All right. So we're going to get started. Good morning. Good morning. Are you still having fun? Yeah. I heard it's pretty intense now
with all the coding and stuff like that, but hang in there. What is BWSI? [INAUDIBLE] So lame. Come on, louder. Louder. OK. That's fine. [INAUDIBLE] So today, the CubeSat
class is on a field trip, so they're not here. And then so is the
Remote Sensing teams, but we do have our
middle school classmates. Say hello. Hi. [APPLAUSE] And I would also like
to welcome our students from Nauset Regional High
School Warrior Works. So raise your hand. So they are running
the shadow program and they will be here for
the final competition. They're working on
their own race car so they will be racing
in the final event. So be nice to them. All right, so we'll get started. How many of you remember what
happened about 50 years ago? Great. How many of you
want to go to space? All right. So today is your
lucky day, yet again. It is my pleasure to introduce
Professor Kerri Cahoy from MIT AeroAstro Department. Also, she was responsible for
studying the CubeSat program class last year. So with that, let's
welcome Professor Cahoy. [APPLAUSE] All right. Thanks everyone. So I'm Kerri Cahoy. I am a professor in the
Aeronautics and Astronautics Department here at MIT. I run a lab called STAR Lab,
Space Telecommunications, Astronomy, and Radiation Lab. And it's about 30
graduate students big. My background is in
electrical engineering and my lab builds shoe box
sized satellites called CubeSat. We've launched three. We have one more
going up this fall. We're building
three more for NASA. We're part of a constellation
with MIT Lincoln that's sending six more in about 2020. And another collaboration
MIT Haystack, they're sending another
two also in 2020, so it's getting a little busy. But I wanted to talk
about space exploration and how we can make it possible
to learn about the hard things about space exploration from
middle school, high school all the way through college
and graduate school. And kind of just
educate you about-- kind of a little bit more about
space exploration why it's hard? Why it's worth doing? And how we can start working
on some of these hard problems using balloons and CubeSats
as kind of first steps. How many people here have worked
with model rockets before? OK. How many people have worked
with the weather balloon before? OK. How many people have
worked with a CubeSat before know what one is? Couple. OK. So just want to make sure
I calibrate properly. Please ask questions. I'm happy to take questions. I will try to scan
for hands and try to uniformly pick across
the room and not just pick from one area. So anyway, so this is
kind of an overview. So I'll talk a little
bit about why we even want to go to space, what
makes it hard, what's a weather balloon? And how can it teach
us how to overcome some of the hard things
about space exploration? What's a CubeSat and
how does that help us? And I'll wrap up with
a summary and some pondering on the mythical
nature of the space business. So why space exploration? Why number one is get
above the atmosphere. So the picture here, and
this picture is showing does anybody know what it is? So this is the
opacity what can get through the atmosphere
in terms of percent and this is wavelength. So this is like radio
waves over here. These are like x-rays
and gamma rays down here. And this is the rainbow here
is where visible light is. And so this is basically,
the air between the surface of the Earth and space blocks
shortwave, gamma rays, x-rays, ultraviolet-- to some extent we
still get sunburn. [LAUGH] And then it lets through
visible light and some near infrared radiation. And then it blocks a whole bunch
more lets through radio waves, and then again blocks
long wavelength light. So basically, everything we ever
do with telescopes and radio telescopes on the
surface of the Earth is really only in
these small pieces. Those are the only
parts of the universe that we can explore from
the ground and understand. So in order to be able
to understand what's going on in terms of the
creation of the universe, the evolution of stars,
planets, and systems. Whether or not there's
life out there, any signals and information that may
be contained in wavelengths other than these little windows,
we don't really know that well. And it's really even hard here
because of radio frequency interference because
of all the fun stuff we've got going on down here
on the surface with wireless and Wi-Fi, radio waves and data. And here, there's
weather in clouds that make it a
little bit difficult to be able to see far out. So we want to go to
space because it's like trying to let explore with
shades down a lot of the time from the surface of the Earth. The other thing is-- this
is a picture of the Earth from Apollo 17 in 1972. It's called the blue
marble image of the Earth. We want to be able
to see the Earth as a whole from a distance
and really take advantage of understanding our planet. We can do things like
look at weather storms. And more importantly,
an image like this is what you would want if
you're looking for early missile warning and defense systems. So for defense purposes,
for science purposes, and also for
communication if you wanted to be able to send
data to the entire planet all at once, the
only way to do that is to send it up to a
satellite and then create a spot beam that covers
large fractions of the Earth and send it back down. That's how you all get cable TV. I know you think it
goes to your house, but really goes up to a
satellite and then down to a radio dish that's
called the a head-end, and then it's distributed
back to cable to your house. So this is how we get
programming on a regular basis. So that's one reason
we go to space. Another is to find out
what other solar system objects are like. This is Mars. This is 360 degree panorama
from the Mars Curiosity Rover at the Vera Rubin Ridge. We can send robots
like the race cars your building and the
things that you're learning to do with build a
normal operation and autonomous navigation. We're sending them to other
planets in our solar system to find out what it's
like to see if there ever was possibly life there. Were they ever habitable? If they were different
in earlier times than they are now,
what happened. Mars used to have a very active
magnetic field that does not anymore. This has crustal remnants. Did that have to do with
the existence of a thicker atmosphere and water
on the surface? We're trying really
hard to find out. There's a lot of-- well, it can be kind of funny. A lot of articles lately
about methane possibly being detected on Mars
and kind of jokes as to where that
might have come from. But it's an open question. What is going on planets
and our solar system? So going to space and
launching these vehicles is one way to find out. NASA just selected the
mission called Dragonfly. That's going to send
the UAV to Titan, which is one of the moons
of Saturn more methane, but it's exciting. So these are exciting
missions that we can learn to be a part of
and some of these missions are long. So they're going to count on
people like you and it's going to be you guys when they're
landing and exploring who are the people
who are operating it. So training you guys
now is a good idea. We can get sample and
sometimes even bring them back. This looks like a lump of coal. But that is a spacecraft. That spacecraft chased a comet. Stuck out a little
aerogel capture screen, grab particles from the
comet, closed itself back up, came back to Earth and
re-enter it at screaming speeds and went from Mach
36 to subsonic and under about 2 minutes. Hit about 2,900 degrees Celsius,
30-ish g of deceleration landed on the surface
intact with it samples. So humanity is kind of
awesome, scientists are nuts. We decided we're going to
go chase down the comet and take a swipe of its tail
and bring it back and study it. Why did we do that? Will this particular
comet use to be a comet that was out kind of
in the corporate belt by Pluto. And then it had a gravitational
encounter with Jupiter and it orbit changed,
and now its orbit that is kind of almost day
Earth distance from the sun. And so we wanted to see what it
was like because its orbit got perturbed, it got knocked
inward and people wanted to go take a whiff of that comet
and bring it back and analyze it in this aerogel. Early warning for solar storms. This is a diagram of
the Sun and the Earth, and the Moon going
around the Earth. And these points,
does anybody know what these points are up there? These are Lagrange points. So these are points where
the gravitational pull between the Sun and the
Earth is just about balance, so that if you had
a test particle and you put it here if it were
a little closer to the Sun, it would go into
orbit about the sun. If it were a little
closer to the Earth, it would go into
orbit about the Earth. But if it's at this
point right here, it kind of hangs out and stays. So these are
Lagrange points kind of points of balance between
the Sun and the Earth. So there's one on the Sun side
along this line called L1. There's one on the far side
so in the shadow of the Sun called L2. This is a great place for
really good astronomy telescopes because it's behind the shadow
of the Earth from the Sun. So it's nice and
dark and unperturbed. So they like to put big
astrophysics and astronomy telescopes out at L2. Over at L3, which we don't
normally put things there. Does anybody know why? It's really far
that's one reason. That's right the
Sun is in the way. So sending radio signals
or any type of signal back to the Earth from
that point is kind of hard. You need to relay. This L4 and L5 point are
called Trojan points. Trojan points are places where
we have asteroids building up in the Jupiter system so
there's the asteroid belt. And so you have debris and
rocks and all sorts of stuff piling up at these. These are stable Lagrange
points and these are unstable. So things don't tend
to pile up L1, L2, L3, but they do at the
Trojan point L4 and L5. So if we were worried
about the Sun, which is this big, angry
fireball that's constantly spewing ionized particles at
us and the solar wind at very high speeds, and we're
only protected by what? Does anybody know? I hear muttering. Our atmosphere
helps a little bit. What else? Our magnetic field. So the Earth is like a magnet. It has liquid iron core
and it has a dipole field, and the Earth's magnetic
field protects us from the ionized
particles coming in from the Sun towards us. So if we wanted to get a better
prediction and the systems going this way, we
would send a spacecraft to L5 that would see anything
being ejected from the Sun. A kernel mass ejection
or something in advance and could warn Earth in advance. Right now we don't
really have that. So wouldn't that be smart to do? Yes. So that's another good
reason to go to space. And then there's also
human exploration. And this week is a good week
to honor a man on the moon. So Buzz Aldrin is shown here on
July 20, 1969, which is going to be 50 years this Friday. And I am saving my Saturn
5 rocket Apollo moon dress to wear on that day. But it's really
important for humans to get out there, reach out
there and touch the Moon, Mars and explore. So really push our
boundaries we're an exploring race and that's
what we've done here on Earth. And we'll continue to do
through the solar system. This is Starman. So this is the most
we've done recently. So this is Elon Musk's
Tesla that if you're not aware of this some Elon
Musk launched his own Tesla car as a test payload on the
Falcon Heavy first launch, and he put it into orbit about
the Sun with a dummy in it. So we have Starman who's
currently in heliocentric orbit about the Sun and has
its own tracking number. And that was last year. So what makes space
exploration hard? What are the hard things? What are the things
that are the challenges that we need to work on? So here's a long list. I'm going to go through
them one at a time. But basically, surviving a
rocket launch operating really far away, you're
moving really fast. You're in a vacuum
so there's no air. You go through really
cold and hot cycles. You have really limited power. You have to deal with radiation
and atomic oxygen corrosion. You've ionizing radiation. You can get hit
by micrometeoroid and also there's a
ton of paperwork. So one at a time here. All the things. So this is a Falcon Heavy
launch of Arabsat-6. Surviving a rocket
launch is no small task. Has anybody been to a launch? T-minus 30 seconds. OK. You feel this
giant pressure wave from two miles away hit you. It's like a strong hot
wind just blow into you. Those rockets are loud and they
shake for a couple of minutes and whatever you build
had better not fall apart, whether they're shaking that
hard and vibrating that much. So just to give you a sense. It's very loud. It's very high
vibration environment. And also, you have
this pressure gradient going from air pressure at sea
level to vacuum really quickly. So surviving that moment
is really quite different. You have to do things like
make sure you glue down your electronics. It's called staking. You have to make sure that
vibration tests and everything, and make sure it's not going to
shake and break off in advance. There are a lot of
different things that we have to take
care of to make sure that we can survive a
launch like this, and have whatever is at the top of
that rocket to survive. Yeah, that's a lot of for us. So I'm going to skip
because if you haven't seen one of these before
the Falcon Heavy booster landings are quite remarkable
and a real accomplishment. I've had students
working at SpaceX. So basically, those side
booster is on the launch. In order to bring
launch costs down, does anybody know how much
it costs to launch a rocket? A lot. About $100 to $115
million regularly. So that's a lot of money. [CHEERING] And here we have the
boosters coming down there. Two of them they're going
to land on launch pads. This upper right pictures
shows them coming down. This is a nice one, too. So designing the control
systems and figuring out just how much fuel,
extra fuel you have to have to be able to bring
them down instead of let them burn out from atmosphere
is really a lot of work and really impressive. So these control systems
keeping them upright and carefully landing them
and getting back to target are really, really impressive. But it should reduce
the cost of launch and make this space
more like air travel where you can reuse the same
plane to go across the country and be really silly if we used
a plane once and then threw it away. All right, so you're really,
really far away in space. What does that mean
for operations? It means you kind of need
a powerful transmitter and receiving dish
to be able to talk to your spacecraft
or your Rover. And you may not be able
to access it all the time. So using these
things are expensive. This is the Goldstone
deep space network dish. It's a 70 meter diameter
dish in California. Yesterday-- just
yesterday, I was up at Westward, Massachusetts
where we have an 18 meter dish. One of the MIT Haystack
and MIT Lincoln sites. You need big
antennas or possibly laser comm systems
or just something that I work on to be able
to talk to your spacecraft. And this is hard these are. Expensive. You have to make sure
that you know what you're doing with your commands. Anybody here play football
or has played football, or do we get none
of the athletes. We might not have
gotten athletes. [LAUGH] But if you've ever
heard of a playbook, you have to have kind of like
a playbook for your spacecraft and for your mission
where you know what you're running in
advance you practiced it on your engineering
model in the lab. And you do that command sequence
and you hope it works out, and then you have to try to
figure out what went wrong. And you have to use
assets like this and have just a little bit of
time on it because using this is also expensive. So that also makes space hard. And you're moving really fast. So this is just an example
of satellites moving quickly. And I wanted to show Elon Musk
starling satellites, which were very reflective and
specular moving across the Big Dipper and Little Dipper. Can you guys see
these dots here? Yup. So this is the Big Dipper. This is a Little Dipper. These are train of 60
starling satellites that Elon Musk put up. And my point here
is that depending on where your satellites
are, you can't just have your big dish pointed
up, and then expect to talk to your satellite or
your Rover or your mission. You may have to
slew the whole thing and track to be able
to point at these, this is moving across the sky. It only takes for something
that's where the space station is and low Earth orbit. It only takes 10
minutes for the thing to go from horizon to horizon. And so you have to have a
system that can point and slew quickly, and it doesn't go
on the same track every time. It can't just go back and forth
and you build like one track and like a roller coaster
that goes back and forth. No, because sometimes
it's over there, sometimes it's over there. Depending on the orbit,
it changes where it is. And so these tracking
systems are kind of a pain and they're moving pretty fast. And so that's a challenge, too. That's kind of hard. The other thing
about moving fast is if you wanted to
move any more than just its orbital velocity. If you want to be able to
enable motion on your satellite and keep it from tumbling and
have it pointing in any one direction, you have
to use actuators like thrusters or
reaction wheels to be able to keep it oriented
in the way that you want. It's possible to mess that up. It's possible to get your
wheels spun up too fast. To get your satellite spinning
so fast that it spontaneously disassembled on orbit. This has happened. It's possible to
have your thrusters doing the wrong thing. It's possible to have your
batteries explode on orbit. So all of these
things are difficult, but having chemical
propulsion systems, hydrazine is one of the fuels
that's used on spacecraft. Does anybody want to
guess how difficult it is to get hold of hydrazine? [LAUGH] It's super
difficult. They make you basically
keep it in a bunker. You have to have all
sorts of licenses. You have all sorts of permits
to transport it around. This isn't easy. Electric propulsion
is a little easier where you can have like ionic
fluids and salts and things that you can use, and maybe
just use xenon and high voltage. But then you have high
voltage, does anybody know how much trouble
you get into when you want to run something
high voltage in a lab? A lot of trouble. So these are hard things. And then you have a lot
of data and sensor data. So how many people
really love geometry? OK, good. Keep that up. How many people know what
a coordinate transform is? OK. [LAUGH] OK. So there are all sorts of
different reference frames and coordinate
transforms that you have to take care of when you're
using sensors on satellites. You have to map
where the sensors are to the correct frame and use
all that data to figure out where your satellite
is currently pointing. Where your sensors basically
put all that sensor data together and then figure
out what you wanted to command your thruster to do. Or your wheels-- how much
you wanted your wheels to spin to get your satellite
to move somewhere else. And pro tip, so you can't move-- translate anywhere without
a thruster in space. And it takes a lot of
energy to go from one orbit plan to the other, actually. It takes less energy to
go to different places along the same orbit,
but moving orbit planes takes a lot of energy. And then there are
wheels and things to tip until your satellite, and we
use the Earth's magnetic field so we can use the fact that
there's a magnetic field there and we can pass current
through a coil of wire and use that to generate a torque
to tip and turn ourselves. So there's lots of
different things. So these are reaction wheels. This is a thruster. This is a hall-effect thruster. These are magnets workers. So these are coils
of copper wire that around, that we
pass current through and they generate a torque
at different orientations with respect to the Earth's
magnetic field in orbit. If you're close
enough to the Earth. If you get far from the
Earth and the field strength weakens as what? So anybody know
the relationship? Our spirit. Yeah. So these are all things
that are important. You're in vacuum. So vacuum is a problem. Does anybody know why
vacuum is a problem? Yeah, there's no air. So if you're hot and you
want to turn on the fans, like everybody is computer
has a fan in it, right? Everybody knows what these are. You probably scavenge them
and like hook them up to. Things so fans don't work. Fans don't work in vacuum. There's no convection. You have to touch something. You have to reach out and touch
something to cool down, right? You have to radiate. So you have to conduct
heat a different way. And that can be
very challenging. The other problem is
when you're in vacuum, if you had a part that
was kind of sealed and it went up in that rocket
from the surface to space, bam! It would explode
depending on how big it is and how strong
that component is. That's a big problem. So to make sure that
you don't have things that are sealed
that shouldn't be that you can outgass properly. There's also this thing
called cold welding. So metals, I don't know. When there's no
air in between them when you're in a vacuum,
when they touch each other they don't know that they're
different pieces of metal. The electrons and the protons
just kind of work together and we'll literally weld. So any metals that touch each
other in the vacuum of space will literally do something
called cold welding. They will stick together like
they are welded together. Like that movie just showed. So you can see cold weld
happening right here. So these are two
different things, and that's a cold weld
happening in microscopically. This happens. So there's the
Galileo spacecraft that have this beautiful big
umbrella high gain antenna. It was supposed to
deploy into a giant dish and send data back to the Earth. It was made of metal. It gets cold blooded
stuck and never deployed. It's right there. That's a big bummer. Space is hard. All right? They had to use really terrible
little low gain antennas to get data back
and try to rescue what they could of the mission
without high data rates. Jupiter is far away. Yeah. You can use coatings,
different coatings to help with that to
keep the metal from being metal on metal. So you would treat
the surface, and we'll talk a little bit more
about that in a second. So yeah, exactly. And then there's outgassing. So anything that touches
the surface and it's absorbed or is absorbed, which
is the adhesion to the surface. Well, outgass when it
gets into a vacuum. So if it was like deposited
into your system on the ground and your lab wasn't very clean
and then you go up to space, all these particles all this
glop kind of evaporates off of your parts and it can land. Let's say you have a beautiful
mirror or beautiful lens, all this gunk can
come off and then just deposit onto your
lens and make it all dirty or deposit onto your electronics
and make them not work. It's fabulous. Lots of problems. So this is one of
the reasons why we try to make sure things that
go into space are so clean. All right, cold and hot. It is worse than some
weather patterns. So basically, what we
have here is the Earth. The Earth is here, the
Sun, we have the eclipse. And imagine that what's labeled
here is the Moon's orbit. This could be any
satellite orbit. And you have the Earth's shadow
that you're going into and then coming out of. When you're in Sun,
this is at the orbit of the Earth 1360 watts per
meter squared coming at you. And when you're back
here, there's none of that and you're really cold. See the cycles of
really hot and cold. And every time you
go around if you're at the same height
as the space station, you're doing this
every 90 minutes. That's a lot of times. You're cycling hot and
you're cycling cold, and you have to make sure
that everything works. One way that
balloons-- and balloons are useful for testing
this is when you're testing a high altitude balloon. This is kind of the
temperature here, and this is degrees Fahrenheit
on the bottom and degrees Celsius here. So this is about 60 degrees
Fahrenheit at the surface. When we have sent up
weather balloons, which I'll show some pictures of. We get to about 30 kilometers
altitude, about 100,000 feet and you go through this
huge temperature gradient. It gets really cold here. And then it flips around
and you have a couple of different inversions. And up here is this
is like temperature, but you don't have
enough particles there for to like be the same as
temperature on the surface. This is just kind of like
particle kinetic energy, but it's not really thermal. It's not the same as the
temperature on the surface. There's not enough gas
for it to be as effective. But you can use
a balloon to test how well your hardware works
going from nominal temperatures to something very cold. This is some data from
an orbit spacecraft where you can kind of see. So this is temperature in
degrees Celsius is inside. The satellite-- this is
outside the satellite. And this is minus
40c to plus 30c and this is time in seconds. And you can see getting hot
and cold, hot and cold, hot and cold as it's going
into and out of eclipse. And you can see this
is inside the satellite and the outside is
even bigger swings. More importantly, you can also
see the battery charge here. So you can see what I'm going
to talk about in a second, which is power that you've lots of
power when you're in the Sun. And then you have
no power and you have to run off of batteries
when you're in eclipse, unless you have some
type of nuclear power. But those are very politically
contentious and only used for deep space
exploration when needed. All right. This is how we test hot and
cold on the ground in the lab. This is a thermal
vacuum chamber. This is a satellite in a
thermal vacuum chamber. These are giant cylinders that
we pump all of the air out of and we use liquid
nitrogen, and sometimes liquid helium if we needed
to get really cold. Liquid nitrogen is how cold? 70 Kelvin? Do I hear some answers
around 70 Kelvin? It's pretty cold, right? What's liquid helium,
does anybody know? It's about 4 Kelvin. That's right. So depending on how
cold you need it to be. You'll have lots of pipes and
tubes going into this thing piping cold gases in to make
it cold just like space, and then you'd have heaters in
here that would heat it up just like space. And these chambers basically
have to be as big as the thing that you wanted to test
for space operations. So there's some very big ones. We have a small one in my lab. So this is sentinel
to a satellite. There are power limitations. So this is a video of a solar
panel test at Lockheed Martin and I just wanted to show-- so these things are huge. Can you see these
people down here? So these are folded
up deployable on geostationary
spacecraft that are just enormous to generate power. So not only do you have to
have these giant solar panels to generate power
for your satellite. They like to be cold. You also have to have a
giant battery packs, just huge banks of batteries. The batteries for the
Hubble Space Telescope. The solar panels
have to charge up so that you can use them to keep
everything alive and running when you're in eclipse when
you don't have enough power. Managing batteries is
the real challenging. Batteries like to
stay warm ironically, so you have to use your
batteries to keep themselves warm. And if something bad happens and
your batteries get really cold, you can lose your whole mission. It's kind of sad. So those are hard things. There are lots of sad things
about space exploration. All right, so
ultraviolet radiation. So the same thing
that makes you tan. Also, tan stuff in orbit. It will make your
glass like your window or your lens go from clear
to kind of Coca-Cola colored. It's really fabulous--
any polymers or glass. It makes plastics brittle,
structures brittle, more easily breakable. And then also, for low
Earth orbit altitudes-- I may have lost
my laser pointer. There we go. We have atomic oxygen. So this is not molecular
oxygen like down here, but atomic oxygen up
near the surface and it corrodes metals rapidly. So this is a picture of
Eureka of silver corrosion that was recovered and shown. So this is just what corrosion
does to metals on orbit. So you have to passivate all of
your metals that go to orbit. It's called anodizing
or alodining. You basically put them in a bath
and you turn them into an anode and you pass a high
voltage to them, and you kind of create this
protective coating on them to keep atomic
oxygen from corroding your satellite in orbit. You also have
ionizing radiation. So we mentioned the Sun
looks so friendly up there. It's actually a really
angry giant fireball that's spewing hot ionized
gasses us all the time. Spirals out from it. We're protected by
our magnetic fields. Like I mentioned before,
as you can see the Earth's magnetic field then. This is the solar wind that
actually blows the Earth's magnetic field way back into a
magneto tale here all the way far back over here. So we have satellites
that are orbiting in here. And all of these
ionized particles-- see these magnetic
field lines that actually get trapped around them
and they spiral around them. And so there are belts
around the Earth where we have ionized particles that
are trapped around field lines. What are ionized particles
and why are they bad? Yeah, up there. [INAUDIBLE] the radio waves. Yeah, so they can
cause charging. They can deposit on satellite
and cause charging and arc discharges. More importantly, they really
mess with your electronics. So you guys program
electronics, right? You like sending commands
and putting things in memory and thinking that those
ones and zeros that you're putting in memory are
staying ones and zeros. Surprise in space they don't. When ionized particles
hit your electronics, they can change the state
of just about anything. And so you have
to design systems that can power themselves
down and back up again. That can look for
errors and correct them and have error
correcting codes and try to design shielding so
that the particles have less of an effect. So these are all sorts
of different levels. These are cosmic rays. Those are from when
stars go supernova, they can come from
anywhere, not from our Sun. This can come from any
direction all the time and they also affect electronics
here on Earth every so often. They get all the way down
through the atmosphere. Then there's from our Sun
solar flare and radiation belt particles. These are the discharges. And you can have all
sorts of problems caused by ionizing radiation. So we have to try to
design electronics that can survive that and
are shielded from that. And be prepared to have our
satellite's reset spontaneously in the middle of
whatever they're doing. Fun. Surprise. Yeah. And then there's
micrometeoroids. If that weren't
bad enough, they're actually like little
things that are just kind of flying through
space and can hit you, just like the video games. Yeah. So there are people
who instead of going searching for gold
like in the gold rush, there are people who go to
Antarctica and melt snow. And they melt snow
and they find things like these micrometeorites that
are found in antarctic snow. So this is an example of what
a micrometeorite looks like. This is about 100
microns across. This is an electron
micrograph image of a hole that was made in a
panel of a satellite called solar max. Wait a minute. How do you get a picture
of a hole on a satellite? Yeah, in this case,
there's a hand right here. This is back when the
space shuttle was working. So the space shuttle used to
go up and service satellites. It would grab satellites and
the astronauts would fix them. That's what it was doing. It was very convenient. We still haven't figured out
a way to do that with robots effectively yet. We're working on it. This particular example
is kind of a funny story because normally the satellite
has some type of spin and they were trying to grab
this satellite to fix it, and they kind of had a
gasket sticking out somewhere it should have been. So they couldn't
grab it with the arm that they were planning on. So you're like, oh, it's not
a problem, it's spinning. We'll just have the astronauts
stick his hand up and grab the panel and then stabilize
it, and they'll fire something to try to cancel the spinning
and that worked terrible. They almost lost the
satellite ended up spinning up super fast. It was almost one of those
spontaneous disassembly is a spinning things. Ground control managed
to get the satellite back under control just in
time, and then they spun it down and then
had the astronaut grab it, which is a much took
longer but a much safer way to do things. But that's a funny
story about that. So anyway, so this
came from a satellite that was taken in on
the space shuttle. Also, licenses. If all of that
weren't hard enough, there's also stacks
of soul sucking mind numbing paperwork
that just makes everybody's lives miserable. If I haven't like
motivated you to get over all of these hurdles for
space exploration for all those awesome reasons that I
talked about at the beginning. There's one more thing. There's a lot of really,
really boring paperwork and regulations and things
that you have to get around and you get on a lot of
trouble if you break the rules. So you have to have licenses
to operate your radio. You have to have
licenses to take pictures with certain types of cameras
and certain resolutions. You have to prove that
your satellite isn't going to stay up
there forever and be a piece of junk in space. You it have that it's going
to come down and burn up in the atmosphere in the
right amount of time. Lots of paperwork. All right. So how can we start attacking
some of these problems and training ourselves to handle
them so that in a few years, we can be the ones who
are operating these Rover Exploration Missions,
these manned Mars Missions? What are the things
we can do now that teach us how to handle
some of these hard things? So weather balloons are
a great way to do this. I showed that profile of the
Earth's atmosphere going up and where weather balloons
are with respect to space. So weather balloon is just
a latex balloon with helium, and you can also use hydrogen
that is lighter than air to go up. For those of you who've
worked on model rockets there are a lot of
analogs to that. You have your balloon. You have a parachute. You have a radio system
and a tracking system. And then you have
your payload boxes. They're roughly
about 6 pounds each. And it's not too difficult
to be able to do this. You can call your
local FAA office and let them know that
you're putting one up if you follow the rules. There's no really special
licenses or paperwork you have to fill out. You just kind of
have to let them know and get there OK for where
we're going to launch it from. So this is Paula. She's in my lab and we are
filling a 1,600 gram weather balloon with helium
from this helium tanks. So weather balloons teach us-- they don't teach us about
some of the things like rocket launches, but they are far away. They do move fast. They are up in vacuum. They do get cold and hot. You don't have a lot
of power, and you don't have to deal with
a lot of the paperwork and the radiation. But you do have to deal
with a lot of these things. For some people you
look at that list and be like, mm-hm,
that's still pretty hard. [LAUGH] Is there an
easier way that we can take a baby
step first before we do the weather balloons? And, yeah, so you can. I brought out an example here of
just a little CubeSat structure with XP radio. And you can do a tethered
balloon really easily without a permit,
without calling the FAA. You just need some kite string
and some helium and maybe a 100 or 200 gram
weather balloon. And you can tie
it to this CubeSat and you can send it
up, at least 150 feet without any permits at
all as long as you're not too close to an airport, right? And you can go up
even up to 500 feet if you let that be, I know,
about a day in advance. So you can do this
pretty much anywhere. Any school field
we've done it here in the MIT football fields,
and this is a great way to get started. So you've missed some
of the harder parts, but you get the far
away moving and you get the power limitations and
you get the remote operation. So this is a great,
easy way to start. So if you've never done this
before and you'd like to and you have a wireless
radio that you can use, or even if you just want
to send a GoPro up and take some pictures, this is
a great way to do it. I can send a GoPro up again
with 100 gram weather balloon and probably one of the
little party helium tanks. And that's fun. So that's a great way to
be able to learn about some of the hard things in space
and we've done this for class. So this is an MIT
football field. This is 100 gram
weather balloon, that's this guy over here. And it's just on a tether and
we can collect data and learn things about attitude
control and imaging, just using a tethered balloon. The only things you really
need stuff that you probably have at home, maybe
not the fishing scale but you can get those on
Amazon for $10 and the helium. Most grocery stores
even have helium. So high altitude
weather balloons are much more fun so they get
really all the way up to space. So this is one that we launched. And Coxsackie, New York, which
is about three hours from here. Went up 106,000 feet
and then it came down in Rutland, Massachusetts. So if you're going to
do a weather balloon, it's like planning
a small hiking trip. So you get up there
and you launch it, and then you have a navigator
and yourself chasing that thing all the way back
to where it lands. It can land anywhere. Try to use some of
the forecasting tools that they have
online to figure out where it's going to land
based on the weather and wind patterns in
advance so that you're landing in a dry area. Yep. Right. So here, it's kind of got the
jet stream pushing it along, and then it finally
gets above it. Once it's above it, it
just goes straight up. And then it pops
because, eventually, the pressure of the helium
that was in the balloon, because the external pressure
is decreasing so significantly it gets to the point where
it's so much that the latex balloon just pops. And then it comes back down
pretty much straight down, and then the jet stream picks
it up again with the parachute and takes it down to
where it's landing. So it can land anywhere. So it's kind of a fun hike
to bring all your hiking gear and some power barge
and water or something, and you're going to
try to find that thing and where blaze orange. So here's kind of
a list of things that everything
you could possibly need for a high
altitude balloon flight. I will say that lots of
zip ties are a good idea. A large bucket to
pretend is your payload is also a good idea because
trying to figure out how much lift the balloon has
on a scale or something else doesn't work so well. Also, those things like
if it's really windy, you'll need like 10
people to try to keep it from blowing down and over. It's kind of fun. So and pool noodles are good to
put on them because they might land somewhere wet and
then, at least, you'll get to see where they landed. So these are all fun things. These are three tanks of tea
tanks of helium in my mom SUV. They clank and
make a lot of noise if you don't put some padding,
but you can fit them in a car and drive them
wherever you need to. And this is a picture
of our balloon bursting. That's kind of the parachute. You can see little
pieces of balloon and that's the Earth
down there from space. So this is really
fun to be able to do. Things that you can fly
in the payload boxes. You basically just
have styrofoam boxes and you want to test them
in advance by throwing them in the freezer. You don't really have to put
them in the oven for this because it gets cold or
not hotter as you go up. So you can get roughing
pump on Amazon for $10 that it'll pump down
your electronics. You can see how well they work
in vacuum, how hot they get, or you can just run the whole
thing and its payload box stick it in a freezer. Make sure it still works. That's a good test. So you need things
like your computer and your camera some
kind of tracker. Lots of batteries. So lithium ion
batteries are good idea. SD cards to save your data. Antennas for your radio
and tracking system. As many sensors as you
feel like putting on it, and then also try to make
sure that it is protected from humidity and
moisture because you might go through cloud on
the way up or something. So you don't really
have control of it. So here's some pretty pictures
from a high altitude balloon test. And then the things that you
want to bring for your recovery so you want to plan for
a hike like literally dress for a hike. Wear a blaze orange in
case you end up somewhere where people might
be hunting, just to be safe people can find you. Have a compass, have
sunblock, a bug spray. And maybe think about
bringing a portable kayak depending on where
it might land. But these can be fun outings
to do as a club or as a group. And again, they're
not really hard. It's an easy thing
to do on a weekend. So one of the
important things is having like one of
those BB gun pellets with like nylon fishing wire
or even a small fishing bait, something that's heavy that
has a fishing wire or nylon cord on it that you
can slingshot up through your payloads, and
pull back down because odds are very high that your
balloon comes down in trees. Almost always comes down in
trees kind of stop things. So this is the parachute and
these are our payload boxes. She wants something that you can
shoot up and over it and pull it down. And so we got it back down. This is my class that
we took out to do this and these are the payload boxes. These little straw things
here are the antennas for their tracker
and they have a bunch of cameras and all
sorts of things cut out the sides of
the styrofoam boxes. You can just get like one
of those styrofoam coolers from Walmart or something and
use that as the payload box. So anyway, I'm really
quickly on CubeSats. So CubeSat are another way. So once you've graduated
from the tethered balloon and the weather
balloon, there's also a tiny satellite that is
pretty easy to get to space. So CubeSats were
invented in 1999 by a couple of professors in
California, Jordi Puig-Suari and Bob Twiggs. And a standardized CubeSat
is essentially the size. And I can pass this around
if you guys want to see it or you can come up and
touch it if you want. It's totally fine. So it's about a 10 by 10
by 10 centimeter cubic. You can stack three of them. The idea here was-- remember how much rockets were? How much were rockets? How much the rockets cost? $150 million, right? In addition to that
$150 million rocket, you have a satellite
that's this big. Do you have an idea of how much
these satellites usually cost? Yeah, $300 to $500 million. That's a lot of
money in one place. So the hard part
is how in the heck do you get somebody--
to convince somebody to let you put your little test
box on their precious rocket with their precious satellite? Anybody have any
ideas how you do that? Yeah, in this case,
you put it in a box. And essentially, put it
in a spring loaded box just like a jack in the box. So the novel contribution
here that made this all happen is they're like, hey, I'm just
going to put my little test satellite in the safe box. It's a safe box. It closes. It doesn't open
until everything's on orbit and you guys as big
mission is out of the way. And then the spring will open. The door will open. The spring will push it out,
and we'll have access to space. So these guys went through
a stack of paperwork and they made this work. And you know what it
works is because these rockets their $150
million rockets, but they're really big. You saw how big that
thing was, right? They have to get that precious
$300 and $500 million satellite just to the perfect orbit. And to do that they
have to have extra fuel and have to be designed
to have extra fuel, because on the day of the
launch the weather conditions might be different, right? So they're not going to
necessarily need all that fuel. They have 10 of
kilograms on their rocket that they end up putting
just dead weight. Just ballast like on a boat. Seriously. They just literally put bricks. And so these guys
are like, well, instead of putting bricks, how
about you put a little boxes? They're safe. They won't hurt your
satellite, and then we can get up to space. So that's what happened and
that's how that all worked out. So these are CubeSats. This is a P-POD deployer. It's just a little spring loaded
jack-in-the-box box that goes on the rocket. So this is a bunch of CubeSats. The satellite is underneath it. This is a ring on the fairing. The top of rockets called the
fairing that nose cone area. And they're just bolted in. And they're little
jack-in-the-box deployers almost for free, and you're
able to get these tiny little systems up to space. And this is history being made. So after a few years
of this, people really started to get the hang of it. And they started
intentionally designing systems that were super capable,
that could fit in this form factor in these little one use
cubes or three use cubes that could do amazing things, because
you could get up to space so effectively and easily. So this is an Indian PSLV, and
it had 88 of these onboard, this whole stack from a
company called Planet Labs, and so this is just
its camera showing it just shooting these things out. So this really, really
changed the way space is done. And now everybody pretty much
any high school, any college can propose to NASA to
launch one of these for free. And all you have to do
is build your satellite and it can go up there. So every November
there's a proposal call and you can submit a proposal
to put a satellite on orbit just like this. It's great to have a lot
of satellites on orbit because our big satellites
that are really far away, this is a geostationary orbit. That means that the
satellites always overhead at the same time. That's how we get
our TV and our cable. So those satellites, you have
a big antenna on the ground, you just looks at
the same place. That satellite
doesn't move, it's just beaming the data down. It's great. But it's really far
away, really far away. So 35,000 kilometers away. So you have a lot of power
huge panels like we saw. The lower orbits are nice, but
they don't cover the same spot at often. So they have these
orbit tracks that sometimes can take two weeks
to go over the same spot twice. So the more satellites
that you have on orbit like if you had a lot
more of these little guys, the better you can
cover the Earth. So these big ones can, yeah,
they can see a lot of the Earth all at once, but
they're so far away. They require a lot of power. And they can't see
things up close and they can't see a lot
of changes that are small. But if you have a
lot of them, you can increase that revisit rate. So just for fun a couple
other ways you can get keeps outs to space
and then I'll wrap. This is the first one
that we send to space. This is a satellite
called MicroMAS-1 on an orbital ATK on
[INAUDIBLE] rocket. And this is kind of a fun one. This rocket went
up to space station and the satellites
were onboard as cargo, and they went to space
station, and they were just basically put on the
robotic arm at space station and ejected off, which I'll show
a quick video of in a second. But the other way you can
get off of the space station is to have an astronaut
throw you off. So this is a fun video to
see if you haven't seen something like this before. So this is a cosmonaut and
there's a Peruvian CubeSat that he pulls out of his little
satchel on one of his EVA, extravehicular activities
on space station. And you just kind
of launches it. It's not a very
common way to go, but every so often people
managed to pull that off. It's a tie. [LAUGH] More often you get
sent up as cargo and then you get ejected
from the robot arm like this. So this one right there is
our first satellite MicroMAS-1 getting ejected. The other nice thing about being
ejected from station instead of from a rocket is that, the
astronauts are actually there to take pictures. Whoo. The rocket images
are not very good, but these are great
images to have. OK. And this is kind of the last
you see of it before you start getting radio communications
from the ground if you're lucky with one of
those big dishes or antennas that you have to set up. All right. So CubeSats check all
the list of things that help us learn about space. So they really do their
great training tools for big space
exploration missions and now they're even big
missions just of themselves, constellations of them
doing Earth's sensing. So anyway, just to summarize
space exploration really lets us learn more about
the Earth, the solar system, our galaxy, our role in the
universe by getting out there. Space is hard. How many people
would agree that I've convinced you space is hard? Yeah. We need to do some
work to make it happen. We can use tethered balloons. We can use weather balloons. We can use CubeSat to help
learn about all those things, check all the boxes and
make sure we understand how to overcome hard. And we can use
CubeSats for free rides to space for student
and research projects. The other thing
that I really want to just-- the one other
thing that I really want to convey before I go
about the space business. Is it can be mythical? It can be like chasing
rainbows and unicorns, or chasing dragons,
or mythical creatures. Nothing really happens
when you wanted to. Everything is always late. Usually, it's delayed
for some reason. Things break a lot. Things don't work as planned
and it really takes people with mental toughness. And a lot of positivity to
be able to go back and do that again and again and
again until you get it right. And to deal with the fact
that 95% of the time you are just working your butt off. You're learning all
the hard things. You're doing all the hard math. You're testing all
the hard tests. And then 5% of the
time it is awesome. So you have to be a little
nuts to be able to make it in that industry. And it's for the
right kind of people and I hope some of you
guys I'll see you there as the years go by because
this is a small community, so we all got to run into
each other eventually. So I'm happy to take
questions and hope you guys have a great lunch. [APPLAUSE] Yep, so you're right that having
a lot of satellites in space can create a lot
of radio frequency interference and noise. For the most part,
they try to give licenses in very limited
bands to help with that. It's really controlled. Some of that stack
of paperwork is just figuring out and
coordinating what radio frequency is you can use. Yeah. Internet over balloons? I think it's a great idea. And they're probably regions
where it makes sense. I will say that
balloons are hard and they're really
unpredictable. So you're trading
those two things. It's still hard. You have a little bit
more access to it. They go up and come down. So maybe there's some
recovery of costs there. It's possible. You try not to have that happen. So when you're treating
all of the surfaces to make sure that there's
no corrosion, for example, or when you're using
like insulating there's like mylar
encapped on that. It's the shiny gold stuff that
you'll see for insulation, just like thermoses insulate. One of the side
effects of that is, it's conductive so you don't
want it touching things because it will short. And the other thing
is sometimes you'll use some of these
coatings and blankets and you'll forget that
they're actually-- they have structural properties, too. So when things get
cold and hot, they'll pull things apart and together-- there's a lot of
interesting things. But for the most part, a lot
of the paints and the coatings are they try to make them pretty
passive so they don't interact. OK. Do I think it's possible for a
CubeSat tag get near a comet. I think if you have a
propulsion system for CubeSats, that's effective enough. It may be possible. I don't know of any right
now that are capable enough to do that. But you could maybe
stage it so you have a spacecraft that gets it
out there and then deploys it, something like that. All right. So thank you, Kerri. We have a teacher who'd
like to present to you. OK. We have an extra one
for your assistant. Oh, thank you. Thank you. Thanks, guys. Hey, I like Beavers. [APPLAUSE]
