Molly Kirkpatrick won the 2023 three minute thesis competition at the University of Wollongong
Since the beginning of time, the cosmos have captured our imaginations and had us questioning “is there anyone else out there?”, “what would it be like to live on a different planet?” and “is the Moon really made out of cheese?”.
We are living in a time where we are finally able to get answers these really complicated questions. For example, through chemical and elemental analysis, we’ve found out that the Moon’s dirt- called regolith- is actually very similar to what we have here on Earth. And NASA’s Artemis mission plans to not only send people back to the Moon, but to set up a sustained human presence there in about a decade.
One of the biggest challenges they are facing is getting supplies to the astronauts on the Moon. ‘Shipping’ things there is really expensive- it costs 1 million USD to send just 1 kg of material to the lunar surface.
We are developing technologies to enable ‘in-situ resource utilization’ which means ‘lets use whatever materials we have wherever we happen to be.’ Can we extract oxygen or water from the lunar regolith? Can we make concrete out of it? Can we use it to make fuel?
Well before we can actually do anything with this material, we first need to know exactly what it is- what elements do we have to work with?
As part of my PhD, I have developed a miniaturised X-ray Fluorescence payload that weighs just over 100g and will tell you just that. It works by shooting X-rays into the regolith; those X-rays are absorbed by the atoms in the soil which causes photons with very specific energies to be emitted. We can detect these emitted photons and determine not only what elements are present, but how much of each we have.
The payload is shown here and is many times lighter than any previous XRF instrument sent to the surface of the moon or Mars and contains all the necessary electronics and software to run the instrument and analyse the results.
The sensor has applications in two main areas: searching for regions on the ground that have a high concentration of specific elements and for process control and monitoring. We can measure a material before and after it has been processed to ensure the valuable material has been processed efficiently.
I have used this tiny sensor to measure changes in the concentration of ilmenite- a mineral that is abundant on the Moon and can be used to generate oxygen. Current testing also indicates that the sensor can be used to monitor the carbothermal processing of regolith, which is just one method we can use to extract that oxygen.
This miniaturised sensor is a small, but mighty piece in the puzzle making in-situ resource utilization and a sustained human presence on the Moon (and beyond) possible.
Watch Molly’s fantastic 3 minute thesis video….you will see why she went through to the semi finals for the Asia-Pacific competition.