Cosmic radiation — a showstopper for space exploration? | Marco Durante | TEDxRheinMain

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Translator: Nadine Hennig
Reviewer: Denise RQ Radiation. Radiation. We are all scared of radiation,
all of us, really. We’re all exposed to radiation, but nevertheless,
we’re all scared of radiation. Now, if you are scared
of radiation on Earth, be prepared; you would be much more scared
if you go on a spaceflight, to the point that the question
of this talk will be: is this a showstopper? Should we just forget about space
because radiation is too high? Well, how much radiation
do we have in space? And you have seen this already.
This is Curiosity. And Curiosity, the MSL,
the Mars Science Lab, made the first measurement
of radiation in space during the transit to Mars
and on the surface of Mars. Now, we know, we know
how much radiation we have in space. How much is there? How much is there on Earth? On Earth, it is
this little square down here, we measure the radiation in millisievert. It’s a strange unit, but basically all of us
receive one millisievert per year. In one year, we get one millisievert
from everything, from the environment, from the soil, from the food,
from the cosmic rays. And then it really
depends on how you live. If you go to the dentist
many times as I do, you get a lot of X-rays
and then your dose is higher. If you travel a lot,
you even get more doses. If you’re married,
if you sleep with another person. We are all radioactive, so if you sleep,
this person sleeping next to you – for at least eight hours per day,
some of my friends 16 hours per day – (Laughter) gets irradiated by the other person, That’s something people should know
before they get married. (Laughter) You should sign an informed consent. (Applause) Just a warning. But I feel worried about that. You can say OK,
but when you want to go to Mars keep in mind that on Mars
you have 200 millisievert per year. So you [can’t] sleep
with the another person. It’s a big deal because [one day on] Mars
is almost like one year on Earth. So it’s much higher [dose]. And even worse, if you are in deep space, you don’t have the protection
of the Martian atmosphere. You don’t have the protection
of the planet itself. You have 700 millisievert per year. 700 millisievert per year in deep space as compared to one millisievert
per year on Earth is clearly a much higher dose. Is this dangerous? Is this a showstopper? The problem is not only the quantity,
[the fact] that you get more radiation, the problem is the quality,
it’s a different type of radiation. We know radiation on Earth. We know X-rays, gamma rays,
beta rays, we all know that. But radiation in space means heavy ions. Iron, this exotic particle
is very heavy, densely ionizing, we say. This is a beautiful image that you see. What you see here is a human cell. This is a human nucleus.
It’s 10 microns approximately. And these two lines that you see here are two iron ions – that you find in space but not on Earth, except in Darmstadt,
at GSI where we have it – going through the cells
and making damage to the DNA. What do we know about this radiation? We really don’t know much
because we don’t know it on Earth. We only know it in space, or if you are exposed to it at GSI
by accident which never happens. The only thing we know, we really know,
comes from the comics. You know this guy?
This is the Incredible Hulk. (Laughter) The Incredible Hulk was actually
exposed to gamma rays. I think, you remember the story. He was working in a nuclear power plant,
and then he got exposed to gamma rays. Then he becomes very nervous,
and green, and very aggressive. (Laughter) This is radiation on Earth,
a typical effect of radiation on Earth. (Laughter) Now, if you go to space, this is
what is going to happen. (Laughter) These are the Fantastic Four. (Laughter) (Applause) When I was a kid,
this was fascinating to me. [One of them can transform into] stone. She’s my favorite,
she turns invisible at will, which is very convenient. This one turns into fire. When I was young, I really loved it. I always wanted to work on radiation
because I thought I could become invisible but it doesn’t work that way. So don’t try it at home, please.
(Laughter) But it’s not all crazy. Hulk gets nervous, and we know that radiation
has some effects on the brain. So you can actually– it’s not impossible. In this story you get the same dose–
I don’t know if you remember, The Fantastic Four were in space,
and then they get exposed to radiation. They are very different, but this is what we call
“interindividual variability.” In clinical treatment,
in radiotherapy, people know that if you irradiate four patients,
you will get four different responses. I mean not so different (Laughter) but still kind of different. So what do we know apart from that? The other thing we know is
that radiation on Earth [includes] photons,
electrons, small particles. And radiation in space, you see,
are these heavy particles. So what do you expect?
You expect something like that. This is our little astronaut on Earth, and he’s getting energy
– the millisievert is really energy – from these lentils, I believe. You make some damage,
but he is still kind of standing. If he goes to space,
upon receiving the same energy, that’s what is going to happen. You have heavier ions,
and less pieces of lentils, same energy, but the effect
is clearly different. So that is what to we try to understand. We try to understand what
the qualitative difference is. But can we protect
ourselves from radiation? Well, you know, this is… I want
to point out as my previous speaker, that this is not a girl playing with sand. This is a serious scientific experiment. Is a serious scientific experiment where this researcher at GSI
is trying to measure the shielding properties
of the Martian soil. Here, it is for you, this is Martian soil. Not really, it’s a simulation
of the Martian soil, but it really looks like Martian soil. I mean, it’s identical,
it’s pretty much the same. I mean, if you want some,
I can sell it for a reasonable price. We even have soil from the Moon. This is lunar soil, which is gray, and actually, this was also shown
by the previous speaker. You have these nice caves. So you can go to Mars,
you can go into the caves, and you would be protected
with this very thick shield. You can even do…
This is Martian concrete. You can do bricks with Martian soil. It is better to use the caves
then to dig because, you know, if you go to a construction site
here in Germany, you see that when people are digging,
they make a lot of dust. You can imagine on the Moon
where gravity is 1.6 that you really make a lot of dust,
so you don’t want to be digging. But this can be effective
if you are on the planet. What about during the transit
when the dose is even higher? You cannot bring heavy shields because weight is what is
really expensive in a spacecraft. So you don’t want to bring a heavy shield. Shielding is a very nice solution
on Earth when you go to the dentist, again not my dentist, but your dentist. Don’t go to my dentist. He uses
a lot of X-rays and no shielding. Your dentist uses not so much X-rays
and plenty of shielding, but that’s heavy. So you will not solve
the problem using passive shielding. You can think of active shielding. You can think of electrostatic shielding, I mean, some kind of electrostatic spheres
that protect the astronauts. Or even better, you can think
of this thing. This is shielding. This is something
I think all of you know. This is a beautiful aurora borealis. What is this? This is
the shielding of the Earth, the magnetic shield of the Earth. The solar wind with these protons
and heavy ions is approaching Earth, is trying to enter
the Earth’s atmosphere, but the Earth’s magnetic field
is deflecting these particles. They go to the poles,
and then they hit the atmosphere, and you see these beautiful colors. Many people are going there
only to see them. The green color is the oxygen. Sometimes it’s more red, that’s nitrogen. So that’s how Earth is protecting life: using a magnetic field. We could think about
using the same system. It’s not so easy, but it can be done. What do we really do at GSI? We simulate cosmic rays. This is a typical…
it’s our accelerator at GSI. We also have many, many people,
thousands of people working there. We also have lawyers, scientists, but also lawyers,
mostly scientists. And we can simulate particles. We need this huge accelerator
because the cosmic rays are so energetic, they are so fast, so you need
a very large and expensive accelerator to simulate space radiation. But there is a nice part of the story. I told you, these particles
are so effective. You do remember the little astronaut
killed by the cosmic radiation which is bad if you are in space. But if you are a patient,
and if you can take the same particles, and you can shoot them in the tumor, not the whole body but only in the tumor,
then you can cure cancer. Well, this is done,
and not very far away from here. It was done in Darmstadt for many years.
Now it’s done in Heidelberg. This is a picture
of a treatment room in Heidelberg, but they are treating
the patients using heavy ions, using carbon ions in this case. I think, this is really fascinating, the possibility that space research
and medicine help each other. The same radiation,
which is a problem in space, can be a cure for cancer on Earth. At the end, shall we go to Mars or not? Well, I think, I was supposed
to give ideas here. It looks like radiation
is a problem. This is clear. Shielding, passive shielding,
can be a solution on the planet but not really on transit. Maybe the best solution, the best idea
is to use magnetic shielding, is to build magnetic fields
for the spacecraft that can do what is done on Earth. it’s not really a new idea. The same idea that God had
a few billions years ago. He said: “OK, I want to make life,
but I created radiation already. What can I do now?” (Laughter) “Maybe I can make a magnetic field.” It is very effective in protecting the Earth and our life
from space radiation. Thank you very much. (Applause)

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