Who has travelled to space?

Space flight is now a venerable industry. Humanity’s first space explorer, Soviet cosmonaut Yuri Gagarin, orbited around the globe on 12 April 1961, more than half a century ago, when Britain remained a colonial power and people were still using halfpennies to buy their fish and chips.

Since then, more than 550 people have blasted themselves into the deep black abyss, although not all agree on how far up you need to go until you hit space, so there is no internationally accepted figure. Only a 10th of those have been women, in big part due to sexist policies by Nasa and Russia’s Roscosmos space agency.

Where have we been in space?

The Soviet Union pulled ahead with the first space walks, but US president John F Kennedy’s announcement that America would put a man on the moon by the end of the 1960s focused the space race squarely on that goal. Apollo 11 touched down on our dusty grey neighbour on 20 July 1969.

A total of 12 men walked on the moon over the next few years, all Americans, but no one has been back there since 1972. In fact, no one has left the outskirts of the Earth since then.

We imagine astronauts floating in free space or bouncing in moon craters, yet the majority of those lucky enough have instead spun around in low Earth’s orbit – between 99 and a few hundred miles high. That’s where the vast array of communications and navigation satellites live, speeding at thousands of miles an hour to avoid plummeting back to earth.

What do we do there?

Even though we did not go back to deep space, humans have begun to live and work outside the Earth’s atmosphere, often conducting experiments on themselves to determine the effects of weightlessness, or microgravity, on the human body.

By 1986, the Soviet Union had launched the Mir space station. When it eventually fell to Earth (thankfully unoccupied) and burned up, our current space outpost, the International Space Station (ISS), was launched. Since 2000, humans have been living in space constantly. There are three up there at the moment, speeding around the globe once every 90 minutes.

What happens to the body in space?

A lot, and until we properly understand how weightlessness affects humans, we won’t be able to send this era’s pioneers further afield to places such as Mars or wandering asteroids. Scott Kelly, a US former fighter pilot and long-time Nasa astronaut, spent a year bouncing around the cramped capsules of the ISS in an attempt to understand the long-term impact of space flight. He doesn’t hold the record for the most extended foray into the void – that is claimed by Gennady Padalka, who spent two and half years of his life up there on several missions – but the Kelly experiment had a natural advantage over others: he has a twin.

Comparing their bodies throughout, scientists were able to assess how bones, muscles and other parts of the body deteriorate in space. There is even a gym on the ISS where astronauts can keep their muscles – no longer needed to prop them up – from slowly wasting away. But they need to wear a harness to keep them from floating off the treadmill. One big issue is that eye problems develop, but Kelly found his body recovered fast on return. He and his twin seemed in similar shape – good news for future deep space missions.

Which countries have human space programmes?

Only three countries, China, Russia and the US, have human space programmes as it remains prohibitively expensive. However, they have provided lifts for space travellers from 40 countries, including a member of the Saudi royal family and even paying customers, such as South African millionaire Mark Shuttleworth, aged just 28.

How much does it cost to send them up?

Astronomical. The ISS is the most expensive machine ever constructed with a price tag at around $150bn (£115bn). Nasa’s space shuttle programme, which kicked off in the early 1970s by promising safe and affordable access to space, hoped to cost just a few tens of million dollars per launch. But as the shuttle was thrown in the scrapyard in 2011, the agency estimated the total cost at $209bn — nearly $1.6bn per flight.

Following the big fight over the shuttle, which looked fantastic but also restricted space adventuring to Earth’s orbit as well as costing a fortune, the US took a side seat in launches. Most astronauts are now sent by the Russian space agency, which sells round-trip rides on its Soyuz spacecraft for between $21m and $82m.

Is human space flight worth the cost?

Anyone involved in space travel will scoff at this, but it’s a good question, and space agencies often don’t communicate their achievements enough. Almost every sector of human progress has benefited from sending people into space. Just the act of attempting the feat forced scientists to invent new systems. The Apollo guidance computer was a predecessor to the microcomputer, now found in all smartphones. Clothes are more fire-resistant because of research on space fires. Remotely monitoring the health of astronauts has led to revolutionary systems for helping patients on Earth. Diseases behave and develop differently in microgravity, which assists scientists in finding cures.

Others say paying for human space flight pumps money into the economy, arguing that spin-off companies from space research and a growing commercial space industry generates seven to 14 times the cost of missions. And Nasa, the most significant global player, is not spending nearly as much as it used to. About $19bn is spent by the US government on its budget, roughly half a percent of all federal spending. During the early Apollo programme, that was between 4% and 5%.

How strong is space cooperation between countries?

The first space race was part of the chest-beating of the cold war, but since then human space exploration has been more about countries working together than against each other. The ISS is a massive collaboration between five space agencies (Nasa, Roscosmos, Japan’s Jaxa, the pan-European agency ESA and the Canadian Space Agency) and was assembled over a period of 13 years from 1998, slowly adding capsules like Lego.

A big exception to this is China, which has gone it alone with its space ambitions, never sending an astronaut to the ISS. In 2006, Beijing reportedly tested lasers against US imaging satellites in what appeared to be an attempt to blind or damage them, and US lawmakers later banned cooperation between Nasa and China’s state agency.

However, the future of any effective human space flight is certainly likely to be cooperative rather than antagonistic. Since 2011, national spaces agencies in 14 countries have attempted to coordinate their dreams into a single vision. The most recent plan, published in January this year, said they had agreed to “expand human presence into the solar system, with the surface of Mars as a common driving goal”.

Play Video 4:05 Can we all move to Mars? Prof Martin Rees on space exploration – video

We’re off to the red planet? Hurray!

Don’t start the countdown just yet. To get to Mars, most people in the human space flight community feel we need to first go back to the moon. “It’s the only logical step,” says Ian Crawford, professor of planetary science and astrobiology at Birkbeck, University of London. “I’m all in favour of sending people to Mars, but the technology, competence, the experience – I think it’s still out of reach”.

The moon has several advantages. It’s only three days away, rather than a several-month round trip to Mars, and has been touted as a location for a research station similar to the one in Antarctica. From their celestial laboratory, scientists could study the impact of radiation exposure and near-weightlessness on the body at a closer distance to Earth, but still within deep space, all while preparing for trips further afield.

So to the moon then?

Well. Not quite either. The Global Exploration Roadmap suggests first building a space station as an orbital base from which to send astronauts back and forth to the moon. This will look similar to the ISS except, instead of rushing around the Earth, it will orbit the moon.

Will we ever get to Mars?

It is a mammoth feat and it would be wise to expect serious delays. “Where we go in space is decided by a combination of what people would like to do and the reality of time and budgets,” says Henry Hertzfeld, director of the Space Policy Institute at George Washington University, Washington DC, and a former policy analyst at Nasa. “The idea of putting people on Mars has been around for a long time. If you read the policies, it is clearly a long-term vision without a date. But we probably are still lacking the technology to keep people for a long time in deep space.”

Who are the new contenders in human space flight?

The US and Russia have been giving way to new players. In 2003, China became the third country to put a person into orbit and India plans to follow in 2022. But the sector-changing impact is undoubtedly coming from the private space.

In what is being coined the “billionaire’s space race”, Elon Musk, founder of Telsa electric cars, Amazon CEO Jeff Bezos and Virgin boss Richard Branson all want to send private citizens to space. Their companies, SpaceX, Blue Origin and Virgin Galactic, are set on making human space travel cheaper.

They join a handful of commercial space flight companies that already work as contractors for national space agencies. Aerospace industry titans Boeing and Lockheed Martin send heavy launchers into space, but that costs at least $350m per launch – several times more expensive than SpaceX’s new $90m Falcon Heavy system.

SpaceX has around $10bn worth of launches already booked and saves costs through reusable spacecraft, where even the rocket boosters land themselves back on the ground and can be dusted off for reuse.

And while it is looking increasingly likely that the ISS will be defunded in the next decade, several private ventures are considering either taking over or rebuilding their own space stations.

What’s next?

As government agencies prioritise the moon, others are looking straight at Mars. Musk has said his life goal is to create a thriving Mars colony as a fail-safe for humanity in case of a catastrophic event on Earth, such as a nuclear war or Terminator-style artificial intelligence coup. For this, SpaceX is developing the Big Falcon Rocket (BFR), which he claims could send crewed flights to the red planet by mid-2020.

Musk says the BFR is partly inspired by Tintin’s rocket and will be the biggest ever made at close to 40 storeys high and capable of ferrying as many as 100 passengers per trip, depending on how much luggage they want to put in the hold.

As well as a healthy satellite launch business, SpaceX is raising money by selling tickets on the BFR for a trip, some would say a jolly, around the moon. Yusaku Maezawa, a Japanese fashion billionaire and art collector, is funding such a mission slated for 2023 and says he is going to invite artists with him for the week-long trip to re-engage the public in the wonder of our universe.

Further reading

An astronaut’s guide to life on Earth, Chris Hadfield

To space and back, Sally Ride

The Right Stuff, Tom Wolfe

The Martian, Andy Weir

Endurance: A year in space, a lifetime of discovery, Scott Kelly