Future (and a bit of the now) of Space Exploration
The universe is a big place. The observable universe alone is 93.016 billion light-years in diameter. It’s been expanding since the big bang, 13.7 billion years ago. And it still is. That’s a lot of space.
So now, you are probably thinking wow that's big. But wait, we can’t explore all that. That's too big, so what's the point? Why explore?
Oh, thanks for asking.
If you have read or watched anything like this before, you’ve probably heard this before, but OK, OK why. Since the start of time, we have been evolving, exploring, and expanding to new unknown lands. Each new step has taken our species forward, whether it be evolving from single-celled organisms to multi-cellular organisms, or apes to modern-day humans, or discovering the place we call America today. But what are our next steps? Be a level I species and be able to harness the energy of a neighboring star? Humans becoming multi-planetary? A base on Mars? Or maybe just being space explorers. These are all steps, but they don't come from anywhere. It takes funding, and interest of the government and public, as well as private companies, to take the competition up to the next level.
Here is a video of Elon Musk saying it beautifully:
Another point that I cannot ignore to mention is how much space inventions have helped us down on earth, yes, on earth. I listed the source down below from JPL, but I will list the most significant to me.
Wireless headphones. LEDs. Camera phones. Computer mouse. Portable computers. Athletic shoes. Yes. Athletic shoes all you shoe people. Listen up.
Environmental Cost
So now that you are ever so thankful for space, let me make you sad by telling you the current environmental cost of exploding things into space.
There’s the video, but if you don't want to listen to Tim Dodd nerding over rocket engines and methane, read my short summary. Or look at his article in the sources but be aware, it’s long although it has some pretty cool graphics (that I will use 😏).
Okay, now. Math. Rockets + lots of toxic stuff + shooting it out the back = bad. Right? But now let me revise. Rockets + lots of toxic stuff + shooting it out the back + getting cool science and stuff + understanding the environmental damage and doing something about it not nearly as bad.
So now, before we get to “doing something about it”, lets “understand the environmental damage” using Tim Dodd’s (The Everyday Astronaut) video. First, let's agree the flames are pretty cool, but what the flames are burning is not.
Alright, let's get a bit technical. Most conventional rockets use RP-1, hydrogen, methane, solid rocket fuel, and hypergolic fuels.
Solid rocket boosters, the long tube-like objects on the sides of the big orange tank on the space shuttle. They are the dirtiest fuel of all. They’re pretty primitive too, they are basically like taking a box of gunpowder and blowing it up to except controlled so it doesn't light up all at once, also if you want less violent imagery to think about it like a candle and how it burns down the wax.
So what do they emit? According to The Everyday Astronaut, they “emit primarily aluminum oxide, soot or black carbon, CO2, hydrogen chloride, nitrogen oxides, hydrogen, and a few other trace gases”. If you are thinking wow that meant absolutely nothing to me then, here is what it does: the gas compounds deplete the ozone layer.
So what about regular rocket fuel? Those are mainly RP-1, hydrogen, and methane. Let's start off with RP-1. RP-1 emits Co2, water vapor, NOx, carbon soot, carbon monoxide which becomes mostly CO2 in the air. Hydrogen emits water vapor and Nitrogen Oxide (NOx). Methane emits Co2, water vapor, and Nitrogen Oxide (NOx). Water vapor may seem harmless, but it is actually a greenhouse gas in the atmosphere.
The falcon heavy, a 550 metric ton Falcon Heavy rocket consists of 400 metric tons of fuel… only to burn in 9.5 minutes. That's roughly equal to 59 6.8 metric ton African elephants. That's the mass of 59 African elephants down to the mass of less than an ant in less than ten minutes.
That should be enough but bear in mind the below image.
I even had trouble seeing that little orange rectange. So now you are thinking but hey there are a lot more planes then rockets well yes there are, but while planes are getting you from New York to LA, rockets got us from earth to the Moon. Which one would you choose? I would choose Moon as long as I'm not the one on it 😬. Also consider the graphic below:
So yes there are more planes, but that emits the same as a ton of rocket launches, so the airline industry is way worse than the rocket industry.
Now that we have established that rockets are bad but not as bad as other things we do, since this article is about the future of space and not planes and toxins from rockets, let's move on to “doing something about it”.
By “doing something about it”, I mean come up with cool new solutions to replace the dirty ☁ dirty ☁ rocket fuels we use today.
Let’s start off with technologies that are not theoretical.
First, Ion thrusters, of course. Ion thrusters essentially throw electrically charged ions at a xenon gas plasma inside a magnetical field chamber so that the protons and xenon attach and shoot out the back at 90 Km a second. Chemical rockets shoot out the back at 5 Km and second. The best chemical rockets have an efficiency of 35% but ion engines on the other hand have an efficiency of 90%. These engines can accelerate for months at a time, at tremendous speeds. They can even go to 200,000 mph.
Solar Sails- Next, Solar sails. Much like wind sails, they use the environment around them to give a push. The solar sails use photons shooting from the sun. Each small push of these photons accelerates the sail a little bit, and they accumulate a lot and end up moving at tremendous speeds. The advantage of these solar sails is that they dont run of fuel. Hence, they can operate essentially forever in that sense. There’s a catch though (as always) the further you go from the sun, the less puch you get. This is the Inverse Square Law, so if you where to go half the distance from the sun to the earth, you would get 4 times as much as at earth. Still, its enough to get us to Alpha Centari, the closest neighboring star. With the rockets we use today, it would take 100,00 years. With solar sails, that trip could be made in 20–40 years!
Nuclear Power & Orion Project- So now something a little more exciting. Nuclear power. Project Orion, (not the capsule, unfortunately) was in the 1960s and was essentially to get humans further out into space than ever before, and it essentially blew up atomic bombs underneath the rocket to accelerate it forward. It could reach 5% the speed of light in 10 days, and 10% in a month. Unfortunately, though, that was canceled and most people wouldn't like to sit on a bunch of nuclear bombs. And I will quote Joe Scott this, “it would be more than all the nuclear bombs ever … per launch”. So now in the modern-day, we have a little less exciting nuclear power … Nuclear Thermal Energy!
The way nuclear thermal energy works is it takes the fuel, H2 (Hydrogen), and superheats it to extremely high temperatures (about 2000 degrees C and if that means nothing to you, 3632 degrees F or a third as hot as the sun). Nasa’s test for this, or NERVA. The NRX A6, the best model they made, had a SI of 869 seconds, roughly 2.3 times SpaceX’s all-new Raptor engine. This one almost destroyed itself several times though. The next version, the NERVA XE, had a 60% success rate, so — pretty good right?
So now, the Future Moonshot Techs, my personal favorites.
Space Elevators. Of course. Have you ever wondered if there was a better way of sending things to space other than blowing up toxic material? Well, how about an elevator? The name says it all, yes, essentially elevators for space. In more detail, it consists of four main parts. The anchor, climber, tether, and counterweight. The station would be the counterweight out in space holding the tether taught, and the anchor would, well anchor it. The climber would be a car to transport people and things back and forth, for a lot cheaper. After production, “the space elevator is projected to reduce the cost [of sending one Kg] 100 fold, reducing the cost from $20,000 to $200”. So now for the big BUT. This is all great and all BUT there is currently no tether that is strong enough to withhold the amount of pressure and space debris it would be faced with. If it were to snap, you’ve got big problems.
Anti-matter propulsion. This is defiantly a far out one. Electrons, a subatomic particle, turns out it has a mirror particle, anti-matter. Anti-matter is extremely rare and is almost impossible to contain. When a matter and anti-matter particles meet, they annihilate each other and turn into pure energy. You can see where this would go. Direct that energy out the back, and get a push in return. One gram of this stuff though would be equal to 80 KTON of nuclear weapons, or 10 million liters of liquid natural gas. This can get you to 72 million mph, or in other words, interstellar travel would be possible. Alpha Centauri, the star I mentioned before would be reachable in 40 years. Now for the big BUT moment. This is all great and all, but as I mentioned before, these are extremely difficult to contain, let alone direct, let alone get in high volume.
Dyson Sphere. Now here’s a really far our one, like, a couple of millenniums out. Have you ever wondered where we could get more energy to fuel the above technologies? Well, little solar panels on earth probably won’t do it all. Oh, well now you are thinking yes yes more solar panels more and yes that's great, but in the future, it won’t be enough. So we need more surface area to create energy on earth? Well, you’ve run out of space so make hundreds of fusion plants? Mine more fuel? Oh, wait we are literally orbiting a star with the power of a trillion nuclear bombs (literally). right. So how can we harness more of that power you ask?
Well according to Kurzgesagt, what if you could disassemble a planet, turn it use those resources, and build essentially millions of mirrors orbiting the sun redirecting sunlight at a collection source. That planet would be Mercury. It is the closest to the sun and is extremely metal-rich. This Dyson Sphere would essentially give us limitless energy.
Ok so now that we have gotten at least a couple technologies (listing them all would make this way too long), we can answer the question “where will they take us? What is our future?”
Nobody can really answer this because you never know what discovery will push humans to push our boundaries next. That's what’s so beautiful about space and the universe as a whole. It will always hold secrets yet to be discovered, and as humans, we are always discovering more and more. So no matter if we use solar sails, anti-matter propulsion, or ion engines to get to Mars, Alpha Centauri, and beyond, we will still keep going. So my answer to that question is: forward.
Key Takeaways:
- Space may seem big and it is, but as humans, we should always stay exploring.
- The environmental cost of current day rockets is pretty bad, but compared to the airline industry, it isn’t nearly as bad.
- There are so many new exciting space technologies, including ion engines, solar sails, nuclear engines, and so much more that will get us where we want to go in a fraction of the time.
Visit the Everyday Astronaut for more space info and make sure to clap!
Article Sources:
