Category: Sample Handling System of Mars 2020 Perseverance Rover

The Mars 2020 Perseverance Rover has an extraordinary sample handling system. The major components include the robotic arm, the adaptive caching assembly, the turret, the drill, the sample containers, and witness tubes. The goal of the Mars 2020 Perseverance Rover’s sample handling system is to collect rock and soil samples and return them to Earth for further analysis to prepare for possible future human exploration on Mars.
There are mainly three steps in the Mars 2020 Perseverance Rover’s sample handling process. The first step is to collect rock and soil samples from a target area that is selected by the relevant science instruments. The second step is to transfer the collected samples into the belly of the Mars 2020 Perseverance Rover for sealing and storing. The final step is to deposit the samples to designated locations on the Martian surface for future pickup and return to Earth.

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Sample Handling System of Mars 2020 Perseverance Rover

Adaptive Caching Assembly of the Mars 2020 Perseverance Rover – part 3

Theoretically, the Mars 2020 Perseverance Rover’s sample caching process for a rock or a regolith can be described as follows.

First of all, Mars 2020 Perseverance Rover will do an initial assessment on the sampling site by the science instruments on the rover. The Mars 2020 Perseverance Rover’s MastCam-Z will spot a potential sampling site and identify a rock for later investigation.

Secondly, the Mars 2020 Perseverance Rover’s SuperCam will exam the rock more carefully in greater detail. After SuperCam confirms that this site or this rock is worthy of caching, the Mars 2020 Perseverance Rover will move closer to the site. Then the abrading bit on the corer of the turret assembly will perform an initial abrasion so that PIXL and SHERLOC can do a close proximity analysis before the rock is decided to be a good potential caching target.

With our 1:2 Perseverance Mars Rover Replica, the users can control the rover to perform the same action as the above two steps. Although it won’t be the real scientific inspection, the movement will be the same.

Although the Mars 2020 Perseverance Rover’s PIXL and SHERLOC instruments have different functions and look for different features, in this step, they both work as the final step and a double-check for if the location is a valuable target for sample caching.

Next, the sample caching process will start. Below are the basic steps:

  1. The Mars 2020 Perseverance Rover’s sample handling arm in the adaptive caching assembly will get an empty sample tube from the sample tube assembly. The sample tube is then transferred to the Mars 2020 Perseverance Rover’s bit carousel’s interior door and inserted into a drill bit. The bit with the sample tube inside will then be transferred to the outer door, waiting for the turret’s corer to take it. Our Mars Rover Replica will perfectly replicate the sample handling arm and it will be able to perform the same action as the Mars 2020 Perseverance Rover’s sample handling arm.
  2. After the turret’s corer picks up the drill bit, the Mars 2020 Perseverance Rover’s robotic arm will start the drilling process and collect a rock core or regolith. Then the robotic arm will bring the filled sample tube back to the bit carousel, and the sample is transferred to the lower door, waiting for the Mars 2020 Perseverance Rover’s sample handling arm to move it back to the adaptive caching assembly.
  3. Different from when the sample tube is moved out of the sample tube assembly, this time, the sample tube with the rock or regolith sample will be moved to the volume assessment station, the vision assessment station, the seal dispenser, and the sealing station respectively before it is brought back to the sample tube assembly for storage.

For our Mars Rover Replica, although you will see how the turret and the tools on it interact with the bit carousel, you might not see the interactions between the tubes and the stations because it will be done inside of the rover’s body. But we will still try our best to replicate the stations and the ability to move for our Mars Rover Replica just like the real Mars 2020 Perseverance Rover’s actions. If you are interested in our Mars Rover Replica, you can check out [1:2 Perseverance Mars Rover Replica Design and Building Diary].

Ideally, these tubes will be dropped to a pre-decided location for the future retrieving mission and returning to Earth.

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Sample Handling System of Mars 2020 Perseverance Rover

Adaptive Caching Assembly of the Mars 2020 Perseverance Rover – part 2

The Mars 2020 Perseverance Rover‘s adaptive caching assembly’s stations are all made from titanium because the physical characteristics of the titanium can reduce the errors due to the temperature changes on Mars from affecting the operations during the sample caching process. The titanium caching component mounting deck is the interface between all the Mars 2020 Perseverance Rover‘s adaptive caching assembly’s stations to the rover. For the adaptive caching assembly’s station of our 1:2 Mars Rover Replica, the materials are still to be determined for the stations because the stations won’t have the actual functions, but we will try our best to also use titanium.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly was designed to fit inside of the Mars 2020 Perseverance Rover‘s body before launching on Mars, but after it lands, the belly pan directly below the adaptive caching assembly is dropped from the rover’s body, because the sample handling arm in the Mars 2020 Perseverance Rover‘s adaptive caching assembly will need to extend around 200mm, or 7.87 inches below the rover’s bottom pan during the sample handling process. Besides that, the rover’s system will do a scan to make sure the sample handling arm will not be obstructed during the operation. For our Mars Rover Replica, the belly pan can also be dropped, but it can be put back as well. The dropping mechanism will be the same as the Mars 2020 Perseverance Rover‘s belly pan’s dropping mechanism.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly’s bit carousel is located on the caching component mounting deck, and a part of it extends through both the top deck on the front and front panel to allow sample tubes and drill bits to exchange easily. Our Mars Rover Replica will perfectly replicate the Mars 2020 Perseverance Rover‘s adaptive caching assembly’s bit carousel.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly interacts with the turret assembly, such as drill bit exchange, through the docking assembly, which located on the front of the bit carousel. There are a rotational bearing mechanism and a return spring mechanism to make sure the docking assembly will return to its original position and re-center after the turret undocks to prepare for the later operations. For our Mars Rover Replica, users can simulate a full interaction between our Mars Rover Replica‘s adaptive caching assembly and turret with the remote control.

Inside of the Mars 2020 Perseverance Rover‘s adaptive caching assembly’s bit carousel, there are 9 drill bits: 6 coring bits, 1 regolith bit, and 2 abrading bits, which are securely locked onto the bit holder. They not only need to survive the drop when the Mars 2020 Perseverance Rover touches down on Mars but also they need to not break when the rover is driving on the bumpy Martian road. Besides these, the bit carousel will need to cooperate perfectly with the corer when each time a sample tube is inserted into the drill. If misaligned, it could be disastrous for the assembly. For our Perseverance Mars Rover Replica, it is not recommended to drop it like the Mars 2020 Perseverance Rover is dropped on Mars, but our Mars Rover Replica can take a certain amount of impact.

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Sample Handling System of Mars 2020 Perseverance Rover

Adaptive Caching Assembly of the Mars 2020 Perseverance Rover – part 1

The Mars 2020 Perseverance Rover‘s adaptive caching assembly is one of the three main components of the sample caching system. The other two main components are the robotic arm and the turret assembly, which are introduced in more detail in [Robotic Arm the Mars 2020 Perseverance Rover] and [Turret of the Mars 2020 Perseverance Rover].

The Mars 2020 Perseverance Rover‘s adaptive caching assembly is located inside of the rover and on the front of the body. There are mainly 6 sub-assemblies of the Mars 2020 Perseverance Rover‘s adaptive caching assembly: the sample tube storage assembly, the sample handling arm, the dispenser, volume, tube assembly, the vision station, the sealing station, and the bit carousel. For our 1:2 Mars Rover Replica, we will replicate the part on the front of the body, and we will try our best to perfectly replicate the part that is inside of the rover’s body.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly’s sample tube storage assembly is for storing both empty sample tubes and filled sample tubes. Although they are placed together, there are sheaths to protect them from contaminating each other. There are a total of 39 sample tubes in the sample tube storage assembly.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly’s sample handling arm is for transferring the sample tubes to different stations in the adaptive caching assembly or for moving the sample tubes to the bit carousel so that the sample tubes are inserted into the drill bits for sample caching purposes.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly’s dispenser, volume, tube assembly is to calculate the number of samples collected and to reduce possible contamination. There are 3 sample tubes in the dispenser, volume, tube assembly. There are 7 seal dispensers, and each seal dispenser has 7 seals, so there are 49 seals in total, 7 of which are spares.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly’s vision station not only takes photos of the sample cached but also performs a second-time calculation for the amount of each sample collected.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly’s sealing station is to seal a sample permanently by triggering seals in the sample tubes.

The Mars 2020 Perseverance Rover‘s adaptive caching assembly’s bit carousel is to keep all the drill bits and helps to insert a sample tube into a drill bit for sample caching.

For our 1:2 Mars Rover Replica, we will try our best to perfectly replicate these 6 sub-assemblies. Although they will not have the same functions as the real Mars 2020 Perseverance Rover‘s adaptive caching assembly, they will be fully motorized and you can simulate the sample handling movement with the remote control.

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Sample Handling System of Mars 2020 Perseverance Rover

Witness Tubes of the Mars 2020 Perseverance Rover

There are two types of sample tubes on the Mars 2020 Perseverance Rover. The first type is the sample containers (or the sample tubes), and the second type is the witness tubes. Our 1:2 Mars Rover Replica will perfectly replicate the structure appearance of the sample tubes.

There are a total of 42 sample tubes that the Mars 2020 Perseverance Rover carries, and 4 of them are dedicated as witness tubes. For each Mars Rover Replica, there will be 42 sample tubes that come with it but if the customers want more as replacements, that is alright as well.  Unlike the sample tubes, the Mars 2020 Perseverance Rover‘s witness tubes do not collect actual rock or soil samples, but they go through the same collecting process as the sample tubes. The purpose is to preserve the drilling condition, or the contamination knowledge, for when the samples are being drilled and filled into the sample tubes so that when the samples are analyzed in the future on Earth, scientists will know how earthly factors or even contamination from the Mars 2020 Perseverance Rover itself affect the condition of the samples. The witness tubes of the 1:2 Mars Rover Replica are perfect replicas of the real Mars 2020 Perseverance Rover‘s witness tubes in terms of the structure appearance including the colors, but the material might be slightly different.

Inside of the Mars 2020 Perseverance Rover‘s bit carousel, there is also a witness tube assembly, which is especially for collecting the contamination knowledge for the bit carousel’s condition, so that in the future, when the witness tubes are returned to Earth, scientists will know the working environment the Mars 2020 Perseverance Rover‘s bit carousel is exposed to. For our 1:2 Mars Rover Replica, the bit carouse and the witness tube assembly might be the last structure to replicate because they are mostly inside of the rover’s body and very sophisticated.

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Sample Handling System of Mars 2020 Perseverance Rover

Robotic Arm the Mars 2020 Perseverance Rover

The Mars 2020 Perseverance Rover‘s robotic arm is located on the front of the rover’s chassis. It has a length of 7 feet or 2.1 meters, which is the same length as its predecessor, the Curiosity rover.  Our 1:2 Mars Rover Replica‘s robotic arm has a length of 3.5 feet or 1.05 meters. The Mars 2020 Perseverance Rover‘s robotic arm wields a rotating 45kg (or 99 lbs) turret assembly, which is 15kg (or 34 lbs) heavier than the Curiosity rover’s turret assembly because it carries bigger science instruments and a bigger corer for drilling compared to the Curiosity rover. The weight of our Mars Rover Replica‘s robotic arm will not be that heavy, because the instruments on it will only be decorations (but ultra-realistic decorations), and the material we use will be lightweight.

The purpose of the Mars 2020 Perseverance Rover‘s robotic arm is to help with exploring the Martian surface and collecting valuable Martian samples. It mimics the human arm – it has joints at its “shoulder”, “elbow” and “wrist” for maximum degrees of freedom. Our Mars Rover Replica‘s robotic arm will also have as many degrees of freedom as the real Mars 2020 Perseverance Rover‘s robotic arm. If the Mars 2020 Perseverance Rover is a human scientist, then the robotic arm is his human arm. At the end of the robotic arm, there is a turret assembly or a hand, and on the hand, there are the science instruments (SHERLOC, WASTON, PIXL), the gDRT, the Corer, and the ground contact sensor which are for Martian rock and soil sample caching. The gDRT and the ground contact sensor are introduced in [Turret of the Mars 2020 Perseverance Mars Rover].

There are some small motors or rotary actuators on the Mars 2020 Perseverance Rover‘s robotic arm, and with these actuators, the Mars 2020 Perseverance Rover‘s robotic arm has 5 degrees of freedom or 5 flexible joints: the shoulder azimuth joint, the shoulder elevation joint, the elbow joint, the wrist joint and the turret joint. Our Mars Rover Replica‘s robotic arm will also have these motors – not the same type or the same size, but the function of the motors is the same –  so that the Mars Rover Replica‘s robotic arm is also 5 degree of freedom. The flexibility of the Mars 2020 Perseverance Rover‘s robotic arm allows it to rotate the turret accurately to a location of interest so that the corer can start its initial abrading operation for the later sampling process, or for the science instruments analyzing process.

After the science team on Earth decides which rocks or regolith to sample, Mars 2020 Perseverance Rover will give the robotic arm the “go” for sample caching. The Mars 2020 Perseverance Rover’s robotic arm will rotate the corer to an angle that is best for the drill bit to operate. Depending on the condition of the drilling site, the drill will choose the rotary mode or the percussive mode for the sample caching. After the sample rocks or regolith are collected, the Mars 2020 Perseverance Rover’s robotic arm will transfer the sample tubes to the bit carousel for the later processes. Although the Mars Rover Replica‘s robotic arm doesn’t have the function like the real Mars 2020 Perseverance Rover, users can control the Mars Rover Replica to drive and mimic the movement of the robotic arm.

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Sample Handling System of Mars 2020 Perseverance Rover

Turret of the Mars 2020 Perseverance Rover

The Mars 2020 Perseverance Rover‘s turret is located at the end of the 2.1-meter-long, 5-degree-freedom robotic arm. It carries the science instruments SHERLOC, WASTON, and PIXL to help with the sample handling process. Besides the three instruments, there are also the gDRT(Gaseous Dust Removal Tool) and the Corer. The Corer is positioned in the middle of the instruments. SHERLOC and WASTON are by one side of the Corer, while gDRT and PIXL are on the opposite side of the Corer. Collectively, they form the Mars 2020 Perseverance Rover‘s turret assembly. Our 1:2 Perseverance Mars Rover Replica will perfectly replicate the structure appearance of the Turret including the SHERLOC, WASTON, and PIXL instruments, the gDRT, and the Corer. 

The Mars 2020 Perseverance Rover‘s SHERLOC, WATSON, and PIXL instruments are introduced in more detail in [PIXL of the Mars 2020 Perseverance Rover Part 1], [PIXL of the Mars 2020 Perseverance Rover Part 2], [SHERLOC of the Mars 2020 Perseverance Rover], and [WATSON of the Mars 2020 Perseverance Rover]. With these scientific instruments the Mars 2020 Perseverance Rover‘s turret carries, the Mars 2020 Perseverance Rover is able to analyze the minerals and chemicals to study whether or not there was life or if it will be possible for humans to live on Mars by carefully and scientifically selecting the most valuable rock and soil samples to collect. Our Perseverance Mars Rover Replica‘s PIXL and the tools on it won’t have the functions as the real Mars 2020 Perseverance Rover, but the Perseverance Mars Rover Replica‘s PIXL replica will stimulate the movement when operating.  

After the Mars 2020 Perseverance Rover‘s robotic arm accurately transports the turret assembly to the location of interest, depending on what this specific mission’s purpose is, the corer will get one of the bits and will do an initial abrading operation. The Mars 2020 Perseverance Rover‘s turret then will rotate and find a position for gDRT to remove dust from the surface to prevent contamination preparing for the sample caching process. The gDRT is a sophisticated tool that consists of the following 7 components:

1. A supply tank with 159g of gaseous Nitrogen

2. A gas tank, or plenum tank which fills gas before every operation

3. Two supplementary supply valves for transferring gas from the supply tank to the plenum tank

4. A valve that releases the plenum tank’s gas

5. A nozzle that will blow the gas to the target surface

6. A valve that acts as the supply tank’s switch for releasing and loading gas before launch

7. A pressure transducer for the pressure reading

In the end, the Mars 2020 Perseverance Rover‘s turret will rotate to positions to allow SHERLOC, WASTON, and PIXL to work.

Our 1:2 Perseverance Mars Rover Replica will perfectly replicate the appearance structure of the gDRT down to very fine details, but it will not have the dust-removing function or the many components. 

Other than the mentioned tools, the Mars 2020 Perseverance Rover‘s turret assembly carries a sensor, the Ground Contact Sensor. The Ground Contact Sensor’s job is to prevent the Mars 2020 Perseverance Rover‘s turret from accidentally touching the ground by giving the robotic arm signals to stop if the turret gets too close to the ground. Our Perseverance Mars Rover Replica will perfectly replicate the appearance structure of Ground Contact Sensor but it will not actually be a sensor.

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Sample Handling System of Mars 2020 Perseverance Rover

Drills of the Mars 2020 Perseverance Rover

There are 3 types of drill bits that the Mars 2020 Perseverance Rover‘s bit carousal carries. The first type is the coring bit, the second type is the regolith bit and the third type is the abrading drill bit – or the abrader. The three types of drill bits are interchangeable depending on what the target samples are or the purpose of the specific operation. There are 6 coring bits,1 regolith bit, and 2 abraders in the Mars 2020 Perseverance Rover‘s bit carousal. In addition, there is one more launch abrading bit which is located in the Corer on the end of the turret assembly.

The Mars 2020 Perseverance Rover‘s drills are designed to have a rotary percussive motion as an efficient way to extract scientifically selected rock and soil samples from the Martian surface. Our 1:2 Perseverance Mars Rover Replica‘s drills will simulate the rotary percussive motion, but the drills cannot actually drill and collect rock samples like the real Mars 2020 Perseverance Rover‘s drills.

The Mars 2020 Perseverance Rover‘s coring drill bit has a height of 228 mm or 8.98 inches, and the diameter of each of the Mars 2020 Perseverance Rover‘s drills is 1 inch or 27mm. The drill bit’s body material is custom 465 stainless steel coated with titanium nitride. The coring bits collect coring samples – cylindrical-shaped rock samples and will preserve the stratigraphy layers as they are so that in the future if the samples are returned to Earth, scientists can study the stratigraphy of the collected Martian rocks. For our Mars Rover Replica, the coring drill bits will have a height of 114mm, and a diameter of 0.5 inches. The material for our Mars Rover Replica‘s coring drill bit will also be stainless steel but we might not replicate the titanium nitride coating.

Each sample core the Mars 2020 Perseverance Rover collects has a length of 60mm or 2.4 inches, the sample core’s diameter is 0.5 inches or 13mm, and the Martian sample itself is around 10 to 15 grams every tube. For our 1:2 Perseverance Mars Rover Replica, the sample tubes will be empty, and you can put some rocks or sands in them for decoration.

Unlike the Mars 2020 Perseverance Rover‘s coring drill bits, the Mars 2020 Perseverance Rover‘s regolith drill bits, with a height of 185.2mm, or 7.29 inches, collect regolith, which means broken rock materials and dust, but the sealing, transferring, and storing processes are the same as the coring drill bits. For our Mars Rover Replica, the regolith drill bits will have a height of 92.6 mm or 3.645 inches.

Different from both the Mars 2020 Perseverance Rover‘s coring drill bits and regolith drill bits, the Mars 2020 Perseverance Rover‘s abrading drill bits don’t collect any samples. The abrader has a height of 130.7mm or 5.15 inches and its job is to abrade or scrape off the top layer of the rocks in order to expose the surface feature that is not exposed to weathering. Then the science instruments will study the exposed rocks and soils for scientific purposes. The two abraders are planned for 74 missions, and they have an optimized pattern design for the teeth so that when scaping the top layer off of the rocks, the exposed surface will be smooth, which is more convenient for the later analysis. Our Perseverance Mars Rover Replica‘s abrading drill bits will perfectly replicate the appearance structure of the Mars 2020 Perseverance Rover‘s abrading drill bits and our Perseverance Mars Rover Replica‘s abrading drill bits have a height of 65.35 mm, or 2.575 inches.

The Mars 2020 Perseverance Rover‘s launch abrading bit has a height of 108.1mm, or 4.26 inches. The launch abrading bit is pre-installed into the Corer chuck at the center of the end of the turret. It provides a sealing cover for the Corer chuck, and additional abrading power if needed. Our Perseverance Mars Rover Replica‘s launch abrading bit will perfectly replicate the appearance structure of the Mars 2020 Perseverance Rover‘s launch abrading bit and our Perseverance Mars Rover Replica‘s launch abrading bit will have a height of 54.05 mm, or 2.13 inches.

Structurally, the Mars 2020 Perseverance Rover‘s three types of bits have mostly the same features such as the percussion interface and bit sleeve. The coring bits and regolith bits will drill into the Martian surface and collect samples, so they have a sample tube interface for exchanging tubes. However, the Mars 2020 Perseverance Rover‘s abraders don’t have the sample tube interface since they don’t collect actual samples. For the same reason, the coring bit and regolith bit can house a sample tube inside but the abrading bits don’t have this feature. Our 1:2 Perseverance Mars Rover Replica will perfectly replicate the drill bits’ appearance structure but they won’t have the actual functions that the real Mars 2020 Perseverance Rover‘s drills do.

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Sample Handling System of Mars 2020 Perseverance Rover

Sample Containers of the Mars 2020 Perseverance Rover

There are two types of sample tubes on the Mars 2020 Perseverance Rover. The first type is the sample containers or the sample tubes, and the second type is the witness tubes, which are introduced in more detail in [Witness Tubes of the Mars 2020 Perseverance Rover].

There are a total of 43 sample tubes on the Mars 2020 Perseverance Rover and 5 of them will be used as witness tubes so eventually, there will be 38 sample tubes with actual samples inside. These tubes will collect, seal and store samples of Martian rock cores, and regolith (broken rocks and dust). Each Mars 2020 Perseverance Rover‘s tube will contain a sample that is carefully and scientifically selected under different and diverse environmental conditions so that it can represent as much geologic diversity as possible of the Martian field site for future analysis. For our 1:2 Perseverance Mars Rover Replica, we will perfectly replicate the appearance and the number of the sample tubes.

The Mars 2020 Perseverance Rover’s sample tubes are made of titanium. There are different coatings on the outer and internal surfaces of the sample tubes. Most of the outer coating is alumina and appears in the color white, but the top and bottom outer surfaces and the internal surface have a coating of nitrided, which appears in gold color. The purpose of the coating is for thermal control. Each of the tubes has a length of 142mm, or 5.59 inches without the seal, which will add 2mm, or 0.08 inches to the sample tube. The sample tube has a diameter of 23 mm or 0.9 inches. As for the sample tubes for our 1:2 Perseverance Mars Rover Replica, we might only use one material, but we will paint the same color as the Mars 2020 Perseverance Rover’s sample tubes.

In order to maintain the cleanness of the Mars 2020 Perseverance Rover’s sample tubes, a fluid mechanical particle barrier glove is designed and attached to each of them. About this fluid mechanical particle barrier glove, we will replicate the appearance structure for our Mars Rover Replica but it won’t actually have the function to maintain the cleanness of the Mars 2020 Perseverance Rover Replica’s sample tubes

After a sample is cashed and studied and carefully sealed, the Mars 2020 Perseverance Rover‘s sample tubes will be left on the Martian surface – a surface that is well-identified for the future sample return mission. If the Mars 2020 Perseverance Rover‘s samples are returned to Earth successfully one day, scientists can learn a great deal from them.