There is a rover on Mars right now, having the greatest adventure in human history. No human is there to feel the cold thin air or look up at the two moons in the rust-coloured sky. A machine is doing it instead. This essay is about why that is not good enough — and what we should do about it.
We built robots to explore for us. That was the idea. And somewhere along the way, they became better at it than we are — because we forgot to upgrade ourselves.
At the bottom of the Pacific Ocean, in the hadal trenches six kilometres below the surface, robotic submersibles drift through permanent darkness past creatures so strange they look like hallucinations — translucent fish with no eyes, jellyfish the size of cars, forests of hydrothermal vents exhaling superheated mineral water in the cold black. No human has been to most of these places. The machines go instead.
This essay is about that upgrade. It is about the science, the audacity, and the urgent necessity of re-engineering the human body to survive, thrive, and experience the most extreme environments on and beyond this planet — before we render ourselves irrelevant to our own story.
"We built robots to explore for us. Somewhere along the way, they became better at it than we are — because we forgot to upgrade ourselves."
The human body is a masterpiece of evolutionary engineering — for one very specific environment. The African savanna, roughly sea level, moderate temperature, abundant oxygen at 21% atmospheric concentration. Every system in the body is calibrated for that narrow band of conditions.
Go 300 metres underwater and the pressure crushes your lungs to the size of a fist. Go to the top of Everest and the oxygen is so thin your brain begins shutting down within minutes without supplemental tanks. Step outside on Mars and the atmospheric pressure is less than 1% of Earth's — your blood would boil before you froze. In space itself, unprotected exposure means unconsciousness in fifteen seconds and death shortly after.
We are, in the bluntest terms, extraordinarily fragile creatures trying to explore an extraordinarily hostile universe.
Our answer so far has been technology worn on the outside — tanks, suits, pressurised capsules, sealed habitats. These are brilliant solutions, but they are fundamentally the same logic as putting a fish in a tank to travel on land. The fish is still a fish. It still needs its water. We are still mammals who need our narrow atmospheric band, we have just learned to carry it with us.
The question this essay asks is radical and simple: what if we changed the fish?
Your lungs contain approximately 700 million tiny air sacs called alveoli. Spread flat, their combined surface area is roughly 70 square metres — the size of a tennis court, folded impossibly inside your chest. This is extraordinary engineering. But it has a fundamental architectural flaw inherited from our fish ancestors: it is a dead-end system. Air flows in, gas exchange happens, and the same air flows back out the same way it came in. Even after a maximum exhalation, about 1.2 litres of residual air remains — a dead zone of used gas that dilutes every fresh breath you take.
Birds solved this problem 150 million years ago. Their respiratory system is a flow-through architecture — fresh air enters, moves through the lung in one direction like a river, and exits through a separate pathway. This is why bar-headed geese can fly over the summit of Everest at 9,000 metres, cruising in air that would incapacitate an unacclimatised human within minutes.
We never evolved this system because, on the African savanna, we did not need it. But we need it now.
Unidirectional airflow architecture — bioprinted lung scaffolds with partially flow-through design, achievable in principle through synthetic biology, would represent the greatest leap in human respiratory capacity since lungs evolved from gills 375 million years ago.
Expanded surface area — triggering developmental genes FGF10 and PDGFRA to create more alveolar branching could increase surface area from 70 to 200–300 square metres, absorbing proportionally more oxygen per breath, passively and permanently.
The hybrid alveolus — alveolar walls partially composed of synthetic materials, more selective than natural membranes, self-repairing through embedded nanoparticles, and capable of extracting oxygen from dissolved water. Not a human lung. Something new — the first organ deliberately designed rather than evolved.
Even if the lungs extract more oxygen, the blood must carry it. And here, the science is not theoretical. It is happening now, in laboratories and clinical trials, in the most consequential quiet revolution in medicine.
Hemoglobin-Based Oxygen Carriers (HBOCs) are engineered hemoglobin molecules that circulate freely in the bloodstream without the red blood cell shell — tuned to carry more oxygen, release it more readily in hypoxic tissue, and survive conditions that would destroy natural red blood cells.
Perfluorocarbon (PFC) emulsions — synthetic carbon-fluorine liquids that can carry 40 to 50 times more dissolved oxygen than blood plasma. Injected as microscopic droplets into the bloodstream, they supercharge the blood's carrying capacity. In 2025, researchers demonstrated PFC nanoparticles loaded with oxygen successfully restoring oxygenation in damaged kidney tissue — proof of concept inside a living body.
And then there is the moment we are living in right now. In early 2026, the first human clinical trial of intravenous hydrogen-oxygen nanobubbles — the NANO-SAFE study — began recruiting. We are, right now, at the precise historical moment where injecting oxygen directly into human blood is transitioning from science fiction to clinical protocol.
"We are at the precise historical moment where injecting oxygen directly into human blood is transitioning from science fiction to clinical protocol."
And beyond all of these is the vision that animates the entire field: fully synthetic blood. Not a supplement, not a carrier, but a complete replacement — engineered molecules that outperform hemoglobin in every parameter. A vial of synthetic blood optimised for deep ocean pressures. A different formulation for Martian atmospheric conditions. Blood as a customisable technology.
Here is one of the most astonishing facts in modern biology: evolution has already solved some of these problems. Not in average humans — but in specific human populations.
The Tibetan people, who have lived above 4,000 metres for 10,000 years, carry a variant of the gene EPAS1 that fundamentally changes how their bodies respond to low oxygen. Where most humans at altitude increase red blood cell production to dangerous levels — thickening the blood, stressing the heart — Tibetans maintain near-normal red cell counts and instead extract oxygen more efficiently at the cellular level. Everest is, to them, merely a very tall mountain. This is not mysticism. It is a genetic difference of a few base pairs. And CRISPR can read that difference, replicate it, and in principle introduce it into any human genome.
The Bajau people of Southeast Asia, who have lived as free-divers for generations, have spleens 50% larger than average — a genetic adaptation that gives them a massive reservoir of oxygenated red blood cells to release during dives. Some Bajau individuals can hold their breath for 13 minutes.
These are proof of concepts written in human DNA. They demonstrate that the parameters we think of as fixed — lung capacity, oxygen efficiency, breath-hold time — are in fact variables. CRISPR gives us the ability to learn from those solutions and apply them deliberately, in a single generation, rather than waiting for thousands of years of natural selection.
Beyond borrowing existing human adaptations, synthetic biology opens the door to borrowing from other species entirely. The hemoglobin of crocodilians carries oxygen 40% more efficiently than human hemoglobin. Tardigrades survive in the vacuum of space and pressures six times the deepest ocean trench. Octopuses extract oxygen directly from water. The genetic toolkit is vast. We have barely begun to open it.
Expanded lungs with synthetic membrane elements capable of extracting dissolved oxygen from water for short periods. Blood supplemented with PFC nanoparticles that triple oxygen carrying capacity. A CRISPR-modified spleen, enlarged like the Bajau, providing an oxygen reserve during dives. The result: a person who can free-dive to 500 metres, remain submerged for 20 minutes, and surface without decompression sickness — because their blood chemistry has been redesigned to handle nitrogen differently.
Lungs with 200+ square metres of alveolar surface, capable of extracting maximum oxygen from thin atmospheres. Synthetic blood with a hemoglobin variant that functions at Martian oxygen partial pressures. Cellular adaptations borrowed from tardigrade biology that protect against radiation damage. Not an astronaut in a suit breathing bottled air — a human being who can step outside in a lightweight garment and breathe.
These are not separate projects. They are the same project, approached from different angles, converging on the same destination: a human body that is genuinely multi-environment — that belongs to the ocean and to space as naturally as it belongs to the savanna.
There is an argument that says: why bother? Robots are cheaper, safer, more capable in extreme environments. Send machines. Keep humans safe. Collect the data.
This argument is coherent and wrong.
It is wrong because it confuses data collection with experience. When the Perseverance rover photographs the Jezero crater delta — an ancient river delta on Mars where life might once have formed — it is gathering information. But information is not the same as meaning. Meaning requires a conscious being to receive it, to feel the weight of it, to stand in that place and understand what it is to be a living thing looking at where life might once have been.
The history of human exploration is not primarily a history of data collection. It is a history of presence — of people putting their bodies in places that had never felt the warmth of a human heartbeat and coming back changed, and changing the world with what they brought. Armstrong's boot print in the lunar dust was not primarily a geological sample collection. It was a statement about what life is capable of.
A robot cannot make that statement. A robot can photograph the statement but cannot be it.
"A robot cannot make that statement. A robot can photograph the statement — but cannot be it."
If we outsource all exploration to machines, we begin a process of progressive self-diminishment — a gradual retreat from the universe into comfort and safety, where we know everything about everywhere but have been nowhere and done nothing. The result, eventually, is a species that has explored the cosmos by proxy while remaining, in its body and spirit, exactly what it was on the savanna a hundred thousand years ago.
The alternative — the hard, expensive, audacious alternative — is to evolve. Not by waiting for natural selection, which operates on timescales of thousands of generations. But by doing what humans have always done best: applying intelligence to a problem and refusing to accept the constraints we were born with.
There is a window, and it is not open forever.
Robotics and artificial intelligence are advancing at a pace that will, within 30 to 50 years, produce machines of such extraordinary capability that the practical case for sending human bodies to extreme environments becomes genuinely difficult to make. The pressure to simply send better robots will be immense and, in purely pragmatic terms, often correct.
The window is the period between now and then — the decades in which synthetic biology, CRISPR gene editing, nanotechnology, and bioengineering are maturing fast enough that upgrading the human body is achievable, but the robots have not yet become so dominant that the effort seems pointless.
We are in that window now. The NANO-SAFE trial injecting oxygen nanobubbles into human blood is happening in 2026. CRISPR therapies are in clinical use. Bioprinted organ scaffolds are being implanted in patients. The pieces exist. The question is whether we will assemble them with sufficient ambition — whether we will look at the oceans and the stars and say, with the full force of human will: we are coming, in our own bodies, and we are redesigning those bodies for the journey.
The robots are already out there, doing magnificent work, sending back extraordinary data. But they do not look up at a Martian moon and feel anything. That feeling — that irreducible, untransferable, wholly human experience of awe — is worth every experiment, every edited gene, every redesigned alveolus, every nanoparticle flowing through redesigned blood.
We are not the finished version of ourselves. And that is not a limitation. It is an invitation.
Part of an ongoing journal — observations recorded when something in the world of science, economics, or human possibility is worth saying. No schedule. No noise. The next entry when there is something worth adding.