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The Secret To Interstellar Travel | Unveiled

VOICE OVER: Noah Baum WRITTEN BY: Dylan Musselman
Interstellar travel has been humanity's dream for decades! Our greatest scientists and engineers have been trying to work out exactly HOW we can branch out from Earth, to live in amongst the stars in the wider universe! The problem is that space is so inconceivably HUGE! In this video, Unveiled explores the science behind interstellar travel... to find out whether we'll EVER be able to jet off to distant planets and alien worlds!
Transcript

The Secret to Interstellar Travel


As a species, human beings have a seemingly innate need to travel and explore. We’ve scaled our own planet with boats, planes, trains and all manner of other vehicles… so, now, we’re busy building all types of spaceship with our sights set on the stars. The problem? Space is a much, much bigger prospect.

This is Unveiled and today we’re uncovering the extraordinary secret to interstellar travel!

Interstellar travel refers to any travel through space between stars or planetary systems. Human beings are the most intelligent species on Earth, but still the concept represents the tallest of tall orders for us. But, of course, that hasn’t stopped us from trying to work it out!

One of humanity’s most pressing questions is whether or not we’re alone in the universe… and in the quest for answers we have already identified a number of planets beyond the solar system that could potentially host life. So, our motives are fairly clear; interstellar travel would enable us to actually visit these worlds, experience them, and broaden our horizons. And, it should be said that in one way we have already managed to leave the solar system - or at least the heliosphere - with the Voyager 1 and 2 space probes, which are both travelling through interstellar space right now. It’ll be a very long time before even they reach anything else of note, though, with even the most generous predictions saying we’re likely to lose them somewhere in the Oort Cloud!

The closest star system to us is Alpha Centauri; home to the potentially habitable planet, Proxima Centauri b. But, right now, it mostly serves as a reminder of just how impossibly far away everything else in the universe is! Because even if, say, Voyager 2 had been specifically pointed in its direction when it was launched (which it wasn’t), at its current speed it wouldn’t arrive at Alpha Centauri for another 75,000 years!

For interstellar travel to become the reality, we need some truly ground-breaking technologies to emerge. For some, there’s hope with ambitious initiatives like Breakthrough Starshot - a company whose backers include the late Stephen Hawking, former directors of NASA, and various Nobel Prize winners. Breakthrough Starshot is aiming to reach speeds of one-fifth the speed of light, and hopes to accomplish it by putting a spacecraft in orbit; equipping it with thousands of chips attached to a lightsail; and energising those chips by shooting them with a laser beam from Earth. It sounds a farfetched plan, but if it were to work, it’d mean propelling something 1,000 times faster than any other man-made object has ever gone before. But even then, truly fast or even practical interstellar travel would have to wait… because even with Breakthrough Starshot-level speeds, it would still take around 24 years to reach Alpha Centauri. It’s a hugely hypothetical mission, but even it would require a life’s work to even potentially pull off.

And projects like it are only really possible with small, once again uncrewed probes. So, what if we want people onboard? Humans (and all the things they need to live) are pretty heavy… so, travelling at any notable speed gets much more difficult to fuel. And, as the Breakthrough Starshot initiative already proves, humans also age quickly compared to the transit times between stars. Turn a compact probe into a people-carrying, life-supporting spaceship, then, and we’re automatically talking about generation ships; huge, sprawling vessels on which whole generations of people will be born, live and die without ever stepping foot onto any kind of terra firma.

If spending your entire existence confined to the cabins of a ship suspended in a seemingly endless void just isn’t for you, however, then perhaps the secret to such a mission lies in futuristic theories on how to preserve the human body instead. Cryonics is usually put forward as the method of choice here, although the chances of it working even close to how it does in the movies are low. The premise is simple; human travellers on an interstellar ship scheduled for centuries en route are placed inside protective pods and their bodies are frozen; upon arrival at their destination they’re ­un-frozen, and they haven’t aged a day in the meantime. We are already trying to apply the technique to real world medicine and surgery - where frozen organ tissue is revived for transplants - but we’re still very far away from effectively “hibernating” a whole, living, breathing person. In fact, the majority consensus in the scientific community is that it’s impossible.

So, we can’t feasibly travel via traditional means, generation ships demand an incredible sacrifice from those who commit their lives to living on them, and sci-fi style body preservation isn’t yet an even slightly reliable alternative… perhaps there’s a best of all worlds? Maybe the key to interstellar travel lies in compromise?

If, to travel to other stars, we really do need to forgo Earth forever, then it’s clear that the voyage would have to be an incredibly long-term project. Unless we somehow manage to also build and control a totally theoretical web of physics-busting wormholes, zapping to and from different star systems is all but physically impossible. But what’s perhaps a little less impossible is the idea of human explorers, over time, setting up bases and ports on other, closer planets and objects, as a means of slowly expanding outwards. This wouldn’t be “racing across space via warp drive”, more “plodding across space, checkpoint to checkpoint” - but it would get us to where we needed to go! We wouldn’t be waiting for far-future, faster-than-light tech that might never transpire, and we wouldn’t be condemned to spending our entire lives in just a spaceship… but those who chose to take the trip would still be giving up Earth for good, in favour of a life dedicated to setting up humanity’s “next off-Earth outpost” - wherever that is.

In theory, it’s simple. In practice, not so much. Our struggles to even begin planning a mission to Mars are testament to just how tricky any journey outside of Earth’s orbit is. And our reluctance to return to the moon is arguably led by the memory of just how difficult the Apollo missions were in the first place! But, if we’re to ever see other worlds, then right now it seems like the only option - a series of one-way trips from one planet to the next until eventually we reach another star system entirely.

The prospect throws up all manner of concerns in itself - including how we could reasonably hope to keep such ardent travellers safe? How we could realistically expect to terraform the new worlds we came across? And how we could even monitor the progress of such a mission, given that it’d play out across multiple lifetimes and reach never-before-known distances from Earth? But all of those problems are still probably easier to solve than the conundrum at the heart of interstellar travel; fast than light speeds.

Even were we to somehow get as close as physically possible to the universal speed limit - at a totally hypothetical and unlikely point in the future - and achieve a manned ship travelling at 99% the speed of light, it would still take us over four years to reach even the closest, alternative star system. A return trip would still demand almost a decade of everyone’s lives. As for the millions of other worlds out there, they could still be forever out of reach, growing further and further away as the universe expands.

So, short of cheating the laws of physics and aiming for what’s physically impossible, we’re in this one for the long haul. As in, the really long haul. Interstellar travel is doable, but only at excruciatingly slow speeds. And the problem is that our “baby steps” out into the universe are actually mammoth journeys in themselves, the likes of which we’re yet to even begin to master. First the moon; then maybe Mars; then the rest of the solar system; then the rest of everything else out there. The secret is patience. Lots and lots of patience.
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