One of the most difficult things about sending astronauts to Mars will be returning them home. Essentially, launching a rocket off the Red Planet's surface will need industrial quantities of oxygen, an important part of propellant: a four-person crew would require about "55,000" pounds or 25 metric tons of it to generate thrust from a seven-metric ton rocket fuel, which is a lot of propellants.
Bur rather than shipping all that oxygen, could the crew make it "out of then 'Martian' air? A first-gen oxygen generator aboard the Perseverance rover of NASA is set to try technology for doing precisely that.
The MOXIE or Mars Oxygen In-Situ Resource Utilization Experiment, is a trial device that stands independently from the primary science of Perseverance.
One of the main purposes of a rover is to capture returnable samples of rock that could bring indications of "ancient microbial life."
While Perseverance has an array of instruments designed to help attain that purpose, MOXIE is focused exclusively on the engineering needed for future human investigation initiatives.
The MOXIE Project
Since the beginning of the space era, scientists have discussed about ISRU or in-situ resource utilization. In a simpler explanation, this may mean living off the land and utilizing what can be accessed and used in the local environment.
These may include things such as looking for water ice that could melt so it could be used or sheltering in caves. It can also be used to generate oxygen for rocket fuel and certainly, for breathing.
According to the Massachusetts Institute of Technology's Michael Hecht, the principal investigator of the instrument, breathing is only one side benefit of MOXIE's true objective.
Rocket propellant is the weightiest useable resource that astronauts will need. Thus, having the ability to yield oxygen at their last stop would make the pioneer manned trip to Mars easier, safer, and more cost-oriented.
Hecht also said, what people usually ask him is if "MOXIE is being developed, so astronauts have something to breathe." But rockets, he continued, "breathe hundreds of times as much oxygen as people."
Electrochemical Conversion
The atmosphere of Mars postures a huge challenge for human life, not to mention the production of a rocket propellant. It is just one percent as thick as the atmosphere of Earth and is 95 percent carbon dioxide.
MOXIE functions by pulling in the air with a pump. It then uses an electrochemical process to separate two oxygen atoms from each of the CO2 molecules.
As the gases run through the system, they are then analyzed to check the amount of oxygen produced, its pureness, and the manner of efficiency the system is working. All these gases are then expelled back into the air after every experiment is done.
It requires a lot of heat, about 800 degrees Celsius or 1,470 degrees Fahrenheit, to power the said electrochemical conversion.
Due to those high temperatures, MOXIE, which is a bit bigger than a toaster, features a suite of heat-tolerant materials.
MOXIE's outer part is coated in a thin layer of gold, which is an ideal indicator of infrared heat and prevents the burning temperatures from radiating into Perseverance's other components.
Full-Scale MOXIE System
According to MOXIE systems engineer at NASA's Southern California-based Jet Propulsion Laboratory, Asad Aboobaker, "MOXIE is designed to make roughly six to 10 grams of oxygen each hour, just enough for a small dog to breathe."
Meanwhile, a complete system geared to produce propellant for the flight back to Earth would require to scale up production of oxygen by around 200 times "what MOXIE will create," explained Aboobaker.
Hecht approximated that a complete or full-scale MOXIE system on Mars might be slightly huger than a household stove and would weigh around 1,000 k kilograms, which is nearly as much as the weight of Perseverance itself.
Reports on this project said, "work is currently being made to develop a prototype for one in the near future." The team is expecting to run MOXIE roughly 10 times over the period of two Earth years or one Mars year, enabling them to watch how well it is working in changing seasons.
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