Previously on Space Travel:
Railguns! Trebuchets! All methods we can use to traverse our local solar system. Things get complicated, though, when we try to look beyond. Halving the time it takes to get somewhere doesn't mean squat when we get to things like light-years.
Let's math this problem real quick. The closest start to us is Proxima Centauri (which I knew off the top of my head, btw; FEAR MY POWER). It's just over four light-years away, or 40,208,000,000,000 kilometers from Earth (on average, anyways). That presents a problem that - fortunately - someone already did the maths for. Skyhooks, as projected, would yeet you at approximately 26.7 thousand kilometers per hour into the cold heart of space.
Which meaaaaaaaans we could be there in just about... 1501897916.66 hours.
Which meaaaaaaaans it'd take roughly... one hundred seventy-one thousand, four hundred forty-nine years.
This is, as scientists put it, an issue. Literally nothing of value could be gained from this. Interstellar colonization? No shot. Maybe if we put everyone into cryosleep or some scud like that we could save a tiny fraction of humanity from Earth's last flaming breaths, but... yeah. That won't do for conquering the galaxy.
Fortunately, we have other things to look at right now. If humanity is at all interested in colonizing other star systems, then it stands to reason that by now we've already colonized our own. Using up the available energy and resources to us in our system is a massive undertaking, but opens up all sorts of crazy things. Thus, I think it's worth taking a closer look at before we move along in humanity's grand journey.
Tier II - Our System
Let's take a closer look at all the cool things that us humans could do with our system given enough time and investment.
- Moon base: We're probably on the moon! Not even probably - almost definitely. It's not a particularly hostile environment, and there are precautionary measures we can take against the radiation and occasional meteor swarms - my favorite being "dig a hole." Most of humanity would probably live underground in massive reformed caverns, capable of creating massive structures with the lighter gravity. Entire ecosystems could be constructed within these habitats... and they'd have to, too. There really isn't any way to terraform the planet, as the gravity's too weak to maintain an atmosphere, and the electromagnetic field's too weak to protect everyone from nasty stuff like radiation. The 'outside' would have to be shielded using [something something t e c h n o l o g y], and it's likely that people would have to get used to keeping space suits handy just in case.
- On the plus side, though, the moon gives us tons of opportunity for other things. First of all, its lighter gravity means that it's much easier to cast off from. It's tidally locked with the Earth, so it might be worth building a massive elevator on the dark side as a sort of makeshift tether and harness the moon's orbital momentum. However, it's also just as viable to build lots of regular skyhooks around the moon. We could build a bunch of railguns on the surface (which require far less energy), and make the moon a first-stop port to the rest of the solar system.
- Other stuff the moon has: resources! It's got plenty of metals, which can be used to maintain its own economy as well as being shipped abroad. Solar power could work decently well in smaller scales, but by far the greatest resource the moon has is H-3. The moon could become the first fusion-reactor-powered body in the solar system, and eventually ship out the stuff to other planets as a clean energy source.
- Mars Colonization: Let me make one thing clear. The reason everyone's talking about building a Mars base is because its close; not because it's viable. It has very little atmosphere (comprised almost entirely of CO2), no global magnetic field, a completely insane weather cycle, and nasty storms of electrically-conducting dust particles that get EVERYWHERE. There's no way to protect against all the space radiation, it's impossible to breath, long exposure to the lower gravity could cause permanent damage, and the literal dirt is toxic.
- But... it's free real estate.
- Now, I've never played any of those space terraforming games, so maybe y'all know more about this than I do. Just bear with me here. To first colonize Mars, you'd need to build small, cylindrical structures containing the bare necessities of life. There would be no windows, literally everything would have to be recycled, and the whole thing would be completely covered in dirt to shield the unhappy astronauts from the radiation. Any work that doesn't absolutely require human hands would be done by remotely-controlled drones so as to protect the astronauts from as much exposure as humanly possible. Mars suits would be incredibly bulky, with myriads more protection than required elsewhere. They'd need to undergo a rigorous sterilization process every time an astronaut returned so as to prevent the toxic microfibrous soil from entering the habitat, or potentially never even enter the habitat in the first place (such as by attaching to the outside).
- Colonizing Mars would be torturous. Fortunately, there are a few things we can do. Mars has plenty of natural resources that we can mine to build things, such as massive containment areas. By far the most viable option would be to construct large reinforced buildings on the surface. Making them airtight would allow us to completely control the conditions within, which means these could be the first viable human habitats for large groups of people. Domes seem decently doable, as they could balance out the pressure most efficiently. However, they'd need to be made with several layers of reinforcement so as to protect the structural integrity of the area. It would probably behoove the engineers to construct several independent airtight chambers within the area itself, so if a breach were to occur, they could protect the vast majority of the dome.
- Until we can come up with perfect insulation, building underground isn't an option. Any breach could allow the toxicity of the soil to seep into the habitat, which would be... y'know. Bad. There could potentially be emergency bunkers and such built there to evacuate people for short periods of time, but long exposure needs to be avoided at all costs.
- However, once the planet is colonized, we've really managed to open up the solar system. Its moons are very viable for large-scale skyhooks, and the abundance of natural resources (namely iron) would make it a hub for mining. It might even become a sort of temporary home to big resource mining industries (the habitats would allow you to stay and oversee operations, meaning the planet wouldn't have much or even any regular residency). It would become a industrial and infrastructural hub, and mark our first major step towards colonizing the solar system.
- Venus is hell. Let me make that ABUNDANTLY clear. VENUS. IS. HELL. The atmosphere is thick. The atmosphere is toxic. It is comprised almost ENTIRELY of carbon dioxide, with an average surface pressure of 1350 psi, or about 91.86 atm. Divers can survive up to 100 atm by not breathing - but, generally speaking, if you're a Venusian colonist, you're going to want to breathe. Not that it matters, of course, because the air here would kill you in instants! Did I mention the fact that it's toxic?? Or that it is literally made of CO2??? There are clouds made of sulfuric acid!!! The CO2 is supercritical!!! The greenhouse gas effect gives the planet an average temperature of 464 degrees Celsius!!! That means liquid lead. That means you won't have time for the supervolcanoes to kill you!!!!
- Venus is not conducive to colonization. Venus is conducive to death.
- *Pant* *Pant*
- ...But I hear you. "Fadran, what if we just terraform it?"
- Here is a link. It will take you to a Kurzgesagt video. They explain the process. I'm not going to go into it, because - frankly - this article is long enough already.
- You wanna hear my opinion? My brother just mentioned it, and I wholeheartedly agree. The place burns at gazillions of degrees, spits geothermal forces like a teen's first pimple outbreak, and soaks up sunlight like nothing else. That said, Venus is also the PERFECT thermal battery.
- We should turn hell into a battery.
- Mercury: Mining! Don't colonize here. It's either scalding hot or freezing cold, depending on what time it is. No atmosphere. Mining only. No humans allowed.
- Jupiter: The moons are all perfectly viable. Like, there's tons of them, and they're all pretty cool to boot! I don't have time to go into any of them, but I think they're all decently viable for bases and such akin to the ones on our own moon.
- Saturn: Prettyyyyyyy!!! Skip.
- Uranus: Did you know that its magnetic field is tipped away from its axis by 60 degrees? Cool, huh? Moving on...
- Neptune: We do not need two blue gas giants. Throw some ship names down below so we can finally combine them!
- Pluto...?: https://xkcd.com/473/
- Other Stuff: Asteroids! They're all pretty dang mineral-rich and mineable. Big ones could be viable for early interplanetary resource-gathering. Here's another Kurzgesagt video that goes into that.
So is that all? We've harnessed the solar system. And... it didn't really help us at all for interstellar travel. We can build... bigger skyhooks, maybe? There's... nothing left for us to use. Is interstellar travel impossible?
- The Sun:
Look forward to part two: Harnessing the power of the sun!