Is there life out there?
It is one of the most significant questions for all of us and an answer might not be far away thanks to British technology.
Meet Bruno. He is British, and together with his two siblings – fellow rover prototypes Bridget and Bryan – is set to be the centrepiece of tests designed to help prove whether there is life on Mars.
In two years’ time a so far nameless six-wheeled machine with a “brain” similar to Bruno’s will be launched to the Red Planet.
There it will look for signs of life in soil samples from six feet below the arid Martian surface and take breathtaking colour images of the surrounding landscape.
But before it can do any of that, scientists will first look to ensure the rover is able to safely negotiate Mars’ surface.
And that’s where Bruno and his siblings will be put to the test.
Testing of the rover prototypes takes place in a giant Hertfordshire hangar containing 250 tonnes of sand strewn with artificial boulders, against a backdrop of panoramic photos from Mars.
Speaking at the facility in Stevenage as “Bruno” trundled slowly by – the rover’s top speed is two centimetres per second – head of science Dr Ralph Cordey talked about the machine’s unique ability to steer itself around obstacles.
He said: “One of the challenges of going to Mars is that it’s so far away in terms of the time it takes radio signals to go there and back – around 40 minutes.
“It’s not possible to drive this sort of machine with a joystick. You’ll crash it. So this rover is designed to be semi-autonomous. It can produce its own 3D map of the area ahead of it, look where it’s being asked to go, and plot its own path.
“It’s aware that some rocks it can’t get over and has to drive round, and it can see ditches and sense what slopes are safe to climb.”
The rover has one navigational weakness, however – it can get confused by shadows.
“There are caves on Mars and craters that cast long shadows,” said Airbus Defence and Space communications director Jeremy Close. “To explore those areas, it’s more efficient to have a human in the loop.”
Cue British astronaut Major Tim Peake, orbiting the Earth as part of the crew of the International Space Station.
Next month he will take part in a pioneering experiment that will see him operate Bruno remotely from space. Major Peake will be asked to drive the rover into a “cave” – simulated by plunging half the Mars sandpit into darkness.
Steering the machine through a barrier raised across the 30 metres (98ft) by 13 metres (42ft) testing area, he will seek out targets marked with an “X”.
Bruno is a stripped down version of the rover, missing all its scientific hardware, yet is designed to weigh the same as the machine on Mars, around 200kg (441 pounds). That is because the pull of Martian gravity is about a third of the Earth’s.
The finished rover will have a drill that can bore down two metres (6.5 feet) below the Martian surface and extract samples to be analysed in its on-board laboratory.
Unlike any Mars rover before it, the ExoMars rover will look for biochemical signatures of life.
They might be organic molecules with a particular left or right “handedness” to their structure that indicates a biological origin, or specific minerals left behind by long-dead microbes.
The planned landing site is a flat equatorial region known as Oxia Planum where there is geological evidence of surface water long ago.
Navigating autonomously, the rover is expected to cover up to 70 metres per day and as much as four kilometres (2.5 miles) in the course of its six month mission.
A colour panoramic camera mounted on a mast in the centre of the machine will capture unmatched images of the planet.
“It will have the ability to put you there in a 3D colour environment, as if you were on Mars,” Dr Cordey pointed out.
Asked how he felt about the mission, he said: “It will help answer one of the really deep down questions that we have.
“You stop and look up into the night sky and wonder, is there life out there? We’ve now got the engineering and science capability to start trying to answer that question.
“It’s not just in the realms of sci-fi – there are good reasons for believing there could have been life on Mars early in its life, just as there was on Earth.
“The surface of Mars is not a nice place for life. There are cosmic rays that bombard the surface, and energetic particles from the sun, and the surface chemistry is very reactive so that any organic material would be rapidly oxidised.
“The place to look for life is under the surface, and that’s what this mission is doing that no other mission has.”