Hello
I’m Dr. Christyl Johnson
the Deputy Center Director for Technology and Research Investments
Investments at NASA’s Goddard Space Flight Center.
In this role
I’m responsible for shaping our missions of the future
in Astrophysics,
Earth Science, Heliophysics, and Planetary Science
and then establishing
a portfolio of technology
investments to enable
the missions of the future.
I love this role because every
day for me is what I like to call
“visioneering”.
Establishing a vision of the future
and then working backwards to figure out
which barriers need to be removed
and what gaps need to be filled
in order to achieve that vision.
Over the past couple of decades
the global space community has had a vision
of sending humans to Mars
not just for a quick visit
but to have a sustainable presence there.
So if you’ll just humor
me for a moment and
envision with me that we have travelled
a few decades into the future
when we’ll have the ability to not only survive
but thrive living on another planet.
Envision living on Mars
after the first humans arrive
and set up an infrastructure that will support communities
and even cities
with significant populations.
Working backwards from that vision
there would be so many challenges
that would have to be overcome
to even have a chance of
making that vision a reality.
For example, creating streamlined
long-duration
radiation exposure space suits
and above ground habitat
materials that could shield the humans
from extremely high levels
harmful space radiation
that will also handle extreme temperature swings.
Once we leave
the protection provided by the Earth’s
magnetic fields
it’s atmosphere and its radiation belts
we are exposed to the Sun’s full radiation
spectrum and all of its
damaging effects.
Mars has no global magnetic field
to deflect energetic particles
and its atmosphere is much thinner than
Earth’s, so we will get only minimal
protection even on the surface of Mars.
This protection
is so important because
occasionally, giant explosions
called solar flares
occur on the surface of the Sun
and release massive amounts of energy out
into space in the form of x-rays,
gamma rays, and streams of protons
and electrons.
This is called a solar particle event.
These solar flares can have serious
and even deadly
consequences for humans
and their equipment
on the surface of Mars and even
traveling to and from Mars.
In order to thrive on any
other planetary body
we will have to move beyond watching
the sun and giving people
short notice to take cover.
We will have to work hard to better understand
the mechanisms that causes
these solar eruptions so that we can
accurately predict them because
you certainly can’t predict something that
you don't understand. So the global
heliophysics community
is already analyzing data from past
and current missions and
designing future missions to address this challenge.
But even
after we develop
the new materials for suits
and habitats that have been tested
to survive long periods
of extreme space radiation exposure
and we are finally
able to predict solar eruptions
we will still have
to address the communication challenge
in order for those innovations to be
effective in protecting our citizens
on the surface and during
travel to and from Mars.
Right now
here on Earth we have grown accustomed
to getting information immediately.
And that’s because we have established
an infrastructure with
communications satellites, GPS satelllites,
repeater towers, and more.
And we still experience
dropped coverage, weak signals,
and slow data transfer speeds on occasion.
Now envision
an interplanetary internet
where not only
do we have to communicate and transfer
information from coast
to coast within one country
or from one country
country to another country
but now we will be transferring information
from one planet
to another planet
I believe we will always
have that expectation
that we will be able to get
information almost instantly.
So imagine all of the
inventions that will have to happen
to make that a reality.
Before traveling to Mars
all the way to Mars
let’s envision what will be
necessary to prepare for communications
with humans who have a sustainable
presence on the surface of the Moon.
We will have
to install sort of Lunanet
which will require a constellation of satellites
to be placed around the moon
using multiple possible options
to communicate back to Earth.
One possible scenario
would have them all to communicate
directly back to Earth
when their rotation in orbit is in the
line of sight with the Earth
or maybe they will communicate with each other
and one of them sends a signal
back to Earth.
Or perhaps they all communicate to a relay
whether that is a relay on the surface
of the Moon or an orbiting relay
that processes the information
and sends it back to Earth.
We would also need to go beyond laser
or optical communication
which right now can already
transmit data at rates
10 to 100 times better
then radio systems.
And then, ultimately using long range
quantum communication systems
to achieve capabilities that are arguably
impossible using classical methods.
Once we have
this kind of communication
infrastructure, we will we be able
to see mechanisms that predict a
solar eruption, send it to the LunaNet
to be processed and sent down
to the surface of the Moon
and then be registered on a hand-held
device or heads-up visor
warning the person of the
solar event giving them ample time
to get to the closest safe shelter.
But following that
train of thought a little further
how will the person
know where the closest safe location
is so that they can get there quickly?
Well,
there will have to be a navigation element
to this LunaNet. And when most
people think of navigation
they think of GPS.
But now, I’d like for you
envision that we have gone
beyond GPS.
Right now our GPS system
has about 31 satellites orbiting the Earth
and contact with at least 4
of those satellites is necessary
to determine your exact location.
The logistics of establishing
a complete communications
capability along with GPS
for each planetary body that we
explore would be a nightmare.
So,
what if we considered
at least for the navigation piece
of the system, not even using
satellites. Yes,
I’m saying a GPS system
with no satellites.
What if we
use neutron stars
to help us navigate?
I know, some of you
are thinking,“what is a neutron star
and how in the world
could we use one to navigate?”
Well, neutron stars
are formed in the supernova explosions
that mark the end of life
for some stars.
We know that they are small and extremely dense.
They are the size of a city
yet they contain the mass of 2
2 suns compressed down
to that small star.
A neutron star emits beams of
electromagnetic radiation
out of its magnetic poles.
But we can only see this light when a beam
of emission is pointing directly towards the Earth
kind of like a lighthouse.
That is why it looks to us
like pulses of light
thus the name pulsar.
They are the strongest magnets known
and can spin hundreds of times per second.
Because of their predictable pulsations
pulsars can provide high-precision
timing just like
atomic-clock signals
supplied through the GPS.
So instead of using
GPS satellites for local navigation
on and between planetary bodies
where the signal
gets weaker the further we go
from each planetary body
we could use these pulsars
for interplanetary navigation.
That would eliminate the need to build so many
satellites and insert them into the
proper orbits and the need
to replace those satellites at the end
of their useful life.
Fortunately, pulsars have lifetimes
ranging from hundreds of thousands
of years to millions of years.
And there are
currently over 2000 known pulsars
with the potential of hundreds
of thousands of others
in our galaxy.
So we could use 4 or more
of these pulsars to pinpoint
location and enjoy
very precise galactic travel.
So I've given you just a few
examples of the visioneering needed
for humans to thrive on Mars.
But there are so many other
challenges that will inspire
visioneers around the world to create
the necessary solutions or inventions.
But now coming
back to the present day
There people debating daily
about whether or not we
already have the technology
necessary to go to Mars.
Some say it will be 10, 20,
or even 30 years.
People are also debating whether
or not humans should even venture to Mars
and what our objective
would be in sending them there.
So now
I’ll leave you with one thought.
No matter what objective
we as a global community have
in sending humans to Mars
and no matter how long it takes us
to establish a clear vision
and then achieve it
one of the greatest parts of this journey
will be all of the impossible
feats we as a Nation
and global community will have to
overcome in order to succeed.
We will have to advance some technologies
and invent completely new ones.
And while inventing
technologies for impossible goals
we will inevitably
find that some the technologies
that fail to meet our requirements
turn out to accidentally
provide revolutionary
improvements in our capabilities
right here on planet Earth.
Thank You.