Rover 'Bruno' helps scientists search for life on Mars


His name is Bruno, he is British, and together with his two siblings he is helping scientists embark on one of humankind's greatest adventures - the search for life on Mars.

Bruno belongs to a "family" of three rover prototypes - the others are named Bridget and Bryan - which are testing the last word in planetary navigation technology.

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.

The British-built rover has star billing in the second half of the 1.2 billion euro (£946 million) joint European and Russian ExoMars mission.

As the ExoMars orbiter hurtles towards Mars at 20,500mph (33,000kph) after its launch on March 14, scientists and engineers are gearing up to start work on the rover that will go into space.

Assembling the complex array of mechanical parts and electronic circuits is due to begin at the UK headquarters of Airbus Defence & Space in Stevenage later this year.

Testing of the rover prototypes takes place in a giant hangar containing 250 tonnes of sand strewn with artificial boulders, against a backdrop of panoramic photos from Mars.

Speaking at the facility 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 & 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."

Searching for life brings with it a new set of technological challenges. It is the reason why the rover has metal, not rubber, wheels, and why no oily lubricants can be used on its moving parts.

ExoMars rover structures engineer Abbie Hutty explained: "You can't have anything organic when you're looking for organic material, even sheaths around cables, gaskets and lubricants."

To withstand the harsh Martian conditions - high doses of radiation and night temperatures that drop to minus 130C - the electronics cannot be too delicate either. That rules out super-fast systems. As a result, the rover's technology, while in some ways highly advanced, is at 1980s level in terms of speed.

"Everything has to be a bit clunky," said Ms Hutty. "The electronics have to be 'radproof' - military grade radiation resistant - and that makes them slower. It limits the rover's top speed because we're governed by how quickly we can process the view of what's in front of us."

The British rover and the Trace Gas Orbiter (TGO) now on its way to Mars together are expected to provide a good indication of whether or not there is, or ever has been, life on the Red Planet.

TGO is designed to sniff out methane in the Martian atmosphere and tell if it is likely to have been generated by microbes or geology.

It is accompanied by a small lander, Schiaparelli, which will test out the parachute and retro-rocket landing system on which scientists are pinning their hopes to get the rover safely on the surface.