Human Expedition to Mars


PRESENTER: Good
afternoon, everyone. Hello, and welcome to MIT’s
2016 Open House Distinguished Lecture series. My name is [INAUDIBLE], and I’m
a junior in course 2 and 18. And for the non-MIT
in the crowd, that’s mechanical engineering
and math respectively. It’s my pleasure to introduce
our next speaker, professor Maria Zuber. Dr. Zuber is the
Griswold Professor of Geophysics and Vice
President for Research at MIT, where she has the responsibility
for research administration and policy at the institute. She oversees MIT’s
Lincoln Laboratory and over 60 laboratories and
research centers on campus. Dr. Zuber’s research
bridges planetary geophysics and the technology
of space-based laser and radio systems. Dr. Zuber is the first woman
to lead a science department at MIT and the first to lead
a NASA planetary mission. In 2002, to Discover Magazine
nagged her one of the 50 most important women in science. And in 2008, she was named the
US News Harvard Kennedy School list of America’s best leaders. In 2013, President
Obama appointed her to the National Science Board. Please join me in welcoming
Professor Maria Zuber. [APPLAUSE] MARIA ZUBER: OK. Thank you, [INAUDIBLE]. Hey. Thanks, everybody, for coming. It’s Mars. Yeah. All right. How many of you people are
scientists or engineers? OK. All right, cool. We got something for you. How many people who
have ever looked up at Mars in the sky at night? OK. How many of you have
seen The Martian? OK. We’ll talk about that. So what I’m going
to do today is going to talk a little bit
about what it would take to do a human mission to Mars. So there are really no
serious impediments other than psychological impediments. The science– we
know lots of science. The technology– technological
problems can always be solved. It’s a money and political will
issue and a question of– it would be expensive,
and you’ll see why. So let’s just start
and think about why we would want to do this. I love Ray Bradbury. The Martian Chronicles
I grew up reading. So we’re all children
of this universe– not just Earth or
Mars or this system, but the whole grand fireworks. And if we’re interested
in Mars at all, it’s only because we
wonder about our past and worry terribly about
our possible future. So what does that mean? So why do we explore
in the first place? Well, the grand challenge of
doing something difficult, national pride. If and when we send a
human mission to Mars, it won’t be a United
States mission to mars. It will be an international
mission to Mars. It will take all
the smart people that we can find to help us
do this and participate in it. Competitiveness– the things
that we teach our students to do– the students
who work for me, they don’t all grow up and go
into the aerospace industry. They go someplace. But the skills they
have, any employer would want to have somebody
who has those skills. And so getting a young
person really jazzed up about doing something
really difficult that’s fun is really a great motivator. So contributing to the
technology workforce and infrastructure,
having the ability– having factories that can
do really precise machining and building really
complicated electronics does a whole lot more than
just help the space industry. Let’s see. Learning to live and work
in a low G environment. The last people that
we sent off of Earth that were in a non-Earth
gravity field but not weightless was when we sent humans to
the moon, which was 1/6 G. And so we don’t have
the right space suits. We don’t have the right
kind of– any kind of the right hardware. Well, we’d like to
discover things. I’m a scientist, so
discovery, that’s my thing. And the worry about
our future part, the preservation of our
species– so there are some– and I’m an optimistic person. I’m not a fatalistic person. But some, like Elon
Musk, feel like we must go to Mars, because
in case we’re stupid and we blow our
whole planet up, we have to have the species
in another place. So that’s not my
personal point of view, but some would say that. So Earth and Mars– so here
are pictures of Earth and Mars to scale. So Mars is about half
the size of the Earth. And here’s a good piece
of cocktail party trivia. Mars is about the same
size as the Earth’s core. That is coincidental. Distance from the sun–
well, we call the distance from the Earth to the sun, the
average distance from the Earth to the sun, an
astronomical unit. So Earth is, by
definition, 1, and Mars is, on average, 1 and 1/2
times as far from the sun as the Earth is. So is has a correspondingly
smaller flux of sunlight. The surface gravity
is about 40% of Earth. It’s 3.7 meters
per second squared. Here’s another coincidence–
so the Earth’s day is 24 hours, and Mars’s is 24
hours and 37 minutes. Now, 24 hours and 37 minutes
sounds a lot like 24 hours unless you’ve got a lander
on the surface of Mars, in which case you have
to live on Mars time. And then a few weeks
of living on Mars time is worse than the worst jet
lag you would ever have. So Earth has a nitrogen
oxygen atmosphere. Mars has a carbon
dioxide atmosphere. And Mars has a lower
surface pressure. So we are going to
talk more in detail about the atmosphere of Mars. So the Martian atmosphere
is 95% carbon dioxide, and the average surface
pressure is 520 Pascals, or 1/200 of the Earth. And so the pressure
at the surface of Mars is equivalent to the pressure
of the Earth’s atmosphere at the altitudes that spy
planes fly, at 100,000 feet. And so the Martian
atmosphere, it is very thin, and it is very tenuous, and it
doesn’t hold heat very well. So here’s a good, fun fact. The surface pressure
varies by up to 1/3 over the course
of a year, so 33%. On Earth, the biggest
atmospheric pressure change that we get– if
you were in the center of a strong tornado, it
would be about a 10% pressure difference. So on Mars, the
atmospheric pressure varies by 1/3 over the
course of the year. And it’s from CO2
in the atmosphere exchanging between one
polar cap and the other. The polar caps on Mars, at least
at the top, are made of CO2. Underneath the frozen
CO2, there’s water. Water vapor– so there’s a
lot of water underneath Mars. And we’re going to talk
about water, because that’s a totally important thing
regarding sending humans to Mars. But water vapor is
a trace constituent of the Martian atmosphere. And so if you took a column
of the Martian atmosphere, and you took all the
water in that column, and you squished it down, it
would be 10 microns thick, where a micron is a
millionth of a meter and a meter is 39
and some inches– so tiny, tiny, tiny amount of
water in the atmosphere. The average temperature is
minus 63 degrees Fahrenheit. Actually, in the summer,
at low latitudes, the temperature can get
up to about 70 degrees, which sounds downright balmy. But the atmosphere doesn’t
hold heat very well, because it’s so thin. So if you could live on Mars
without a space suit, which you can’t, and it was
the summer and you were in the low latitudes,
your feet would be 70 degrees, but your head would freeze. And so if you could
have a pitcher of water on Mars in the liquid form–
which you can’t, but if you could– and you poured
it out of a thermos, it would freeze before
it hit the ground. So it’s a great place, but it’s
not the most hospitable place. Lots and lots of
dust– so dust is a huge, huge, huge
consideration for Mars, because dust gets
into everything. And when you’ve got
a machine, think about anything– that’s it got
to turn wheels, doors– you’ve got to take into account dust. And obviously, liquid water
is not stable at the surface. But I’m saying
pure liquid water. We’re going to come back to
the liquid water on the surface part, because it does appear
that very salty brines are metastable on the surface. So here’s a picture
of the same place on Mars at two
different times, taken from one of the cameras on
Mars Exploration rovers. And you can see the difference
of how the atmosphere changes. So the atmosphere is
very, very, variable. Mars is also far away. So this is a picture of
the Earth-Moon system. And this picture was taken
from a camera in Mars orbit. So I actually have this picture
in the wall of my office. And every time a
student comes in and they say, oh, I want
to go to Mars someday, I point to this
picture and I say, everything you know and love is
really really, really far away, and you would have
to leave all that. Do you want to do that? And they all say,
of course, yes. Sign me up. So this picture was taken
from the Mars Global Surveyor spacecraft. Here is a picture of Earth
from the surface of Mars. So you see? So there it is. And think about it. Isn’t it cool that we can figure
out where Earth is in the sky and then tell a
camera on a rover to point to the right place
and set the exposure so we get the right amount of
light in it to get that? So now let’s talk
about going to Mars. Actually, this is a nice picture
of the launch of the Pathfinder Rover from the 1990s. So going to Mars
is not that easy. In fact, most Mars missions
to date have failed. So here, everything
in red failed and everything white succeeded. And this was my call, and I
set the bar really low for what determines success. And in fact, in our–
there is some lore, in fact, that there’s a
great galactic ghoul that eats spacecraft when
they get close to Mars. But this is just a theory. We have never seen this. So that’s just an
artist’s conception. So about 40% of Mars
missions have failed to date. The orbiters have been more
successful to the landers. And that’s the bad news. But the good news is
that we’re doing better than both Ty Cobb’s
lifetime batting average– and he was considered
successful– or Ted Williams when he had
his magnificent season in 1941. And of late, we’ve had more
successes than failures. But things can just
go terribly wrong. It really is
difficult. And we’ve got a couple more en route,
so this is an evolving story. So if you want to go to
Mars, you need a rocket. And so here’s a rocket. This is the space launch system. Block 2, which is proposed
to be able to take humans to Mars– it’s a
heavy lift launch vehicle. This would be the third
generation of this launch vehicle, but not even the
first generation of this launch vehicle exists yet. And so the SLS Block 1
is under development. It’s a $7 billion
development effort. And the Block 2 would be
considerably more complicated. And I have no idea whether
this will come in on budget. Things in the
human space program tend to be less
close to coming in on budget than on the
robotics side of things. We need a crew vehicle. So this is the only
piece of hardware that actually exists that’s
in the least bit relevant. Although this is not
what we would send, but this is a new
crew vehicle that would be rated for taking
astronauts out of Earth orbit. And it’s not that big. If you compare this to
the Hermes in The Martian, this is– well,
it would be cozy. Let’s put it that way. We’d need something
bigger than this. We would need a surface
ascent and decent module– so I just took the
one from The Martian since we don’t have one– as
well as a space transportation system. So take a look at
that, because I’ll show you one of the
plans for one of them that NASA has under development. So you can launch to Mars
once every 26 months. OK That’s the launch window. So you’ve got several
weeks where you can launch. And so if you’re going to
send people there and then bring them back,
there are two classes of trajectories that you can
explore– so either short stay or a long stay. So in a short stay–
so this is the orbit of Venus, Earth, and Mars. So in the short stay,
you launch from Earth. So you head over to Mars. You arrive at Mars. And it takes about six months
to do this transit here. And so you can stay one to
two months on the surface. And then to come
back– well, Earth is not in the right place. So Earth is not here
when you’re here. And so what has to happen is
you come in and you go to Venus and get a gravity
assist from Venus, and then you come around
and come back to Earth. So if you do this,
it minimizes the time you’re away from Earth. You’re spending a lot of
time away from Earth and not too much time on Mars. Or you could do a long
stay and say, well, if we’re going to go, we want to
spend most of the time on Mars. And so you can
launch from Earth. You get to Mars, and
then you stay– so it takes about the same time. You stay on Mars,
then, for about a year and a half, about 550 days. And then you can take a
straight shot back to Earth, and now Earth is
in the right place, because Earth has gone
around the sun again. And so the full mission duration
here is about 2 and 1/2 years. So it’s a long time,
long time to go. And it actually doesn’t matter
too much what your thrust is– a little more thrust, a little
less thrust– here we are victims of celestial mechanics. Earth and Mars have to be in the
right place for this to happen. So radiation– so
one of the things that’s The Martian, the book and
movie, just glossed right over is radiation. They just said, oh,
we shielded for it. We corrected for it. But radiation is
actually a huge deal. So we have made some
measurements of radiation from Mars orbit. And so there’s an
instrument called MARIE, which measured
galactic cosmic rays and solar energetic particles. And so here’s a dose
over particular orbit. So all this stuff
down here, this is the galactic cosmic rays. And then you get these solar
energetic proton events. So you get these big spikes. And then just based on
the cosmic rays, which are kind of quasi-uniform,
and not taking into account these stochastic peaks here, you
can just take the cosmic rays and then say, all
right, on average on a year, what’s your dose
on the surface of Mars. And so high doses
are here in red, and low doses are here in blue. And so this is accumulated
radiation over a year. And this actually looks a
lot like the Mars topography map, where red is
high and blue is low. And the reason that the
doses are much lower here is that these are the
lowest elevation areas. So there’s more
atmosphere shielding the cosmic rays and the solar
and energetic proton events from that. But we have better
information now, because the Curiosity Rover,
which is at Mars right now, has collected radiation
measurements from Gale Crater. So again, we have the cosmic
rays, the galactic cosmic rays and the energetic particles. And so radiation– you say,
OK, well, Mars is farther away. It’s 1 and 1/2 times as far
from the sun as the Earth is. And the galactic cosmic rays
are the same everywhere. And so why aren’t the solar and
energetic proton events worse? And there’s really two reasons. Mars doesn’t have
a magnetic field, and the magnetic field
shields these particles from coming to Earth. And Mars also has
a thin atmosphere. So thanks to these
collective measurements, we do, however, know
that radiation is not a show stopper for doing
a human mission to Mars. So the best estimates
that we have for a long-duration mission
would bring humans back to Earth and have an
accumulated dose that’s the maximum allowable dose
that you could really have, and it would correspond
to increasing your cancer risk by about 5%. So if you worked in any industry
that dealt with radiation, that would be the maximum
lifetime accumulated dose that would be allowed
for you to have exposure. But that’s good news. And you can always
shield against radiation, but shielding is really,
really, really, heavy. So that’s a problem. Power– so if you’re
on the surface of Mars, you don’t have as much sunlight
as you have on the Earth. And so you need to have power. And there have been
all kinds of studies done to estimate how much power
one would need a day or night usage. At night, you have to stay warm. In the day, the sun is useful,
having us require less power. So there’s a couple of
ways you can do that. This is a model of
a possible mobile– if you go to Mars, first of
all, it’s going to be nuclear. You’ve got to use
a nuclear reactor. There’s no way to get enough
power just using solar. It can’t be done. Game over. So here’s, actually,
a design by NASA that actually looks a lot
like what Mark Watney used in The Martian. This is the nuclear generator
here in the backseat, and here are the solar
panels that put out a charge during the day. So this is an actual
design by NASA. But what’s more likely
to happen is that you would take a small generator. You would bury it, and then
you would surround it by water to absorb the neutrons
and reduce the radiation. The weight of water that would
be required to shield this is as much as the weight
of the reactor itself. So the weight of
this reactor that one would have to take to
have enough power to use is 3,300 kilograms. So it’s heavy, heavy, heavy. And that’s a problem. So there have been
calculations that have been done that have
showed the amount of mass that one could take for
different kind of scenarios. So here’s a short stay. Here are some longer
stay scenarios. And so here’s the landed
mass and various other parts of the system. And so you’re up here at
100,000 kilograms or so. And just to put that in some
kind of a context, it costs, I would say, about
$20,000 per kilogram to get something off of
the surface of the Earth. So you don’t want to
take anything with you that you might have
there, because it’s so expensive to send it. So one of things
that is explored is something called in
situ resource utilization. And one of the things
that you would do there is make your own rocket
fuel when you’re on Mars. And so there’s actually a
test that’s going to go. The Mars 2020 Rover has
an MIT experiment on it, an experiment
that’s called MOXIE. And what MOXIE is going to
do is take carbon dioxide from the air, which is CO2,
and separate into CO plus O, and make liquid oxygen
as a rocket fuel, and demonstrate that
so that you wouldn’t have to take rocket
fuel with you to get off the surface of Mars. That’ll be the
first demonstration of the in situ resources. Rocks– well, you
must land safely. And so I would say in planetary
science now, landing on Mars is the hardest thing that we do. And the reason that it’s hard
is that the atmospheric pressure varies a lot. The atmosphere is turbulent. The earth’s atmosphere–
if you’ve flown in a plane, you know that the
atmosphere is turbulent. The atmosphere of Mars,
even though it’s thin, is also turbulent. And you have rocks all over
the place on the surface. And so actually, in
experiments where we’ve sent landers
and put airbags, there’s actually a wind limit
of 20 meters per second. You shouldn’t land
on Mars with airbags if the wind is more
than 20 meters a second. Because if they come down
and hit the rocks vertically and the wind is blowing, it’s
going to shift it this way, and any kind of material is
not as strong and shear as it is just in a normal force. And actually, for the
Mars Exploration rovers, the first one landed,
and then the second one landed several weeks later. And in the meantime, a
dust storm kicked up. And the dust storm
heats the atmosphere and causes the winds to blow. And so I was one of
the reviewers looking at the landing, and we
spent about two days trying to decide whether or not
to open the parachutes two seconds earlier to
compensate for the warmer atmosphere. And of course, if
you open them earlier to slow it down more as it’s
coming in– if you open it up earlier, it’s going faster,
and so it’s a greater stress on the cables of the parachute. And so there was worry that
the parachute would break. But I think the
surface wind velocity was 18 meters per second
when it finally landed. So it’s very challenging. Dust storms– they
are pervasive on Mars. Here’s a dust storm
that’s blowing off the north polar cap. Here are Lidar returns
from the atmosphere showing the distribution of dust. The way that dust gets lofted
into the Martian atmosphere– this dust is a micron in
size, so it’s very, very fine, and so it doesn’t take much
wind at all to loft it. So here’s a dust
storm in the surface. Here’s a Lidar map
of a dust storm. And these are dust storm tracks
at one of the Mars Exploration Rover landing sites. So it’s not like, oh, every
once in awhile, you have a dust tornado or a dust devil coming. So now I’m going to show
you– if this works, which I hope it does– this is a movie
of dust devils at the Curiosity landing site. So there they come. So this is what it’s
like all the time. So you need to worry about that. it So the global dust storms
on Mars happen every Mars year. And one Mars year is
about two Earth years. And so the global dust
storms– they usually start in the southern hemisphere
during the southern hemisphere summer. And the reason for that
is because Mars’ orbit is more elliptical than
Earth’s orbit is, and Mars is closest to the sun
in southern hemisphere summer. So you have the
greatest warming there. So here, blue is clear
and red is dusty. And this is a bunch of
thermal images that were taken starting in June, in mid-June. And you can see here by
the beginning of July, there’s a dust storm that
is growing and growing. And when they take off, they
go global in about a week. And what happens is– so
these dust storms start. You kick up dust
into the atmosphere, and then the dust
heats the atmosphere, and it makes it warmer. And so this area is warmer. This area is colder. So you have a pressure
gradient, and it makes it windy. And the extra wind
kicks up more dust from the surface,
which makes it dustier and changes the pressure
gradient even more. And so it’s a positive
feedback effect. So this is the difference
between a clear atmosphere than in a dusty atmosphere for
that particular dust storm. And so it’s true– dust
storms are a big deal on Mars. And at the beginning
of The Martian, you saw that they left because
there was this big dust storm that came in. First of all, it wouldn’t
come in quite that fast. And it couldn’t, because the
Martian atmosphere is so thin. Even if it was really
windy, it couldn’t blow over a spacecraft. So that was– Andy Weir took
some liberties with that. But this tau is a property
called optical depth, and this shows you– so was
is taken from the Opportunity Rover. So these are pictures of
the surface showing you an optical depth of 1
basically means you can’t see. And so Mars commonly has very
high optical depths where you just can’t see anything. And then the atmosphere
is thin, but the dust is so thin– it’s
a micron– that it takes months for the dust to
settle out of the atmosphere. And anybody going
to Mars is going to have to deal with this. Because you’re going to land. You’re going to want to
be there in the summer when this happens
at low latitudes. So here are some Apollo images. Just look at how the dust
gets into everything. Here’s one of the Mars rovers. You can see the dust all
over the solar panels so that the solar
panels lose efficiency. Here, astronaut– filthy. Poor Jack Schmidt. Look at how dirty they are. So it’s a dirty business. Locomotion– I’m not going
to go into it to detail describing this slide. This is the square
root of a Froude number out there for anybody who is
a scientist or an engineer. And so all that I
want to say about this is that human locomotion
is optimized for 1 G. So if you are at anything other
than 1 G, you are non-optimal, and you are expending
more energy. There’s just no easy way
to get around looking at this from energetics. So for the moon, the
mood had such low gravity that the space suits actually
supported themselves. But that’s not
the case for Mars. The space suit– it would be
difficult for a human being to have mobility
with that space suit. And on Mars,
though, actually, it looks like– this is
actually some research that was done under the
supervision of Dave Newman from MIT, who’s now the NASA
Deputy Administrator, who showed that it might actually
be more efficient on Mars to run than to walk. But you would need
to design a suit that had enough mobility to do it. So we need a new space suit. And this is just more
Apollo data showing you that this stuff gets studied in
great detail that just showed that you spend a lot more
energy on a walking traverse than if you have a rover. So you really want to
take a vehicle with you, because it’s going
to be very difficult for the astronauts get around. And let me tell
you– in geology, you don’t want to go on
the flat, smooth places. You want to go on the
rugged hills, like this. And so a lot of effort is
underway looking at how human mobility– how they
would climb and get around and go to all the
very interesting areas. And these are not all areas
that you can take rovers to. So a great deal of effort
goes into the mobility of how humans would actually
work on the surface of Mars and what the interplay
of humans and robots would be on the surface of Mars. So Julie Shaw from our AeroAstro
department works on that. Water– so if you send humans
to Mars, you need water. And we know– we know pretty
much exactly how much water Mars has on the surface. And this is another good
cocktail party trivia– 85% of the Greenland ice cap
is the amount of water that is on the surface of Mars. But it’s frozen. And I said that liquid
water wasn’t stable on Mars, but it looks like salt-rich
water actually does flow on the surface of Mars. And these are some
images that were taken from the Mars
Reconnaissance Orbiter spacecraft. And what I want to call your
attention to is these flows. Sometimes they’re there,
and sometimes they’re not. You only see them on
equator-facing slopes when the temperature
goes above freezing. So small amounts of
water are liberated from very shallow depths beneath
the surface and flow out there. And so they’re accessible, but
they would need to be purified. But it’s a lot easier to take
a water purifier and get water than it is to take
water with you. So I’m going to show
you the same image here. So this is now re-projected. So if you were flying along
that cliff in a helicopter, this is what it would look like. And you can see here
these flows of water. So this is metastable
liquid water on Mars. But at shallow depths
beneath the surface, there is frozen water,
and there is a lot of it. So this particular–
this is a view of the North Polar
region of Mars taken by a neutron spectrometer. And the blue means no neutrons,
and no neutrons means water. And the way this works is
galactic cosmic rays come in, and they knock neutrons–
water captures the neutrons. It makes heavy water,
and then neutrons don’t come off the surface. So whenever you’re
missing neutrons, you know you have water. And this instrument can sample
down to about a meter depth. So there are places in
the high latitudes of Mars where there is vast,
abundant frozen water within a meter of the surface. So you really don’t
need to take water. And we know where it’s at. We know where it’s at. But we wouldn’t
necessarily want to land at the poles because of energy
considerations and lighting considerations. And so at low latitudes,
they’ve been mapped in detail. And so here’s a
particularly good area in the vicinity of the
Schiaparelli Crater. And so in this area here, it
contains the highest water content in the region, so more
than 10 weight percent water, which means that that’s so
much water that the water can’t be held up in a mineral matrix. So it could be that that
would be a good place to land. So there is actually, from
a water-accessible water standpoint, exactly
where you would land if that was a consideration. OK. So that’s it. And in geology, you always end
a presentation with a sunset. Always. And on Earth, we have blue
skies and red sunsets. And on Mars, we have pink
skies because of all the dust in the atmosphere. But we have blue sunsets. Because when the sun passes
through, blue wavelengths get transmitted most efficiently. And so this was a picture
taken from the Curiosity Rover in Gale Crater. And there is– NASA continually
studies and updates scenarios for putting humans on Mars. And the latest one, I think,
came out in about 2011 or so. And it’s about 500
pages, and it’s all engineering wire diagrams
and things like that. But if you are interested
in that kind of thing– and let me tell you,
it’s great reading if you’re so disposed– you
can just download it online. Thank you very much, and I’ll
be happy to take some questions. [APPLAUSE] Right there. AUDIENCE: What do
you think about some of the non-governmental
projects, like the Mars One. MARIA ZUBER: So I’ll
tell you, the government is in a difficult situation,
because the public is risk averse. And so you have to have a
very, very high probability of success if the
government does something. And so the
non-government efforts, they’re a long way from
being where they need to be. But this is going to be like
exploring the new world. Ships go over the horizon,
and you don’t see them again, and eventually, one gets there. AUDIENCE: Would
you bet your money on a government agency or a
non-government agency landing first? MARIA ZUBER: At this point,
I would say government, but I’m pulling for
the non-government. I would help them. But it’s expensive. Any other questions? Let’s wait a minute
for people to leave who are going to leave, and
then we’ll answer the questions. We’re going to let
them some people leave, and then we’ll answer
some questions. OK. Next question. Right there. AUDIENCE: What are
China’s plans with that? MARIA ZUBER: China’s plans. China has very
ambitious space plans. And their near-term
plans are for the moon, and they’re currently
working on another moon rover to put there. But they both have plans to put
humans on the moon and a rover on Mars. And their technical
capability is increasing. Right there. AUDIENCE: In The Martian,
they asked China for help. MARIA ZUBER: Well, China
actually offered help, and they accepted it. We should all work
together on this. One over there. AUDIENCE: I have
a quick question. From an optimistic
point of view, when would you expect people
to get actually foot on Mars? MARIA ZUBER: So the
planning is for 2030. But, but, but, but,
but– but NASA also planned to return samples
from Mars by 2005. And we haven’t done that yet. OK. AUDIENCE: There are so many
movies sending people to Mars. Which is your favorite one? MARIA ZUBER: The Martian is the
one that’s closest to– yeah. They’re all good. You’ve got to put
a lot of what you know on the shelf for a couple
of hours and just enjoy it. But The Martian is pretty close. Matt Damon is speaking
at our graduation. Was there a question back there? AUDIENCE: Which
technology do you think would help us the most in
feeding all of our astronauts out there? And can you grow potatoes? MARIA ZUBER: Yeah. That part was
accurate, actually. That part was accurate. There’s a lot of research
on growing things on Mars, analog soils. And so that’s been studied. That was pretty close. But the most important thing
about going to another planet is getting off the Earth. So most of the energy
that gets expended is taking you out of the
Earth’s gravitational well. So the most important technology
is a good, heavy lift launch vehicle. AUDIENCE: Why don’t we
start from the moon? MARIA ZUBER: Why don’t
we start from the– there are discussions that
we should go back to the moon first, because we have to learn
how to be off-planet again. We have to learn how to work
in non-weightlessness again. You wouldn’t use– there are
different energy requirements. You would need a
different space suit because of the different
thermal conditions. And it’s not Mars. I think there are
arguments pro and con. I personally think
that what will happen is sending a crew vehicle
just to do an Apollo 8-like thing, flying around
Mars and then coming right back. And we would learn
a lot by doing that. Right there. AUDIENCE: So I
know you were even advocating for more funds
for science and technology in lots of different areas. What do you find are the
main impediments to that? MARIA ZUBER: The
main impediments to funding for science
and technology? So overwhelmingly,
the Congress is supportive of investments
in science and technology, because they realize that
our national competitiveness derives from our innovation. And the impediment is
really just medical costs and social security costs. And it’s just that those numbers
are increasing and increasing and increasing, and
space science funding along with everything else is
in the discretionary bucket along with veterans’
benefits and other things that we– energy
and cancer research. All these things
are super important. And that bucket keeps
getting squeezed and squeezed and squeezed, because
the medical costs and social security costs keep
increasing and increasing. Yeah. AUDIENCE: I read that it
was blocked on the storm. It’s still blocked. Is there any plan to unblock it? MARIA ZUBER: You bet
there’s plans to unblock it. It was still blocked
last time that I looked. But they’ll get it. Keep at it. Yeah. AUDIENCE: So you know technology
is exponentially becoming more and more powerful. We’re in a technology era. And all companies
now spin themselves as technology companies,
because you can’t be a company and not be a technology
company nowadays. What is the key innovation
area or the key opportunity? Where would the leap come from
that would get us from point A to point B? Because we’re
going to get there. It’s just a matter of where
is the innovation going to come from. Where do you think it
needs to be focused on? MARIA ZUBER: So for a Mars
mission, or just in general? I’m responsible for
all research at MIT, so it’s a– if I
say one, I’m going to get a lot of other
people around here mad. AUDIENCE: We know there’s a
lot of technological innovation across right now. What I’m saying is where could
you apply that to space travel? What exponential growth
needs to happen in technology to get us there? MARIA ZUBER: So I would
say in heavy lift. So we need it in
the propulsion area, although I think that
we could do that. I actually think it’s
going to be in software. Because when things go wrong
in space– let me tell you, because I have personal
experience in this– it is never the
super high tech FPGA. It’s always somebody not
zeroing out a do loop. So the lander that crashed
at the south pole of Mars was not zeroing out a do loop. So it’s innovations
in software, I think, that are really going
to be the game changers. But another thing,
though– if you want to take hardware
materials, advanced materials, lightweight materials,
radiation-resistant materials, there’s a whole lot to be
done in that arena as well. AUDIENCE: You just mentioned
propulsion as one of the areas that we should have improvement. There’s different fuels
that are being researched. Is there any one in
particular that you feel optimistic about
in one group’s research? MARIA ZUBER: Yeah. I wouldn’t pick a
winner in that one. NASA is looking at three
different variants on that, and we’ll have to decide. Yeah. AUDIENCE: You said
that solar energy wouldn’t be possible on Mars. Could you explain
more about that? MARIA ZUBER: Oh, no, I didn’t
it wouldn’t be possible. I said it wouldn’t be enough. So because the sun doesn’t
provide you with as much energy as you need to do all
the functions that you have on Mars. And even if you let
the sunlight build up, we don’t have good
enough batteries. So batteries would
be another enabler. Yeah. AUDIENCE: Radiation
exposure during travel time to Mars and back as
one of the concerns? MARIA ZUBER: Oh,
yeah, it is a concern. So in a six-month trip to
Mars, it’s about 20 to 40 REMs, if that means
anything to you, which is a substantial exposure for
a worker in a nuclear plant. That’s substantial. But it’s not a game stopper. But you can always
reduce that by shielding. But shielding is very heavy, so
it’s– the reason I’m saying– these are engineering
trade studies. So you can trade of– it’s
dollars, mass, radiation. There are just trades here,
and you just do the trades, and you set your
risk accordingly. Yeah. AUDIENCE: What do you
think about the latest project of sending very
small items over to Pluto at very high speeds
with solar-powered wind, solar winds. MARIA ZUBER: It’s bold. How about that? Well, you’ve got to go within a
half a solar radius to the sun, so it would be cooking. The hardest instrument
that we ever designed, I ever worked on the
design of, was one to go in orbit around Mercury. Because it just fries. Think about the leads
on your electronics, the thermal stresses. Because it’s going to go there. It’s just going to
get hot, hot, hot. And then it’s going
to flip around, and then it’s going to
get cold, cold, cold. And you’ve got to be able to
design for that whole thing. So how you do that
with a small mass? You solve a lot of problems with
mass, and they don’t have mass. It’s a good problem to work on. Yeah. AUDIENCE: Are there plans
to deal with the influence of microgravities? Because the astronauts are
going to go there for two years, and then they’re going to come
back in a really hard reentry? Will they be able
to survive that? MARIA ZUBER: Well,
one of the things that is an issue when you
send astronauts into space is bone loss. And so they really have
to exercise vigorously. And the good news is
we have a lot of data on that from the space station. And in fact, very, very
vigorous exercise– we’ve had a guy come back
with virtually no bone loss. So you can get around that. Now, if you stay 550 days
on the surface of Mars, then you’re used to 40% G,
so that would be interesting coming back. And we have no data on that. Yeah. AUDIENCE: Do you think
human beings would ever destroy the Earth so much so
that it’s so uninhabitable that Mars was an option? And if so, what
would we have done? MARIA ZUBER: Could humans–
do I think they would? I hope they don’t. AUDIENCE: If that
happens, what do you think would be the
number one thing that would– MARIA ZUBER: It would
be nuclear war, I think. We have enough nuclear
warheads to take out the Earth. AUDIENCE: How about AI? MARIA ZUBER: What? AUDIENCE: How about AI,
artificial intelligence? MARIA ZUBER: Maybe. Climate change– well,
climate change– so let me tell you climate change. Climate change– it
will be horrible, but it would not
wipe out the Earth. What it would do is–
well, sea levels will rise. So all the people who
are along the coast– if you think the mass migrations
out of the Middle East now are a lot, that
is nothing compared to what will happen when
the West Antarctic ice sheet comes off. And then we could lose
growing seasons, which means that large
parts of the world would– once you lose a growing
season, you’re at great risk. But there would be
people who would be able to deal with
that, but not everybody. But nuclear war could
take out everybody. Yeah. This is depressing. We’re talking nice– AUDIENCE: It’s
almost collaboration, because NASA has– there’s
other nations like Chinese and Russians– MARIA ZUBER: So
NASA’s collaboration is pretty strong with Russia,
Canada, the European countries, even some Middle Eastern
countries, but not with China. In fact, we’re not
permitted to collaborate using NASA funding with China. Yeah. AUDIENCE: [INAUDIBLE]? MARIA ZUBER: So the
question was a lot of those failed missions
are from the United States, and what did that cost us. Well, most of the
failed missions are from the United States
because the United States has sent most of the missions. So our hit rate is
actually pretty good compared to some others. But how much does it cost? Actually, I don’t know,
because I haven’t added it up. That’s an interesting
thing to do. But what I will say is that
when a mission to Mars fails– fails– it’s not a
complete failure. Because sending
a mission to Mars is not just buying
a bunch of stuff and bolting it together
and sending it. It’s a lot of people
figuring out how to do that. So much of your investment
helps you succeed the next time. And so because this is so hard,
and because it’s at the cutting edge, if we succeeded at
everything that we did, we want to leave that
stuff to somebody else. But it wouldn’t be very
interesting to us at MIT, I think. Yeah. You want to go next? AUDIENCE: Is the atmosphere
of Mars thin enough to make meteor impacts
a significant thing? MARIA ZUBER: The question
is is the atmosphere of Mars thin enough that
you see meteor impacts. And yes. In fact, I took out of the
talk– we got this picture. There’s a iron meteor
this big that was found. And then there’s
all this work that’s been done using image analysis
from orbit of seeing new impact craters that were formed
since the spacecraft got there from– because Mars is
closer to the asteroid belt, so there’s more junk
there than there is in the Earth neighborhoods. So there’s a lot of new
impact craters on Mars. They’re not too big. Yeah. AUDIENCE: It seems like there’s
lots of different open source projects within math–
finding the next largest prime, genomics, those
solving by lots of people. I haven’t heard as
much– maybe I’m ignorant in that area– within
the states in NASA programs. Are there such open source– MARIA ZUBER: Oh, no. We don’t do things– oh, no. No. Well, in NASA, everything
is configuration control. You don’t change anything
without a committee. AUDIENCE: [INAUDIBLE] back. MARIA ZUBER: Oh,
the data that comes back– yeah, the
data comes back. There’s a lot of codes
out there to analyze it. But anything that’s
actually in space is very, very, very
tightly controlled. Yeah. AUDIENCE: How big is
Mars’s atmosphere compared to the Earth? MARIA ZUBER: How big is it? I don’t know. How thin? It’s, at the surface,
1/200 of the Earth. So it’s practically a vacuum. We call it an atmosphere, but
it’s practically a vacuum. So we’re going to take–
we’ll take two more. Yeah. AUDIENCE: So can we already
send some instrument on Mars? MARIA ZUBER: Oh, yeah. So where do you think
all this stuff came from? Yeah. That’s data. That’s all data, except for the
little clips from The Martian. So it’s data. Yeah. OK. Last question. AUDIENCE: What do you think
about terraforming Mars and heating up the atmosphere? MARIA ZUBER: What do I think
about terraforming Mars? I’ll tell you what– any
planet is a complex system, and you have to
be really careful about unintended consequences. And so while theoretically
it’s possible, you have to think about what
you’re ruining to do that. So I wouldn’t sign
up for that one. OK thank you. I’m going to cut it off now. [APPLAUSE]

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