Nanotechnology and Space
By: Vraj Patel
Tags: Solar Sail, Space, Mars, Space Elevator, Nanotechnology

Recently, I had the opportunity to dive a little deeper into the realm of nanotechnology and learn about the technological advancements in the past years that have brought this field in the limelight. From a young age, I have held a deep interest in space technologies and been a huge fan of sci-fi movies, so I wondered about how nanotechnology can help with space exploration.

Nanotechnology

If you don’t know what nanotechnology is, it's basically building “stuff” on the nanoscale. To better visualize how small it is, the diameter of one carbon nanotube (a type of nanoparticle) is one nanometer, which is one ten-thousandth (1/10,000) the diameter of a human hair. Building systems at this scale enables us to make objects that are both lightweight, and extremely strong.

Carbon Nanotube on top of a strand of hair

After doing some research, I came across three theoretical space technologies that may be made possible with the help of nanotechnology: Space Elevators and Solar Sails and Mars Bases.

Space Elevator

A space elevator is basically a lift to take humans, supplies, food and space crafts to a certain height in space. For spacecraft, this can be a launching point for them as it would require less fuel to exit the earth’s gravitational pull. Currently, it takes about $20000 to put one kilogram of cargo into space, but with a space elevator, that number can be reduced down to a mere $200.

A space elevator is divided into 4 major components: Anchor, Counterweight, Tether and Lift

If you’re interested, Kurzgesagt has a great video explaining how it works.

The anchor is buried into the, and a tether connects the counterweight to the anchor. The counterweight is positioned in space, so there is tension in the tether. A lift then uses this tether to go up and down the elevator. Setting a rocket into orbit requires vertical and horizontal force, which costs huge amounts of money, but an elevator would reduce the need for an upwards force and use the earth’s rotation to aid in the horizontal force.

As promising as it sounds, there are quite a few hurdles in the way for us to be able to make this a reality. One major one being the tether. We need the tether to be made of some sort of lightweight material. This is where nanotech can come into play. Carbon-Nanotubes fit the profile and can be a great medium to construct the tether out of. The one problem for this can be the price. Carbon-Nanotubes typically cost $100-$700 per gram, but with recent technological advancements, the price can be reduced to $15-$35, which is progress nonetheless.

Solar Sails

Solar sails are a method of propulsion that relies on solar radiation from a star. Although this method may not be the best when venturing into the void, its something that can be used to travel within our solar system with ease. The basis on which solar sails were created was to decrease the cost of space crafts. If you could run a spacecraft with a giant sail, why use a rocket?

Spacecraft using a solar sail (on the right) to orbit the earth

With solar sails, they need to be made out of a material that lightweight, strong and extremely thin. Again, nanotubes can come to the rescue! With their ultrathin and light properties and strong graphene-based structure, they are perfect for the job. Additionally, researchers in Singapore were able to use carbon nanotubes to develop a self-healing supercapacitor. Having this sort of property is essential as if the sail were to rip or get impaled by space debris, it would be able to heal itself.

Mars Base

Finally, Mars bases. If you've followed Elon Musk and his hopes for the future, you're already aware of the motion to colonize Mars. It has traces of water, a livable atmosphere, and everything us humans could hope for, but with a little surprise, a tiny nanoscale surprise…MARS DUST. If you’ve ever wondered why Mars’s atmosphere looks red, it's because of the constant presence on this ultrafine dust. Mars dust is much finer than dust on Earth, and its electrostatically charged, meaning it will stick to everything. To make matter worse, it contains perchlorate salts and is toxic to humans. If it is tracked into the habitats, it may be dealy. So having this easily breathable dust enter the bodies of astronauts and make them extremely ill is definitely unappealing, but what can we do?

Mars Dust Storm

You guessed it, Nanotubes! Carbon nanotubes are already being used to filter out harmful particles from the air. Some recent developments also involve CO2 filters to remove the immense amount of this greenhouse gas from our atmosphere. The way it works is the carbon atoms bond with these particles from the air and hold on to them. If a similar filtration device can be made to filter out the perchlorate from Mars dust in a habitat, living on mars may be made a bit more possible.

Another issue with living on mars is gathering energy. Not having a sustainable infrastructure to generate energy on Mars is another problem that needs to be tackled. Some people suggest using nuclear energy, but Mars doesn’t have easy access to radioactive elements. But Mars does have huge amounts of radiation hitting its surface.

Going solar is a great idea, but would not be efficient enough. Traditional solar panels can only absorb visible light, which there isn’t much of, but quantum nanodots are able to absorb any wavelength of energy from the electromagnetic spectrum. Having domes over settlements made of QND solar panels ensures the crew is protected from the harmful radiation coming off the sun, and that this radiation is converted into energy. A Win-Win situation!