Landing site selected for UK's ExoMars rover in 2021

A group of scientists and engineers in Leicester has recommended Oxia Planum as the best landing site for the British-built Mars rover. Due to land in 2021, the ExoMars rover will be the first of its kind to travel across the Martian surface and drill down to determine if evidence of life is buried underground. Dr. Graham Turnock, Chief Executive of the UK Space Agency said: "After the Earth, Mars is the most habitable planet in the solar system, so it's a perfect destination to explore the possibility of life on other planets, as well as the history of our own." Both of the potential landing sites - Oxia Planum and Mawrth Vallis - preserve a rich record of geological history from the planet's wetter past, approximately four billion years ago, however the potential for science return had to be balanced with the prospect of landing safely. Professor John Bridges, from the Space Research Centre, University of Leicester, a member of the Landing Site Selection Working Group, explains why Oxia Planum has been recommended: "After over 4 years of careful study of HiRISE and more recently CaSSIS images Oxia Planum was chosen because scientists were convinced that its fine grained sediments, deposited during the ancient Noachian epoch, were ideally suited for the exobiology rover. "With an enormous catchment area the sediments will have captured organics from a wide variety of environments over a long period of time, including areas where life may have existed. The fine sediments should also be ideal for the ExoMars drill - it aims to get to 2 metres depth.

"Remote identification with the Mars Express and Mars Reconnaissance Orbiter Infrared spectrometers shows the presence of clays and other minerals giving clues to its aqueous history. A large group of scientists have been working on proposing, characterising and down selecting the sites, all of which had fascinating aspects, but Oxia Planum is the clear winner on both science and engineering constraints."

The UK Space Agency is the second largest European contributor to the ExoMars mission, having invested euro 287 million in the mission and Pounds 14 million on the instruments. This, in addition to successful negotiations with the European Space Agency (ESA), secured key mission contracts for the UK space sector.

Sue Horne, Head of Space Exploration at the UK Space Agency said: "I have been working on ExoMars for over 10 years and am amazed at the ingenuity and dedication of UK engineers and scientists in building the rover and instruments that will work in the extreme environment of Mars. Our end goal is in sight and it is getting very exciting."

The government's modern Industrial Strategy is backing businesses to succeed by increasing investment in science, because countries that invest in ideas create more opportunities for business. The ambition is for the UK be the world's most innovative economy - and the development of the ExoMars rover in the UK is a part of this ambition.

Airbus Defence and Space in Stevenage is leading the build of the rover while the UCL Mullard Space Science Laboratory is leading on a key instrument known as the PanCam, a high-resolution 3D camera which will be used to look at the terrain and rocks to try to detect signs of life. The University of Leicester and Teledyne e2v are working on the Raman Spectrometer with STFC RAL Space providing some of the electronics, including the data processing board.

The recommendation was made following a two-day meeting held at the National Space Centre in Leicester, UK, which saw experts from the Mars science community, industry, and ExoMars project present and discuss the scientific merits of the sites alongside the engineering and technical constraints. The Leicester recommendation will be reviewed internally by ESA and Roscosmos with an official confirmation expected mid-2019.

Bernese Mars camera CaSSIS sends first colour images from Mars

The Mars camera CaSSIS on the ExoMars Trace Gas Orbiter has returned its first colour images of the red planet. The camera system, which was developed at the University of Bern, is now ready for the start of its prime mission on April 28, 2018. The Colour and Stereo Surface Imaging System (CaSSIS) has been designed by an international team under guidance of the University of Bern. The Mars camera is on board of the ExoMars Trace Gas Orbiter, a European Space Agency/Roscosmos mission. It has now returned its first colour images from the orbit at Mars. The camera system was switched on 20 March and has been undergoing tests in preparation for the start of its prime mission on April 28, 2018. "We have had a couple of minor software issues in the initial test phase", says Principal Investigator, Nicolas Thomas from the Center of Space and Habitability (CSH), University of Bern in Switzerland, "but the instrument is actually in good health and ready to work." The UniBern team transmitted a completely new software version to the instrument at the start of test phase. "It is amazing that you can totally change the software in an instrument flying around Mars more than 100 million kilometres away and that it works", says Thomas.

Korolev crater (Mars)

Some of the first images have been spectacular. The example image is from the rim of an ice-filled crater called Korolev at high latitude in the northern hemisphere. The bright material is ice that can be seen on the rim of the crater (which is much larger than the image).

The picture has a resolution of just over 5 metres and outperforms the resolution of images from Hubble and other telescopes by far. In the future, CaSSIS should operate from slightly lower altitudes to give resolutions of less than 5 metres.

"We were really pleased to see how good this picture was given the lighting conditions", says Antoine Pommerol, a member of the CaSSIS science team at the CSH working on the calibration of the data. "It shows that CaSSIS can make a major contribution to studies of Mars's carbon dioxide and water cycles."

The image is a composite of three images in different colours that were taken almost simultaneously by CaSSIS on April 15, 2018. They were then assembled to produce this colour view.

"Our aim is to fully automate the image production process", says Thomas. "Once we achieve this, we can distribute the data to the community quickly for analysis."

Observing dynamics on Mars

CaSSIS is designed to complement the data acquired by the other payload on TGO and other Mars orbiters while also enhancing our knowledge of the surface of Mars. It is now known that Mars is more dynamic than previously thought.

Of particular interest to the 25-strong science team from 9 countries (incl. US and Russia) is the chance CaSSIS offers to study changes that occur over the day and over the Martian seasons. Further studies of recently discovered liquid water on the surface will be one of the main aims.