Written by TKS Boston student, Amelia Settembre.
Space… the final frontier.
For years upon years, mankind has stared up at the stars and wondered “what’s next?”
Now, we’re closer than ever to an answer. As we prepare to send humans into the vacuum known as ‘space’, there’s much we have to first understand about what’s out there, and what technology we’re developing to work with it.
Since space is so vast, we’ve been exploring it for years, and there’s still so much we don’t even understand yet. Despite this, here’s a rundown of the last 50 or so years working with space.
That’s just a quick overview of what we’re doing, but in order to fully understand the depth of what we’re working with, we still have to understand what’s out there and where we fit into all of it.
Space. Just the word sounds pretty vast, and to scientists, it equates to a whole lot of unknowns and variables. First of all, let’s start with a run-down of some of the more basic celestial bodies you can locate in space.
This obviously isn’t everything, but it’s enough to get started. Our solar system is a part of the Milky Way galaxy. While we mostly consider ourselves to be pretty close to the center of the galaxy, we’re really not. In fact, nothing could be farther from the truth.
The Milky Way galaxy is a spiral galaxy, meaning it has a center and then “arms” that come off and curve around the center of the galaxy in a spiral shape. Our solar system is located on the edge of one of these arms, and we’re still working to understand why our galaxy hasn’t flown off the edge of the Milky Way just yet.
Another property of space to understand is the shape. What’s the shape of the universe? Since the universe is constantly expanding, there is no definite shape. However, the closest thing we’re going to get is the shape of the space-time continuum.
The biggest running theory is space-time being completely two-dimensional. Our perception of a three-dimensional might just be that, a perception, but we still have yet to understand why we see the world as three dimensional if we only exist in two-dimensional space.
Gravity (another important part of understanding the universe) would be pictured as a “dent” in space-time. Now, since objects with a greater mass have a greater gravity, they’ll also make larger dents in the space-time continuum. The real kicker here is actually black holes, a still very debated subject. You see, black holes are so dense that they have an innumerable mass, leaving us with a ginormous dent in space-time.
However, the idea of a flat space-time can also support worm-hole theories. It allows space-time to fold in on itself, meaning that where it touches there’s a seamless flow from one section of the universe to another section, or what we know as wormholes.
Despite this, there’s another theory of a spherical universe. However, much is still developing about this theory, mostly because it would throw off a lot of the going understanding of how our universe works.
So to break it down: Space is the vacuum that extends between stars and planets.
So we’ve got ‘space’ down to a definition of a couple of words, but it’s a lot more complicated than just that. Astrophysics has relations with many other fields of science, but there’s one that always throws it for the loop. Quanta. The notorious quanta.
Quanta and astrophysics just don’t agree. This is because of the physics quanta adheres to its own set of laws, ones completely different from the physics the rest of scientific fields follow. We call the laws of quanta ‘quantum physics’.
“If [quantum theory] is correct, it signifies the end of physics as a science” — Albert Einstein
Einstein was drastically opposed to any idea at all of quantum physics, simply because the idea that physics had two different sets of laws drove him crazy.
It’s not like that for all scientists, though, and many called ‘string theorists’ spend their time trying to prove any connection at all between quanta and regular physics. There hasn’t been any success just yet, but scientists are still working hard to try and prove the relevance of string theory to the known universe.
So what does this have to do with space technology?
Well, to understand our future in the space field, we’re going to have to gain a greater understanding of our universe, and what the properties of space are. We’ll never understand it all, but before we can move past a certain point in our development, we’re going to have to make connections that we haven’t before. But enough about the future implications, let’s work with what we’ve got, starting with what gets us into space.
Rockets were invented way back when by the Chinese, who started using them around 1230 during war with the Mongols. They referred to these rockets as ‘arrows of flying fire’, and during the battle of Kai-Keng, they unleashed these terrifying weapons on their unsuspecting enemies. This would be the first official use of solid-propellent rockets in our world.
So flash-forwards a little less than 800 years, and we’re here in the present day, using rockets to launch men into space, propel satellites quickly into orbit and across our solar systems, and much, much more.
There are two different types of fuel that rockets use: either liquid fuel or solid fuel. Both are used in contemporary rockets, and different space associations have different preferences on which they like to use.
A rocket works with storing the fuel in a cylinder along with an oxidizer. Liquid fuel rockets also feature a pump in the inside, and both have combustion chambers from which hot gases shoot out of in exhaust.
Here’s a step-by-step process of what happens to get a rocket into the air (both fuel types).
If the launch is successful, the rocket is airborne, but if the launch is unsuccessful, the scientists on the ground have to be prepared for that outcome. Since the technology is still being perfected, failed launches still occur, but we’re starting to lower that number.
Sticking with the rocket boosters, SpaceX has started to work on boosters that land the rocket, carefully bringing it back down to the ground to land and launch again. These “reusable boosters” use similar processes to push down on the ground as the craft is landing, allowing for a more gentle landing process.
Satellite. That’s a pretty common word. They’re responsible for our internet, for our communications, and for gathering data of other planets. That’s a lot. But how exactly do they work?
Well, satellites mainly use radio waves for sending the information. When used orbiting the Earth, satellites are pretty efficient, but when gathering data from other planets, it takes much longer.
By no means are satellites perfect. They work by sending radio waves from an antenna on the satellite to a dish receiver on the other side, which picks up the messages and sends them to a computer in an understandable format. Satellites have had many different purposes over the years, going from communications to data receiving to spying.
To that end, there’s even a type of sensor that can be hooked up to a satellite that scans for different amounts of metals on planets. The data is interpreted by spikes in the readings, which demonstrate the amount of a particular metal on the planet’s surface.
This may prove to be especially useful for commercial asteroid mining in the future since being able to scan asteroids for amounts of metals would increase the productivity potential mining tenfold.
Another problem we have with satellites is that the radio waves can be obstructed by asteroids or planets or even dust clouds (to some extent). So because we can’t have direct communications and we use radio waves, it’s still pretty easy to block messages from either being transmitted or received. We still have a ways to go, but technology is still evolving pretty quickly.
A Chinese company built a quantum satellite dubbed ‘Micius’ and launched it in 2016. This satellite was designed to orbit 1.200 kilometres above the surface of the Earth, using entangled qubits to send messages very quickly from the satellite to the Earth’s surface. Better yet, no obstructions could block the transmission because of the entangled nature of the particles. Of course, we’re still moving forwards in the field, and Micius is by no means the be-all-end-all for our future with satellites.
So that’s how some of the actual technology works, but what do we need to sustain humans in space safely?
Well, as humans, we have requirements that we don’t even think of necessarily. What first comes to mind is food, shelter, water, and maybe air. Of course, we still require these in space, but there’s a whole lot more that we require in outer space. Here are two main problems we face when sending humans into space.
As of now, there’s still a lot we don’t know, and still solutions we haven’t developed, but we’re working. So at some point, humans may have solutions to these problems, but we’ll always still be working and innovating.
In short: there’s still so much we don’t understand about the universe, and we’ll never give up the search to learn and comprehend our universe. In the immortal words of Gene Cernan,
“Curiosity is the essence of our existence”
We won’t give up our endeavours because these endeavours make us who we are. We’re humans.