The future of space travel

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Hello, I'm Tom Whipple,

and welcome to Inside Science

from the BBC World Service.

What we thought this week would constitute

the Ultimate Science magazine show.

Well, there would have to be space in it, obviously.

But proper space.

We've interplanetary travel, satellite imagery,

and properly space age things like atomic thrusters.

There would also need to be some mind-boggling particle physics.

And you matter.

Or something like that.

And naturally, you would need Caroline Steele

to talk about the week's news.

Well, we have the lot.

Welcome, then, to the Ultimate Science magazine show.

And welcome, Caroline.

Caroline, what have you got to rival

anti-matter atomic thrusters and satellites?

I've got beavers.

Fabulous.

Good, that's enough, that's all we need to know.

Um, let's start with this.

Are we at last getting the space-faring future

we were promised way back in the 1960s?

Next month, it now looks likely that humans will

at last blast off on a mission around the moon.

With Artemis continuing the work the Apollo missions started.

But while all eyes were on Cape Canaveral,

NASA has announced not merely a minor orbital correction

of its future space policy,

but a full planetary slingshot.

This week, NASA announced accelerated plans for a moon base.

Something those Apollo astronauts would have surely assumed

would have happened long ago.

And in the most retro-futurism move of all,

it promised something else.

Atomic thrusters, or to use a slightly less Jetson's term,

nuclear electric propulsion for travel to Mars.

So, what is a nuclear-powered spaceship?

Why is it taken so long to get one?

And how will it allow us to boldly go more boldly?

We're joined by Dr. Hannah Sargent.

Hannah, thank you for joining us.

What's your role in space?

What do you do?

Hi, yeah.

So, I'm a planetary scientist,

but I've also got another hat,

which is looking to take the technology

that we've been developing for space nuclear power systems

and sort of commercialising in that.

So, yeah, this is a really hot topic for us right now.

Okay, well, let's talk about it.

So, as I understand it,

there are different kinds of nuclear propulsion.

What are they?

And what's this one that we're talking about?

You've got your sort of your normal conventional rocket,

which is what we call chemical propulsion.

But what we're looking at doing now,

what NASA are committing to doing now,

is using nuclear electric propulsion.

So, you take a nuclear reactor, put it in space.

It's a much more efficient way of generating thrust.

But it's really, really hard to do.

There's only ever been one nuclear reactor in space ever.

And it was tested like 50, 60 years ago.

Just because it's just so challenging

to get one of these systems in space.

So, NASA committing to this is really exciting.

Because there's been so much development work on the ground.

But actually, launching one is going to be a huge leap forward.

So, just explain it.

So, you've got a nuclear reactor.

It's generating electricity, presumably,

in the way that nuclear reactors do on Earth.

And then it's using that to fire off a propellant superfast.

Yes. So, it actually uses very little propellant,

but it can power it continuously.

So, it's this slow build of thrust

over very long distances.

So, it's particularly efficient for long distance missions.

So, if you're heading out into the solar system,

you can build up speed over long periods of time.

So, you can actually get to very, very high speeds.

This wouldn't be for taking off them.

We're not talking about a nuclear reactor that takes off.

This is, once it's in space, it's used for those longer missions.

Exactly, yeah.

Therefore, you only need enough fuel to get you out of Earth's gravity

using standard chemical propulsion.

And then you can switch on your, well, yeah, switch on your reactor

and your electric propulsion,

and then start this slow burn to your destination.

And should we be worried about sending a nuclear reactor into space?

What happens if it goes wrong on the way up?

Yeah, I mean, public perception is a really big part

of the regulation side of things.

So, yeah, people hear nuclear and they panic.

But actually, the development work that goes into space nuclear power systems,

so much of it is to demonstrate that

in any sort of viable accident scenario,

so let's say, you know, the rocket explodes on the launch pad

or it accidentally reenters Earth's atmosphere and it burns up,

there will be no dispersion of fuel of this nuclear material.

So, so much of the design goes into making sure it is extremely safe and sealed

so that in any accident scenario,

you're not going to end up with materials sort of discarded over a city.

And is that why it's taken so long?

Because we've had, you know, modular reactors sitting on aircraft carriers

and subs for ages,

and it does feel quite an obvious thing to put one in a space rocket.

Yeah, a lot of it is to do with, well, firstly, the need

and two is the regulation side of things.

We've been able to do a lot of space exploration

without needing this technology.

We've been able to do a fair amount using sort of solar panels

and sort of smaller radio isotope power systems,

which don't require as much fuel.

But yeah, this regulating this sort of thing is a big challenge,

so it's important that there is government buy-in,

which obviously NASA have to support that regulatory process.

And why can't we just use solar panels?

There's always sun in space.

Why do we need to bother blasting up uranium?

Well, it depends how far away from the sun you're going.

So, if you're heading to Mars,

we have historically done missions to Mars using solar power,

but it's hard, and we actually end up using some smaller power systems,

nuclear power systems on the surface of Mars.

So, most Mars rovers include what we call an RTG,

which uses radio isotope power,

which is sort of radioactive decay, releases heat,

and creates a bit of electricity,

because even at Mars, it's just not quite enough.

So, if we want to send humans and build bases,

we're going to need a lot more power.

And actually, one of the benefits of these space nuclear power

electric propulsion systems is that because it's so efficient in fuel,

you can bring much bigger cargo.

So, if we want to send bigger missions to Mars,

or do more science in the outer solar system,

with bigger spacecraft, we're going to need this alternative propulsion system.

Thank you very much. That was Dr. Hannah Sargent.

Caroline, are you a fan of moon bases and nuclear propulsion?

I am. Big fan.

All this chapter makes me think of back in the 70s,

when NASA was considering the surface of the moon

as somewhere to store nuclear waste.

And I found a fun quote from a NASA paper back from 1978,

where they said,

of the five space destinations considered,

the lunar surface and solar orbit options are the most attractive.

And basically, thank God we didn't end up putting nuclear waste on the moon,

because we'd be having to navigate that whilst building a lunar base.

And there's something about finding a nice pristine location

and deciding, I know what I want to do with it.

Yes, rather than how north we get around these piles of nuclear waste

that have been building up for decades.

There was a piece of news that particularly excited you this week.

Yes, so we've got some big news from Sun, which is a particle,

huge particle physics lab near Geneva.

So, on the 24th of March, 92 anti-protons took a 20-minute drive in the back of a lorry

around Sun's main site, which I just think is so unbelievably cool.

I visited that main site in Sun just at the end of last year.

Sun is so big that the lab feels like a village.

And I just wish I could have been there to see people's faces

as a lorry drive passed with anti-matter in transport written on the side.

And here, I've got a clip from one of the scientists involved in the project.

So, this is Stefan Ulmer, he's a physicist at Henrik Hein University in Germany.

Okay, we are super happy that we managed for the first time to transport

anti-matter out of this facility in particular anti-protons,

because this opens in principle an entire new universe for precision measurements outside of Sun.

Just remind us, so what is anti-matter, what is anti-protons?

So, all matter has an anti-matter counterpart, which is basically kind of theoretically identical,

but has an opposite charge and opposite magnetic properties.

So, the anti-matter counterpart to an electron is a positron.

And fascinatingly, when anti-matter and matter collide,

they annihilate each other and release a lot of energy,

which makes this trip in the back of a lorry even more impressive,

because you can't have these anti-matter particles colliding with matter.

Well, I think it's time to go to a particle physicist.

We have Dr. Harry Cliff from the University of Cambridge here.

Harry, I guess my first question is, why have you got anti-matter at Sun?

How have you been making it?

So, I mean, there's an amazing place at Sun called the anti-matter factory,

which is this big building.

It looks a bit like a factory at the outside, where they make this stuff and store it and do experiments on it.

And the way it's made is there's a particle accelerator that accelerates ordinary protons,

smacks them into a target, and then equals empty squared.

You get matter and anti-matter created, and you kind of funnel off the anti-protons,

and then you have to actually decelerate them,

so you put them through a decelerator that slows them down,

and eventually you bring them into some kind of storage vessel.

So, as you sort of said in your introduction,

if anti-matter touches matter, it annihilates and turns into radiation.

So, the big challenge is how do you store this stuff in a way that prevents it from touching the containers

of the vessel you're keeping it in?

And that's the big challenge.

And of course, it's even more challenging to then take it out of the laboratory

and move it around on the back of a lorry.

OK, so how do you do that?

So, you have got something where there's this major flaw that you can't touch it,

but you need to hold it.

So, how do you hold it?

So, the way it's done is using this thing called a penning trap,

which is a sort of electromagnetic bottle, if you like.

So, you bring the anti-protons into this vessel,

and there are a series of electrodes and magnetic fields,

and you use that to manipulate the anti-protons.

So, these anti-protons have electric charge, they're negative,

and you can use their electric charge to manipulate them.

So, by basically applying well-designed electric and magnetic fields,

you can kind of bounce them around inside this vessel,

inside a kind of electromagnetic container,

if you like, that keeps them away from the physical walls of that vessel.

And so, that's been done routinely for a long time now at CERN,

but what had never been done before was taking one of these traps on the road

and actually, stably controlling the anti-protons as you move around.

So, I'm really pleased for you that you've taken your anti-protons for a walk.

Why do you want to?

I mean, the reason that this stuff is interesting is it really tests a really deep,

fundamental principle of the universe, which is the symmetry that relates matter

and anti-matter to each other.

And there is this big mystery, which is that,

according to our current theory of particle physics,

in the very early universe, you should have made equal quantities of matter and anti-matter,

and then they would have annihilated each other.

And we would end up with a universe that contains nothing,

but radiation, just some photon sipping about.

But we live in this incredibly rich universe with lots of stuff in it,

and that is a fundamental mystery that we just do not understand.

And we're trying to understand that in various different ways,

but one of the ways you can understand that is by trapping anti-matter

stably and then performing precision measurements on this stuff.

And what they're doing at the basic experiment is measuring the properties of anti-proton.

So, measuring in particular something called its magnetic moment,

which is basically how magnetic are these little particles,

and comparing it to the ordinary proton.

But the problem they have at the anti-matter factory is they're

these stray magnetic fields caused by the decelerator that they use to

slow these anti-protons down.

So, they can't do the level of precision that they want to do on sites.

They have to then trap these anti-protons and take them elsewhere

to do really, really high precision measurements.

That's the basic idea.

And what happens if I'm going down the auto-barn or something,

and I see one of your, one of these sort of suns,

anti-proton delivery vans coming past?

What happens if it crashes?

Because these turn into pure energy if they touch matters.

Is there a chance you'll be moving an anti-matter bomb?

No. So, I mean, if anyone's seen the film Angels and Demons,

this is a key plot point where some nefarious people steal anti-matter from

Sun, but the number of anti-protons that we're talking about is tiny.

So, 92 anti-protons, the amount of energy that that releases when it

annihilates is you wouldn't even notice it.

The collision of the truck would be much more serious than the

release of gamma rays from the anti-proton.

So, no, I mean, to have an any kind of measurable impact,

you'd have to be storing orders of magnitude like trillions and trillions

of orders of magnitude more of this stuff.

So, it's completely safe from the point of view of, you know,

you're not going to get some massive explosion.

The lorry has far more energy in it than the anti-protons.

This is more broadly, this is happening just before Sun

is going to be shut down for I think almost two years.

What can we expect to see once it reboots there,

and people like you at LHCB get back to work?

Yeah, I mean, it's an exciting time.

So, we're about to enter what's called long shut down three,

where there's going to be a really major upgrade to the large

hadron collider.

So, this is to take it to its next version called the

high luminosity large hadron collider, which will

increase the rate that we collide protons by a factor of 10.

So, that means in the future we'll be collecting data at a much,

much faster rate than we have before.

And that will allow us all the experiments at the LHC

to measure processes much more precisely to search for

rarer, more elusive particles like dark matter

that we haven't seen before.

For LHCB, we're actually already in a very exciting phase.

We've just had a big upgrade to our experiment.

We've got this huge data set, which is, you know, a brilliant resource

to study the differences between

matter and antimatter to search for new particles

that we haven't seen before.

So, it's really a kind of an exciting moment.

And, you know, what we really hope is that we'll be able to carry on this journey

into the future.

There has been some funding cuts proposed to

high energy physics in the UK.

So, it's looking a little bit uncertain at the moment,

but this is really important science.

And we, there's amazing discoveries that lie ahead.

As a science journalist, I occasionally wake up in a cold sweat

and think that the entirety of sun has been some sort of hoax

perpetuated on the public to make us believe mad things.

And the latest mad thing is you've got a box

full of a tiny number of particles that's basically empty

and you're moving it and you're seeing if people like me will

will be credulous enough to believe it.

How do we actually know you've got anything in your box?

Well, I mean, you can come and have a look if you like.

I think there are real time detectors that monitor

the number of anti-protons in the box and you get a reading out.

Okay, yeah, it's true.

You can't look in the box and see them with your own eyes.

It's only 92 of them.

But, you know, we have instruments that tell us these things are there.

You know, but you can come and look at the output of the of the detector

and hopefully that will convince you.

Though, I guess that we're getting into philosophy now.

You know, what is real?

What can you really see?

You know, what can you trust?

But I can promise you to my best of my knowledge,

there is not a big hoax being performed on the rest of the world

by the people at Sun.

Thank you very much.

That's Dr. Harry Cliff and Good Luck

with your philosophical empty box.

Caroline, you stated on anti-matter?

I am.

I'm just, I'm sad Sun's shutting for a couple of years.

Means we're going to see fewer particle physics stories, I guess.

I also want to know what the Sun physicists get up to for two years.

I think they spend a lot of time looking through data.

A lot of data processing.

Well, maybe if it is a hoax, they just go skiing

and it was all about skiing all along.

Moving on.

You're listening to Inside Science from the BBC World Service.

Tell us what science you think we should be investigating.

Our email address is inside science at bbc.co.uk.

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Now over to Roland Peas to see what's caught his attention this week.

My attention's been caught by satellite observations

that captured pretty much the birth of a major tsunami in the open ocean.

It reminds me that not long ago,

we'd know nothing of these earthquake triggered surges

until they ran up onto distant coastlines

inundating communities and landscapes.

Countless mobile phone videos of the 2004 Indonesian event

transformed scientists' understanding of the effects of a tsunami

though only a little of how they originate.

That changed with this earthquake off Kamchatka

on Russia's Pacific Coast last year,

only a little weaker than the 2004 event,

which sent 15-meter waves onto the nearby shoreline

and smaller ones across the Pacific Basin.

An ocean sensing satellite SWOT passing over happened to catch

its early moments as I've been hearing from analysts Ignacio Sepulveda.

70 minutes after the initiation of the earthquake,

one of the altimeter satellites was flying over that area

and I would say that that satellite had the lack of take a picture

of the leading wave of the tsunami

and because it was so early after the earthquake,

the satellite could see not only the typical leading wave of the tsunami

but also the satellite could see some shorter waves

like in behind the big leading wave of the tsunami.

And the importance of those short waves and smaller waves

are that they are bringing critical or key information

of how that tsunami was created in the earthquake region.

These trailing waves, only 30 or 40 centimeters high,

stretched out over tens of kilometers

so you'd hardly notice them if you're on a boat,

may sound insignificant,

but scientifically they're important.

Think of understanding a voice with all the high frequencies

muffled out of earshot.

This is, like for once hearing, the un muffled tsunami waves

pushed up by the deep ocean movement of the seabed

due to a powerful earthquake.

How much movement depends on what parts of the tectonic plates shift.

The thin, flexible edge of the continental crust

close to the ocean trench that rings the Pacific seafloor

or the more sluggish, thick crust closer to shore.

The SWOT images can say.

In this tsunami, most of the sleep actually was not located close to the trench

but you could see that actually you had a little amount of a sleep

getting closer to the trench.

That finding is something that is very difficult to obtain

with other types of sensing technologies.

But are you saying in a sense that the major part of the earthquake

was concentrated in a bit where it was less likely to push the water so much?

Exactly. So basically when you have a deeper earthquake,

what happens is that actually you will deform the seafloor

but that deformation rather than be concentrated in a smaller region is more spread.

So the characteristic of this generated tsunami will be kind of different

compared to an earthquake that happened very close to the seafloor

where the energy will be more concentrated in a smaller area.

Given how deadly tsunamis are and how difficult they are to prepare for,

Ignacio says satellite images like the Kanchatka one he's just analysed

will do a lot to clear up the driving mechanisms.

First of all, for this specific event, now we are understanding better

how is the rupture processes happening near to the trench.

So that is important because typically when we are creating, for example,

evacuation plans or we are trying to prepare coastal communities for tsunamis,

for example, we try to establish some scenarios of tsunamis

and we prepare coastal communities for those hypothetical scenarios.

Typically we need to use some science in order to come up with those hypothetical scenarios.

And this type of measurements that we did now with the satellite allow us to understand

how we are creating tsunamis close to the trench.

And now with this information and hopefully in the future while we start to collect more

satellite images for future tsunamis and an earthquake, we will start to improve and build up

our knowledge of the tsunami genesis close to the trench.

So the importance of this finding and moreover, the importance of this satellite is that actually

is showing us another piece of information of the puzzle to try to understand

earthquakes and tsunamis.

Which can't be a bad thing. Ignacio Sapulveda is a tsunami expert at San Diego State University

and his analysis was just published in science.

Thanks, Roland. Caroline, have you got any news for us?

Yes, so I want to talk about beavers. What are your feelings about beavers?

They're massively pro-beavers.

So we wiped them out in Britain about 400 years ago after hunting them to extinction for their

meat and their fur because, you know, be the hat, so sort of furry top hats were really popular.

And their testicles, I think.

Oh, I didn't know about the testicles.

They were something involving beaver testicles.

Yeah, poor beings.

Or say grams maybe, yeah.

Oh, yes, they release something from their bone basically that we use in perfume,

which is bizarre or used in perfume.

Hopefully we don't anymore.

Anyway, we're now trying to reintroduce them as of February last year in the UK.

So they're being legally released also illegally released by activists who sort of want

this process to happen faster.

In fact, apparently there's two behind an astacarpark in Fruim in Somerset.

And the reason why we want to reintroduce them is because we think they're good for our climate.

So by building dams, beavers flood streams and turn them into wetlands and wetlands can be

great carbon sinks, meaning they store carbon dioxide.

Now, the news bit is, so for the first time we can now quantify quite how good for the

environment beaver wetlands are.

So there's been a new paper in nature communications, earth and environment,

where researchers at the University of Birmingham have studied a beaver engineered

wetland in Switzerland, which has been there for 13 years, and they've measured both the

carbon dioxide stored and released.

So in terms of capturing carbon dioxide, you have photosynthesis.

You have carbon being stored in water, sediments, deadwood that sort of builds up in the wetland,

and you also have carbon dioxide being released into the atmosphere by microbes,

which break down things like the deadwood.

And basically, the scientists have found that over this 13 years,

the carbon storage has dominated.

In fact, the wetland has stored over a thousand tons of carbon,

which is ten times more than similar areas without beavers.

So big thank you to beavers, basically.

I went to see some beavers on confusingly the river otter,

and I remember asking them, except had the guerrilla releases of beavers,

and I said, do you know who's doing that?

And I was like, no, no, haven't got a clue.

No idea who they are.

But I remember one of Boris Johnson's more memorable phases,

because this is a cross-party issue is we should build back beaver.

So build back beaver.

I think we absolutely should, and please there's more good news about beaver.

Can you tell me about your next story?

So yes, this is a bit of a gear change.

So it's according to a recent preprint, so it's not peer reviewed yet,

but hopefully an entire pig brain has been preserved

with its cellular activity locked in place with minimal damage.

And basically, some people and scientists are saying,

you know, could this be done with humans in the future,

where basically rather than kind of freezing and then defrosting our brains in the future,

instead we preserve the exact cellular structure

and then remake our brains.

So this is for the mad cryogenic people who want to be immortal?

It's for people who want to be immortal,

but it's slightly different in that you're not being frozen

and then brought back to life.

Instead, your exact circuitry is being frozen,

and then you're hoping to replicate that in the future,

either in a computer or in a different brain or something.

So the kind of the future of it is all very, very, very uncertain,

but kind of the science behind it is pretty interesting.

So the kind of the problem that this research is looking to solve

is that when we die within minutes of our blood stopping to flow,

enzymes start breaking down our neurons and our cells start digesting ourselves.

So that's a huge limitation for cryonics, right?

Unless you're sort of instantly frozen,

this process is going to have started taking place.

And so what these scientists did with a pig brain

is straight after the pig died,

they flushed out blood, introduced chemicals,

which essentially locked the cellular activity in place,

and then they studied how well it worked,

and basically found if they did 18 minutes after death,

the cellular damage was too much, it didn't work.

But at 14 minutes after death,

they could get a sort of near-perfect pig brain.

So they have preserved the essence of what it is to be that pig, hopefully?

I think it's worth saying that, you know,

this hasn't been replicated in multiple pig brains.

It hasn't happened in a human brain.

And even if we were able to preserve the kind of exact cellular state

of a human brain, we are miles off the kind of hopeful future

of being able to replicate brain.

So scientists have managed to sort of replicate

a very small part of a mouse brain that took seven years.

And then even if we did manage it,

if you replicate a brain,

are you really living on?

What is consciousness?

What is consciousness?

Oh dear.

Look, I think that is a marvelously,

creepily positive thing to end the show on.

All that remains is for me to say

from UC Inside Science, let's build back Beaver and Caroline.

Thanks so much for having me on and build back Beaver.

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