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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.