August 3, 2012

expert comments and background information before Mars Curiosity rover landing

NASA’s Mars Curiosity rover, the latest spacecraft to be sent to our neighbouring planet, was due to land around 6.30am UK time Monday 6 August 2012.

Dr Pete Edwards, Department of Physics, University of Durham, said:

“Is there life on Mars? Despite launching more than twenty spacecraft to the red planet we still don’t know. The most ambitious mission to date, Mars Curiosity, aims to land a rover on Mars which will study rocks and soils, searching for the chemical building blocks of life and clues to the planet’s ancient climate.

“If successful, Curiosity will be the largest man-made object ever to land on another planet. Let’s hope all goes well in the early hours of Monday morning when the rover has its own close encounter with Mars.”

Dr Susanne Schwenzer, Open University, said:

“We already know that there is water on Mars, now, we want to know the temperature of the water and whether it is clean and supportive of potential life – or if it is poisonous. We also want to know if Mars has niches where microbial life could have existed.”

Additional information: Susanne joins a mission led by Dr John Bridges, Reader in Planetary Science at the University of Leicester. The Mars Science Laboratory mission, landing NASA’s most advanced planetary rover called Curiosity, is a deploying the most powerful suite of instruments yet sent to the Red Planet. The rover is scheduled to land at 6.31am UK time on Monday 6 August, beside a Martian mountain within Gale Crater called Mt. Sharp, to begin two years of unprecedented scientific detective work. Curiosity will also carry the biggest, most advanced suite of instruments for scientific studies ever sent to the Martian surface. The rover will analyse a dozen or so samples scooped from the soil and extracted from rocks. The record of the planet’s climate and geology is essentially “written in the rocks and soil”-in their formation, structure, and chemical composition. The rover’s onboard laboratory will study rocks, soils, and the local geologic setting in order to decide if the conditions on Mars were able to support microbial life. Prior to the landing, the MSL spacecraft will decelerate significantly from a speed of about 13,200 miles per hour to enable the rover to achieve a landing speed of about 1.7 miles per hour. The success of the landing is a critical milestone toward the goal of sending humans to Mars by 2030.

Dr Patrick Harkness, Lecturer in Space Systems Engineering, University of Glasgow, said:

“The Curiosity rover is the most capable spacecraft ever to be landed on Mars. However, its large size means that this landing is particularly energetic and an ambitious entry, descent and landing is needed to place the rover on the surface.

“Arrival at Mars means entering the Martian atmosphere at the high velocity needed for interplanetary flight. As the spacecraft starts to encounter the atmosphere, compression and friction result in high temperatures. A heat shield is required to protect the rover from these conditions, and when the velocity has fallen due to aerodynamic drag a parachute will open to reduce the velocity still further. The heatshield, no longer needed, will be allowed to fall away.

“However, Mars’ atmosphere is very thin and Curiosity is very heavy. Even with a parachute, the rover will be falling much too fast to survive an impact with the ground. At lower altitudes, therefore, the parachute is jettisoned and retro rockets will fire to slow the descent still further. It is at this point the most interesting part of the landing takes place – the ‘sky crane’ manouvre.

“If the rockets were firing right into the ground as the rover landed, they would kick up a lot of debris which could damage the rover’s wheels or instruments. So the rover will be lowered on lanyards from the module containing the retro rockets, allowing the rockets’ exhaust to disperse before it reaches the ground. We hope it will be set down very gently on a smooth surface, and the lanyards will then be cut to allow the rocket module – the ‘sky crane’ – to fly away and crash at a safe distance.

“When Curiosity arrives, it will start searching for evidence of past – or even present – life on Mars. To do this it has drill tools that will allow it to look beneath the surface. On Earth, a magnetic field generated in the Earth’s liquid core shields us from some of the sun’s radiation, but on Mars – with a much weaker magnetic field – shelter might only be found under the ground. Samples from beneath the surface will be shaken in special chambers and examined by instruments that can tell us about how they were formed. Other experiments involve firing lasers at the rock to examine the particles released and, of course, measuring the radiation on the surface so that we can estimate the protection human explorers will need in the future.

“Curiosity could potentially operate for years, powered by its nuclear generators, and – if all goes well – it will tell us a lot about the climate on Mars today and what conditions must have been like in the past. We suspect that Mars had oceans when the earliest life evolved on Earth, and perhaps Curiosity will bring us closer to finding out if the same processes took place on Mars. If we should find evidence to suggest that we are not alone in the Universe, our view of ourselves and our planet will surely be changed forever.”

Professor Sanjeev Gupta, Imperial College London, said:

“Earlier Mars landers and rovers examined the Mars surface but didn’t give us the opportunity to study the geology of thick piles of sediments in detail. Sedimentary rocks are the history books of a planet, preserving information about past environmental conditions. On Earth, they also preserve evidence of past life. This new phase of exploration will enable us to analyse the geology in much more detail, giving us an exciting opportunity to learn more about our nearest neighbour.

“NASA chose Gale Crater as the landing site because it has a number of really exciting geological features that we are hoping to explore. These include a canyon and what appears to be a lake bed on the floor of the Crater, as well as a channel and a delta, which we think may have been carved by water. We will use the rover’s cameras, including one which is like a powerful magnifying glass, to study the geology up close.

“We think that Gale Crater was formed sometime between the early warmer, wetter Noachian Epoch and the colder, drier Hesperian Epoch of Mars’ history, making it a really interesting site to study. The geology and mineralogy of the Crater may help us to piece together the reasons why Mars’s climate changed so dramatically.

“I am really excited to be working with such a distinguished team in a completely new work environment on such an immense project. If William Smith were alive today I am sure he’d do what us geologists in the team are planning to do – roll up our sleeves and get down to mapping the geology of this crater.”

Additional information: Professor Gupta is one of only two UK scientists to take part in the Mars Science Laboratory (MSL) mission. The mission, which will be controlled remotely by scientists at NASA’s Jet Propulsion Laboratory in Pasadena USA, is expected to touch down on the red planet on 5 August 2012. The $US 2.7 billion operation will involve a team of 200 scientists from around the world who will be assessing whether Mars has had conditions favourable for life. They will also be determining whether conditions were favourable for preserving a record of evidence in the rock about whether life has existed there. NASA’s Mars Science Laboratory spacecraft is currently travelling through space and in early August, after a 154 million mile journey, the craft will reach Mars’ outer atmosphere at speeds of approximately 13,200 miles per hour. The heat shielded spacecraft will use the atmosphere as a break to slow down initially. At an altitude of seven miles a parachute will be deployed to further slow the descent towards the surface of Mars. As it nears the ground a another craft will be ejected, which will use jet power to stabilise its decent, hovering above a drop zone and carefully winching a mobile six-wheeled, nuclear powered science laboratory – approximately the size of a Mini Cooper – out of its innards and onto the surface. The entire landing procedure is expected to take approximately 10 minutes. The mobile laboratory, which is equipped with cameras, a robotic arm, and a range of instruments to study the geology and geochemistry of Mars, will land on the floor of Gale Crater. The Crater, located near the planet’s equator, is between 3.5 to 3.8 billion years old, with a 5.5 kilometre high mountain at its centre called Mount Sharp. This not the first time that Professor Gupta has studied Martian geology, in January 2009 he studied a set of spectacular satellite images and published a paper in the journal Geology, which suggested that Mars was warm enough to sustain lakes three billion years ago – a period of time that was previously thought to be too cold and arid to sustain water on the surface. The research suggested that during the Hesperian Epoch, approximately three billion years ago, Mars had temporary lakes made of melted ice, each around 20km wide, along parts of the equator. The Mission is planned to last for one Martian year, which is 98 weeks. Professor Gupta will spend part of that time at mission control in the Jet Propulsion Lab. Each day, hundreds of scientists will work together round the clock, analysing data beamed back to mission control, planning experiments and devising the next day’s program for the Rover. Professor Gupta’s Mars research is funded by the UK Space Agency and supported by NASA.