Sending robots to to the Red Planet
Getting to Mars is a tricky business. Space is a dangerous and inhospitable place but if we're successful, we can look for microbial life on the red planet. Paul Meacham works on the ExoMars prototype rover, Bruno and he explained to Graihagh Jackson what it takes to get to Mars...
Paul - Mars is not the easiest place to get to. It’s actually very demanding. Even just getting off the surface of the Earth is difficult because our gravity, it doesn’t feel very strong to us. But it is an incredible force to overcome.
Graihagh - And then getting there I imagine is what, 9 months?
Paul - It is a very long time, yes. Nine months in cruise and of course, during that whole time, you're away from the Earth’s protective layer. So, you're subject to the full elements of space. It’s quite tricky to overcome that.
Graihagh - To give you an idea - to get off the surface of the Earth, you need tremendous amounts of power.
So, if you're strapped on top of a rocket, it’s not a very pleasant place to be. You are getting blasted with lots of vibrations, lots of soundwaves. So, you’ve got to build your spacecraft to be able to withstand all those forces and not transmit too many of them to the actual passengers.
Graihagh - How do you test that?
Paul - Essentially, you’ve just got environmental test facilities. Where you have a big table that shakes the spacecraft. We even have a room where we do an acoustic test. So essentially, we stick the spacecraft in there and then we blast it with sound waves. It’s not a particularly pleasant place to be because if you were a person in that room when we were testing one of our spacecraft, you would be killed.
Graihagh - That’s not all, the radiation can wreak havoc on your electronics. In the Apollo missions, something like 3 days in space was the equivalent of 12 chest x-rays.
Paul - That’s right. They flew through what we called Van Allen belts which are belts of radiation that surround the Earth. It’s particularly a high energy environment. But yes, as you say, that was only 3 days and we’re talking 9 months. So, the equivalent dose is much, much higher.
Graihagh - Not to mention temperature…
Paul - The rover’s main structure is called a bathtub and it has this space equivalent of double glazing in order to create a thermal barrier through which heat can't get in and heat can't get out. And then when you do that, you can create quite a habitable microenvironment within that cocoon.
Graihagh - And then there’s the landing. It’s not only ExoMars that have struggled to land rovers on the surface; back in 2003, the Beagle probe famously didn’t manage to open its solar panels and power up. What I’m trying to say is It’s one big job for people like Paul.
Paul - We certainly do and that’s why facilities like the Mars Yard are so important because it allows us to practice everything we’re going to need to worry about when we get to Mars on Earth.
Graihagh - This is the weirdest place I've ever been. I don’t know quite how to describe it.
Lost for words I was, but imagine a giant sand pit filled with bright orange sand and a mixture of real rocks and polystyrene boulders taped to the walls were vistas of Mars. Bar the lack of weightlessness, the scorching effects of radiation, and the bountiful levels of oxygen, I did feel like I was traipsing around Mars. This is the Mars Yard and no, it isn’t a film set. It’s where scientists like Paul test out prototypes of the ExoMars rover which will be sent to the red planet in 2018 for more scientific tests. The latest prototype is rather fondly referred to as Bruno.
Paul - Bruno has on him all the sensors the real rover will need to drive itself autonomously as the cameras and all the sensors in the wheels and that sort of thing. so essentially, we practice driving the rover by itself in this Mars Yard.
Graihagh - Can we take him out for a spin?
Paul - Yes, we certainly can.
Graihagh - Am I allowed to tread on the sand?
Paul - You can.
Graihagh - And away Bruno goes. Bruno looks like a giraffe. Instead of 4 legs, he has 6 wheels and the wheels resemble the sort of things you get on tanks.
It’s painfully slow going. But hopefully in 2020 when the rover launches for real, one hopes we’ll be able to answer the question of whether there once was microbial life on Mars.
Bacteria is one thing, but what about intelligent life? Jim Al-Khalili again...
Jim - Well, one way is point our radio telescopes to listen out for signals from space. After all, we’ve been broadcasting our presence into the universe ever since we invented radio and television a hundred years ago. So, whether it’s an accidental or deliberate signal from any alien civilisation, we’re listening out for those signals. So this is what SETI, the Search for Extraterrestrial Intelligence is all about, but that is looking at life that has advanced enough to become technologically able to send out signals.