welcome back to Smarter Every Day.

This is my drill press.

Out of all things that humans could send up to Mars

on a nuclear powered robot,

a drill was one of the most important things we sent.

And the reason we did this,

well think about this.

This is the board and you've seen tree rings right?

If we were to drill into this board,

and then analyze the shavings that come out of that hole,

because of the tree rings we could go back in time and understand

what was going on in this board when the tree was younger right?

That's exactly why they sent a drill to Mars.

We want to understand if there were organic molecules

inside the rocks of Mars when they formed.

But in order to do that you have to drill below the surface

and then analyze the powder.

But every article I've ever read about the drill

and about how they analyze the powder

doesn't really satisfy me.

So today on Smarter Every Day

I'm at JPL.

This is Mark Rober.. Crazy!

He's gonna give me a tour of what?

- Uh OK.

- You missed your cue.

- Sorry. [laughs]

- We've gotta start over, he missed his cue.

- I just realized..

- This is my buddy Mark.

You remember all that fancy rocket business where we

descended the curiosity rover down to the Martian surface

with these fancy rocket cranes?

Yeah he helped work on that.

But more importantly he owes me a ton of favors

so I asked him if he could introduce me to the

people behind the drill on the rover.

I wanted to understand exactly how this thing works.

- So we are going to the Mars yard,

which basically is a simulation of the Martian surface.

- Yeah look both ways before you cross the street and go to Mars.

- Behold.. Mars!

- So this is the Curiosity garage?

- Yeah, so they'll bring it out here in the yard

You can see here's the tracks.

But then when they're just working on something inside

they bring it back into the shack.

- Wow. Oh man so is this the only one?

Is this one of a kind?

- It's one of a kind.

The only one on planet Earth.

- I guess it's two of a kind.

I'm Destin, what's your name?

- Megan.

- Can I shake your hand from a long way away?

Nice to meet you Megan.

You're running the test?

- I'm running it right now, yeah.

- That's pretty awesome.

He hasn't let you talk at all,

but I really want to talk to you but there's a rover in between us.

This duplicate of the curiosity rover exists

so scientists and engineers can test software

and tricky manoeuvres without having to risk damage

to actual flight hardware.

OK we decided to quit messing around

and Megan's actually gonna tell us what the tools are.

You know all the tools right?

- I know a lot about the drill and the Chimra since I tested them.

- Yeah?

- So this is kind of the butt end of the drill right here.

- Can I walk over there?

- You can come over here.

- I will. So you're clipped in, right?

- I am clipped in..

- To the grounding point, OK.

- And so this what you see right here

we call Chimra,

I have no idea what that acronym is..

- It's basically the tool belt right?

- This is the sample processing.

- OK I really need to apologize right now,

because I started geeking out so hard

because I was in the room with the rover,

that I forgot I was making a YouTube video.

And I started asking questions and they were

awesome questions, and then they let me run a command

on the mast, and I moved it around.

It was incredible.

Anyway, I went back and I tried to summarize

everything I learned while I was offline in this one take.

I'm so sorry.

So this is the main mast which is the RSM.

Which stands for what?

- Remote Sensing Mast.

- OK and there's two probes on the side here

and these are both for weather.

One of them on Mars actively doesn't work at this moment in time.

Because it didn't work at landing right?

OK so this is the arm here that I'm using to gather

samples on Mars,

and it uses Megan's drill bit, right,

- The official name.

- The official name. So that's the drill bit,

and it should have enough life to meet our primary

objectives on Mars, and after that goes bad for whatever reason

if we want some icing on the cake then you've got

two extra drill bits located down here that you can

autonomously swap out.

- Correct.

- And that'd be the first time that's ever been done on a different planet.

And it's gonna happen cause you worked on it right?

- I want it to happen.

It would be really awesome to see.

- Excellent. So over here,

looking at the samples.

So before we decide what samples we're gonna analyze by putting them in this little hole right here

we can put the samples on the plate,

we can measure their size, both by the fiducials there on the checkerboard

or by dropping it through that funnel right?

- Right.

- And then once we do that,

we can then, if it meets the critera we can

put it in this hole and analyze it.

And after you analyze it you dump it overboard.

- Yep.

- Did I get it all right?

- Yep.

- You're a good teacher.

Clearly Megan's a genius,

however there were still some questions that I had.

I wanted to understand the exact interaction

between drill bit and rock.

Which is why I came to see Ryan.

What's your title?

- Drill systems engineer.

- So what's this right here?

What do you have?

- This is a drill bit assembly.

- OK.

- This is not only our drill bit,

which if you take a closer look this is a masonry bit,

it's not like the cutting bits that you have on

your handheld carpentry drill.

It's more of a chisel and it's designed for impact drilling.

- OK. So how does it work?

- So first we set our drill,

preload our drill stabilizers against the rock

to make sure that we have a nice stable configuration.

Then we feed forward until we contact the rock.

- OK.

- We start our drilling operation with a process we call start hole.

So if you can imagine, if we're on a rock and not perfectly aligned

and there's all these surface features,

little divots on the rock,

the bit's gonna want to walk around

Imagine like if you're trying to cut metal

you usually put a little pilot hole before you start drilling.

- So you don't break the bit,

Is that the same reason you do it here?

- Yeah, so we have a process we call start hole

that starts the first 5mm of our hole

and basically what we're doing is chiselling little divots to carve out an asterisk shape.

[hammer drill sound]

Then we drill that out and we repeat that process

as many times as it takes to get down to 5mm.

Then we have a good starting point for the rest of our drilling.

[hammer drill sound]

It's not the rotation that's really cutting the rock

so much, it's really the hammering action.

[hammer drill]

Like a jackhammer and then the rotation we do is mainly

for drawing the powder up through the sheath.

We continuously drill until we bottom out the drill.

Literally we're bumping up the front face of the

drill bit assembly against the rock.

Before we drill we do a triage,

we drill a little bit so we can see what the powder is going to look like

because we are worried about if it turns out

that this material has, it's hydrated and it's

somewhat sticky then it could clog up our drill bit assembly.

- Is it, on Mars?

- It can be, and that's one of the interesting

science findings recently is that there's a water cycle,

an active water cycle near the surface of Mars

even at Gale Crater.

- Do you have any of the drill bits that are outside of the drill head?

- Not with me here but I can show you one at my desk

if you're interested in seeing what that looks like.

I have a 3D printed model of this where the bit itself is metal but the rest

of the housing is clear plastic so you can see through.

- No way, can we go do that?

- Yeah.

- So what you drill, you auger the material up into this right,

this housing?

- Exactly. Yeah into the first of our two chambers within the drill bit assembly.

So we have two chambers in the drill bit assembly specifically

so that it gives us some freedom to be able to move the

robotic arm around without worrying about spilling

material back out through the exit tube before we're ready

to transfer it.

So once we draw it into the first chamber it's in that first chamber

until we transfer it through this little slot you can see here.

- Yeah.

- So we transfer it through that slot.

We use percussion to shake things up

and we use gravity to control which direction the stuff is going.

- So that's the mass flow you were talking about.

- Yeah.

- Can I pretend to be the robotic arm for a second?

- Please.

- Yeah OK so basically you've got that slot,

and so you want to keep that slot down

so you want to go drill,

and then you pick it up and as long as that slot's

up top then you keep all your sample right?

- That's right.

- OK and so then at that point

whenever you get it to where it needs to go you can then

rotate it over and then dump it through that little slot right there

into the next chamber?

No wait back this way right?

- That's right.

- OK so you kinda..

- Through the slot to the second chamber.

- Almost bumped, almost into your hand like this right?

Nope, then you rotate again and it goes out that port.

- That's right.

[drill]

- OK so we've drilled our rock and now we've got the powder

on the inside of the rock.

In a very specific circumstance if you find a special rock

and you think you might actually have organic molecules

on the inside of that rock, you've got to baseline your instruments.

In order to do this, JPL got pretty clever.

They put these cans on the front of the rover

to be used only in certain circumstances.

I'm gonna let Megan explain what they're for.

So in these cans there's what's called OCM

which is organic check material?

- Yep that's right.

- OK and so the idea is you have a known sample that you can test