Conceivably it can do up to 100 metres a day, which is Formula 1 stuff as far as planetary rovers are concerned. All in all it’s a very exciting and very powerful beast.
Dr John Bridges
November 2011, the Atlas V-541 launch vehicle began a 560 million kilometre journey from Cape Canaveral, Florida, to Mars with the rover Curiosity on board. Part of NASA’s long-term Mars Exploration Program, the mission aims to carry out a range of analyses that will determine whether the red planet was ever habitable to microbial life.
All being well, the rover is scheduled to land on the surface of our nearest planetary neighbour at 6:31 am (GMT) on Monday 6th
August. It would seem that all is indeed well; the team at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, were so confident that the spacecraft is on course that they decided to cancel the final trajectory correction that had been anticipated.
Before he left for the JPL last week, ScienceOmega.com had the opportunity to speak to Dr John Bridges from the University of Leicester Space Research Centre, who leads a team which also includes researchers from the Open University and CNRS France. After a competitive round of proposals from across the world, Dr Bridges was one of the two United Kingdom scientists selected to participate in the MSL project.
"For a number of years now I’ve studied Mars by looking at remote data returned from Mars spacecraft and by studying Martian meteorites," he told me. "For instance, in the dissection of Mars meteorites we have found clay and certain carbonate minerals which were formed from water. We have been able to say quite a lot about Mars from that, but the next logical step is to do the analyses in situ
on the surface of Mars."
The planned landing site of the rover is within the Gale crater alongside Mount Sharp, a huge mound of sediment in which experts believe the history of the planet lies buried.
Officially known as the Mars Science Laboratory (MSL), the rover is the largest robotic vehicle to be sent to the surface of the red planet in the history of Martian exploration. It is also the most expensive, at a cost of around 2.5 million dollars. MSL carries an array of sophisticated pieces of equipment to enable it to fulfil its mission, as Dr Bridges described.
"Curiosity is packed with very powerful scientific instruments. It has a mass spectrometer and an X-ray spectrometer on a robotic arm. It has stereo cameras and a descent imager, as well as ChemCam, a laser that can be fired in pulses at a rock surface. This generates a spark and from the resultant spectra we can determine what rocks are made of."
The car-sized robotic vehicle is also remarkable for its considerable speed in comparison to previous generations of Mars exploration rovers Sojourner, Spirit and Opportunity.
"Conceivably it can do up to 100 metres a day, which is Formula 1 stuff as far as planetary rovers are concerned. All in all it’s a very exciting and very powerful beast."
There is a 13 minute delay in transmission between here and the red planet, which means that real-time interventions – during the landing, for example – are not possible. Communication links are provided by the NASA Deep Space Network of antennae located around the Earth. The various teams of scientists involved maintain control from the comfort of their laboratories.
"For the first 90 days we’ll be controlling the rover and its instruments from the Jet Propulsion Laboratory (JPL) in Pasadena, sending commands and telling it where to move to," explained Dr Bridges. "After those 90 days, we will go back to our home institutions and control it remotely."
On the JPL Mars Science Laboratory website th August in the UK – we should start getting data and thumbnail images through," stated Dr Bridges, who will be one of the first to examine the images beamed back from the craft. "It is planned that the next day we will start seeing the descent imagery. The probe will be taking images as it comes down on the Sky Crane landing system, which will be very exciting."
A critical stage in the landing manoeuvre, dubbed the ‘seven minutes of terror’, will see the MSL spacecraft decelerating from a speed of approximately 13,200 miles per hour (or 5,900 metres per second) to 1.7 miles per hour (0.75 metres per second) in order to touch down safely.
Previous methods using inflatable airbags to cushion the landing would not have worked for Curiosity, hence the development of the innovative Sky Crane system, which will lower it to the surface on nylon cords. I concluded by asking Dr Bridges about his expectations for the landing.
"It will be a nerve-wracking time, but I feel cautiously optimistic about it and I’m expecting great things from this very exciting mission."