- Look, I told you,
it doesn't matter why I want it
or how much it costs.
Just get me that space car.
Do it, do it!
Let's just say that for some super villainy reason,
you wanted to steal the only sports car currently in space.
How would you do that?
Let's get technical.
(Over the phone) Get it to me now!
(intense rock music)
In early 2018, a one Elon Musk,
after taking suggestions on Twitter,
decided to christen the launch
of his Falcon Heavy Rocket with the silliest
thing that you could imagine.
That silly thing just happened to be his personal
midnight cherry Tesla Roadster.
After launching in February,
that road car became the first in the cosmos,
carrying a towel and blasting David Bowie.
It was a heck of a spectacle, sure,
but the car isn't just lost to the void now.
We know exactly where it is.
All an enterprising super villain
would have to do then is get to it,
and I'm not saying I'm one of those
or that you should do it,
I'm just saying this is how you could do it,
very very important distinction there.
First, it's not like government agencies
or Musk himself is going to help us nab a space car
that's already traveled the equivalent of 37 times
all of the world's roads put together, no.
So, we're gonna have to take a quick crash course
in orbital mechanics and maneuvers.
Probably not the best choice of words there.
And don't you worry about how we're actually going
to intercept and then return the Tesla to us.
I so happen to have a Tesla capture device
that I cons...
that I found at a yard sale.
What we really need is a plan and a pathway through space.
When should we launch?
How long will it take us to get to the Roadster?
What will the trajectory look like?
Oo, it's all coming together,
he said innocently (laughs maniacally).
A rendezvous in space isn't as easy
as just point and then thrust it
and that's because everything in space is moving.
Gravity is everywhere, it affects everything
and so, in effect, everything in the universe
is always falling around something else,
whether that be the earth around the sun
or a galaxy around another galaxy,
and so any orbital maneuver
inside our solar system, for example,
has to take into account this omnipresence of gravity.
For example, if you wanted to launch a rocket
from Earth to Mars, and you just point and shoot
without gargantuan thrust,
you're gonna miss.
So instead, bending to gravity's whim,
we're gonna want to take some kind of curved path,
not a straight one, that will take us,
not just to where Mars is,
but to where Mars will be
when our rocket gets there
millions of kilometers later.
This kind of orbital maneuver is one of the simplest
and easiest, in terms of fuel
and it's called a Hohmann Transfer.
So, we're gonna wanna learn the mechanics
of this kind of transfer
if we're gonna pull off grand theft strato...sphere.
Stra...
So, let's learn by doing
and return to the example that we just laid out.
How would we really get a rocket from Earth,
where it would launch from,
to Mars, where there's definitely
not a subterranean base of mine, for sure.
We know we have to take some kind of curved path again,
but we have to be exact or else we're going to miss Mars,
where something is definitely not being
constructed right now, don't even worry about it at all.
So, let's get more technical.
The idea during a Hohmann Transfer
is to take some kind of elliptical path
to your destination, but when you get there,
you have to remember that a celestial body
or a planet or what have you,
has a lot of velocity on it's own.
So, when you get there,
you're gonna have to match that velocity in some way,
and so, this kind of maneuver won't just take one burn
to launch you off of a planet like Earth,
it's actually gonna take two,
one to launch you off of your planet
and then, a second to match the new orbit
of the thing you are trying to intercept.
When performed correctly,
this kind of maneuver looks like this.
This is NASA launching their Insight Mission.
It looks relatively straightforward and easy,
but it only looks that way.
There's actually a lot of math involved.
So, if we only have really probably one shot
of stealing star man, we're gonna learn the math
behind this kind of transfer, step by step.
(phone rings)
All right, I'm gonna let that go to voicemail.
(Through the phone) Answer me, you coward!
Just how much velocity do you need
to add to or subtract from a rocket
in order to get it to Mars or even a space car,
that's right, it's super...
space enthusiast pop quiz time.
Here is the sun and Earth and Mars
in their respective orbits.
I'll lay out all the variables that we want.
To get from the earth to Mars
with one of the simplest transfers that there is,
we're gonna have to know the orbital velocity of Earth,
the orbital velocity of Mars
and the velocities that we need
to both enter and exit our transfer elliptical orbit.
The force keeping Earth and Mars in orbit around the sun,
gravity, can be modeled like the tension in a string,
if you tied a rock to the end of a string
and was swinging the rock around in a circle,
but you could also model it like
a simple gravitational interaction.
So, you can use these equivalences
to solve for the orbital velocity
of both Earth and Mars around the sun.
If we take Newton's Gravitational Constant as G here,
the big M as the mass of our sun
and R being the distance between the sun
and the planet that we're concerned about.
Now, I was not joking about a pop quiz.
What is the orbital velocity of Earth around the sun?
You can look up Newton's Gravitational Constant,
the mass of the sun and the distance
from the earth to the sun.
Now, don't just look up the orbital velocity of Earth,
I want you to really try it.
It's empowering, you can pause the video
right now...I'll wait.
(elevator waiting music)
The correct answer, if we round, is B,
30 kilometers per second,
that's how fast the earth is going in orbit around the sun.
How'd you do?
Using the exact same reasoning,
look up the distance between the sun and Mars
and solve for the orbital velocity of Mars.
I'll wait.
(elevator waiting music)
The correct answer is
24 kilometers per second around the sun, C.
How did you do?
Did ya get it?
Because now, it's time to get a little bit more--
(phone rings)
complicated.
Ssh, say I'm not here.
(Over the phone) I know you're there!
If you wanted to find out the total amount of energy
of a body orbiting something like a star,
you would need it's energy of motion,
it's kinetic energy and you'd also need
it's gravitational potential energy,
which is the same energy as anything has
sitting in a gravitational field.
Anyway, the total amount of energy
of an orbiting body is also equivalent
to half the gravitational potential energy
at the average distance between two bodies,
and this is really important
because this will enable us to calculate
how much velocity we will need
to both enter and exit an elliptical path
between two points.
We can use this relationship
to solve for velocity here, too,
and we get the velocity that we need
to both enter and exit our elliptical transfer orbit
based on R being the distance
between the sun and Earth
and the sun and Mars,
and remember, that A here is those distances
added together and then divided by two.
Pop quiz!
Using the distance between the earth and the sun
as our first, what velocity do we need
to initiate our transfer orbit?
(elevator waiting music)
The correct answer is A, 33 kilometers per second.
Did ya nail it?
I bet you did, you nerds.
Now, use the distance between Mars and the sun
to find our exit velocity, pop quiz!
(elevator waiting music)
The correct answer is B, 21 kilometers per second.
Did you get it?
Because if you did, that deserves one gold skull.
We don't give out stars for this kind of mission.
So, now that we know all of our numbers,
what is the total amount of velocity
that we need to give our rocket
to make it from Earth to Mars?
This is a critical calculation
in any orbital maneuver called Delta V,
pop quiz, what is it?!
We want the absolute distance
between all of these velocities.
How much velocity will take us
to launch off of Earth to get us
into that elliptical orbit
and then, how much will it take us
to speed up or slow down to exit from that orbit
and match Mars' orbit?
Take a shot at it right now.
I'll wait again, ah!
(elevator waiting music)
Did you get 6 kilometers per second?
Well, let's check our work.
You can find Delta V maps
for real interplanetary travel
pretty much anywhere on the internet.
So, if we look at the pathway,
you would need to take, in terms of velocity,
from Earth to Mars and you add all those up,
what do we get?
Well, I got 5.7 kilometers per second.
Look how close we were with six.
We calculated a space mission kinda.
That deserves one gold skull,
maybe even two, kinda, yeah!
We did the basic calculations, sure,
but to steal a space car,
we might need some help.
We already know the Tesla Roadster's
exact location in space.
We also know that it's going 40 times faster
than a Bugatti Veyron.
Thanks to the laws of physics,
we should be able to accurately track
the position of this space car for centuries.
Now, while we could do the same kind
of Hohmann Transfer calculations that we just did
to get to this space car,
as you can see, the orbit of this car
is not quite as nice and circular
and centered on the sun as Mars is.
So, I'm not gonna lie,
these calculations we just went through
aren't really gonna cut it
and the math would be a little bit above our pay grade.
So, instead of going through a bunch
of complicated math and then, getting it wrong,
why don't we, instead, play around
with a very specific and specifically helpful calculator?
(rock music)
Sup, nerds?
Welcome back to another Let's Play, of course.
Today, we're checking out Planetary Transfer Calculator,
which you can go and check out at
http://www.transfercalculator.com.
As you can see here, we have the orbits,
the standard orbits that we're looking at here.
We have the earth orbiting around the sun
and we have Mars orbiting out around here
and what's cool about Transfer Calculator
is that you can actually add other minor bodies
and we can add star man.
So, let's turn that on right here.
So, now, we see star man's orbit in red.
Now, what this calculator does,
is make hundreds of Hohmann-like transfer calculations.
It iterates them down to find the simplest best transfer,
the lowest energy transfer from anywhere
you wanna go to another place.
So, we can actually now calculate our path
using a lot of mathematical help
from the people who created this,
our path from Earth to, let's say, the Tesla Roadster.
I'ma set the time to when I'm filming this Let's Play,
(chuckles) as we always do streaming.
Yeah, am I right?
So, I'ma set the time to now
and then, I am going to go ahead and calculate our transfer.
I get, if we launch next February,
which is the best time to launch,
according to this calculator,
it looks like it'll take us just about
16 1/2 months to intercept the Tesla Roadster
and then, it would take another 16 1/2 months
to get back to Earth, presumably,
and with a Delta V of about 4 1/2 kilometers per second.
So, this is a much longer transit time,
as you can see here,
to the Tesla Roadster than it would be to Mars,
but it's a much lower Delta V.
So, with all these numbers,
we should be able to set our super villainy plan in motion.
This is all we need.
We can see the ship coming within intercept range
of the Tesla Roadster now in just a couple months time.
That's pretty cool.
I like Transfer Calculator quite a bit, all right.
Ah, Bearcat comes in with a five dollar donation.
"Hey, Kyle/discount Thor, you really did
"a great job."
(Scoffs) Discount (scoffs again).
(rock music)
If we use this specific trajectory,
within a few years,
we should be able to get our hands
on the only road car that has ever existed in space,
and when our undisclosed Tesla capture spacecraft lands,
we will have an awaiting semi-truck
to whisk it away to super villain auction.
Of course, we probably won't be able
to make back even one percent
of the mission costs from the car sale,
but hey, it's the super villain principle of the thing,
which I'm not and I'm not saying you should do this
and don't tell Elon.
So, if you're a super villain
and you have millions of dollars
burning a hole in your pocket
and staff and infrastructure and rockets
and the knowledge of orbital mechanics,
there is a relatively simple trajectory
towards carjacking the star man
and if you do pull something like this off,
now that I support or condone it,
tell them it was, "Because Science."
(Chuckles) Space car.
(Upbeat electronic music)
You know what might actually be
more impressive than a super villain
stealing a space car, is if Elon Musk
did all of this himself.
If he launched it into space
and then, with his reusable rocket technology
in a couple years, was able to successfully
return a space car back down to Earth,
and then, he restored it,
and then, he was driving it around
headquarters in Hawthorne,
now that would be impressive,
and it would improve his rocket technology,
and I guess I just gave him a great idea for some PR.
You're welcome.
(electronic music)