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  • On July 30th 2020, a United Launch Alliance  Atlas V rocket lifted off from Cape Canaveral,  

  • Florida. Carrying the next generation of Mars  Exploration Vehicles.The Perverence Rover  

  • and the Ingenuity Helicopter.

  • And, today, on February 18th 2021, if all  goes to plan, the two vehicles will land  

  • safely on the Martian surface after their  long 7 month journey to the Red Planet.

  • Only about 40 percent of missions  sent to Mars have been successful  

  • and perseverance will have to endurevicious and complicated landing sequence,  

  • as it's creators wait, powerless to intervenewaiting for news of its success back in Pasadena.

  • Perseverance rover is the largest and heaviest  rover JPL has ever sent to Mars. Heavier than the  

  • Curiosity Rover by 100 kilograms, and with that  extra weight comes a whole host of new gadgets.

  • This isn't just some slightly upgraded version  of the curiosity rover. Perseverance is  

  • benefiting from almost 10 years of advancement  of technology. It's packed with fascinating and  

  • novel technologies that will form a stepping  stone in humankind's eventually first steps  

  • on the surface of the red planet. This is the  insane engineering of the Perseverance Rover.

  • Perseverance, hopefullyis now safely on the ground  

  • where it will live a long  illustrious life on the red planet.

  • We have learned some things from the  Curiosity Rover that will hopefully  

  • help Perseverance avoid the struggles  it's predecessor is experiencing.

  • We have made an entire video on the struggles  of the Curiosity Rover wheels and how they  

  • have been gradually falling about on the harsh  Martian service. In the end the engineers at JPL  

  • did not opt for shape memory alloy wheels  like the ones we discussed in that video,  

  • but simply increased the diameter of the wheelsdecreased their width and increased the thickness,  

  • while incorporating sturdier curved threads  that will better resist crack growth than  

  • Curiosity's sharp cornered threads. [1] They  have also forgone the rectangular cut outs which  

  • imprinted morse code, spelling out the Rover's  origins, in the rusty dirt of its new home.

  • There is a whole host of new software upgrades  too. Like the algorithm that determines when  

  • to open the parachute. In the last mission the  parachute simply deployed when the target speed of  

  • 1450 kilometres per hour was reached, after  most of the hypersonic re-entry speed of  

  • 21,450 kilometres per hour had been bled off. [2]

  • For perseverance, JPL wanted to increase the  accuracy of their landing, so this time around  

  • the chute will open when it is approaching  the optimal trajectory for the landing site.  

  • It will also be scanning the surface of the  landing site and correlating those images to  

  • it's pre-existing map to allow the skycrane  to choose the best landing site with minimal  

  • obstacles. Perseverance's ground navigation  systems have also been significantly upgraded,  

  • with it's optical sensors feeding data  to a machine learning vision algorithm.  

  • Allowing Perseverance to find it's own  path through the rough terrain of Mars,  

  • where Curiosity had to constantly stop and start  with help from it's earthbound controllers.

  • Perseverance is benefiting massively  from the past decade of improvements  

  • in autonomous flight and driving developed  by the drone and automotive industries.

  • This will mean Perseverance will be able  cover much more ground during its life,  

  • here, in Jezero Crater [3]. A massive crater  that was once home to a lake the same size  

  • as Lake Tahoe. You can see the  remnants of this ancient river bed  

  • and delta spilling into what may have  once been a habitable body of water.

  • It is here that Perseverance will scour for  signs of life. Before we get into all the  

  • gadgets it will use to do this, let's look  at how Perseverance will power them. The  

  • Perseverance Rover features the same Radioisotope  Thermoelectric Generator as the Curiosity Rover.  

  • RTG's work by converting the heat from the  natural decay of a radioisotope into electricity.

  • It uses a simple principle called the  Seebeck Effect to generate electricity.  

  • [4]The seebeck effect essentially allows  us to generate an electric current  

  • through a heat differential, as charge  carriers, both electrons and electron holes,  

  • will move from hot to cold. So  if we have two semiconductors,  

  • one with charge carriers in the form of electrons  and one with charge carriers in the form of holes.  

  • A potential difference between the two  semiconductors will form when a heat  

  • gradient is applied. This potential difference  causes a current to flow in the external circuit

  • These two semiconductors need to be both  thermally insulating, to ensure this heat gradient  

  • is maximized, but also electrically conductive  to maximize the current. These two material  

  • properties are typically linked. Copper is  both a great electric and heat conductor,  

  • while iron is a poor electric and heat conductorHaving a single material that is a great electric  

  • conductor and a poor heat conductor is extremely  rare. For this reason two unique materials are  

  • used for the p and n type semiconductors. Lead  Telluride for the n-type and an alloy commonly  

  • called Tags for the p-type, which is formed from  tellurium, silver, germanium and antimony. [4]

  • Now we just need a consistent  heat source. Thankfully  

  • radioactive substances  generate heat as they decay.

  • The perseverance rover RTG uses 4.8  kilograms of plutonium dioxide as it's heat  

  • source. This radioactive material primarily  produces alpha waves, which is essential,  

  • as this form of radiation is most efficiently  converted to heat in a compact space. [5] [6]

  • While Plutonium 238 also releases  minimal beta and gamma radiation,  

  • decreasing the weight of shielding needed to  protect the electronics onboard from these more  

  • powerful kinds of ionizing radiation, an essential  characteristic for a lightweight spacecraft.

  • The Plutonium 238 is also formable into a ceramic  like material that will break into large chunks,  

  • rather than being vaporised and spread in the wind  during a launch failure, where it could be inhaled  

  • or introduced into the food chain. [7] [8]

  • The electricity this unit can  provide will gradually degrade,  

  • from it's maximum of 110 watts at launchas its plutonium heart naturally decays.  

  • Losing half of its energy every 87.9 years, which  is much longer than the 138 day half life of the  

  • early polonium 210 RTG prototypes. [8] Another  advantage of Plutonium 238 for this application.

  • This will power all the instruments onboard,  

  • like the Moxie instrument, which  is one of the new devices I am  

  • most excited about aboard Perseverance. Moxie is a new oxygen generation device  

  • that will test a vital technology  for any future human mission to Mars.

  • You may wonder, like I did, how is this  different from the oxygen generation present  

  • in the international space station. There is  obviously a limited supply of oxygen there.  

  • Why do we need to test this  new technology on Mars,  

  • when we obviously have a tried and tested  method of creating oxygen already. Surely?

  • The international space station does not  really recycle oxygen. Oxygen is created  

  • on the international space station through  the electrolysis of water. [9] This produces  

  • hydrogen and oxygen. The hydrogen is then reacted  with carbon dioxide to form water and methane.  

  • The methane is then simply exhausted into space  while the water is fed back into the system.

  • The international space station  requires regular resupply of water  

  • as we are losing 2 hydrogen atoms  for every oxygen molecule we create.  

  • This is not a closed loop system and water is  a pretty heavy material to be shipping to Mars.

  • The perseverance rover will test  a new method of oxygen creation  

  • using this device which will use solid  oxide electrolysis to instead break  

  • the plentiful carbon dioxide in the Martian  atmosphere into Oxygen and Carbon Monoxide.

  • It's operation is fairly simple. Air will be taken  in through a dust filter by a specialized pump  

  • designed to be as light and compact as possible  called a scroll pump. [10] Scroll pumps are  

  • pretty cool. They consist of two spiral scrollsone stationary and one rotating. Air is taken  

  • in at the inlet here and as the secondary  scroll rotates in traps and squeezes air  

  • against the primary stationary scroll. This  continues to happen as the volume between the  

  • two scrolls decreases down the spiral, causing an  increase in pressure, in this case it takes the  

  • variable pressure Martian air, which is typically  about 100 times lower than earth's atmosphere,  

  • and compresses it to match earth's sea level  pressure. These kinds of pumps are lightweight,  

  • energy efficient and reliable. Making them the  perfect air pump for the Perseverance Rover.

  • The pump feeds the carbon dioxide rich air  through a cell stack. Each stack consists of  

  • a catalytic cathode, a solid electrolyte, and  an anode. [10] As air passes over the cathode,  

  • which operates at 800 degrees celsius, the  Carbon Dioxide is split into carbon monoxide  

  • and oxygen ions, according to this reaction. The  oxygen ion passes through the solid electrolyte  

  • to the anode where it is oxidizedcombining with a second oxygen atom,  

  • to form gaseous O2, which is then passed out  of the anode cavity and tested for purity.

  • Animation Extra 1 Potential 3D Render of the unit on table  

  • top here, but there is footage of the device: Moxie can produce 20 grams of oxygen an  

  • hour. However the unit will not run continuously,  

  • as it draws too much electricity, which  will be needed for other operations.

  • B-Roll Highlight RTG, Moxie and BatteriesNot sure where batteries are located 

  • In total the system needs 168 watts,  

  • which is actually more than the 110 watts  the RTG can provide at any one moment,  

  • so this operation will need to be supplemented by  the two lithium ion batteries that are included on  

  • board to make up for the low power RTG, allowing  it to store excess power during down time.[11]

  • This device is exciting, because  this is a clear statement of intent.  

  • Oxygen is going to be a vital resource for any  future human missions. And , this is actually  

  • a scaled down prototype of the full sized version  NASA eventually wants to send to mars, along with  

  • an empty rocket. The full scale version will  produce about 2 kilograms per hour, which will  

  • gradually be stored inside the awaiting rocket  over the course of a year and a half, providing  

  • life sustaining air for any future human missions  and the oxidizer needed for the ride home. [12]

  • The next device, which is also depending onfuture Mars mission to complete its purpose,  

  • is the core sampling drill. The curiosity rover  sampling system drilled and scooped soil into this  

  • instrument, the SAM, standing for Sample Analysis  at Mars. The SAM is located here on the rover.

  • It contained multiple tools  that would be commonplace  

  • in many earth bound labs. A mass  spectrometer, a gas chromatograph  

  • and a tunable laser spectrometer. Each  looking for different signs of life on Mars.

  • Perseverance has replaced the space this  unit took up with a totally new system.  

  • The Sample Caching System. The robotic arm of  the rover features a coring drill which will  

  • cut out cylindrical core samples from the Martian  surface. Once collected the robot head mates with  

  • the drill bit carousel where it transfers the  bit and the sample tube into a rotating carousel  

  • that takes it to the belly of the rover  where another robotic arm resides.

  • Here a number of operations takes placeFirst the arm pulls the sample tube out of  

  • the drill bit and takes multiple images of it  before and after calculating the volume of the  

  • sample. [13] Then it stores it in one of the 42  slots under the belly of the rover, where they  

  • will remain until the rover deposits them in these sample tubes at a designated caching  

  • spot on the surface of Mars. This is  where things get really interesting.

  • There are plans to send another rover, designed  by the ESA, to Mars in 2026. [14] This rover will  

  • deliver the samples back to it's NASA designed  lander which will load them into a mars ascent  

  • vehicle. Blasting the samples into orbit, where an  ESA Earth Return Vehicle will be waiting for it.

  • We are attempting to bring soil back  

  • from Mars….with robots. If that isn't  insane engineering I don't know what is,  

  • and we have barely scratched the surface  of what this rover is capable of.

  • There is a whole host of new sensors on board  that do not require Perseverance to collect soil.  

  • Each using different forms of electromagnetic  radiation to investigate the ground below them.  

  • The SHERLOC instrument on the robotic head will  look for signs of biosignatures using Raman and  

  • Luminescence spectroscopy, which both detect  molecules based on how they interact with UV  

  • light. [15] It will sit about 5 centimetres off  the ground where it will focus it's UV laser  

  • onto the soil and be able to detect chemicals  that would indicate the presence of past life.

  • The Rover also has an x-ray imager can PIXL that  will be able to visualise the texture of the  

  • ground below it looking for tiny variations in  geology that would indicate that microbial life  

  • has altered the environment, [16] while also  being able to detect chemical compositions by  

  • observing the fluorescence of the target  under x-ray electromagnetic radiation.

  • There are several other sensors, like  the ground penetrating Radar imager  

  • located at the rear of the rover, which will give  us visualizations of the composition of geology  

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