionally sent into Saturn to measure conditions in its atmosphere before it burned up.

November, 2000: International Space Station

Many countries and space agencies have collaborated on building the ISS. In November, 2000 the first permanent crew arrived on the ISS, and ever since then there has always been at least one human in orbit around Earth.

March, 2009: Kepler Space Telescope (USA)

This mission, and the K2 mission that followed it, tries to find planets around other stars using a few different ways. Scientists are examining stars in our part of the Milky Way galaxy.

December, 2015: Falcon 9 (SpaceX, USA)

Traditionally, rockets have had payloads (a satellite, a capsule, a Space Shuttle) strapped to them, then the rocket burns up as it re-enters the atmosphere. SpaceX developed a rocket that will land back on a launch pad so it can be re-used, lowering the cost of space travel.

December, 2021: James Webb Space Telescope (USA)

Again, as seen in Telescopes, the JWST improved on Hubble and has been giving excellent pictures and data so far in its mission.

Future Missions

There are many planned missions to various places inside the Solar System in the next few years. And it's not just the United States and Russia that are working on missions now. Many other countries have developed space programs of their own, for example:

• Japan

• India

• China

• South Korea

• Israel

• United Arab Emirates

For a comprehensive list of missions currently ongoing and which are planned for the near future, The Planetary Society keeps track of many of them. This list is updated often with revised timelines and new missions.

People on Mars?

The most obvious mission is a crewed landing on Mars. People have had their sights on Mars for decades now, but for obvious reasons it would be an extremely difficult feat to accomplish.

Getting there is hard enough:

Consider, though, that an uncrewed mission to Mars is much easier than a crewed mission. If you have people aboard your vehicle has to be much larger, you have to carry supplies to keep people alive, and you have to be able to bring those people back to Earth.

The next best thing is to have an uncrewed probe go to Mars, collect samples, and bring those back to Earth for closer study:

The Perserverance rover is already on Mars, and has already collected some good samples to be returned at a future date. When is that? Hopefully within the next few years. But it's not going to be cheap:

A crewed mission to Mars will be much, much more expensive -- and dangerous. So, is it worth it?

Challenges of Microgravity

Humans have evolved to live on Earth's surface, with all the things that come with that:

• there's about 20% oxygen in the air

• gravity is pulling down on you all the time

• your muscles have to work hard to keep you upright

• your heart has to pump blood up to your head

• your bones have to support your weight

When an astronaut is in orbit around the Earth, they don't feel like they're being pulled down. But, of course, they are "falling around the Earth" all the time. This sense of floating is called microgravity, and it produces many strange effects, one of which is demonstrated here by Canadian astronaut David Saint-Jacques:

But, more seriously, astronauts need to exercise for hours a day. Since their muscles aren't constantly fighting gravity, they can get weak if they don't work out a lot. Also, their bones can get weak in an environment like this, which might be a big problem in the future.

Taking a shower is definitely unusual:

And, it's somewhat unpleasant, but... well... what happens when you vomit in space? Chris Hadfield tells us what to do.

As you can imagine, there are many different video clips like this, and they are endlessly entertaining. But it raises the point: human bodies have evolved to work with gravity, not in its absence. So, any long space flight is going to present a lot of challenges as we float in a vehicle between Earth and Mars, or someplace farther than that, for months and possibly years at a time.

Practice

The Basics

1. Who was the first person in space, and what country was he from?

2. State the difference between crewed and uncrewed space exploration.

3. Briefly describe three of the challenges humans would face if they were in a microgravity environment for a long time.

Extension

Given all the challenges of crewed space exploration, there are still many advantages of putting people into space. Come up with a pros vs. cons table for crewed and uncrewed space exploration: draw a chart similar to the one below, then put at least three items in each box.