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The Future of Human Spaceflight – Who Actually Goes? · Talking Science

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Welcome to today's deep dive. I'm your host and
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I'm sitting here with our resident space expert.
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Hey, everyone. Really glad to be here. So we're
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talking about this crazy new era of human spaceflight
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today. And to those of you listening, if you
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want to understand the modern space race, you
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actually shouldn't look at the physics. Right.
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Yeah. The physics hasn't really changed. Exactly.
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You need to look at the accounting because for
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like. 60 years, the story of human spaceflight
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was effectively stuck in a museum. We were operating
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under an economic model that was frankly just
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insane. It really was. I mean, imagine buying
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a Boeing 747 jumbo jet, flying it across the
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ocean exactly once, and then just throwing it
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into the sea. It is absolute madness when you
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frame it that way. You build this staggering
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multimillion -dollar masterpiece of precision
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engineering over the course of years, and then
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you fire its engines for maybe 10 minutes. Right.
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And then you just let it burn up in the atmosphere
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or sink to the bottom of the ocean. Okay. Let's
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unpack this. Our mission today is to take an
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honest, really unhurried tour of where space
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travel is actually heading. We want to strip
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away the jargon so anyone without a science background
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can understand it. Yeah, it's so important right
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now. We are separating the genuine, exciting
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reality from the glossy, premature hype you see
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everywhere. And to do that, we kind of have to
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start with that old baseline. Right, the way
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we used to do things. Yeah. For most of the space
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age, spaceflight was this incredibly narrow script.
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You had highly trained government astronauts,
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staggeringly expensive single -use rockets, and
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we were confined mostly to low Earth orbit. Let
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us define low Earth orbit for a moment, just
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to establish our geography for everyone listening.
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Sure, yeah. We are talking about the region just
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a few hundred kilometers above the surface of
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the planet. It's where the International Space
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Station circles the Earth. And keeping humans
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alive up there for over two decades is a... Profound
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achievement. But functionally, it's just skimming
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the very edge of the atmosphere. It's like stepping
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out onto your front porch. But because we were
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throwing away the vehicle every single time we
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went to the porch, the cost of putting even a
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single kilogram of cargo into space was astronomically
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high. No one could afford to go any further.
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Right. So the transition we are seeing today,
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this sudden massive explosion of space news and
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all these rocket launches, it didn't come from
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a magical new fuel. Or some sudden leap in propulsion
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physics. It was an accounting fix. Exactly. It
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came from solving that specific accounting problem.
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Yeah. It all comes down to a deceptively boring
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word, which is reusability. Reusability. So instead
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of a one -shot object, the main stages of these
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modern rockets like the massive towering cylinders
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that house all the most expensive engines and
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complex plumbing, they're now designed to fly
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back. Yeah. They do their job pushing the payload
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up through the thickest part of the atmosphere.
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They detach and then they physically turn around.
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Which still blows my mind every time I see a
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video of it. Oh, it looks like sci -fi. They
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reignite their engines and they land themselves
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upright on a concrete pad or, you know, a drone
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ship out in the ocean, right? What's fascinating
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here is the ripple effect of that economic shift.
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When you can inspect a rocket, refuel it, and
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just launch it again a few weeks later, the cost
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of putting mass into orbit. just plummets. And
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when the cost drops, the barrier to entry basically
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vanishes. It completely changes the ecosystem.
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I mean, for decades, human spaceflight was almost
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exclusively the domain of massive national governments.
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They designed the vehicles, built them, operated
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them. But now, because it's so much cheaper,
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private companies are the ones building and operating
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the vehicles. The government agencies are acting
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much more like customers now. Right. They're
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essentially hailing a taxi instead of building
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a custom car in their own garage. And this commercial
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pressure has driven like a really ruthless kind
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of innovation, right? Absolutely. Companies are
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competing for contracts. Yeah. Which accelerates
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the whole pace of development. But it also opens
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the door to completely new and sometimes pretty
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controversial markets. Like space tourism. Yeah.
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We have all seen the headlines of wealthy tourists.
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taking these brief suborbital trips just to float
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in zero gravity for a few minutes. And I think
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it's totally fair for you, listening right now,
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to view that with some mixed feelings. It's a
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complicated issue for sure. Right, because it's
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an undeniable engineering marvel that commercial
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space tourism is even possible. But it brings
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up totally new questions about safety standards
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and, well, accountability. Yeah, a billionaire
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taking a highly publicized joyride is... Very
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different from the grand exploratory purpose
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that space travel is typically sold on. Right.
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It feels a bit disconnected from the whole expanding
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human horizons thing. Tourism is definitely an
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offshoot of this new, cheaper access to space,
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but it is not the core mission of humanity expanding
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into the cosmos. So if commercial pressure has
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solved the cost of getting into orbit, the next
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barrier to deep space is weight. To go further
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than low Earth orbit, we kind of have to stop
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carrying all our fuel with us. We have to learn
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to live off the land. Right. And that dictates
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exactly where we have to go next. The nearest
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big target is the moon, obviously. But the stated
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aim of current programs is entirely different
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from the Apollo missions, isn't it? Very different.
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Apollo was a geopolitical sprint. The whole goal
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was to prove a capability, plant a flag, collect
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some rocks and get home safely. And beat the
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Soviets. Right. Exactly. But the modern architecture
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is designed around permanence. The goal is to
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return and this time to stay. But if you want
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to stay on a, you know, a bare and rock, you
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can't just set up camp anywhere. You have to
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be incredibly strategic. You do. So the primary
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target for these upcoming missions is the Lunar
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South Pole. And why there? It comes down to this
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concept, cause in -situ resource utilization.
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Which is a very dry technical way of saying living
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off the land. Exactly. Yeah. So at the Lunar
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South Pole, there are these really deep craters
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where the angle of the sun means the crater floors
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have been in permanent freezing shadow for billions
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of years. trapped inside those dark craters is
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water ice. Water, which in the context of space
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exploration is basically the single most valuable
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resource imaginable. It really is. I've heard
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it called the ultimate space currency, but I
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have to play the skeptic here for a second. Go
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for it. I understand that if you have ice, you
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can melt it for drinkable water, but people talk
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about this water as rocket propellant. Wait,
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water puts out fires. How do you turn ice at
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the bottom of a frozen crater into rocket fuel?
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That's a great question. You use a process called
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electrolysis. Okay. If you have solar panels
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set up on the crater rim, where there is near
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constant sunlight, you can use that electricity
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to shock the water. That electrical current splits
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the H2O molecule into its base components. Which
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are liquid hydrogen and liquid oxygen. Precisely.
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And those are the exact two propellants used
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in a lot of high -performance rocket engines.
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They are. You burn the hydrogen and oxygen together,
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they combust with tremendous force, and the exhaust
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byproduct is just water vapor. That's wild. It
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is. And this is crucial because of something
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physicists call the tyranny of the rocket equation.
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Oh, I always see that term thrown around. Break
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that down for someone listening who has never
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taken a physics class. Sure. Think about packing
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your car for a cross -country road trip. Imagine
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if there were no gas stations anywhere on the
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route. Okay, so I have to bring all my own gas.
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Right. You'd have to carry all the gasoline for
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the entire trip in your trunk. But gas is heavy.
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So now your car is incredibly heavy, which means
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you need a bigger engine to move it. Oh, I see
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where this is going. Yeah, that bigger engine
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burns more gas, so you have to pack even more
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gas, which makes the car even heavier, requiring
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an even bigger engine. It's a vicious compounding
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cycle. Exactly. Every pound of payload you want
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to take to the moon requires massive amounts
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of fuel just to lift it off the launch pad on
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Earth. And that is why finding water on the moon
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is such a game changer. Shipping every single
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drop of water, every breath of air, and every
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tank of return fuel from Earth would just, it
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would bankrupt any space agency. Absolutely.
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Yeah. But if you can mine the ice that is already
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sitting there in those craters, you suddenly
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have an oasis and a gas station in one. A permanent
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lunar base actually becomes a realistic proposition.
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Right. If we connect this to the bigger picture,
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though, we really need to inject a serious dose
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of reality here. Okay, let's hear it. The hardware
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for these lunar missions is physically being
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built. The metal is being cut. But space programs
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are enormously expensive and infinitely complex.
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When you hear bold announcements that humans
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will walk on the moon again by 2025 or 2026 or
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whatever the current target year happens to be.
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You should treat those dates with extreme caution.
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Highly extreme caution. Historically, spaceflight
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schedules always slide to the right on the calendar.
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They always get delayed. Always. We are trying
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to invent systems that must operate flawlessly
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in a hard vacuum with extreme temperature swings
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and lethal radiation. Delays are a feature of
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the engineering process. They aren't a bug. So
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if returning to the moon, which, by the way,
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is only three days away, is facing immense delays
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and budget hurdles, that brings us to the destination
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that generates the absolute most breathless hype.
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Mars. Mars. Mars captures the public imagination
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like nothing else. Yeah. But this is where the
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public really needs to separate genuine engineering
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progress from pure salesmanship. Right. Going
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to Mars with a human crew is not just a longer
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moon mission. It's an entirely different category
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of difficult. Let's look at the sheer brutal
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reality of the orbital mechanics here. Like I
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said, the moon is a three -day trip. When the
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oxygen tank exploded on Apollo 13, they were
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in a terrible situation. But they could essentially
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turn the ship around, coast around the moon,
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and limp back to Earth in a few days. The entire
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rescue mission played out in less than a week.
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Right. But Mars is entirely different. You can't
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just point a rocket at Mars and press launch
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whenever you feel like it. Oh, Earth and Mars
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are orbiting the sun at different speeds. Think
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of them like two runners on a track. Earth is
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on the inside lane, moving faster. Mars is on
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the outside lane, moving slower. So you basically
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have to wait for the Earth to catch up and pass
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Mars. Exactly. The planets only align favorably
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for a trip, what physicists call a Holman transfer
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window, roughly every 26 months. Wow, every two
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years. Yeah. And when you launch, you aren't
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aiming at where Mars is. You are aiming at where
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Mars will be. and six to nine months, intercepting
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it on his orbital path. Here's where it gets
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really interesting and honestly kind of terrifying.
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Because of that orbital dance, once you commit
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to a Mars mission, you are completely locked
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in. There is no abort button. Right. A crew is
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committed to a mission lasting well over a year,
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maybe up to three years, depending on the alignment.
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You are hundreds of millions of kilometers away.
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If a life support valve fails six months into
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the journey, there is zero possibility of Earth
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sending a rescue ship. None. You have to be totally,
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uncompromisingly self -sufficient. And during
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that multi -year journey, a whole series of biological
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nightmares basically begin to compound on the
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human body, right? Oh, yes. Let's start with
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radiation. Down here on Earth, we are protected
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by a thick atmosphere and a powerful magnetic
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field that deflects incoming space weather. We're
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in a nice little bubble. Exactly. But the moment
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you leave Earth's protective bubble... Astronauts
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are exposed to galactic cosmic rays and severe
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solar particle events. It's like an invisible,
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relentless storm of high energy particles just
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tearing through the ship. It is. Those particles
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literally punch microscopic holes in human DNA.
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It significantly raises the risk of cancer. cognitive
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decline, and just general cellular destruction.
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So why not just build thicker walls on the spaceship,
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like lead shields or something? Because of the
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rocket equation we just talked about. Oh, right,
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the weight. Exactly. Trying to shield a spaceship
12:03
against cosmic rays with heavy metals is like
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trying to build a submarine out of cast iron
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so it can fly. That's a great analogy. By the
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time the walls are thick enough to protect the
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crew from radiation, the ship is too impossibly
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heavy to launch off the Earth. We just do not
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yet have a practical, lightweight solution for
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long -duration radiation shielding. And even
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if you solve the radiation, you still have to
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survive the environment inside the ship itself.
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Weightlessness. Right. We see videos of astronauts
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doing flips on the space station, catching floating
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droplets of water in their mouths. It looks incredibly
12:36
fun. But the human body evolved under the constant
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downward pull of a 1G environment. It did. Without
12:43
gravity, the human body essentially decides it
12:47
no longer needs its structural support system.
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Which sounds bad. It is very bad. You see severe
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rapid bone density loss. The skeleton starts
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dissolving its calcium into the bloodstream.
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And the muscles begin to waste away from lack
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of use. But honestly, the craziest part to me
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is what happens to the fluids. I was reading
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about this fluid shift mechanism. Down here on
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Earth, our hearts have to work overtime, pumping
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blood uphill against gravity just to keep our
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brains oxygenated. Yes, the cardiovascular system
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is fighting a constant battle against gravity.
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Right. In space, gravity is gone. But the heart
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doesn't know that. It keeps pumping blood toward
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the head with that same aggressive pressure.
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So essentially you have fluid aggressively flooding
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the upper half of the body. It raises the intracranial
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pressure. We've seen this on the space station
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during standard six month deployments. Astronauts
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develop vision problems because the fluid pressure
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literally pushes against the back of their eyeballs,
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flattening them. Wait, flattening them. That's
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horrifying. It really is. And we have studied
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this for six months. Yeah. But a three year round
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trip in zero gravity that is completely uncharted,
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highly dangerous medical territory. OK, so let's
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assume a miracle. You survive the radiation.
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Your bones haven't turned to chalk. Your eyeballs
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are fine. You finally arrive at Mars. Okay, you're
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there. Now you actually have to land a massive
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habitat module full of people. And Mars has what
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engineers consider a profoundly awkward atmosphere.
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Awkward is the perfect technical term for it,
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actually. Really? Yeah. Earth has a thick atmosphere.
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If you want to land a heavy capsule here, you
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use a heat shield to absorb the worst of the
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friction, and then you deploy massive parachutes
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to drift safely to the ground. And the moon has
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absolutely no atmosphere, so parachutes are useless
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there. You just fire rocket engines to slow down
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all the way to the surface. Right. But Mars is
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stuck in the middle. The atmosphere is about
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1 % as dense as Earth's. So it's barely there.
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Barely there. But it is just thick enough that
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if a spacecraft hits it going thousands of miles
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an hour, the friction will generate a terrifying
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envelope of superheated plasma that will melt
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the ship. So you still need a heavy heat shield.
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You need a massive heat shield. But once the
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heat shield does its job, that 1 % atmosphere
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is far too thin to slow a heavy crew -sized vehicle
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down to safe landing speeds using parachutes
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alone. Oh, because there's not enough air to
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catch the chute. Exactly. You hit terminal velocity
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much faster, and on Mars, that terminal velocity
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is a lethal crash speed. So you cannot just float
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down. You cannot. You have to transition from
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a hypersonic heat shield entry to parachutes,
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and then at the very last moment, ditch the parachutes,
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ignite massive rocket engines, and execute a
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powered descent to the dirt. Which sounds incredibly
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complicated. Doing that with a small robotic
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rover is an engineering miracle. Doing it with
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a multi -ton human habitat is a profound problem
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we have not yet solved. When you add all of this
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up, the orbital lock -in, the radiation, the
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eyeball crushing fluid shifts, the awkward atmospheric
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landing, the sheer terror of being millions of
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miles from a spare part. There is just this gaping
15:56
chasm between We are building a rocket that can
15:59
reach Mars and we will have a functioning human
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city on Mars. There really is. The confident
16:05
predictions of Martian settlements popping up
16:07
in a decade or two are, well, they're purely
16:10
aspiration. This raises an important question,
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though. Given the terrifying biological hurdles,
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the extreme costs and the undeniable risks to
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human life, why are we trying to send fragile,
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squishy humans into deep space at all? It is
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a debate that genuinely divides the scientific
16:26
community. Because there's an incredibly strong
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argument that we should only send robots. A robotic
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rover, like the Perseverance rover currently
16:33
on Mars, is the ultimate low -maintenance explorer.
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They don't eat, they don't sleep, and they don't
16:38
complain about the food. Exactly. A robot does
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not need breathable air. It does not need a massive
16:44
water tank. It doesn't need complex temperature
16:47
controls to stay at exactly 72 degrees. Right.
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And most importantly, it is a one -way trip.
16:53
You do not need to pack the massive rocket fuel
16:55
required to launch it back off the surface of
16:57
Mars and bring it home. That saves so much weight.
17:00
Unbelievable amounts of weight. Yeah. For pure
17:02
scientific discovery, robots offer vastly more
17:05
data per dollar spent with absolute zero risk
17:09
to human life. So what does this all mean? If
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sending machines is so flawlessly logical, why
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does the human spaceflight program still receive
17:17
so much funding and attention? It's a great question.
17:20
I think the counter argument is driven by intangibles.
17:22
Things you cannot easily measure on a spreadsheet
17:25
or a budget report. Right. There is a sincere
17:27
belief held by some really brilliant people that
17:30
humanity has a fundamental primal drive to go
17:32
ourselves. Like a rover taking a high definition
17:35
picture of a Martian sunset is scientifically
17:38
valuable. Sure. But a human standing in the dust,
17:41
looking through a visor and describing that sunset.
17:43
Uh. That changes our perspective entirely. Yes.
17:47
There is the power of inspiration. A human footprint
17:50
on another world fundamentally alters what the
17:53
next generation believes is possible. There are
17:56
also highly practical arguments for the human
17:59
struggle, too. Like the spinoff tech. Exactly.
18:02
By forcing ourselves to invent systems that keep
18:05
humans alive in incredibly hostile environments,
18:07
things like advanced water purification systems,
18:10
closed -loop life support, and highly efficient
18:13
hydroponic agriculture, we develop vital technologies
18:16
that spinoff and help us survive on a changing
18:18
Earth. And finally, there is the long -term sci
18:21
-fi argument. The idea that to ensure the long
18:24
-term survival of the human species, we cannot
18:26
keep all our eggs in one basket. Right. The insurance
18:29
policy. Yeah, becoming a multi -planetary species
18:31
acts as an insurance policy against a planetary
18:34
catastrophe on Earth. Both sides of this debate
18:36
are completely valid. It really comes down to
18:38
what you believe space exploration is fundamentally
18:41
for. Is it a laboratory for scientific data?
18:44
Or is it the next frontier for human expansion?
18:47
Which brings us to the ultimate takeaway for
18:49
you listening today. The future of human spaceflight
18:53
is in a more dynamic, chaotic, and exciting place
18:56
than it has been since the 1960s. The most useful
18:59
stance for anyone watching this unfold is a kind
19:03
of hopeful realism. We should be genuinely thrilled
19:06
by what reusable rockets and private competition
19:09
have unlocked. It's amazing. It is. The dropping
19:12
cost of access to space is a true paradigm shift.
19:15
But we also need to be totally clear eyed about
19:18
the brutal biological and physical realities
19:20
of deep space. When you see aggressive timelines
19:24
attached to incredibly hard goals, keep the rocket
19:27
equation and those fluid shifts in the back of
19:29
your mind. The frontier is opening, but it will
19:32
open slowly, carefully and expensively. We hope
19:35
this unhurried tour has given you a new lens
19:37
for the next time you see a sensational headline
19:39
about Mars. But before we wrap up, I want to
19:42
leave you with one final thought to mull over.
19:44
We spend so much time talking about the physics
19:46
of getting to Mars, but let's imagine we actually
19:48
succeed. Imagine we establish a permanent human
19:51
outpost on that freezing, irradiated desert.
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Think about what that day -to -day life actually
19:56
looks like. Every breath of oxygen you take,
19:59
every sip of recycled water, the warmth keeping
20:02
your blood from freezing. It is all entirely
20:05
dependent on perfect machinery operating without
20:08
failure. It is an existence completely enclosed
20:11
in a fragile artificial machine. So the question
20:14
is, how will living in that environment where
20:16
stepping outside for a walk without a pressure
20:18
suit means instant violent death fundamentally
20:21
change human psychology? That's a terrifying
20:24
thought. If you were born in a machine, entirely
20:26
dependent on a machine for your next breath,
20:28
how does that change what it means to be human?
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That might be the most profound unknown frontier
20:33
of all. Thank you for spending your time with
20:35
us today and exploring the brilliant, delicate
20:37
future out there in the dark.