“The headmaster wants to see you.”
I had just finished my higher biology exam at Buckhaven High School in Fife, Scotland, when I heard these words.
Usually, it’s not a good sign to be summoned by the school headmaster.
I remember anxiously making my way over to his office.
What I didn’t know at the time, was that the conversation I was about to have would change the course of my life in ways I could never have imagined.
I took a deep breath and entered the office.
It turned out I’d been selected to take an all expenses paid trip to Houston to attend an international space school at NASA’s Johnson Space Center. How could I turn that down?
I spent three weeks in Houston touring Mission Control, meeting astronauts, and learning about the challenges of sending humans into space.
More than anything, I was inspired by the people I met. They took great pride in working together as a team on ventures that were wildly ambitious, unimaginably difficult, and historic in scale and significance.
As I stared out the airplane window on the flight back to Scotland, I knew that was it. I wanted in.
Inner space exploration: From NASA to DEEP
Fast forward to today, after 20 incredible years with NASA I’ve joined DEEP to help realize the mission of making humans aquatic.
At first glance, shifting from space to subsea might seem unlikely. But the reality is the two fields have many parallels.
There are similarities in the human and technological challenges that must be overcome to support human life in space and beneath the waves.
What’s more, if you’re going to send a human into space, one of the best ways to prepare that person is to have them live and work under the ocean in a subsea space analog.
A simulated spacewalk during NEEMO 14, a NASA analog mission conducted from the Aquarius subsea human habitat.
Human performance in extreme environments
My school trip to Houston set me on the path to study mechanical engineering. I received my undergraduate and master’s degrees from the University of Edinburgh. A year of my master’s degree was spent working in the Flight Mechanics Laboratory at Johnson Space Center. I worked on an experimental spacecraft program, X-38, designed to be an emergency crew return vehicle for the International Space Station.
That same year, I volunteered as a human test subject and realised I was particularly interested in the human aspect of spaceflight – how humans responded to the space environment both physically and mentally.
The challenge is not just about keeping humans alive in an extreme environment, but ensuring they are healthy and able to perform at a high level too.
So, after finishing my master’s degree, I moved back to Houston and completed my PhD in Kinesiology while working in the Neuroscience Lab at Johnson Space Center.
Over the years that followed, my background in both engineering and science meant I gradually gained an understanding of what humans needed to survive and thrive in space, while also recognizing the engineering and operational implications of design choices.
But you might still be wondering, how does this translate to subsea human habitats exactly?
The parallels between the ocean and space
Let’s start with one of the clearest physiological similarities.
Like space, the subsea environment is extreme. Sustaining human life in both environments involves similar physiological considerations.
One of my areas of expertise within human health and performance is decompression sickness. As a quick primer, decompression sickness or “the bends” is a dangerous condition caused by dissolved gases escaping from the body’s tissues when we experience a reduction in atmospheric pressure.
I’ve conducted a lot of research into how to predict and mitigate the risk of decompression sickness. This is something that’s important for spaceflight because there are various scenarios in which decompression risk is a significant challenge. For example, if a cabin depressurizes unexpectedly, or when we do a spacewalk (because spacesuits operate at a lower pressure than the vehicle).
When we go back to the moon and on to Mars, astronauts will live in a habitat or rover with an atmosphere designed to let them safely and efficiently go out and explore in their spacesuits, while still allowing them to function as normally as possible while they're living in the space vehicle. I led NASA research in this area for several years, which is directly affecting the designs of spacesuits, moon rovers, and human habitats.
There’s a clear parallel with undersea living here.
Decompression sickness is a risk when diving. Living in a subsea habitat is a very effective way to reduce that risk while allowing much more efficient work and exploration of the area surrounding the habitat. A primary reason for living in saturation in a subsea habitat is so we can complete as many dives as we need without decompressing until the end of the mission.
While there’s a lot of knowledge and technology shared between subsea and aerospace researchers in this regard, the connection between living in space and living under the ocean runs much deeper.
It’s this deep connection that led me to live under the sea.
The ultimate space analog
For training and research purposes, NASA has several analog programs. I have been involved in my share of these, from exploring Arctic impact craters and active volcanoes, to zero-gravity aircraft. Each analog is used because it provides a useful simulation of one or more aspects of space that can be used for training astronauts, and to develop technology that will later be used in space.
But the analog that provides the best overall simulation of spaceflight – according to a formal NASA assessment and my own personal experience – is subsea missions.
NASA rated NEEMO, its subsea human habitat operation, as a near-equivalent to the International Space Station for simulating spaceflight behavioural health and performance conditions.[1]
Why does NASA perform subsea missions?
What really sets subsea missions apart from other analogs is they provide realistic mission-like activities, while also being in what NASA would call an isolated, confined, and extreme (ICE) environment.
Typical mission activities include things like:
Research, maintenance, life support, and outreach tasks that crewmembers perform inside the habitat.
Reduced gravity excursions to conduct science and engineering tasks outside of the habitat.
Busy mission timelines, communication protocols, and pressure to perform important research tasks correctly and on-time.
Physiological stressors of the unnatural atmosphere and limited food options.
You can simulate different aspects of space exploration in different analogs, but subsea missions are unique in combining all the critical elements of spaceflight in one mission-like analogue. This is critical to simulating the cumulative and interdependent effects of so many stressors all at once.
But it’s not just the activities that matter. The environment and context within which they are happening matter too.
The problem with simulating a space mission in a safe, air-conditioned building is that you can make the crew isolated and confined, but when something goes wrong you can just open the door, go home, and try again another day.
The extreme environment of living subsea is fundamentally different than pretending to be on a mission. When you’re subsea, it’s just you and your crewmates in a small living area, with little or no direct contact with other humans. Your safety and the safety of your crew depends on getting everything right, making it analogous to the critical decisions made in spaceflight. This is the reason why so many astronauts are also aquanauts who have trained and certified via underwater NEEMO (NASA Extreme Environment Mission Operations) missions.
My role at DEEP
In my final role with NASA, I led the international strategy for protecting astronaut health and performance on future missions to the moon and Mars. Through my work with DEEP, I aim to help define and implement a similar strategy that will make humans aquatic.
Achieving DEEP’s mission requires not only that we keep humans safe and healthy underwater, but that we allow them to thrive and to want to be there.
My 14 days in the Aquarius undersea habitat as a NEEMO 14 mission crewmember convinced me of the immense value of subsea human habitats as an analog for spaceflight. More than that, though, living underwater profoundly changed my view of not the ocean, our whole planet, and our place within it.
Exploring the subsea world and making it accessible to humanity will both enrich our lives and protect the ocean.
Follow the journey
Follow our progress in making humans aquatic by following us on social media @deepengineered and visiting our Newsroom.
[1] NASA. (2016, April). Analog assessment tools. NASA.