This is my brand new, custom-built satellite called SATGUS. And in about a month, she'll be zooming way up in space at five miles per second.

But what makes SATGUS so special is that she's got a phone right here and a camera right here,

and her sole purpose is to take your selfie in space with the Earth photobombing you. And it gets even cooler because if you tell me the city you live in, when you upload your picture to

the satellite will not only take the selfie over your city, but we'll tell you precisely when that

will happen. So if you go out in your yard and wave, you'll technically be in the photo twice.

It's incredible we live in a day and age where just an everyday civilian like you and me can just

decide to build something and send it to space. So today I'm going to give you a six-step crash course that will tell you all you need to know to

build and launch your own creation to space one day. And these six steps are very near and dear to my heart because these are the exact same six steps I

first learned when I was a young engineer at NASA working on the Mars Rover. So for step one, right out of the gate, you've got to first design your creation digitally in CAD, and

that stands for computer-aided design. And it's really the first step for anything that gets made and manufactured these days.

From a Mars Rover to an iPhone to a hammer to a shampoo bottle cap. CAD is critical for visualizing what it will look like and helping make design decisions about what

should go where. In our case, after a few months of the design phase, we landed on something that looked like

this, and it might look really impressive, and in many ways it is, but we sort of cheated and saved

ourselves a lot of time and money because this is something called a CubeSat. About 25 years ago, a couple of Stanford

professors realized every satellite that goes to space needs all the same basic elements like solar panels, radios, and computers. So instead of everyone having to start from scratch and reinvent the wheel every time they

Standardize the basic necessary hardware and sizes. Of the most common sizes used, the smallest is a 1U satellite, which is just a little bit bigger

than a Rubik's Cube. And then there's the 2U, which is just two Rubik's Cubes, so double that, then the 3U, the 6U, and the 12U.

And this is the size we're using for SATGUS. The way it works then is all the hardware necessary for the basic functionality of the

satellite, like the flight computer, takes up this space. But then that leaves all this extra room for the payload.

In other words, the purpose of your satellite, like what do you want it to do? In our case, that would be a camera and a screen for taking the pictures.

So for your first creation you'll be sending to space, I highly recommend you make it a CubeSat because that will reduce your development costs 100 times

from tens of millions of dollars to hundreds of thousands of dollars. So I want to talk about what's actually on SATGUS, because you'll need a lot of the same hardware yourself.

But first, let's talk about what makes it unique, which is our payload, or how we're going to take

the pictures. Once we get to space and everything's looking good, these two spring-loaded panels rotate open.

On one, we've got a Google Pixel phone and a radiation-resistant case, and then on the other, we've got a camera that's specifically been designed to withstand the harsh

space environment. So once we beam your picture up to the satellite, we'll display it on the phone, and then the camera

will take an HDR picture and then beam the image back to Earth. And you'll notice there's actually an identical setup of a phone and camera on the other side of

SATGUS as well. That's basically a full backup system, since we can't go to space and fix things if there's a

problem with the primary camera. For power, it's not feasible to run an extension cord all the way up to space,

so it's got two fixed solar panels that dump their power into some 120-watt-hour batteries.

The solar panels provide enough power to fully charge your phone nine times every 90-minute orbit if they are optimally pointed at the sun.

But this actually creates a big problem for us. We have to point this way at the sun to charge the solar panels,

but then we have to point this way at the Earth to send and receive pictures, and then this way down

at the Earth to take the selfies. So how do we move around in space when there's no fuel or thrusters and there's no atmosphere to

push against, so propellers won't work? Well, here's a hint; see this cube? It's just hanging by the swivel mount and it doesn't have

any thrusters or propellers attached to it either. And yet, when I push this button, I can get it to magically rotate

and then stop. So can you guess what's going on inside to make that happen? Well, if we take off the panels to take a look,

the trick is this spinning disk, or flywheel.

Because angular momentum must be conserved. If the flywheel starts spinning one way, physics says the cube must rotate the other way to

maintain equilibrium. So if you orient these three flywheels—we call them reaction wheels—all 90 degrees apart from each

other, then you can spin them up and down to orient the whole satellite to any direction you

want in space. And just like you could see here, they're incredibly precise.

Now, because rotating the satellite is critically important, for a backup, and to help unspin these

flywheels once they get to their max rotation speed, we've also got three torque rods, again, all

oriented 90 degrees to each other. These are super ingenious and such a simple design. You can even make one yourself where you just run a bunch of wire around a $2 piece of crystalline iron.

And when you run a current through that wire, it creates a magnetic field. You can see proof of that here because when we turn it on, it moves this compass.

But that new magnetic field will want to line up with Earth's magnetic field, just like how normal

magnets want to line up together. So you can see here, simply by turning it on and running current through the wire, seemingly by

magic, you can change the orientation of this little floating platform. Another challenge we have is SATGUS needs to know exactly where it is at all times relative to the

Earth, so it knows when to snap your selfie as your neighborhood is passing underneath, along with a bunch of other reasons.

To solve that, we've got a GPS on board, but that only tells us our location, not our orientation.

So for orientation, we've got an IMU, just like your phone does when it knows you've rotated it, as

well as two star trackers that take pictures of the stars and match them against a catalog of star

pictures to understand which way you're facing. But sometimes they can't see the stars because the sun's blinding them.

So there's also two sun sensors that locate the brightest spot in the sky and just assume it's the

sun, and those work great for coarse measurements. For the penultimate critical piece of hardware, we need to be able to talk to it.

For that, we've got two different radios, one slow and one fast. There's a UHF that has low data rates, and that's for basic commands and telemetry communication, and

then an S-band which is for higher data rates, like actually transmitting the pictures. And the final piece of hardware on SATGUS that you're also going to need for your own space build

is the flight computer. This is the brains of the satellite, and it takes all the inputs from the sensors and radios and

then makes the choices on where to spin and take the pictures. For step two of building and sending something to space, we need to analyze our design because there

are four main ways space tries to kill you. So we need to investigate each of these and make sure we're protected.

The first is that it will try and shake you to death. Technically, this actually happens on the launch pad before you get to space.

But the rockets necessary to escape the Earth's gravity are so massive and powerful, the violent rumble inside the rocket is strong enough to break most items we use on a daily basis here on Earth.

Especially if you're vibrating at the same rate as the rocket. And here's what I mean by that.

You know how if you push someone on a swing at just the right time, they go higher and higher?

- Is that too high? - No! - Is that too high?! What?! Fire! But then if you push at the wrong time, you actually mess up their swinging and they slow down.

Everything has a resonant frequency, from your phone right after it hits the ground to your house in an earthquake.

To illustrate, I've got three masses here that all weigh the same.

They're just attached to different rod lengths. So as I increase the shaking of this base plate, see if you can spot when we hit a resonant frequency.

Oh, there it is, for the long one. It becomes like the swing because we're adding more and more energy with each shake...

until it breaks. And now, once again, if I increase how frequently the base shakes, or its frequency, and we go past

the resonant frequency of the big one. Now, the longer rod is fine, but the middle one hits its resonant frequency

and now it breaks. Now, if I do this once more and maybe pause at the first resonant frequency,

and maybe I pause at the second, and then I crank it all the way up, we get close, but we never quite hit the resonant frequency of the small one.

And that's the key. The shaking base plate represents the rumbling, shaking rocket. We have to make sure all of our hardware has a resonant frequency above the rocket's, just like

the short one did, so it doesn't break off like the longer two. But how do we do that?

- Well, remember that CAD model we created in step one to organize and package everything? We put it to double use because now we turn it into a finite element model. This means we take the whole structure and divide it into a lot of little chunks called a mesh.

Each chunk is small and simple enough where we can use really basic physics equations to see how it will affect the chunks next to it if you start vibrating them. So now the computer just has to solve lots of really simple equations that are all connected,

as opposed to one single impossibly difficult equation, to make sure that the resonant frequency for the whole satellite and each individual part are all higher than the rocket shake frequency.

After that, even though we know we won't overlap with that low resonant frequency where things will go really bonkers, it's still a pretty violent shake. So we use that same finite element model to make sure all the pieces on the satellite are still

strong enough to withstand even those lower-level forces. The second way space tries to kill you is it wants to both burn and freeze you to death.

Here on Earth, we've got a nice cozy atmosphere that acts like a giant blanket that both holds in heat from the sun and then moves it around through wind, which keeps the temperatures relatively stable. But in space, there's no atmosphere and no wind.

So in a single orbit, parts of the satellite can get as hot as 212°F in the sun and then as cold as -112°F in the shade. That's like going from nearly twice the hottest temperature ever recorded in a desert on Earth to

the coldest temperature ever recorded in Antarctica every 90 minutes. If we don't protect against it, those temperature swings would freeze or overheat the electronics pretty fast. So once again, we use that mesh that makes the math really simple.

Only now we investigate how heat spreads through the metal structure when it's in direct sunlight or in Earth's cool shade. And once you've done that, you now know where to place the heaters, such as near the flight

Computer, so we can make sure it doesn't get too cold in the shade, and then surface coatings as radiators to make sure it doesn't get too hot in the sun.

The third way space is trying to kill you is to sunburn you to death. An hour in direct sunlight in space is equal to an entire year of standing in the sunlight on Earth.

Thanks again to our protective, helpful atmosphere. So we need to effectively put sunscreen on the satellite by placing critical electronics behind a

thick enough piece of metal or glass, or else the extreme harsh radiation from the sun and other

sources would damage the electronics. But how thick should it be? Because we have a very tight weight budget, we can't afford to make an enclosure thicker and

heavier than it absolutely needs to be. Well, as an example of how we figured that out, we took our Google Pixel and placed it in a radiation

chamber that mimics the harsh space environment, then blasted it with radiation, and it actually lasted about 10 minutes, which is pretty impressive.

Plus, it looked really cool. And so now that we know exactly what amount of radiation causes phone screen failure, we can

calculate how thick the aluminum and glass enclosure needs to be to make sure we stay well below that value.

In our case, the necessary 'sunscreen' ended up being aluminum that's six millimeters thick and a

radiation-hardened glass that's five millimeters thick. Speaking of super advanced phones in space, we partnered with both Google Pixel and T-Mobile to

make this whole thing happen. Google Pixel was the obvious choice to take the first ever selfie from space because of its

specifically tested durability, bright, high-resolution display, and the Real Tone technology that accurately displays all skin tones. And then T-Mobile, because they're already partnering with

Starlink to provide satellite coverage to keep you connected in places you never thought possible. So they were experts when exploring how to communicate with our selfie satellite.

I Tried Building My Own Space Satellite

Former NASA engineer. Current CrunchLabs founder and friend of science.

Answers to some common questions:

1) I make a monthly toy we build together on a video, that gets delivered to your house that teaches you to think like an engineer.  Check it out at- https://crunchlabs.com
2) I studied Mechanical Engineering in School.  I did my undergrad at BYU and Masters at USC.
3) I worked for NASA JPL for 9 years, 7 of which were working on the Curiosity Rover (I made a video about it you should def totes watch cause it's probably my favorite of all my videos).  Then I made some Halloween costumes.  Then I worked for Apple in their Special Projects Group doing Product Design as a Mechanical Engineer for 5 years. Then in 2022 I created CrunchLabs to deliver monthly toys that teach you to think like an engineer.


Mark Rober

SATGUS 위성 소개 및 우주 셀카 프로젝트

새로운 맞춤형 위성 SATGUS 소개, 초속 5마일 속도로 우주 비행

SATGUS의 특징: 우주에서 지구를 배경으로 셀카 촬영 기능 탑재

도시 정보 입력 시 해당 도시 상공에서 셀카 촬영 및 시간 정보 제공

일반인의 우주 위성 제작 및 발사 가능성 언급

우주 위성 제작 및 발사 6단계 과정 소개 (NASA Mars Rover 작업 경험 바탕)

위성 설계 및 제작 단계 (CubeSat 활용)

1단계: CAD(Computer-aided design)를 이용한 디지털 설계

CubeSat 활용을 통한 시간 및 비용 절감

CubeSat 표준화된 하드웨어 및 크기(1U, 2U, 3U, 6U, 12U) 설명

기본 기능 하드웨어와 탑재체(카메라, 화면) 분리 설명

CubeSat 활용을 통한 개발 비용 절감 효과 강조

탑재체(payload): 우주 환경에 맞는 카메라와 방사선 차폐 케이스 장착된 Google Pixel 휴대폰

전력 공급: 태양 전지판과 120와트시 배터리

위성 방향 조절: 반작용 휠(flywheel)과 토크 로드(torque rod) 활용

위치 및 방향 인식: GPS, IMU, 별 추적기, 태양 센서

통신: UHF 및 S-band 무선 통신 장치

비행 컴퓨터: 센서 및 무선 통신 장치 데이터 처리 및 제어

우주 환경 위험 요소 분석 및 대비

1. 진동: 공진 주파수 분석 및 구조 강화

2. 온도 변화: 히터와 방열기 설치

3. 방사선: 알루미늄과 방사선 경화 유리 차폐

4. 진공: 가스 방출 방지 및 부식 방지

우주 셀카 참여 방법 및 위성 수명

spaceselfie.com 웹사이트를 통한 셀카 사진 업로드 및 촬영 시간 정보 제공

참여자에게 우주 셀카 미션 패치 발송 및 로켓 발사 관람 기회 제공

3단계: 위성 제작 (15초 제작 영상)

하드웨어 및 소프트웨어 통합 테스트 (태양 전지판, 카메라, 화면 등)

4단계: 진동 및 온도 테스트 (shake and bake)

발사 장치에 위성 탑재 및 포장

5단계: SpaceX Falcon 9 로켓 발사 (캘리포니아 Vandenberg 공군기지)

Vandenberg 기지 발사의 전략적 이유 (전 지구 촬영을 위한 궤도)

발사 과정 설명 (로켓 분리, 궤도 진입 등)

6단계: 위성 운영 및 모니터링 (임무 제어실)

위성 수명 종료 과정 (궤도 붕괴, 대기 마찰에 의한 소멸)