ExoMars 2016 TGO-Schiaparelli - ExoMars

Frequently Asked Questions

Frequently Asked Questions

ExoMars 2022 F.A.Q.

ExoMars 2022 is the second mission of the ExoMars Program and comprises the first European rover Rosalind Franklin and the Roscosmos surface platform Kazachok.

The 12-day launch window of the ExoMars 2022 mission opens on 20 Sep and closes on 1 Oct 2022. The launcher is a Proton-M rocket from the Baikonur Cosmodrome (Kazakhstan).

Rosalind Franklin is expected to land along with the Russian lander Kazachok in the Oxia Planum region (17.28° N, 334.29° E) on 10 Jun 2023, around 15:22 (LMST), which corresponds to 12:15 Universal Time Coordinated (UTC).

The European rover Rosalind Franklin has been designed to survive for a nominal mission of 211 sols. An extended mission may hopefully be possible after this period which includes 20 sols of solar conjunction.

The number of communication passes varies — it is typically in the order of 2 to 3 per sol. The nominal case is one pass in the morning (we tell the rover what to do) and one in the evening (it tells us what it did). In average, 150 Megabits of data per day of operations is expected.

The sol 211 of the ExoMars 2022 mission corresponds to 6 Jan 2024.

The Post Landing To Egress (PLTE) phase nominally lasts for 10 sols, i.e. the first 10 sols of the mission. The egress from the surface platform is expected to happen on 20 Jun 2023.

The Commissioning Phase follows the PLTE. This phase may start with a circumnavigation of Kazachok, provided the terrain allows this. Thereafter, the rover must travel some 100 meters away from the lander before it can open its Analytical Laboratory Drawer (ALD). This is to avoid risking contamination with propulsion engine byproducts (such as ammonia). We have given a name to the place at which we will open the ALD and perform the first tests with its instruments — the Science.0 location. Science.0 because it is "preparation" for the real science, which will happen at the Experiment Cycle 1 site (EC1). All in all, the total duration of the Commissioning Phase could be in the order of 20 sols.

The solar arrays have a surface equal to 2.39 squared meters.

Power generation capability depends on the latitude, solar longitude, optical depth, and dust deposition on solar arrays. The estimated daily energy generation for the rover is in the order of 1200 Wh.

The solar conjunction of the year 2023 is expected to occur from 18 Nov 2023, 05:14 UTC to 4 Dec 2023, included.

Mars will remain visible for 10 months after opposition and then become lost in the glare of the Sun around 24 Nov 2025; as it approaches its next conjunction expected to occur in early 2026. The solar conjunction of the year 2026 will start on 9 Jan 2026.

The rover does not have any system capable of removing the dust. The solar arrays have been designed so that the rover has enough power to run all its instruments throughout its nominal mission duration. Hopefully we can benefit from the cleaning effect of occasional dust devils — as was the case for NASA's Spirit and Opportunity — which are able to clean most (up to 99%) of the dust accumulated on solar panels.

The first element of the Rosalind Franklin drill is called the "Drill tool". It is 69.30 centimeters long. There are other elements, including three extension rods, that must be connected to reach the drill's full 2-meter extension.

The Drill tool comprises 3 additional rods besides the initial one. Each additional rod enables the rover to drill 48.90 centimeters deeper. The total length of the drill string is 200 centimeters and aims to collect samples below the Martian surface.

The vertical speed of the drill varies according to the material properties such as permittivity, permeability, and density. The drilling speed in the air is about 50 mm per minute, while it varies between 0.3 and 30 mm per minute for a solid material (sand, clay, etc.).

The drill enters the material with a speed of 360 degrees per second, i.e. 60 rotations per minute.

The tactical planning is defined on a daily basis during the operations. The steps are the following:

Step 1: Telemetry retrieval and processing
Step 2: Data assessment
Step 3: Activity plan negotiation and integration
Step 4: Activity plan validation and simulation
Step 5: Activity plan uplink

A sample collected by the Drill has the following properties:

• Sample volume: 2 milliliters
• Sample diameter: 1 centimeter
• Sample height: 2.5 centimeters

A sample can be a whole core, a fractured core, or unconsolidated material. It all depends on the nature of the unit being drilled into.

Oxia Planum (17.28° N, 334.29° E) is a 200 km-wide clay-bearing plain located on the planet of Mars inside the Oxia Palus quadrangle on the eastern boarder of Chryse Planitia. The plain lies between the Mawrth Vallis outflow channel to the north-east and the Ares Vallis outflow channel to the south-west. Oxia Planum was chosen as landing site because of its age (3.6 billion years old) and its relatively smooth topography and its abundance of hydrated minerals.

The scientific objectives, in order of priority, are:

• to search for possible biosignatures of past Martian life,
• to characterize the water and geochemical distribution as a function of depth in the shallow subsurface,
• to study the surface environment and identify hazards to future human missions to Mars,
• to investigate the planet's subsurface and deep interior to better understand the evolution and habitability of Mars.

The Trace Gas Orbiter (TGO), Mars Reconnaissance Orbiter (MRO), MAVEN (MVN) and possibly Mars Express (MEX) are the 4 orbiters that could support the ExoMars 2022 mission.

The Mars Organic Molecule Analyser (MOMA) has 31 ovens. Among those, 19 are pyrolysis ovens. That is, ovens where organic molecules are desorbed using heat only. The other 12 ovens include derivatization agents. Derivatization agents attach to specific molecules, and in some cases specific parts of molecules, to protect them during the thermal volatilization process, such that they can be extracted and detected. We have three different derivatization compounds, so 4 ovens are used for each type. Each oven has a volume varying between 0.263 and 0.291 ml (temperature-dependent).

An EC comprises all actions necessary to select, approach, study a target location, and transmit the collected data to ground. Depending on the distance that the rover must travel and on the analyses performed, a typical EC can last between 15 and 20 sols. In a "reference" EC, the rover approaches an outcrop, observes it, collects and analyses a surface sample to confirm the scientific interest of the target (e.g., is it a sedimentary rock formed in the presence of liquid water?). The rover then proceeds to investigate the subsurface to find a suitable unit to acquire a sample from. It collects a subsurface sample and studies its mineral and organic composition.

A VS is reserved for the very best locations. A VS consists on obtaining and performing a complete series of measurements on samples obtained at 0, 50, 100, 150, 200 centimeters depth at one site. The goal is to see how composition and the preservation of organic molecules changes with depth. This would only be done at a place where a material especially interesting has been found. A VS can last in the order of 20–30 sols.

The rover's driving speed of the rover depends mainly on how easy or difficult the terrain is—rocks, wheel slippage, etc. The average speed is in the range of 32 to 40 meters per hour (1.1 cm/sec). Nevertheless, the locomotion subsystem (LSS) has the capability to drive the rover at a drive speed of 100 m/h on a straight line, i.e. zero curvature and zero crab angle.

Because Rosalind Franklin has six driven and six steered wheels, it can move in different ways: 1) It can drive straight; 2) it can do Ackermann steering — that is, navigate using smooth curves; 3) it can crab — move sideways; and 4) it can point turn. Additionally, the rover has motorized "knees" that allow it to use its wheels as feet, in a type of alternating gait called "wheel walking". The latter is very useful when the terrain is loose and there is a risk of getting stuck.

The different mobility application modes are the following:

• Direct Driving (DDrive): this mode allows the Ground to send open-loop rover body level maneuver commands (Generic Ackerman, Generic Point Turn, Stop) to the Rover without the intervention of the Rover Trajectory control. It is sufficient to perform egress from the Landing Platform and might also be used for contingency purposes. This mode is entered and exited on Ground TC reception.

• Locomotion & Localization only (LLO): this mode is similar to the Direct Driving mode as it provides the capacity to the Ground to send open-loop rover body level maneuver commands (Generic Ackerman, Generic Point Turn) to the Rover but with the Localization functionality enabled which allows the rover to track its movements on the surface thus allowing the rover to stop once a command termination condition has been met (such as distance travelled or heading change) rather than stopping after a stop TC reception like the DDrive mode. This mode is entered on Ground TC reception and exited automatically when the required distance has been travelled or the required heading change is performed.

• Follow Path (FPath): this mode allows the Ground to load a predefined path to the Rover Trajectory Control function and request for its execution. This mode is entered on Ground TC reception and exited when the demanded path has been travelled by the rover or when an abort command is received.

• Check Path (CheckPath): this mode allows the Ground to load a predefined path to the Rover Trajectory Control function and request for its check by the navigation module and its execution. This mode is entered on Ground TC reception and exited when the demanded path has been travelled by the Rover or when an abort command is received.

• Autonomous Navigation (AutoNav): this mode allows the Ground to load a target destination for the Rover to autonomously navigate to. This mode is entered on Ground TC reception and exited when the demanded path has been travelled by the rover or when an abort command is received.

• Automatic Stand-Up (Auto Standup): this mode allows the Ground to correct the Backdriving of any DEP axis. This mode is entered on Ground TC reception and exited when all DEP axis are fully deployed (i.e. in vertical position) or when an abort command is received.

Mobility of the rover is impacted by a high number of parameters that are either dependent or independent of the operators. The list of parameters includes but is not limited to:

• The terrain slope: a 15-degree slope is acceptable when the rover drives on a bedrock; a 10-degree slope is acceptable when driving on a bedrock with a thin layer of regolith. In the worst case, the rover can pass a slope of about 20 degrees. Therefore, very high slopes (positive or negative) should be avoided as much as possible for the sake of the rover’s physical state.

• The terrain subsidence (soil hardness): even though the rover can get out of dramatic situations (e.g. sinking) thanks to its mobility capabilities, subsiding terrains must be avoided – being blocked implies a specific procedure that may take several sols, leading to a loss of science opportunities. In particular, a loose type of terrain should be considered challenging for traverse.

• The presence of obstacles (ground hazard): a target might be unreachable if the terrain is particularly harsh. Should the target be reachable, one must ensure that a drilling can be performed as well.

Additionally, the situational awareness and other implicit parameters (wheels status, etc.) could be important in the decision making.