ExoMars 2020 Mission
The ExoMars program, consisting of two missions, is the first step of ESA's Aurora Exploration Program and is developed in a broad ESA and Roscosmos cooperation, with a contribution from NASA in the areas of Mars proximity Communications and the scientific payloads. It addresses the scientific question of whether life ever existed on Mars and will demonstrate key technologies for entry, descent, landing, drilling and roving on the Martian surface. 1) 2)
The 2020 mission of the ExoMars program will deliver a European rover and a Russian surface platform to the surface of Mars. A Proton rocket will be used to launch the mission, which will arrive to Mars after a nine-month journey. The ExoMars rover will travel across the Martian surface to search for signs of life. It will collect samples with a drill and analyse them with next-generation instruments. ExoMars will be the first mission to combine the capability to move across the surface and to study Mars at depth. 3)
During launch and cruise phase, a carrier module (provided by ESA) will transport the surface platform and the rover within a single aeroshell. A descent module (provided by Roscosmos with some contributions by ESA) will separate from the carrier shortly before reaching the Martian atmosphere. During the descent phase, a heat shield will protect the payload from the severe heat flux. Parachutes, thrusters, and damping systems will reduce the speed, allowing a controlled landing on the surface of Mars.
The ExoMARS 2020 Program will secure the development and qualification of the following technologies:
• Entry, Descent and Landing (EDL) of a payload on the surface of Mars
• Surface mobility with a Rover
• Access to the sub-surface to acquire and analyze in-situ Mars terrain samples
• Qualification of Russian ground-based means for deep-space communication in cooperation with ESA's ESTRACK
• Adaptation of Russian on-board computer for deep space missions and ExoMars landed operations
• Development and qualification of throttleable braking engines for prospective planetary landing missions.
The above activities will be carried out in accordance with the ESA Policy on Planetary Protection, which complies with the COSPAR planetary protection recommendations.
The ExoMars Program scientific objectives are to:
• Search for signs of past and present life on Mars
• Investigate the water/geochemical environment as a function of depth in the shallow subsurface
• Investigate Martian atmospheric trace gases and their sources
• Investigate and solve scientific problems within the composition of Mars Surface long-living stationary platform.
A further objective of the ExoMars Program is to provide data relay services, through the TGO (Trace Gas Orbiter), for landed assets on the surface of Mars until the end of 2022.
All these objectives will be pursued as part of a broad international cooperation with Roscosmos and NASA, having as long-term goal an international Mars sample return mission.
The two ExoMars missions are foreseen, respectively, for 2016 (launched from Baikonur on March 14th, 2016) and July-August 2020.
The RSP (Rover and Surface Platform) mission of the ExoMars program of ESA, planned for launch in 2020, will deliver a European ExoMars Rover and a Russian Surface Platform to the surface of Mars. The primary objective is to land the rover at a site with high potential for finding well-preserved organic material, particularly from the very early history of the planet.
ExoMars RSP (Rover and Surface Platform)mission and system concept
The ExoMars RSP mission is foreseen to be launched into a direct transfer to Mars in July 2020. The transfer is ballistic; there are no deterministic Deep Space Maneuvers (DSM), only stochastic navigation maneuvers, some of which have a deterministic component for planetary protection reasons (Ref. 1). 4) 5) 6) 7) 8)
In the current mission design, the launch period for 2020 has a duration of 20 days. Out of these 20 days, with the six allocated Proton-M/Breeze-M launcher programs, it will be possible to have at least six days of launchability within the launch period arranged in groups of two: two days at the start, two in the middle and two at the end of the launch period. The days in between are gaps of non-launchability.
All dates in a given launch period lead to arrival on the same date, fixed on 19 March 2021. This simplifies operations planning and ground station booking, though it also removes one degree of freedom from the trajectory design.
The 2.9 ton SCC ( SpaceCraft Composite), developed by Thales Alenia Space in Italy under ESA contract, is composed of a CM (Carrier Module) and a 2 ton DM (Descent Module) provided by Roscosmos of Russia, which carries the 350 kg RM (Rover Module), also provided by ESA.
Industrial consortium: On the 2020 mission, Thales Alenia Space in Italy, is in charge of the design, development and verification of the entire system, the development of the Carrier Module navigation and guidance system and perform EDL/GNC development, the Rover System, including the Analytical Laboratory Drawer (ALD) as well as supplying basic parts of the DM, including the Radar Altimeter. In addition, Thales Alenia Space in Italy implements a deep technical partnership with Lavochkin for the development of the Descent Module (DM). OHB is in charge to develop the CM as well as ALD SPDS Mechanism and delegated tasks, the Rover Vehicle itself is provided by Airbus Defence and Space in UK. Leonardo is developing the ExoMars 2020 drill, which will dig into the Mars subsoil to a depth of two meters and ALTEC (Aerospace Logistics Technology Engineering), a Thales Alenia Space in Italy (63.75%) and ASI (36.25%) company – will also be responsible for the design, development and maintenance of the ROCC (Rover Operation Control Center) and for controlling the Rover on the Martian surface (Ref. 14).
Figure 1: Illustration of the interplanetary transfer of the ExoMars 2020 mission (image credit: ExoMars collaboration)
Figure 2: EDL (Entry Descent and Landing) phase of ExoMars (image credit: ExoMars collaboration)
The CM (Carrier Module), developed by OHB (Bremen, Germany), implements all the tasks needed to carry the whole system close to Mars atmospheric borders. It executes all the necessary maneuvers in interplanetary transfer and targets the trajectory such that the DM will enter at the required entry flight path angle and that the lander will touch down at the required location. Separation of the CM from the DM is currently foreseen to occur at EIP-30 minutes. The CM is not foreseen to operate after separation form the DM (Descent Module).
The CM and DM modules are mated by means of a separation mechanism bolted on both sides on 8 I/F points (pyrolocks on DM Rear Jacket side). Cable disconnection at separation is implemented by cutters.
The DM (Descent Module), developed by Lavochkin (Ru) with the contribution of key European Hardware and Software system contributions (see below), is a blunt-shape reentry capsule made of four separate main parts, FS (Front Shield), RJ (Rear Jacket), LP (Landing Platform) and PAS (PArachute System), performs the Entry, Descent and Landing on the Martian surface of a Landing Platform.
In particular the European Hard- and Software contributions consists of:
• The On-Board Computer, developed by Crisa (E), which manages the whole ExoMars 2020 mission during Cruise, EDL and Mars Surface Operation phases running the whole Mission Software,, developed by TAS (I).
• The IMU (Inertial Measurement Unit), developed by Airbus Defence and Space (ADS-F), which supports GNC during both Cruise and EDL phases
• The Radar Altimeter, developed by TAS (I), which is used to control the landing phase
• The UHF Transponder and Landing Platform Antenna, developed, respectively, by QinetiQ (UK) and Tryo (E), used for the proximity communications with the TGO
• The PArachute System, developed by TAS (F).
The DM accommodates the RM and provides for its egress to the Martian surface.
Figure 3: ExoMars RSP selected landing sites (image credit: ExoMars collaboration)
The LP (Landing Platform), following the departure of the Rover, becomes SP (Surface Platform) for a long-lived stationary science instrument suite to study the Martian environment at the landing site. The 45 kg instrument suite with a planned lifetime of 2 Earth years is foreseen to consist of twelve instruments: In particular:
- TSPP (4 Cameras)
- MTK (Meteorology Package)
- RAT-M (Radiometer)
- MAIGRET (magnetometer)
- SAM (Seismometer)
- LaRa (Radioscience Mars Geodesy)
- PK (Dust Studies)
- M-DLS (Atmospheric Laser Spectrometer)
- FAST (Trace Gas Fourier Spectrometer)
- MGAK (Gas Analytical Package)
- Adron-EM (Neutron Spectrometer)
- HABIT (Humidity And Radiation Sensor)
The RM (Rover Module), developed under the responsibility of TAS (I), consists of a RV (Rover Vehicle) which carries an ALD (Analytical Laboratory and Drill) for subsurface sampling (down to 2 m).
The RV is made by Airbus Defence and Space (ADS-UK), the ALD is developed by TAS (I) with OHB (D) providing the sample processing and handling mechanisms and the Drill is developed by Leonardo (I) . The Rover Module contains European, Russian and NASA scientific payloads. The Rover is designed to deploy and egress from the DM Landing Platform, and to perform science exploration on the Mars surface with a suite of dedicated instruments.
RM Scientific package consists of the Pasteur Payload (PPL) composed of:
• 6 Survey Payloads
- Panoramic Cameras (WACs + HRC) PanCam
- Ground Penetrating Radar for Water Ice Subsurface Deposit Observation on Mars - WISDOM
- Close-Up Imager - CLUPI
- Mars Multispectral Imager for Subsurface Studies - Ma_Miss (in Drill)
- Neutron Detector – ADRON-RM (Roscomos - IKI)
- Infrared Spectrometer for ExoMars - ISEM (Roscomos - IKI)
• 3 Analytical Payloads (part of ALD)
- Infrared Microscope (MicrOmega)
- Raman Laser Spectrometer (RLS)
- Mars Organic Molecule Analyzer - (MOMA)
Note: The ALD is an integrated laboratory able to collect and prepare Martian terrain specimen from the Drill, handle and process them to the on board scientific instruments for in situ analysis, in a ultra-clean environment.
ExoMars RSP Mission Management
The 2020 mission operations, planning and execution will be performed by the MOC (Mission Operation Center) located at ESOC in Darmstadt with the support of:
• the SCC MOC
• the Rover Operations Control Center (ROCC)
• the Surface Platform Payload Operations Control Center (SPOCC)
• the TGO MOC, starting only from the EDL phase.
In particular ESOC/MOC will be responsible of controlling the SCC (and DM/LP) since Launcher separation up the Rover egress on the Mars surface. ESOC/MOC will be also responsible through ERCO (ESA Relay Coordination Office) in leading the ESA Data Relay Orbiter operations acting as data communication hub also to/from ROCC and SPOCC, starting from Launch until the egress of the RM after the LP landing on the Martian surface. Note: this very delicate last phase of the mission is named Post Landing to Egress (PLTE). 9)
After the RM egress, the ExoMars Rover mission will be independent and developed under the full responsibility of the ROCC while the Landing Platform Mission will be under the responsibility of the SPOCC (both via ERCO).
The X-band communications will use:
• The ESA Ground Station & Communications Subnet (ESTRACK)
• The NASA Ground Stations & Communication Subnet (DSN), to be considered for "critical phases" like Safe Mode(s) or Flight Software upload or for "extreme contingencies" like the loss of SCC attitude
• The Russian Ground Stations & Communication Subnet (RNS).
During the LP (Landing Platform) mission the communication are performed via UHF band between On Board Computer (OBC1) and TGO (or NASA available Orbiters) during scheduled communication windows on visibility passes.
The Science Data Archive will make use of:
• The Pasteur payload Science Data Archiving and Dissemination located at ESAC, Spain
• The Science Data Archiving centers (NASA PDS and ESA PSA)
• Russian Science Ground Segment (NNK).
Figure 4: Illustration of the ExoMars overall communication link (image credit: ExoMars collaboration)
ExoMars RSP system architecture
Hereafter, pictorial views of the main components of the ExoMars 2020 spacecraft together with the avionics block diagram are shown.
Figure 5: ExoMars RSP Elements (image credit: ExoMars collaboration)
Figure 6: Detail views of the Rover Module, ALD, Drill and Spacecraft Composite (image credit: ExoMars collaboration)
Figure 7: ExoMars avionics architecture (image credit: ExoMars collaboration)
Figure 8: Artist's impression of the ExoMars 2020 rover (foreground), surface science platform (background) and the Trace Gas Orbiter (top), not to scale (image credit: ESA/ATG medialab)
Launch: A launch of the ExoMars 2020 mission is planned for the summer of 2020 on a Proton rocket of Roscosmos from Baikonur and arrive at Mars nine months later.
Development status of ExoMars 2020 - RSP (Rover and Surface Platform) Mission
• February 7, 2019: The ExoMars rover that will search for the building blocks of life on the Red Planet has a name: Rosalind Franklin. The prominent scientist behind the discovery of the structure of DNA will have her symbolic footprint on Mars in 2021. 10)
- A panel of experts chose ‘Rosalind Franklin' from over 36 000 entries submitted by citizens from all ESA Member States, following a competition launched by the UK Space Agency in July last year.
- The ExoMars rover will be the first of its kind to combine the capability to roam around Mars and to study it at depth. The Red Planet has hosted water in the past, but has a dry surface exposed to harsh radiation today.
- The rover bearing Rosalind Franklin's name will drill down to two meters into the surface to sample the soil, analyze its composition and search for evidence of past – and perhaps even present – life buried underground.
Figure 9: Rosalind Franklin with microscope in 1955 (1920-1958). Rosalind Elsie Franklin was a British chemist and X-ray crystallographer who contributed to unravelling the double helix structure of our DNA. She also made enduring contributions to the study of coal, carbon and graphite (image credit: MRC Laboratory of Molecular Biology)
- "This name reminds us that it is in the human genes to explore. Science is in our DNA, and in everything we do at ESA. Rosalind the rover captures this spirit and carries us all to the forefront of space exploration," says ESA Director General Jan Woerner.
- The name was revealed this morning in the ‘Mars Yard' at Airbus Defence and Space in Stevenage, in the United Kingdom, where the rover is being built. ESA astronaut Tim Peake met the competition entrants who chose the winning name, and toured the facility with UK Science Minister Chris Skidmore.
- "This rover will scout the martian surface equipped with next-generation instruments – a fully-fledged automated laboratory on Mars," says Tim. "With it, we are building on our European heritage in robotic exploration, and at the same time devising new technologies."
- The rover will relay data to Earth through the ExoMars TGO (Trace Gas Orbiter), a spacecraft searching for tiny amounts of gases in the martian atmosphere that might be linked to biological or geological activity since 2016.
- Rosalind has already a proposed landing site. Last November a group of experts chose Oxia Planum near the martian equator to explore an ancient environment that was once water-rich and that could have been colonized by primitive life.
Figure 10: ExoMars Rover: from concept to reality. This video focusses on the rover and explains what it plans to achieve on Mars (video credit: ESA)
- The second part of the ExoMars program is ongoing.
- In Stevenage, UK, a rover is being built that will carry a drill and a suite of instruments dedicated to exobiology and geochemistry research. It will be the first mission to combine the capability to move across the surface and to study Mars at depth.
- The primary goal of the ExoMars program is to address the question of whether life has ever existed on the red planet.
- The first part of the program was launched in March 2016 with the Trace Gas Orbiter. The second part is planned for launch in 2020 and comprises the rover and surface science platform.
On our way to Mars, and back
- Looking beyond ExoMars, bringing samples back from Mars is the logical next step for robotic exploration. ESA is already defining a concept for a sample return mission working in cooperation with NASA.
- "Returning martian samples is a huge challenge that will require multiple missions, each one successively more complex than the one before," says David Parker, ESA's Director of Human and Robotic Exploration.
- "We want to bring the Red Planet closer to home. We want to delve into its mysteries and bring back knowledge and benefits to people on Earth. Returned planetary samples are truly the gift that keeps on giving – scientific treasure for generations to come," he adds.
- Long-term planning is crucial to realize the missions that investigate fundamental science questions like could life ever have evolved beyond Earth?
- ESA has been exploring Mars for more than 15 years, starting with Mars Express and continuing with the two ExoMars missions, keeping a European presence at the Red Planet into the next decade.
• January 17, 2019: Navigation software destined for the ExoMars 2020 mission to the Red Planet has passed a rover-based driving test at ESA's ‘Mars Yard'. 11)
- ESA's ExoMars rover will drive to multiple locations and drill down to two meters below the surface of Mars in search of clues for past life preserved underground.
- A half-scale version of the ExoMars rover, called ExoMars Testing Rover (ExoTeR), maneuvered itself carefully through the red rocks and sand of the 9 x 9 m ‘Planetary Utilization Testbed', nicknamed the Mars Yard, part of ESA's Planetary Robotics Laboratory at ESTEC in the Netherlands.
Figure 11: A half-scale version of the ExoMars rover, called ExoMars Testing Rover (ExoTeR), maneuvered itself carefully through the red rocks and sand of 9 x 9 m Planetary Utilization Testbed, part of ESA's Planetary Robotics Laboratory in its ESTEC technical center in the Netherlands (video credit: ESA)
- Carefully calculating its onward route, ExoTeR progressed at a rate of 2 m per minute – still several times faster than the actual ExoMars rover will drive, which will progress at 100 m per martian day.
- The two-day rover test was conducted by ESA robotic engineers, joined by a team from France's space agency CNES in Toulouse. They have more than two decades of experience in autonomous navigation for planetary rovers, culminating in developing the ‘AutoNav' suite of software that was doing the driving.
• November 27, 2018: The sun set on a week of trials for the ExoMars rover prototype named Charlie (in the foreground). The first of two field trials for the mission, known as ExoFiT, took place in the Tabernas desert in Spain between 13-26 October (Figure 12). 12)
- While Charlie was located in Spain, mission operators and instrument scientists were based over 1000 km away at mission control in Harwell, UK, near ESA's ECSAT (European Center for Space Applications and Telecommunications), where ExoFit was managed. The distance was crucial as teams operating a rover on the Martian surface must contend with infrequent communication possibilities and must run science operations with what little information they have. The rover itself is designed to carry out activities such as a traverse or observations in between communication blackouts as well as send data to Earth in preparation for the next martian day.
- During the 10-day trial, the team practised driving the rover off its landing platform (in the background of this image), targeting sites of interest, and sampling rocks. Decisions were made based on data transmitted by the rover together with maps of the terrain.
- Naturally, the team encountered technical difficulties, to be expected in real test conditions. Rainfall disrupted events and forced the team to adapt and optimize their time. In the second week, the team managed to finish activities scheduled for two martian days in a single day.
- The scenarios in general tested the rover's radar instrument, close-up imager, panoramic mast imager and drill, with more specific tests aimed at replicating what will be performed on the martian surface. Once on the Red Planet, the rover drill beneath the surface to look for signs of life.
- A lot is learned during these simulation studies to fine-tune equipment and train mission specialists. The issues encountered in the field trial will be addressed and tested again in a second field campaign introducing more complex autonomous rover operations.
- Set for February 2019, the second field trial will take place in the Atacama desert of Chile. Atacama is one of the most similar terrains on Earth to Mars, with the added benefit of drier weather and the nearby European Southern Observatory's Paranal Observatory over the Tabernas desert.
- The operational challenges observed provide valuable inputs for the ExoMars rover and other planetary rovers such as the Sample Fetch Rover of the NASA-ESA Mars Sample Return mission. Currently in the concept phase, ESA is working with international partners to achieve its vision of Europe's expanding role in space exploration.
Figure 12: ExoMars rover field trials in the Tabernas desert in Spain (image credit: Airbus/ESA)
• November 9, 2018: The ExoMars Landing Site Selection Working Group has recommended Oxia Planum as the landing site for the ESA-Roscosmos rover and surface science platform that will launch to the Red Planet in 2020. - The proposal will be reviewed internally by ESA and Roscosmos with an official confirmation expected mid-2019. 13)
- At the heart of the ExoMars program is the quest to determine if life has ever existed on Mars, a planet that has clearly hosted water in the past, but has a dry surface exposed to harsh radiation today.
- While the ExoMars TGO (Trace Gas Orbiter), launched in 2016, began its science mission earlier this year to search for tiny amounts of gases in the atmosphere that might be linked to biological or geological activity, the rover will drive to different locations and drill down to two meters below the surface in search of clues for past life preserved underground. It will relay its data to Earth through the Trace Gas Orbiter.
- Both landing site candidates – Oxia Planum and Mawrth Vallis (Figure 15) – preserve a rich record of geological history from the planet's wetter past, approximately four billion years ago. They lie just north of the equator, with several hundred kilometers between them, in an area of the planet with many channels cutting through from the southern highlands to the northern lowlands. Since life as we know it on Earth requires liquid water, locations like these include many prime targets to search for clues that may help reveal the presence of past life on Mars.
- "With ExoMars we are on a quest to find biosignatures. While both sites offer valuable scientific opportunities to explore ancient water-rich environments that could have been colonized by micro-organisms, Oxia Planum received the majority of votes," says ESA's ExoMars 2020 project scientist Jorge Vago. "An impressive amount of work has gone into characterizing the proposed sites, demonstrating that they meet the scientific requirements for the goals of the ExoMars mission. Mawrth Vallis is a scientifically unique site, but Oxia Planum offers an additional safety margin for entry, descent and landing, and for traversing the terrain to reach the scientifically interesting sites that have been identified from orbit."
Figure 13: One example of how the Oxia Planum landing site candidate for the ExoMars 2020 mission is being analyzed. The map outlines a boundary that encapsulates the range of possible landing ellipses, with some added margin. The colors represent the variety of surface terrains identified, including plains, channels, impact craters and wind-blown features, for example. It is not a geological map intended for scientific analysis, but rather a tool used to identify different surface textures and where potential hazards may lie (image credit: IRSPS/TAS; NASA/JPL-Caltech/Arizona State University)
Legend to Figure 13: The narrow ellipses with the black outline mark the most likely landing zones for the extreme case of the very beginning and end of the launch window respectively (the launch dictates the arrival inclination and there are other scenarios in between). The central touchdown point in Oxia Planum is the same regardless of the actual launch date in the 25 July–13 August 2020 launch window. -The background image is from the Thermal Emission Imaging System instrument on NASA's Mars Odyssey orbiter.
Figure 14: The OMEGA infrared spectrometer on board ESA's Mars Express, and CRISM onboard NASA's Mars Reconnaissance Orbiter (MRO), have identified iron-magnesium rich clays like smectite over hundreds of square kilometers around the Oxia Planum site. The origin of the clays – perhaps due to alteration of volcanic sediments – is of keen interest to researchers looking for a terrain where traces of life have been preserved and could be studied by a rover. This image was taken by MRO's high resolution camera HiRISE and shows a relatively flat surface in this region. Images like these have been used in the assessment of the various landing site candidates (image credit: NASA/JPL/University of Arizona)
Figure 15: The two candidates for the landing site of the ESA-Roscosmos rover and surface science platform that will launch to the Red Planet in 2020. Both landing site candidates – Oxia Planum and Mawrth Vallis – preserve a rich record of geological history from the planet's wetter past billions of years ago. They lie just north of the equator, separated by a few hundred kilometers, in a region with many channels cutting through from the southern highlands to the northern lowlands. -The background used in this image is from NASA's Viking orbiters (image credit: NASA/JPL/USGS)
- The Landing Site Selection Working Group also emphasized that the discoveries generated during the landing site selection process are essential to guide the science operations of the ExoMars rover.
- The recommendation was made today 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 quest to find the perfect landing site began almost five years ago, in December 2013, when the science community was asked to propose candidate locations. Eight proposals were considered in the following April, with four put forward for detailed analysis in late 2014. In October 2015, Oxia Planum was identified as one of the most compatible sites with the mission requirements – at that time with a 2018 launch date in mind – with a second option to be selected from Aram Dorsum and Mawrth Vallis. In March 2017, the down-selection identified Oxia Planum and Mawrth Vallis as the two candidates for the 2020 mission, with both undergoing a detailed evaluation over the last 18 months.
- On the technical side, the landing site must be at a suitably low elevation level, so that there is sufficient atmosphere and time to help slow the landing module's parachute descent. Then, the 120 x 19 km landing ellipses should not contain features that could endanger the landing, the deployment of the surface platform ramps for the rover to exit, and the subsequent driving of the rover. This means scrutinizing the region for steep slopes, loose material and large rocks.
- On the science side, the analysis had to identify sites where the rover could use its drill to retrieve samples from below the surface, and to define possible traverses it could make up to 5 km from its touchdown point in order to reach the maximum number of interesting locations.
Figure 16: The two candidates for the landing site of the ESA-Roscosmos rover and surface science platform. The study area of each landing site is indicated by the black outline; the shape corresponds to the different landing ellipses defined by factors such as different launch dates within the launch window and, in the case of Mawrth Vallis, local topography constraints resulting in different landing ellipse centers depending on the launch date. The map is color-coded corresponding to elevation: whites and reds are higher than yellows and greens. The data was obtained by the Mars Orbiter Laser Altimeter onboard NASA's Mars Global Surveyor (image credit: NASA/JPL)
Legend to Figure 16: Both landing site candidates lie close to the transition between the cratered northern highlands and the southern lowlands of Mars. They lie just north of the equator, in a region with many channels cutting through from the southern highlands to the northern lowlands. As such, they preserve a rich record of geological history from the planet's wetter past, billions of years ago.
• September 27, 2018: Thales Alenia Space in the UK achieves the major milestone of delivering its IMU Flight Models to Airbus Defence and Space in UK for integration with the ExoMars Rover. Exomars is a project under international cooperation between ESA (European Space Agency) and Roscosmos (Russian Space Agency), Thales Alenia Space is the prime contractor for the global program. 14)
- The IMU (Inertial Measurement Unit) designed by Thales Alenia Space in the UK has been delivered for integration in to the ExoMars Rover mission. The IMU enables the Rover's navigation during its mission, providing critical data on its orientation, speed and direction.
- Designed, built and tested in Thales Alenia Space's advanced facilities in Bristol, UK, these next generation IMU's utilize a new modular concept that provides 3 axis orientation, angular rate, velocity and acceleration measurement.
• June 27, 2018: A ground penetrating radar antenna for ESA's ExoMars 2020 rover being pre-cleaned in an ultra-cleanroom environment in preparation for its sterilization process, in an effort to prevent terrestrial microbes coming along for the ride to the red planet. 15)
- Part of the Agency's Life, Physical Sciences and Life Support Laboratory based in its Netherlands technical center, This 35 m2 ‘ISO Class 1' cleanroom is one of the cleanest places in Europe. It is equipped with a dry heat sterilizer used to reduce the microbial ‘bioburden' on equipment destined for alien worlds.
Figure 17: The item seen here is the WISDOM (Water Ice Subsurface Deposit Observation on Mars) radar antenna flight model, designed to sound the subsurface of Mars for water ice (image credit: ESA–A. Dowson)
- "After pre-cleaning and then the taking of sample swabs, the antenna was placed into our dry heat sterilizer, to target the required 99.9% bioburden reduction to meet ExoMars 2020's cleanliness requirements," explains technician Alan Dowson.
- To check the effectiveness of this process, the swabs are subjected to a comparable heat shock and then cultivated for 72 hours, to analyze the number of spores and bacteria able to survive. The viable bioburden is then calculated for the surface area of the WISDOM antenna. If this level is below the mission's maximum then it is cleared for delivery."
- All the cleanroom's air passes through a two-stage filter system. Anyone entering the chamber has to gown up in a much more rigorous way than a hospital surgeon, before passing through an air shower to remove any remaining contaminants.
- The chamber's cleanliness is such that it contains less than 10 particles smaller than a thousandth of a millimeter per cubic meter. A comparable sample of the outside air could well contain millions.
- By international planetary protection agreement, space agencies are legally required to prevent terrestrial microbes hitchhiking to other planets and moons in our Solar System where past or present alien life is a possibility.
• May 29, 2018: A representative model of the ExoMars rover that will land on Mars in 2021 is beginning a demanding test campaign that will ensure it can survive the rigors of launch and landing, as well as operations under the environmental conditions of Mars. 16)
- The ExoMars rover will be the first of its kind to drill below the surface – down to 2 m – and determine if evidence of life is buried underground, protected from the destructive radiation that impinges the surface today.
- Like any space mission, the rover's mechanical structure, along with its electrical and thermal components and its interfaces with the scientific instruments, have to be tested to check they can survive their journey in space and operations at the destination.
- As such the rover ‘structural and thermal model' was recently transferred from Airbus Defence and Space in Stevenage, UK, to the Airbus site in Toulouse, France. This week, the model will be shaken on a vibration table to ensure it can survive the intense juddering as the Proton rocket carries it into space.
- Furthermore, the rover model will be subjected to the shocks associated with entering another planet's atmosphere at high speed and as parachutes open, and finally the touchdown onto the Red Planet's surface.
- Two months of thermal tests will follow under Mars atmosphere conditions, to qualify the rover for being able to withstand the frigid temperatures and large daily temperature variations on Mars.
- The tests will be conducted in a chamber to simulate the low atmospheric pressure of Mars – less than 1% of Earth's average sea level pressure – and its carbon dioxide-rich atmosphere. The rover will also need to operate at temperatures down to –120ºC. A closed compartment inside the rover, where martian soil samples will be analyzed, will be thermally controlled to maintain temperatures between +20ºC and –40ºC.
- The current test campaign is expected to last until the beginning of August 2018. The rover model will then move to Lavochkin, Moscow, where it will be sealed inside a replica descent module and again subjected to vibration, shock and thermal tests.
- Another test model will soon start an eight month-long campaign focusing on the rover's movements and navigation over a variety of different ground types, ranging from fine-grained soil to larger boulders.
- The mission will travel to Mars inside an aeroshell, with the rover mounted on a surface science platform. Once safely delivered to the Red Planet's surface, the landing platform will deploy its solar panels and ramps, and within a few days the rover will drive off the platform and begin its exciting exploration of Mars.
- "This campaign kicks off a series of tests that will verify the mechanical and thermal design of the ExoMars rover, essential preparation that brings us a step closer to roving on the Red Planet," says Pietro Baglioni, ESA ExoMars rover team leader.
Figure 18: Photo of the ExoMars rover structural model (image credit: ESA)
ExoMars 2020 Surface Platform Payloads
The rover will leave the surface platform and travel across the surface of Mars to search for signs of well-preserved organic material, particularly from the early period of the planet. The surface platform, which is the responsibility of Roscosmos and the Space Research Institute of Russian Academy of Sciences (IKI), will remain stationary and will investigate the surface environment at the landing site. The set of sensors and instruments on the surface platform will operate during its nominal mission lifetime of one Earth year.
The main science priorities for the surface platform are context imaging of the landing site, long-term climate monitoring, and atmospheric investigations.
Sensors and instruments on the surface platform will also be used to study the subsurface water distribution at the landing site, to investigate the exchange of volatiles between the atmosphere and the surface, to monitor the radiation environment and compare it with measurements made with the radiation dosimeter on the FREND instrument (on the ExoMars 2016 Trace Gas Orbiter), and to carry out geophysical investigations of the planet's internal structure.
In November 2015, ESA approved the selection of six European elements. This includes two European-led instruments, and four sensor packages to be included in two Russian-led instruments.
The two European-led instruments proposed are the LaRa (Lander Radioscience) experiment and the HABIT (Habitability, Brine Irradiation and Temperature) package.
LaRa will reveal details of the internal structure of Mars, and will make precise measurements of the rotation and orientation of the planet by monitoring two-way Doppler frequency shifts between the surface platform and Earth. It will also be able to detect variations in angular momentum due to the redistribution of masses, such as the migration of ice from the polar caps to the atmosphere.
HABIT will investigate the amount of water vapor in the atmosphere, daily and seasonal variations in ground and air temperatures, and the UV radiation environment.
The four European sensor packages in the two Russian-led instruments will monitor pressure and humidity, UV radiation and dust, the local magnetic field and plasma environment.
The surface platform will have a mass of 827.9 kg, including a scientific payload of 45 kg. The instruments are listed in Table 1.
Table 1: Instruments of the ExoMars 2020 Surface Science Platform
ExoMars 2020 Rover Payloads (ISEM, Ma_MISS, ADRON-RM, CLUPI, MOMA, MicrOmega, PanCam,LRS, WISDOM)
The ExoMars rover will be equipped with a drill to collect material from outcrops and at depth down to 2 m. This subsurface sampling capability will provide the best chance yet to gain access to chemical biosignatures. Using the powerful Pasteur payload instruments, the ExoMars science team will conduct a holistic search for traces of life and seek corroborating geological context information. 18) 19)
ISEM (Infrared Spectrometer for ExoMars)
ISEM s a pencil-beam infrared spectrometer that will measure reflected solar radiation in the near infrared range for context assessment of the surface mineralogy in the vicinity of the ExoMars rover. The instrument will be accommodated on the mast of the rover and will be operated together with the panoramic camera (PanCam), high-resolution camera (HRC). ISEM will study the mineralogical and petrographic composition of the martian surface in the vicinity of the rover, and in combination with the other remote sensing instruments, it will aid in the selection of potential targets for close-up investigations and drilling sites. Of particular scientific interest are water-bearing minerals, such as phyllosilicates, sulfates, carbonates, and minerals indicative of astrobiological potential, such as borates, nitrates, and ammonium-bearing minerals. The instrument has an ~1° field of view and covers the spectral range between 1.15 and 3.30 µm with a spectral resolution varying from 3.3 nm at 1.15 µm to 28 nm at 3.30 µm. The ISEM optical head is mounted on the mast, and its electronics box is located inside the rover's body. The spectrometer uses an acousto-optic tunable filter and a Peltier-cooled InAs detector. The mass of ISEM is 1.74 kg, including the electronics and harness. 20)
This instrument will be a mast-mounted infrared spectrometer, designed to determine the major mineral composition of distant rocks, outcrops, and soils. ISEM will be used to help scientists decide which surface targets the ExoMars Rover should approach for a more detailed investigation. 21)
ISEM is mounted on the Rover's mast together with the PanCam High-Resolution Camera (HRC) and Wide Angle Cameras (WAC). ISEM can be pointed to the desired direction in azimuth and elevation by means of the mast's pan and tilt mechanism. During a typical operation, the PanCam WAC, which has a field-of-view of 37° x 37°, will image a large panorama, while the PanCam HRC, with a field-of-view of 5° x 5°, will image a few targets within this panorama at high resolution. At the same time, ISEM, which has a field-of-view of 1°, will measure the infrared characteristics of these same targets by recording the spectra of solar light reflected from the planet's surface and modified by absorption and scattering in the atmosphere. Using the combined visual plus spectroscopic characterization, the science team on Earth will be able to help plan Rover operations by choosing the most promising targets for drilling.
The spectrometer will also be used to identify and map the distribution of rocks that have had a change in composition caused by chemical weathering due to interaction with water-bearing ices, liquids, and vapors. This process is known as aqueous alteration. Of particular interest are measurements that will allow scientists to distinguish between various classes of silicates, oxides, hydrated minerals and carbonates.
The main science objectives of ISEM are:
• To search for and study minerals bearing hydroxide (OH) or water (H2O)
• To carry out a geological investigation and study of minerals and rocks in the thin uppermost layer of the martian surface
• To identify and map the distribution of any aqueous alteration products on the landing site
• To perform a real-time assessment of the composition of the surface in selected areas, to support the identification and selection of the most promising drilling sites
• To study variations of the properties of atmospheric dust and of the gaseous composition of the atmosphere, in as far as this is possible with limited number of observation cycles.
Ma_MISS (Mars Multispectral Imager for Subsurface Studies)
The Ma_MISS experiment is the visible and near infrared (VNIR) miniaturized spectrometer hosted by the drill system of the ExoMars 2020 rover. Ma_MISS will perform IR spectral reflectance investigations in the 0.4–2.2 µm range to characterize the mineralogy of excavated borehole walls at different depths (between 0 and 2 m). The spectral sampling is about 20 nm, whereas the spatial resolution over the target is 120 µm. Making use of the drill's movement, the instrument slit can scan a ring and build up hyperspectral images of a borehole. The main goal of the Ma_MISS instrument is to study the martian subsurface environment. Access to the martian subsurface is crucial to our ability to constrain the nature, timing, and duration of alteration and sedimentation processes on Mars, as well as habitability conditions. Subsurface deposits likely host and preserve H2O ice and hydrated materials that will contribute to our understanding of the H2O geochemical environment (both in the liquid and in the solid state) at the ExoMars 2020 landing site.
The Ma_MISS spectral range and sampling capabilities have been carefully selected to allow the study of minerals and ices in situ before the collection of samples. Ma_MISS will be implemented to accomplish the following scientific objectives: (1) determine the composition of subsurface materials, (2) map the distribution of subsurface H2O and volatiles, (3) characterize important optical and physical properties of materials (e.g., grain size), and (4) produce a stratigraphic column that will inform with regard to subsurface geological processes. The Ma_MISS findings will help to refine essential criteria that will aid in our selection of the most interesting subsurface formations from which to collect samples. 22)
Located inside the ExoMars Rover's drill, Ma_MISS will be the instrument in closest contact with the Martian subsurface. Ma_MISS will image the walls of the borehole created by the drill to study Martian mineralogy and rock formation. This will provide valuable information for the study of subsurface soil and rock layers (i.e., stratigraphy), the distribution and state of water-related minerals, and will help to characterize the geophysical Martian environment. 23)
As the Rover drills into the upper surface of Mars, Ma_MISS will illuminate the hole's cylindrical wall through a transparent window situated in the drill tool. It will capture the reflected light, analyze its spectrum, and transfer the data on the hole stratigraphy to the Rover computer for further analysis and relay to Earth.
Ma_MISS exploits the movement of the drill to acquire data from all around the borehole. The rotation of the instrument as it descends will allow images to be built up in both horizontal (ring image) and vertical sequences (column image).
Ma_MISS's main science objective is to study the Martian subsurface. This is key to understanding the chemical and physical processes that led to the formation and evolution of the site being investigated. — The Martian surface is highly influenced by external processes such as weathering, erosion, sedimentation and impact, all of which alter its original properties. The investigation of subsurface layers is the only approach that permits measurements on samples close to their original composition. The analysis of unexposed material by Ma_MISS, together with data obtained from the spectrometers located inside the Rover (Raman, MicrOmega, MOMA), will be crucial for the interpretation of the original conditions of rock formation on Mars.
In-situ analysis of the Martian subsurface provides information that can be used in the following investigations:
• Assessing the habitability of the drilling site and searching for possible indicators of life.
• Determining the presence of ice or water at the drilling site.
• Documenting the mineral distribution and composition, and identifying the nature of local geology and chemistry.
• Studying the Martian surface layers in terms of hazards and resources relevant to the potential for survival of humans on the surface.
Figure 19: The sapphire window on the drill permits observation of the Martian soil, while the Ma_MISS optical head is protected from scratches and dust (image credit: SELEX Galileo)
ADRON-RM (Autonomous Detector of Radiation of Neutrons onboard Rover at Mars)
ADRON-RM is a Russian project selected for the joint European Space Agency-Roscosmos ExoMars 2020 landing mission. A compact passive neutron spectrometer, ADRON-RM, was designed to study the abundance and distribution of water and neutron absorption elements (such as Cl, Fe, and others) in the martian subsurface along the path of the ExoMars rover. 24)
The ADRON-RM instrument is under development at the Space Research Institute (IKI), Moscow, Russia, under contract with the State Corporation Roscosmos and will be contributed to the joint ESA-Roscosmos ExoMars mission by Roscosmos. While onboard the rover, ADRON-RM will measure the spatial variability of neutron flux emitted from the martian surface. The data processing procedure will convert the raw data into an estimation of bulk water distribution and abundance of neutron absorption elements, initially chlorine and iron. The instrument will also provide continuous monitoring of the neutron component of the radiation background and expand our knowledge about Mars' surface radiation, which will inform with regard to future human missions to the planet.
The main objectives of the ADRON-RM scientific investigation include the following measurements and activities:
• Measurement of the distribution of bulk hydrogen content (in the form of free or bound water) at the stationary platform location and along a rover traverse;
• Evaluation of the bulk composition of major soil neutron absorption elements (Cl, Fe, S, Ti, etc.) at the stationary platform location and along a rover traverse;
• Monitoring of the neutron component of the natural radiation background and estimation of neutron radiation dose at the martian surface from GCRs (Galactic Cosmic Rays) and SPEs (Solar Particle Events);
• The potential to monitor seasonal changes of the neutron environment due to variations of atmospheric and subsurface properties. The mission duration is currently limited to slightly more than 200 sols on the surface, which will provide the potential to observe at least one transition between two seasons. If the rover survives beyond its estimated lifetime at the surface, it could potentially offer full coverage of the martian seasons.
The ADRON-RM is designed as a single unit (Figure 1). The principles and design are inherited directly from the DAN (Dynamic Albedo of Neutrons) instrument onboard NASA's 2011 MSL Rover mission. DAN consists of two separate units integrated at the two sides of the rover: a pulsed neutron generator (DAN/PNG) and detector element (DAN/DE). DAN can be operated both in active and in passive modes of measurements. In active mode, the DAN/PNG produces 2 µs pulses of high-energy (14.1 MeV) neutrons emitted into the 4π steradians around the DAN/PNG. In passive mode, the DAN/DE measures neutron albedo from the subsurface, which is produced by the rover multimission radioisotope thermoelectric generator (MMRTG) and GCRs.
Figure 20: Three-dimensional view of ADRON-RM instrument (image credit: IKI)
CLUPI (Close-Up Imager)
CLUPI onboard the ESA ExoMars Rover is a powerful high-resolution color camera specifically designed for close-up observations. Its accommodation on the movable drill allows multiple positioning. The science objectives of the instrument are geological characterization of rocks in terms of texture, structure, and color and the search for potential morphological biosignatures. We present the CLUPI science objectives, performance, and technical description, followed by a description of the instrument's planned operations strategy during the mission on Mars. CLUPI will contribute to the rover mission by surveying the geological environment, acquiring close-up images of outcrops, observing the drilling area, inspecting the top portion of the drill borehole (and deposited fines), monitoring drilling operations, and imaging samples collected by the drill. 25)
The camera system will take images of rock and unconsolidated material at very fine, tens of micrometers to centimeters. These images will help scientists determine the environment – for example: aqueous, volcanic, etc. – that gave rise to the rocks that are analyzed. This will provide the geological context and therefore improve the scientists' ability to interpret the results obtained by the other rover instruments. 26)
Another very important objective of CLUPI will be to search for morphological biosignatures on outcrops. The primitive types of microorganisms that could have existed on Mars would be very small, probably less than a micron to not more than a few microns in size, but their colonies and biofilms are much larger. Traces of these features may be preserved in the Martian rocks either as mineral-replaced structures and/or as carbon remains trapped in the Martian sediments and encased in a mineral cement. Although the individual cells will be too small to be recognizable in outcrop by CLUPI (complex sample preparation and use of powerful microscopes is necessary for this), the Close Up Imager will be able to image concentrations of colonies forming a spotted, carbon-rich texture called thrombolitic, or forming laminar biofilms.
CLUPI will be an imager with the ability to focus from 10 cm to infinity. At a distance of 10 cm from the object, the resolution of the images will be high – about 7 µm/pixel. To give color images, the camera will have three layers of pixels – red, green and blue.
CLUPI will be located on the drill box of the rover. By using the degrees of freedom provided by both the rover and the drill box, CLUPI will be angled and raised so it can observe in a variety of viewing modes. The use of two fixed mirrors – one flat and one concave – will provide three FOVs (Fields of View).
Figure 21: CLUPI imaging unit (image credit: Space Exploration Institute, Switzerland)
MOMA (Mars Organic Molecule Analyzer)
The objective of the MOMA instrument onboard the ESA/Roscosmos ExoMars rover is to analyze volatile and refractory organic compounds in martian surface and subsurface sediments. The MOMA investigation directly addresses the ExoMars scientific objective to search for signs of past or present life on Mars. It achieves this by analyzing a wide range of organic compounds that may be found in drill samples acquired up to 2 m below the martian surface. MOMA must first volatilize organic compounds so that they can be detected by a mass spectrometer (MS). Volatilization of organic material is achieved by either one of its two operational modes: (1) heating of the sample to induce evaporation and/or thermochemical decomposition (pyrolysis) and liberate species into the gas phase, possibly also being preceded by a chemical derivatization step to aid in this gas-phase transition, and (2) direct interrogation of the sample by intense ultraviolet (UV) laser pulses inducing prompt desorption into the gas phase. In the case of operational mode (1), the organic compounds will be separated by gas chromatographic columns before they reach the MS, while in the case of operational mode (2), the laser-desorbed species are sent directly to the MS without further separation. Either mode enables direct detection of indigenous martian organic molecules (in some cases, as unfragmented parent ions) and will thus be of high diagnostic and scientific value. MOMA can also detect some thermally released inorganic molecules (e.g., SO2) or laser-desorbed fragments of inorganic minerals (e.g., iron oxide or silicate fragments). By characterizing the types, distributions, and molecular structures of detected organics, MOMA can provide powerful insights into the origin and processing of potential molecular biosignatures. 27)
Team organization: The MOMA instrument is assembled from modules produced and tested at several institutions. The Rosetta heritage ovens and tapping station (TS) are developed at the Max Planck Institute for Solar System Research (MPS) in Germany. The gas chromatograph (GC) is built at Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA) and Laboratoire ATmosphères, Milieux, Observations Spatiales (LATMOS) in France with some German participation in the electronics by MPS. Pyrolysis GC testing campaigns have been managed in a partnership between the German and French teams. The MS and its drive electronics, as well as the main electronics of MOMA, are developed by NASA's Goddard Space Flight Center (GSFC) and its partners at the Space Physics Research Laboratory (SPRL) at the University of Michigan in conjunction with Battel Engineering. The laser drive electronics are built at MPS, while the laser head (LH) is designed and built at Laser Zentrum Hannover (LZH).
MOMA is the largest instrument in the ExoMars Rover, and the one directly targeting biomarkers. MOMA will answer questions related to the potential origin, evolution and distribution of life on Mars. In addition to studying the samples collected by the drill, MOMA will also analyze gases in the Martian atmosphere. 28)
MOMA has two complementary operational modes: Gas Chromatograph-Mass Spectrometry (MOMA GC-MS) and Laser Desorption-Mass Spectrometry (MOMA LD-MS).
Figure 22: The MOMA instrument and its modules (image credit: Max Planck Institute for Solar System Research)
MicrOmega (Micro-imaging system)
MicrOmega is a visible near-infrared hyperspectral microscope that is designed to characterize the texture and composition of martian samples presented to the instrument within the ExoMars rover's analytical laboratory drawer. The spectral range (0.5–3.65 µm) and the spectral sampling (20 cm-1 from 0.95 to 3.65 µm) of MicrOmega have been chosen to allow the identification of most constituent minerals, ices/frosts, and organics with astrobiological relevance within each 20 x 20 µm2 pixel over a 5 x 5 mm2 field of view. Such an unprecedented characterization will enable (1) identification of most major and minor phases, including the potential organics; (2) ascription of their mineralogical context, as a critical set of clues with which to decipher their formation process; and (3) location of specific grains or regions of interest in the samples, which will be further analyzed by Raman Laser Spectrometer and/or Mars Organic Molecule Analyzer. 29)
MicrOmega is designed to identify, at grain scale, the mineralogical and the molecular composition of the Martian samples collected by the ExoMars drill. MicrOmega along with MOMA (Mars Organics Molecule Analyzer) and RLS (Raman Laser Spectrometer), will characterize the collected samples, and specifically the organic substances they may contain. 30)
In particular, MicrOmega will analyze the samples with a view to unravelling their geological origin and composition by examining the minerals that they contain. Some minerals can act as monitors of the physical and chemical conditions under which the materials are formed. These data will be vital to characterize the past and present geological processes, climate and environment of Mars and specifically, to help identify evidence of carbon or the past presence of water. They can, therefore, be used to assess whether these samples might have acted as a suitable habitat for life, and whether they have preserved bio-relics.
In addition, MicrOmega can be used to locate grains of particular interest (for example, grains that may have been processed by liquid water) in a totally non-destructive manner, so as to assign them as targets for Raman and MOMA LD-MS observations.
PanCam (Panoramic Camera)
The scientific objectives of the ExoMars rover are designed to answer several key questions in the search for life on Mars. In particular, the unique subsurface drill will address some of these, such as the possible existence and stability of subsurface organics. PanCam will establish the surface geological and morphological context for the mission, working in collaboration with other context instruments. Here, we describe the PanCam scientific objectives in geology, atmospheric science, and 3-D vision. We discuss the design of PanCam, which includes a stereo pair of Wide Angle Cameras (WACs), each of which has an 11-position filter wheel and a High Resolution Camera (HRC) for high-resolution investigations of rock texture at a distance. The cameras and electronics are housed in an optical bench that provides the mechanical interface to the rover mast and a planetary protection barrier. The electronic interface is via the PanCam Interface Unit (PIU), and power conditioning is via a DC-DC converter. PanCam also includes a calibration target mounted on the rover deck for radiometric calibration, fiducial markers for geometric calibration, and a rover inspection mirror. 31)
This instrument will provide stereo and 3D imagery of the terrain around the Rover, for the benefit of the mission as a whole. In particular, the Panoramic Camera will be used: 32)
• To help locate the landing site and Rover position with respect to local geographical references;
• To provide the geological context of the sites explored by the Rover;
• To support the selection of the best sites to carry out exobiology studies;
• To study properties of the atmosphere and of other variable phenomena.
PanCam will also support the scientific measurements of other Rover instruments. It will capture high-resolution images of locations that are difficult to access, such as craters or rock walls. Then, it will monitor the sample from the drill before it is ingested and crushed inside the Rover, where the Analytical Laboratory instruments will perform a detailed chemical, physical, and spectral analysis.
LRS (Raman Laser Spectrometer)
The LRS on board the ESA/Roscosmos ExoMars 2020 mission will provide precise identification of the mineral phases and the possibility to detect organics on the Red Planet. The RLS will work on the powdered samples prepared inside the Pasteur analytical suite and collected on the surface and subsurface by a drill system. Raman spectroscopy is a well-known analytical technique based on the inelastic scattering by matter of incident monochromatic light (the Raman effect) that has many applications in laboratory and industry, yet to be used in space applications. Raman spectrometers will be included in two Mars rovers scheduled to be launched in 2020. The Raman instrument for ExoMars 2020 consists of three main units: (1) a transmission spectrograph coupled to a CCD detector; (2) an electronics box, including the excitation laser that controls the instrument functions; and (3) an optical head with an autofocus mechanism illuminating and collecting the scattered light from the spot under investigation. The optical head is connected to the excitation laser and the spectrometer by optical fibers. The instrument also has two targets positioned inside the rover analytical laboratory for onboard Raman spectral calibration. The aim of this article was to present a detailed description of the RLS instrument, including its operation on Mars. To verify RLS operation before launch and to prepare science scenarios for the mission, a simulator of the sample analysis chain has been developed by the team. 33)
The Raman instrument provides a powerful tool for the definitive identification and characterization of minerals and biomarkers. Raman spectroscopy is sensitive to the composition and structure of any mineral or organic compound. This capability provides direct information of potential organic compounds that can be related with present or past signatures of life on Mars as well as general mineralogical information for igneous, metamorphous, and sedimentary processes, especially water-related geo-processes. 34)
The Raman laser spectrometer will be used:
• to identify organic compounds and search for signatures of life;
• to identify the mineral products and indicators of biological activities;
• to characterize mineral phases produced by water-related processes; and
• to characterize igneous minerals and their products resulting from alteration processes (e.g. oxidation).
Raman will also support the scientific measurements by correlating its spectral information with other spectroscopic and imaging instruments such as the MicrOmega Infrared Spectrometer. Furthermore, the Raman instrument is capable of measuring the sample at a fast-pace (within minutes) in order to release the selected sample for further analysis by other ExoMars instruments (e.g. the MOMA instrument).
WISDOM (Water Ice Subsurface Deposit Observation on Mars) radar
The search for evidence of past or present life on Mars is the principal objective of the 2020 ESA-Roscosmos ExoMars Rover mission. If such evidence is to be found anywhere, it will most likely be in the subsurface, where organic molecules are shielded from the destructive effects of ionizing radiation and atmospheric oxidants. For this reason, the ExoMars Rover mission has been optimized to investigate the subsurface to identify, understand, and sample those locations where conditions for the preservation of evidence of past life are most likely to be found. The Water Ice Subsurface Deposit Observation on Mars (WISDOM) ground-penetrating radar has been designed to provide information about the nature of the shallow subsurface over depth ranging from 3 to 10 m (with a vertical resolution of up to 3 cm), depending on the dielectric properties of the regolith. This depth range is critical to understanding the geologic evolution stratigraphy and distribution and state of subsurface H2O, which provide important clues in the search for life and the identification of optimal drilling sites for investigation and sampling by the Rover's 2-m drill. WISDOM will help ensure the safety and success of drilling operations by identification of potential hazards that might interfere with retrieval of subsurface samples. 35)
The WISDOM radar is being developed through an international and multidisciplinary collaboration of science and technical teams. The instrument is being built and tested by a French–German consortium supported by the French Space Agency CNES (Centre National d'Etudes Spatiales) and DLR (German Space Agency ), Deutsche Forschungsanstalt für Luft-und Raumfahrt, led by Valérie Ciarletti (Principal Investigator) from LATMOS (Laboratoire Atmosphères, Milieux, Observations Spatiales) in Guyancourt, France. LATMOS, in collaboration with Laboratoire d'Astrophysique de Bordeaux (LAB), is responsible for the electronics unit (EU) hardware manufacturing and delivery, while the Technische Universität Dresden (TUD, Germany) is responsible for the antenna system, under the supervision of Dirk Plettemeier (Co-Principal Investigator).
The WISDOM radar will provide a detailed view of the Red Planet's shallow subsurface structure by sounding the upper layers of its crust. Unlike traditional imaging systems or spectrometers, which are limited to studying the visible surface, this radar will access what lies beneath. WISDOM will provide the three-dimensional geological context of the terrain covered by the Rover. This additional perspective is vital for a better understanding of the planet's evolution, and the impact of its changing geology and climate on past and present habitability. 36)
WISDOM will study the nature of the subsurface remotely, using radar pulses from a UHF ground penetrating radar, covering the frequency range from 500 MHz to 3 GHz, to map the subterranean layers. It will provide high-resolution measurements, with a vertical resolution of a few centimeters, down to a depth of 3 m, complementing the 2-meter reach of the Rover's drill. The instrument can transmit and receive signals using two small antennas mounted on the back of the Rover. The WISDOM measurements will be used to identify optimal drilling sites by determining the nature, location and size of potential targets, and to ensure the safety of the drilling operations by minimizing the likelihood of contact with potential hazards.
WISDOM's main science objectives are:
• To investigate the three-dimensional geology and geological evolution of the landing site, and provide information on the general physical characteristics of local rocks, the rock layering and structure;
• To characterize the electromagnetic properties of Martian soil in order to map the scale of diversity in the shallow subsurface; and
• To observe the local distribution of well-compacted, sedimentary deposits that may have been associated with a water-rich environment in the past.
ExoMars 2020 parachute deployment campaign
The largest parachute ever to fly on a Mars mission has been deployed in the first of a series of tests to prepare for the upcoming ExoMars 2020 mission that will deliver a rover and a surface science platform to the Red Planet. 37)
The spacecraft that will carry them is due for launch in July 2020, with arrival at Mars in March 2021. The rover will be the first of its kind to drill below the surface and determine if evidence of life is buried underground, protected from the destructive radiation that impinges the surface today.
A carrier module will transport the rover and the science platform to Mars within a single aeroshell. A descent module will separate from the carrier shortly before reaching the atmosphere, whereupon a heatshield, parachutes, thrusters and damping systems will reduce the speed, delivering them safely to the surface.
Kiruna campaign March 2018: The focus of the latest test, conducted in sub-zero conditions in Kiruna, Sweden earlier this month, was the 35 m-diameter second main parachute. The test demonstrated the deployment and inflation of the parachute with its 112 lines connected to a drop test vehicle, via the deployment of a smaller 4.8 m-wide pilot chute.
The complete parachute system, with a total mass of 195 kg, is stowed in a dedicated canister. The second main parachute of 70 kg, is folded with its 5 km of cords in a precise way – a process that takes around three working days – to ensure it is extracted properly.
The assembly was lofted 1.2 km above the ground with a helicopter, and the sequence initiated after the vehicle was released. About 12 seconds after the pilot chute was inflated, the second parachute release was triggered.
GoPro cameras 38) on the 500 kg test vehicle looked up at the parachute inflation, and onboard equipment sent telemetry in real time as it descended in about two and a half minutes to the ground.
Figure 23: A helicopter carries a drop test vehicle to an altitude of 1.2 km before releasing it to monitor the deployment of the second stage main parachute, as part of a series of tests to prepare for the upcoming ExoMars mission (image credit: ESA/I. Barel)
"The successful deployment of our large ExoMars parachute using a smaller pilot chute and its subsequent stable descent without damage, is a major milestone for the project," says ESA's Thierry Blancquaert.
Figure 24: The deployment of the large 35 m-wide parachute of the upcoming ExoMars 2020 mission was tested in a low-altitude drop test earlier this month. The image captures the inflated ring-slot parachute with the drop test vehicle suspended underneath (image credit: ESA/I.Barel)
"It was a very exciting moment to see this giant parachute unfurl and deliver the test module to the snowy surface in Kiruna, and we're looking forward to assessing the full parachute descent sequence in the upcoming high-altitude tests."
That testing will see the equipment dropped from a stratospheric balloon from nearly 30 km, to more accurately represent the low atmospheric pressure on Mars – a vital aspect when considering parachute inflation.
The subsequent tests will also investigate the full parachute deployment sequence, which comprises two main parachutes, each with a pilot chute.
The dual parachute approach accommodates the much heavier descent module of the ExoMars 2020 mission – some 2000 kg compared with nearly 600 kg of the previous mission.
Figure 25: The ExoMars 2020 parachute deployment sequence that will deliver a surface platform and rover to the surface of Mars in 2021 (following launch in 2020). The graphic is not to scale, and the colors of the parachutes are for illustrative purposes only (image credit: ESA) 39)
Legend to Figure 25: The graphic highlights the main events concerning the parachutes, a sequence that is initiated after significant slowing of the 3.8 m-wide entry module in the atmosphere with the aeroshell's heatshields. Then the first pilot parachute is deployed, and shortly after the first main stage parachute, which measures 15 m in diameter and has a disc-gap band design. It will open while the module is still travelling at supersonic speed and will be jettisoned prior to the deployment of the second pilot chute and second stage main parachute once at subsonic speeds. The second stage main parachute has a ring-slot design and is 35 m in diameter, the largest to ever fly on Mars.
The second pilot chute remains attached to the main parachute in order to prevent rebound of the deployed parachute. During latter stages of the descent (not pictured) the aeroshell's front heatshield will be discarded, and the landing platform will be released for its final descent and propulsive braking phase. Once safely on the surface, it will subsequently deploy ramps for the rover to drive down and on to Mars.
The last two stages depicted in this graphic were the focus of a low-altitude parachute deployment test conducted in March 2018. The full sequence will be tested in follow-up high-altitude tests.
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4) Anatoly Zak, "Russia continues works on ExoMars lander design," Russian Spaceweb, 6 April 2018, URL: http://www.russianspaceweb.com/exomars2018-2017.html
5) Diana Beatriz Margheritisa, Bruno Musetti, Enrico Andrea Nisticò, Silvia Procchio, "Planetary Protection on COSPAR Category IVb ExoMars Mission 2020," Proceedings of the 69th IAC (International Astronautical Congress) Bremen, Germany, 1-5 October 2018, paper: IAC-18,A3,3A,10 URL: https://iafastro.directory/iac/proceedings/IAC-18/I
6) Miracle Israel Nazarious, Abhilash Vakkada Ramachandran, Maria-Paz Zorzano, Javier Martin-Torres, "Calibration and preliminary tests of the Brine Observation Transition To Liquid Experiment on HABIT/Exomars 2020 for demonstration of liquid water stability on Mars," Proceedings of the 69th IAC (International Astronautical Congress) Bremen, Germany, 1-5 October 2018, paper: IAC-18.A3.3B.8, URL: https://iafastro.directory/iac/proceedings/IAC-18/IAC-18/A3/3
7) Robert Paul, Daniel Redlich, Tim Tattusch, Markus Thiel, Christiane Bergemann-Mecucci, Fabio Musso, Stephen Durrant, "Flight-Model Test Results of the Mechanism Suite in ESA‘s ExoMars Rover Analytical Laboratory Drawer," Proceedings of the 69th IAC (International Astronautical Congress) Bremen, Germany, 1-5 October 2018, paper: IAC-18.A3.3B.4, URL: https://iafastro.directory/iac/proceedings/IAC-1
8) Maurizio Deffacis, Lorenzo Bramante, Marco Barrera, Roberto Trucco, Paola Franceschetti, Luc Joudrier, Adam Williams, "The Mars Terrain Simulator: an indoor analogue facility to validate and simulate ExoMars Rover Operations and to support the ExoMars Surface Mission," Proceedings of the 69th IAC (International Astronautical Congress) Bremen, Germany, 1-5 October 2018, paper: IAC-18-B6.3.5, URL: https://iafastro.directory/iac/proceedings/IAC-18/IAC-18/B6/3
9) Diego Bussi, Marco Barrera, Roberto Trucco, Federico Salvioli, Massimo Rabaioli, Eugenio Topa, Andrea D'Ottavio, Livia Savioli, Liliana Ravagnolo, Giovanni Martucci di Scarfizzi, Paola Franceschetti, Luc Joudrier, Adam Williams, Tanya Lim, "Challenges in the definition, validation and simulation of the ground operations of the ExoMars 2020 Rover surface mission at the Rover Operations Control Centre (ROCC)," Proceedings of the 69th IAC (International Astronautical Congress) Bremen, Germany, 1-5 October 2018, paper: IAC-18-B6.3.6, URL: https://iafastro.directory/iac/proceedings/IAC-18/IAC-18/B6
10) "ESA's Mars rover has a name – Rosalind Franklin," ESA, 7 February 2019, URL: http://m.esa.int/Our_Activities/Human_and_Robotic_Exploration/Exploration/
11) "ExoMars software passes ESA Mars yard driving test," ESA, 17 January 2019, URL: https://www.esa.int/Our_Activities/Space_Engineering_Technology/
12) "ExoFitness," ESA, Human and robotic exploration image of the week, 27 November 2018, URL: http://m.esa.int/spaceinimages/Images/2018/11/ExoFitness
13) "Oxia Planum favored for ExoMars surface mission," ESA, 9 November 2018, URL: http://m.esa.int/Our_Activities/Space_Science/ExoMars/Oxia_Planum_favoured_for_ExoMars_surface_mission
14) "Thales Alenia Space successfully delivers a key element for European Space Agency's Exomars 2020 mission," TAS, 27 September 2018, URL: https://www.thalesgroup.com/en/worldwide/space/press-release/thales
15) "Sterilizing an antenna for Mars," ESA, 27 June 2018, URL: http://m.esa.int/spaceinimages/Images/2018/06/Sterilising_an_antenna_for_Mars
16) "Red Planet Rover set for extreme environment workout," ESA, 29 May 2018, URL: http://www.esa.int/Our_Activities/Space_Science/ExoMars/Red
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18) "Habitability on Early Mars and the Search for Biosignatures with the ExoMars Rover," ESA, 1 July 2017, URL: http://exploration.esa.int/mars/44970-publications-archive/?farchive_objectty
19) Andrew J. Coates,Ralf Jaumann, Oleg Korablev, Valérie Ciarletti, Igor Mitrofanov, Jean-Luc Josset, Maria Cristina De Sanctis, Jean-Pierre Bibring, Fernando Rull, Fred Goesmann, Harald Steininger, Walter Goetz, William Brinckerhoff, Cyril Szopa, François Raulin, Frances Westall, Howell G. M. Edwards, Lyle G. Whyte, Alberto G. Fairén, Jean-Pierre Bibring, John Bridges, Ernst Hauber, Gian Gabriele Ori, Stephanie Werner, Damien Loizeau, Ruslan O. Kuzmin, Rebecca M. E. Williams, Jessica Flahaut, François Forget, Jorge L. Vago, Daniel Rodionov, Oleg Korablev, Håkan Svedhem, Elliot Sefton-Nash, Gerhard Kminek, Leila Lorenzoni, Luc Joudrier, Viktor Mikhailov, Alexander Zashchirinskiy, Sergei Alexashkin, Fabio Calantropio, Andrea Merlo, Pantelis Poulakis, Olivier Witasse, Olivier Bayle, Silvia Bayón, Uwe Meierhenrich, John Carter, Juan Manuel García-Ruiz, Pietro Baglioni, Albert Haldemann, Andrew J. Ball, André Debus, Robert Lindner, Frédéric Haessig, David Monteiro, Roland Trautner, Christoph Voland, Pierre Rebeyre, Duncan Goulty, Frédéric Didot, Stephen Durrant, Eric Zekri, Detlef Koschny, Andrea Toni, Gianfranco Visentin, Martin Zwick, Michel van Winnendael, Martín Azkarate, Christophe Carreau, and the ExoMars Project Team, "Habitability on Early Mars and the Search for Biosignatures with the ExoMars Rover," Astrobiology,Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1533
20) Oleg I. Korablev, Yurii Dobrolensky, Nadezhda Evdokimova, Anna A. Fedorova, Ruslan O. Kuzmin, Sergei N. Mantsevich, Edward A. Cloutis, John Carter, Francois Poulet, Jessica Flahaut, Andrew Griffiths, Matthew Gunn, Nicole Schmitz, Javier Martín-Torres, Maria-Paz Zorzano, Daniil S. Rodionov, Jorge L. Vago, Alexander V. Stepanov, Andrei Yu. Titov, Nikita A. Vyazovetsky, Alexander Yu. Trokhimovskiy, Alexander G. Sapgir, Yurii K. Kalinnikov, Yurii S. Ivanov, Alexei A. Shapkin, and Andrei Yu. Ivanov, "Infrared Spectrometer for ExoMars: A Mast-Mounted Instrument for the Rover," Astrobiology,Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1543
21) "ISEM - Infrared Spectrometer for ExoMars," ESA, 25 August 2017, URL: http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2302
22) Maria Cristina De Sanctis, Francesca Altieri, Eleonora Ammannito, David Biondi, Simone De Angelis, Marco Meini, Giuseppe Mondello, Samuele Novi, Riccardo Paolinetti, Massimo Soldani, Raffaele Mugnuolo, Simone Pirrotta, Jorge L. Vago, and the Ma_MISS team, "Ma_MISS on ExoMars: Mineralogical Characterization of the Martian Subsurface," Astrobiology, Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1541
23) "Ma_MISS - Mars Multispectral Imager for Subsurface Studies," ESA, 25 August 2017, URL: http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2133
24) I.G. Mitrofanov, M.L. Litvak, S.Y. Nikiforov, I. Jun, Y.I. Bobrovnitsky, D.V. Golovin, A.S. Grebennikov, F.S. Fedosov, A.S. Kozyrev, D.I. Lisov, A.V. Malakhov, M.I. Mokrousov, A.B. Sanin, V.N. Shvetsov, G.N. Timoshenko, T.M. Tomilina, V. I. Tret'yakov, and A.A. Vostrukhin, "The ADRON-RM Instrument Onboard the ExoMars Rover," Astrobiology, Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1566
25) Jean-Luc Josset, Frances Westall, Beda A. Hofmann, John Spray, Charles Cockell, Stephan Kempe, Andrew D. Griffiths, Maria Cristina De Sanctis, Luigi Colangeli, Detlef Koschny, Karl Föllmi, Eric Verrecchia, Larryn Diamond, Marie Josset, Emmanuelle J. Javaux, Francesca Esposito, Matthew Gunn, Audrey L. Souchon-Leitner, Tomaso R.R. Bontognali, Oleg Korablev, Suren Erkman, Gerhard Paar, Stephan Ulamec, Frédéric Foucher, Philippe Martin, Antoine Verhaeghe, Mitko Tanevski, and Jorge L. Vago, "The Close-Up Imager Onboard the ESA ExoMars Rover: Objectives, Description, Operations, and Science Validation Activities," Astrobiology, Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1546
26) "CLUPI - Close-UP Imager," ESA, 25 August 2017, URL: http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2301
27) Fred Goesmann, William B. Brinckerhoff, François Raulin, Walter Goetz, Ryan M. Danell, Stephanie A. Getty, Sandra Siljeström, Helge Mißbach, Harald Steininger, Ricardo D. ArevaloJr., Arnaud Buch, Caroline Freissinet, Andrej Grubisic, Uwe J. Meierhenrich, Veronica T. Pinnick, Fabien Stalport, Cyril Szopa, Jorge L. Vago, Robert Lindner, Mitchell D. Schulte, John Robert Brucato, Daniel P. Glavin, Noel Grand, Xiang Li, and Friso H. W. van Amerom; the MOMA Science Team," Astrobiology, Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1551
28) "MOMA - Mars Organics Molecule Analyzer," ESA, 25 August 2017, URL: http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2132
29) Jean-Pierre Bibring, Vincent Hamm, Cédric Pilorget, Jorge L. Vago, and the MicrOmega Team, "The MicrOmega Investigation Onboard ExoMars," Astrobiology, Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1642
30) "The MicrOmega Infrared Spectrometer," ESA, 25 August 2017, URL: http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2129
31) A.J. Coates, R. Jaumann, A.D. Griffiths, C.E. Leff, N. Schmitz, J.-L. Josset, G. Paar, M. Gunn, E. Hauber, C.R. Cousins, R.E. Cross, P. Grindrod, J.C. Bridges, M. Balme, S. Gupta, I.A. Crawford, P. Irwin, R. Stabbins, D. Tirsch, J.L. Vago, T. Theodorou, M. Caballo-Perucha, G.R. Osinski, and the PanCam Team, "The PanCam Instrument for the ExoMars Rover," Astrobiology, Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1548
32) "PanCam - the Panoramic Camera," ESA, 25 August 2017, URL: http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2127
33) Fernando Rull, Sylvestre Maurice, Ian Hutchinson, Andoni Moral, Carlos Perez, Carlos Diaz, Maria Colombo, Tomas Belenguer, Guillermo Lopez-Reyes, Antonio Sansano, Olivier Forni, Yann Parot, Nicolas Striebig, Simon Woodward, Chris Howe, Nicolau Tarcea, Pablo Rodriguez, Laura Seoane, Amaia Santiago, Jose A. Rodriguez-Prieto, Jesús Medina, Paloma Gallego, Rosario Canchal, Pilar Santamaría, Gonzalo Ramos, and Jorge L. Vago; on behalf of the RLS Team, "The Raman Laser Spectrometer for the ExoMars Rover Mission to Mars," Astrobiology, Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1567
34) "RLS - Raman Laser Spectrometer," ESA, 25 August 2017, URL: http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2130
35) Valérie Ciarletti, Stephen Clifford, Dirk Plettemeier, Alice Le Gall, Yann Hervé, Sophie Dorizon, Cathy Quantin-Nataf, Wolf-Stefan Benedix, Susanne Schwenzer, Elena Pettinelli, Essam Heggy, Alain Herique, Jean-Jacques Berthelier, Wlodek Kofman, Jorge L. Vago, Svein-Erik Hamran, and the WISDOM Team, "The WISDOM Radar: Unveiling the Subsurface Beneath the ExoMars Rover and Identifying the Best Locations for Drilling," Astrobiology, Vol. 17, No. 6-7, Published Online:1 July 2017, https://doi.org/10.1089/ast.2016.1532
36) "WISDOM - Water Ice and Subsurface Deposit Observation on Mars," ESA, 25 August 2017, URL: http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2128
37) "First test success for largest Mars mission parachute," ESA, 29 March 2018, URL: http://m.esa.int/Our_Activities/Space_Science/ExoMars/
38) GoPro Inc. is an American technology company founded in 2002 by Nick Woodman. It manufactures action cameras and develops its own mobile apps and video-editing software. URL: https://en.wikipedia.org/wiki/GoPro
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The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (firstname.lastname@example.org).