Why Humans Have Never Been to Mars
In 1961, President Kennedy declared that America would go to the moon… and just eight years
later, Apollo 11 successfully landed on the lunar surface for one of the most iconic moments
of the 20th century. Fast forward to today, though, and we’ve now been talking about
going to Mars for decades. So why are we still to set foot on the Red Planet?
This is Unveiled and today we’re answering the extraordinary question; Why haven’t
humans been to Mars yet?
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There are plenty of reasons to want to go to Mars, both from a scientific and a humanitarian
point of view. For one, Mars is the planet in our solar system most similar to Earth.
Venus is closer in size, but because of its scorching atmosphere there’s no real hope
of us landing there anytime soon - so we’ve tended to look in the other direction. For
many, Mars then holds a real possibility of harbouring some basic forms of life; a ground-breaking
discovery for humanity, if it’s ever made. And finally, we’re also better able to study
the Martian landscape up close thanks to various advancements we have already made - including
Mars landers and orbiters. Scientists are constantly trying to work out exactly why
the atmosphere there thinned so drastically and became clogged with carbon dioxide…
in part to try and prevent the same thing happening to Earth. More than that, though,
Mars is also seen in the minds of many as humanity’s escape route, should we ever
need to relocate from our own planet for any reason. So, all things considered, if we could
get there we surely would have done by now.
The main and most obvious problem is distance. Mars is much further from Earth than the moon
is. The journey to the moon takes around three days; the journey to Mars can take anywhere
from 150 to 300 days. If you were to travel to Mars, somehow safely step outside for just
one hour, and then head back to Earth, the round trip would take close to two years to
complete. And it isn’t just a question of time, either. The mammoth journey presents
a massive problem in terms of fuelling the ship that takes you there and supplying you
(and anyone else in your crew) with enough food, water and essentials for you to survive.
In many ways, it’s a far more complex task than even the enormous undertaking of the
Apollo missions in the ‘60s and ‘70s.
Our first spacecraft of any kind to reach Mars’ orbit was Mariner 4, launched in 1964.
It took 228 days for it to reach its far-off destination but, of course, there were no
humans on board. Every subsequent Mars mission has followed suit, although the journey times
have gradually reduced. But still, if anything goes wrong with any of our current Mars probes
- say they crash, or we lose contact with them - it’s only ever time and money lost,
not lives. Clearly the unprecedented danger levels of a prospective manned mission to
Mars are another major reason why we haven’t been there yet.
On a more fundamental level, when it comes to putting anything even into orbit the problem
is weight. Even for a relatively small machine without people, it takes a tremendous amount
of energy and fuel to achieve enough speed to break out of Earth's gravitational pull
and into space. Throw in the extra weight of the astronauts themselves, the extra room
and facilities they’d need to live, food, water, life support systems, exercise machines,
communications equipment… and the load gets heavier and heavier; meaning it requires more
and more fuel to get off the ground; which makes the ship heavier still. According to
NASA calculations, it could take as much as 50% of the total fuel used for an entire Mars
mission just to get the crew off of our planet’s surface and into Earth orbit. Considering
that after launch, the ship has to fuel a journey that’s upwards of 34 million miles,
we’re going to need a lot of fuel! Various proposals have been made to work-around the
issue, including from private companies like SpaceX, with plans to launch future Mars missions
from the moon (which has a much lower escape velocity, meaning it’d demand less energy)…
But plans like those are almost equally difficult to actually put into action, so weight and
fuel are two other leading reasons why we’re yet to jet off. The technology to send a shuttle
to Mars with humans and all the necessary equipment on-board just hasn’t been developed
yet.
But, even if we had the tech to get there, would we really be in a position to actually
go? Landing on the moon was difficult enough but landing on Mars could be harder still!
Because the moon doesn’t have an atmosphere, previous missions have used retrorockets to
guide a ship into steady orbit. Landing on Mars is more complicated because there is
an atmosphere, and because the firing of retrorockets to slow the shuttle would demand yet more
fuel (and more weight). An alternative method could be aerocapture, which actually uses
a planet’s atmosphere to slow the shuttle down enough to safely land. It’s risky,
though, and requires absolute precision. If entry is too deep, the shuttle goes up in
flames; if it’s too shallow, the craft could miss the planet entirely.
But say we were confident on how to land a team of astronauts on the planet’s surface
- after all, we have already landed various rovers - what then? Upon arrival we’d need:
a safe way for astronauts to explore, a dependable way to launch back off of Mars for a return
journey and, should we be planning to build a permanent base, then reliable options for
a long-term stay. By now we have a fairly full understanding of what works (or more
often what doesn’t work) about the Martian atmosphere, so exploring should be relatively
easy. Building a base or setting course for home, though, anything but! In fact, if we’re
aiming to ever fly to and from Mars - irrespective of how quickly we get there, and even if we
developed a futuristic, super-light, super-efficient fuel - we’d likely need multiple ships safely
on the planet (each bringing different bits of equipment) before even one of them could
feasibly “head home”. And that means that an astronaut’s journey to Mars is far more
than the already incredibly long commute in itself. Some are today predicting that, for
the first ever humans on Mars, it’d be a lifelong commitment. Even if the mission was
executed perfectly with zero complications, injuries or fatalities, the accomplishment
would represent such an incredible logistical effort that they might still never come back.
And all of that’s before we even really consider how much it would all cost. Estimates
vary wildly, but it’s clear that this could become one of the most expensive projects
ever attempted. In 2002, a joint ESA and Russia plan (involving two ships) came out at $20
billion; The USA Vision for Space Exploration in 2004 said $11 billion; Meanwhile NASA’s
Mars Exploration Program has been subject to significant budget cuts across recent years.
With NASA commanding a generally smaller percentage of US federal spend today than it has in the
past, it’s no wonder that we’ve seen private companies step forward with ideas on funding.
The now-bankrupt Dutch organization Mars One once cited $6 billion; For Elon Musk’s SpaceX,
Mars missions could one day be funded by deep space tourism - with regular “tickets”
to Mars perhaps costing $100,000 each. The figures are all still mostly based on theoretical
or plain hypothetical ideas, though. The one thing they all have in common? They’re all
very, very big numbers!
But despite that, humans going to Mars still feels like an inevitability. As though it
will one day become a reality. For now, though, we can only satisfy our seemingly innate need
to explore and discover by talking about what might or might not happen; by contemplating
what’s possible. If we do ever get there, then it’d be a monumental, ground-breaking
step in our exploration of the solar system, our transformation into an interplanetary
species, and perhaps even the continuation of humanity as a whole. But saying we’ll
get there and actually doing it are two very different things. And that’s why humans
have never been to Mars.
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