Skip to content
Health, Sports & Psychology
Author:
  • Video
  • 5 mins

John Zarnecki in conversation with Ralph Lorenz

Updated Wednesday, 30th March 2011

Professor John Zarnecki reminisces with his old team mate at the Science Museum about their amazing project to land the Huygens probe on Titan.

This page was published over five years ago. Please be aware that due to the passage of time, the information provided on this page may be out of date or otherwise inaccurate, and any views or opinions expressed may no longer be relevant. Some technical elements such as audio-visual and interactive media may no longer work. For more detail, see our Archive and Deletion Policy

Watch

Listen

Read

 

Professor John Zarnecki Professor John Zarnecki Professor John Zarnecki Professor John Zarnecki John Zarnecki

Well Ralph, who’d have thought that nearly 20 years after we started together, we’d be here at the ScienceMuseum still talking about penetrometers, about the Surface Science Package, hard to believe isn’t it?

Ralph Lorenz

Yeah, it didn’t seem real at the time.  It was just all diagrams and the idea that we might send something there and then it became real.

John Zarnecki
What I like about this is that conceptually it’s so simple isn’t it, the way it works?

Ralph Lorenz

Yeah, there’s really not much to it.  There’s just this white disc here which generates an electrical charge when it gets squeezed and so when that gets rammed into the surface of Titan we get a signal that tells us something about what the surface is made of.

John Zarnecki
That’s right and that’s why it appealed to us, because of its simplicity, it was quite possible that the probe would be destroyed on impact or within seconds of impact, so we wanted something that would make a quick and relatively simple measurement.

Ralph Lorenz

And at the time a lot of people thought that maybe Titan was covered in an ocean of liquid hydrocarbons and this was just kind of hedging our bets of, well, what if it is a solid surface we need to measure something about.

John Zarnecki
Yes, because in the case of a liquid we would get no signal.

Ralph Lorenz

Yeah, this would be useless.  I remember spending a lot of time working out the splashdown dynamics of a probe in liquid hydrocarbons and looking at all the Apollo data and of course that was all a wasted effort, but we didn’t know it was going to be wasted.

John Zarnecki
Well no, none of it is wasted effort and of course what’s interesting is that you showed didn’t you and other people as well that actually there was a good chance that the probe would survive splashdown and as long as it wasn’t severely damaged it should have floated for quite a long time.

Ralph Lorenz

That’s right.  I think one of the other experiments was beefed up because of that analysis.  I suppose I really deserved my PhD, didn’t I? 

This is the one that the wires just bent that nice way, it just felt like it came together the best, this was the one we were going to send.

John Zarnecki
Absolutely.

Ralph Lorenz

And then something happened.  It’s here.

John Zarnecki
Instead of one and a half billion kilometres away on the surface of Titan.

Ralph Lorenz

Yeah, but I guess that’s why we make a spare, right?

John Zarnecki
And of course, people probably don’t understand but even just optimising the shape of the end is an important part isn’t it?

Ralph Lorenz

I think we had a two hour meeting about whether this should be 14 millimetres in diameter or whether it should be 20. 

John Zarnecki
And of course it’s all about getting a clean signal from the surface of Titan, getting it reliably and relatively unambiguously, in a way that you could interpret, in the case especially if there were no images or there was no other data, this could have been -

Ralph Lorenz

That’s right.  It could have been the only information.

John Zarnecki
That’s right.  Luckily most other things worked so we had fabulous images and so on.

Ralph Lorenz

And we had to think, well, is this going to work at 200 degrees Celsius below zero, is it going to survive the radiation dose, how will it handle buffeting under the parachute, will the vibration trigger it, yeah, we had to think about every little aspect of this.

John Zarnecki
Look, there it is Ralph.

Ralph Lorenz

Yeah.

John Zarnecki
Who’d have thought it?  We started in Canterbury didn’t we, we went to Titan and then here’s the probe.

Ralph Lorenz

And now here it is.

John Zarnecki
Or, at least a model of it, here in the ScienceMuseum.

Ralph Lorenz

Yeah it probably wouldn’t be here if it hadn’t been so successful.

John Zarnecki
Yeah, we just didn’t think of things like this did we all those years ago?  It was all about the nitty-gritty of the details of the instruments.

Ralph Lorenz

Yeah, remember how we talked for hours and hours in meetings about how those little veins at the bottom should be canted and how fast to make it spin and then it ended up it spun the wrong way.

John Zarnecki
You’re absolutely right, it ended up spinning the wrong way as it descended down through the atmosphere, and of course that really complicated the analysis didn’t it of the data, it was some time before the camera team could put all the images together in the right sequence.

Ralph Lorenz

But as scientists we like puzzles, right, if it was too easy it wouldn’t be as much fun.

John Zarnecki
Yeah.  Can you imagine what it must be looking like now sitting on the surface of Titan?  Do you think that it’s now getting covered with a layer of hydrocarbon goo?

Ralph Lorenz

It’s probably getting grimy, but one day, maybe a year from now, maybe a thousand years from now, there’s going to be a big methane rainstorm and maybe a flash flood will come down that streambed that it’s sitting on and tumble it around or float it down.  It probably won’t stay there forever.

John Zarnecki
But there really is a good chance isn’t there that we’re going to go back, perhaps not next year, but within, certainly within a generation, within the next 10, 20 years, we’re going to go back and we’re going to go back with some very exciting vehicles with some sort of aerial platform; what’s your take on it?

Ralph Lorenz

Well we’ve found with Cassini and Huygens just how interesting a place Titan really is, so you’re right, I think we’re definitely going to go back sometime in the next decade or two, and probably with much more ambitious technology than we have with Huygens, maybe in a hot air balloon, maybe a lander, certainly an orbiter, we’ll learn a lot more about this strange place.

John Zarnecki
Yeah, and of course the technology of this was pretty much the technology of 20 years ago.  It seemed pretty good then, in some ways it’s pretty crude now, isn’t it, by today’s standards?

Ralph Lorenz

Well I remember we didn’t have laptops, compact laptops with lots of documents all in PDF files; it was all done in paper and fax machines.  There wasn’t a World Wide Web.  Somehow the team in Poland connected with you in Canterbury and you were in touch with the ESA people in ESTEC and they were in touch with JPL in the States, all with faxes.

John Zarnecki
And somehow it worked.

Ralph Lorenz

Somehow it all came together.  Yeah, all those bolts have to be in a specific place, and the holes have to line up and somehow all that gets worked out on paper, that’s the amazing thing about these projects I think.

John Zarnecki
And anyway as we were saying, let’s hope in 20 years’ time, 25 years’ time, there’ll be another probe sitting over there or maybe as you say a balloon, Huygens Mark II.

Ralph Lorenz

That would be great to see.

John Zarnecki
And let’s make a date.  Let’s meet here and talk about the next one.

Ralph Lorenz

Righto.

6’16”

 

 

Take it further

Want to explore the world of astronomy? Find out about OU courses focusing on this area and get a taste with our free LearningSpace unit on telescopes and spectropgraphs.

Virtual planisphere

Use our virtual planisphere to track the night skies throughout the year.

Titan in more depth

Professor Zarnecki lecture

Visit John Zarnecki's profile page.

 

Author

Ratings

Share

Related content (tags)

Copyright information

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?