Destination Titan Page #3

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fiction in the sense that somehow we were going to

build this thing that was going to

travel a billion miles through space

and then parachute down through

this atmosphere at minus 200 Celsius

and touch the surface of

one of the moons of Saturn.

It just boggles the mind that

you can contemplate doing that.

Ralph is enthusiastic about

everything he turns his attention to,

and he became very quickly

embroiled in all aspects of Titan.

And one of the tasks that we assigned

to him was to develop the penetrometer.

One the things we really want to

answer with the Surface Science

Package is what is the actual

nature of the surface of Titan?

What's it made of? Is it solid like

ice or is it slushy or is it liquid?

This part of the package, called a penetrometer,

aims to do that by measuring how hard we land in it.

As the probe comes down,

we measure the impact forces.

It's very strange, you sort of come

into this from the outside thinking

that there's some massive team of

top notch engineers and scientists

who've done this all before and that you

will be allocated some little part of it.

And the reality is, there's

never enough people

and everyone is improvising because nobody's

built anything that went to Titan before.

So it was at first a little

strange and surprising that

I'd get to do this but it

was an incredible opportunity.

In the early days of the project,

we were being followed by a

BBC crew who were filming

some aspects of the project for

an Open University programme.

It was an eye opener

- the first time I'd been involved in that kind of thing.

They actually set up a little

video diary for us,

a little passport photo, where you just sit in

front of this video camera and say what had happened.

It's April 13th, last week we

donned these crazy suits and went in

the clean room to assemble the

engineering model penetrator.

This instrument will perform

thermal properties measurements

to show the thermal conductivity and

the temperature of the Titan ocean.

This will be sent to a way to be

shaken, baked,

and electrically tested

in what is called the top hat,

that is the thing that

holds all the experiments.

As you can see, it's

quite small and fiddly,

but I'm rather pleased with it.

Science students tend to be nerdy,

and, I think, as a group

we conformed to that stereotype,

so that it means you're really

utterly focused on what you're doing

when you have three years where you have no

other commitments other than to do your research,

and because building a space experiment

going to Titan is such a motivating thing,

it was really wonderful

actually to have that focus.

The penetrometer was a fairly simple

sensor in concept,

but actually doing it well took

a lot of work and a lot of effort.

Ralph was involved with running a load of prototype

tests and dropping things into bucket of sand

and seeing how different

tip shapes responded, etc.

I remember one of the first things we did

was got some sand from Whitstable Beach

and that was a huge mistake because it was real

sand at the sea and so it was all wet and salty.

And, of course, salty water is an

electrical conductor and of course

the signals we got from

that were just terrible.

It was building an instrument to go

somewhere that we didn't know what

we were going to land on, and that

was a real part of the fascination.

It's one thing to make a measurement in a laboratory,

it's another to make an experiment that is going

to work, for sure, seven years later after

travelling through space for a billion miles,

that's going to work

at 200 degrees below zero

and that isn't going to suffer

any kind of problem.

The biggest fears we had were landing on absolutely

sharp, exposed ice, which meant the runners of the

probe might die pretty quickly, and our challenge

was to get the data back before the probe died.

At the time, one of the main

speculations about Titan's surface

was that it was covered by a

global ocean of liquid methane

and so I spent quite a

lot of time doing my PhD

modelling the splashdown

dynamics, looking at all the old

Apollo literature of how a capsule

decelerates when it hits the water,

and trying to figure out how much

the Huygens probe

would decelerate if it landed

in liquid methane.

A lot of it was theoretical stuff.

Do we have global oceans, do we have seas,

do we have lakes, anywhere in between?

The natural speculation was,

Well, it'll be like landing

on Mars or landing on the moon but we had no

idea what the materials really are, if it's ice

or if it's ground-up ice like sand, or if it's

some sort of organic dust that's very fluffy.

So we had to consider

all these possibilities.

We certainly didn't know anything

that would let us

exclude any of them.

This is the final engineering

model of the Huygens Surface

Science Package, containing

its nine different sensors.

We've got here

the speed of sound instrument

to measure the speed of sound in

the atmosphere and on the surface.

Here we have the sonar,

designed to send a signal down to the

surface of Titan or to the bottom

of the lake to measure its depth.

Inside this enclosure here, we've got

six further instruments to measure

various properties of the liquid

or the solid surface,

and finally

we have here the penetrometer.

MUSIC:
"Future Proof"

by Massive Attack

Yeah, output lines are clear and we're

running at about 6 PSI over ambience.

Once you get into the

hardware phase of the project,

there's testing, testing, testing,

and some of these tests run

for tens of hours at a time.

There were times when I felt

that I knew my milkman better than

my family because I was arriving

home at 5 o'clock in the morning.

Can we have temperatures

please, James?

Top cavity 111, bottom cavity 114.

For this particular mission, one of the really unusual

things was when we got there, we were going into

a very, very cold environment, so many of the

sensors we needed to test in liquid methane.

It is a little bit hazardous, so we were

doing this on the roof of the physics building,

I guess the logic being that if we blew up,

we only blew ourselves up and no-one else.

A project like this

inevitably put strains

on all the individuals involved,

and that's challenging enough.

I'm not sure that my family really

understood quite what I was doing,

they sort of supported me, but probably

thought that I was the crazy scientist

and maybe every family

had to have one crazy scientist.

I was very lucky in the sense

that I'm quite a self-motivated,

self-driven kind of guy so

I didn't need a lot of handholding.

And that was just as well

because John was a busy man.

The job he was doing as a university lecturer and

building a space experiment was quite demanding,

and he was going through some

personal difficulties at the time too.

The early days of the project coincided

with the breakdown of my marriage,

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