Image Created by Joey Serricchio
Despite 2020 being a year of chaos, the space industry continues to deliver with breakthroughs and innovations. Mankind has rapidly made progress in decreasing the ridiculous prices in rocket launches by creating reusable parts and the ambition to become an interplanetary species.
NASA has announced its timeline to return to the Moon by 2024 through the project ARTEMIS, which is divided into 3 missions: ARTEMIS 1, ARTEMIS 2, and ARTEMIS 3. Currently, ARTEMIS 1 Mission is to perform the first integrated flight test of NASA’s Deep Space Exploration Systems. The purpose of ARTEMIS 1 is to assure the safety of the crew module during re-entry from outer space, proper descent, splashdown into the ocean, and recovery of the module. Once all the safety precautions are complete, NASA will initiate the ARTEMIS 2 Mission.
Then there is the innovative Elon Musk and SpaceX setting his ambitious eyes on Mars. On May 27, 2020, we saw SpaceX and NASA send the first astronauts launched on American soil since July 8, 2011, to the International Space Station (ISS). With emerging technologies flowing into society, anything will be possible to reach the status of “interplanetary species”.
Well, that’s amazing. Now what? What technology will aid us to live in space?
In 1931, this revolutionary masterpiece arose from the laboratory to give mankind a good slap in the face of what is possible! Aerogel is the world’s lightest (least dense) solid ever made and its composition is 99.8 % air by volume. A one-inch disk of classic silica aerogel weighs around half a gram!
Ever eaten Jell-o or Gelatin? It's 99% liquid, but somehow retains a solid structure? Aerogel starts off as with properties of a liquid alcohol-like substance and a solid nanostructure. By replacing the liquid in the pores with air, aerogel retains its solid nanostructure, but the micropores that were once filled with liquid are now filled with air.
Let’s imagine an air particle were to heat up below a disk of aerogel. The air particle will become excited and begin to move all over the place with more energy. Think of a fly trying to survive from the flyswatter in your hand. It just wants to escape and gets excited. But how will an excited particle be able to navigate an obscure network of micropores when the width of the pores is smaller than the distance air molecules travel on average before colliding with another particle?
With this amazing property of aerogel, the hot and excited air particles fail to diffuse through the aerogel and transfer heat and energy to the other side of the aerogel. Aerogel can withstand temperatures of up to 1000 degrees Celsius (1832 degrees Fahrenheit!)! Because of this, aerogel has been given the honorary rank of Super-Insulator. Despite being 99.8 % by volume, aerogel can withstand a few thousand times their own weight in an evenly-distributed one-directional loading plane. To play that out, take a piece of silica aerogel that weighs around 5 grams. It can withstand around 3500–5000 grams on top of the aerogel with the weight being distributed evenly.
Aerogel is such an amazing product and some people might believe that producing aerogel is no sweat. Easier said than done. As history has taught us, for every innovation in technology, it comes with a huge cost and huge amounts of energy expenditure. Manufacturing aerogel is expensive because we need to remove the liquid from the gel without damaging the solid structure and replacing the liquid with air. At first observation, one might say, “Oh, what the heck, Carlos! Just evaporate the liquid and it will free the pores!” Unfortunately, I will have to disagree with everyone on this method.If you were to evaporate the liquid to liberate the pores, the liquid molecules will pull on each other, bringing the solid nanostructure of the aerogel along. Better known as Capillary Action; the solid structure will continue to be pulled on by the liquid around the middle of the aerogel, resulting in the entire structure to crumble and collapse in on itself.
However, a more complex system than just evaporation must occur to manufacture aerogel that will not collapse. This process requires us to take the gel and place it in a high-pressure vessel known as an autoclave. We must replace the alcohol-like silica inside the solid structure with liquid carbon dioxide (CO2). We begin to heat the gel to both a high temperature, high-pressure point known as The Critical Point. The Critical Point is when the liquid inside the solid structure has both properties of liquid and gas, which is known as a Supercritical Fluid. Because of this, the liquid molecules of CO2 that were once pulling on each other will no longer be able to. The Supercritical Fluid (CO2) will be able to fill the pores properly and depressurize to be left with a solid nanostructure with micropores filled with air: Aerogel.
While producing aerogel on the global stage will be a challenge that innovators around the world are willing to solve, that has not stopped ambitious associations from using this masterpiece to their projects. NASA consistently customizes its innovative technologies with aerogel for certain purposes. Currently, all of the Mars Rovers have used aerogel to insulate all the precious electronics from freezing during outer space and on the cold days and nights on Mars.
Speaking of outer space, there is no atmosphere, temperature regulation, no magnetosphere, etc. Aerogel would definitely play a role in satellites to decrease the cost of the payload system in rockets, as well as to insulate the systems in extreme temperatures.
Aerogel on Mars could provide colonies on Mars for three specific reasons. Aerogel can encapsulate greenhouses to keep food and crops at a stable temperature to be produced and be consumed. Aerogel can insulate habitats for human life that maintain a stable temperature, as well as to keep Martian soil and high amounts of Cosmic Radiation out of the Martian homes. Finally, aerogel can be applied to heating up the poles on Mars, which contain water and gases required to build an atmosphere where life can thrive.
So, what are you waiting for? Let’s “light this candle” and terraform Mars! DANGER!…
Houston, we have a problem!
“Sometimes you have to take a step back to move forward”.
Question everything… not this time. Aerogel is a product of the future. However, even this lightweight king can be dethroned. Aerogel is hydrophilic. The silica aerogel will absorb the water and collapse on itself; limiting the quality and usage of the aerogel. New innovations have made aerogel impervious water, but it does not solve the brittleness problem.
Aerogel is brittle. Aerogel may be able to hold thousands of times their weight in applied force through an evenly-distributed one-directional loading plane, but when you place a direct point load on the aerogel (pinching the aerogel), it will instantly shatter into small pieces. Your precious disk of aerogel now looks like broken pieces of glass that no longer serves any use.
But if that prevents aerogel from being a household innovation for the future, what are the possible outcomes if we send this technology to Mars?
Image Created by Joey Serricchio
Water and Gases: Underneath the Martian surface, there is water and gases to aid in “building” an atmosphere that can support life. The aerogel must be hydrophobic or the aerogel will absorb the moisture and the aerogel property of superinsulation can kiss itself good-bye.
Greenhouses and Homes: if a small object were to hit the aerogel (doors or windows) in a direct point load, Martian dust, Cosmic Radiation, and temperatures will instantly destroy the colonies constructed on Mars…. And then we die.
Now, hold on! Sorry if I scared you, but remember, these are worst-case scenarios. The human race will not allow for marginal errors to occur on risky endeavors such as terraforming Mars.
Aerogel’s true successor…
Aerogel will most certainly be a tool for the future of space exploration and technology. However, aerogel will definitely not have a purpose on Earth. Let’s use the window worst-case scenario again. If you had aerogel as windows on Earth, a bug could have the potential to shatter the aerogel into small shards (the bug places a direct point load on the aerogel). Obviously, we would cover the aerogel with robust material to protect the aerogel. What material can team up with aerogel to become the indestructible duo of emerging space technologies?!