#IWSG: The Spice of Life

May 4, 2022 ~ J.S. Pailly ~ 17 Comments

Hello, friends! Welcome to this month’s meeting of the Insecure Writer’s Support Group, a blog hop created by Alex J. Cavanaugh and co-hosted this month by Kim Elliott, Melissa Maygrove, Chemist Ken, Lee Lowery, and Nancy Gideon. To learn more about this amazingly supportive group, click here!

“Do one thing and do it well.” I’ve heard this aphorism over and over again throughout my life, and there’s a certain common sense simplicity to it that I find appealing. Whenever life gets complicated and I feel like I’m being pulled in too many directions at once, I really wish I could pick just one thing to do—I wish I could be permitted to focus all my time and energy on just one thing, without any distractions, so that I could have a chance to do that one thing exceptionally well.

Last month, I participated in the A to Z Challenge. For anyone who doesn’t know, the A to Z Challenge is a month-long blogging event. Participants post twenty-six blog posts, one for each successive letter of the alphabet. All of my posts were about humanity’s future in outer space, or perhaps I should say humanity’s potential future in outer space. Our species has so much potential! But I do realize there’s no guarantee that we’ll live up to our potential, though.

In order to ensure my success with the challenge, I canceled any other plans I’d made in the month of April. I used up a bunch of vacation days at my job. I made sure I got my taxes done super early this year. I put a few of my other creative projects on hold, temporarily. I engineered my whole schedule so that I would able to do just this one thing: blogging. Did I do it well? That’s a subjective thing, of course, but I feel that I did the best I possibly could on most of my posts. And it felt good.

However, there came a point when I started to miss working on my other creative projects. Being able to “do one thing and do it well” feels nice, but to really thrive, I need variety in my creative life. My muse was kind enough to hold back on new ideas during the A to Z Challenge. Now, however, there’s a backlog of ideas that my muse would like me to work on—and I am eager to get to work on those new ideas!

“Do one thing and do it well” can be good advice, for a short time. When life gets complicated, sometimes we need to stop and have the simplicity of doing one and only one thing for a while. But when I think about my lifelong goals, when I think about my own future as a writer/artist/blogger, there’s a different aphorism that I’d rather live by: “Variety is the spice of life.”

Our Place in Space: The Z-Series Spacesuits

April 30, 2022April 28, 2022 ~ J.S. Pailly ~ 26 Comments

Hello, friends! Welcome to Our Place in Space: A to Z! For this year’s A to Z Challenge, I’ll be taking you on a partly imaginative and highly optimistic tour of humanity’s future in outer space. If you don’t know what the A to Z Challenge is, click here to learn more. In today’s post, Z is for…

THE Z-SERIES SPACESUITS

Oh my gosh, we actually did it. This is the final post of this year’s A to Z Challenge! All month long, we’ve been talking about humanity’s future in outer space. We’ve talked about the space vehicles that will take us to other worlds, and we’ve talked about the kinds of habitats we could build on other worlds once we get there. But there’s one thing I’m sure you’ve all been wondering about this whole time: what are people in the future going to wear?

Quite a few years ago, NASA introduced a prototype spacesuit for future missions to the Moon and Mars. They called it the Z-1 spacesuit. For some reason, the color scheme looked suspiciously like Buzz Lightyear. A few years later, NASA introduced an updated design called the Z-2 spacesuit, which had glow-y parts that made it look like something out of Tron.

The Z-1 used mostly “soft” materials in its design, which gave astronauts increased mobility and flexibility; however, these soft materials did not provide much protection. If you trip and fall on the Moon, you don’t want your spacesuit to rip or tear—not even a little bit! So the Z-2 used a mix of soft and hard materials, in an attempt to strike a better balance between safety and mobility.

As I understand it, the really important thing is that the Z-series suits have a big, giant hatch in the back. This hatch-back design makes it much easier to get in and out of your spacesuit, compared to more traditional spacesuit designs. First, you open the hatch. Next, you stick your arms in the arm tubes and your legs in the leg tubes. Your head goes into the fishbowl part. Then, just close the hatch behind you, and you’re good to go. Easy!

So will astronauts in the future be wearing Z-3 or Z-4 spacesuits as they explore the Moon, Mars, and so on? No. No, they won’t. I can’t find a source explicitly stating that development of the Z-series spacesuit was canceled, but I’m 99% sure development of the Z-series spacesuit was canceled. At the very least, there hasn’t been any new news about it for years. In the meantime, NASA has introduced other spacesuit designs, like the xEMU (eXploration Extravehicular Mobility Unit), intended for use on the Moon, Mars, etc.

It is worth nothing, though, that aspects of the Z-series designs—including the very convenient hatch in the back idea—have been incorporated into the xEMU. Fans of the Z-1 and Z-2 suits can find some consolation in that.

Predicting the future is hard. A lot of cool ideas have been proposed for space exploration, and quite a few of those ideas are now in active development at NASA, E.S.A., or elsewhere. Some of the things we talked about this month may actually happen someday; others may be quietly canceled, like the Z-series spacesuits. So whenever you see someone (like me) talking about what the future is going to be like, take what they say with a grain of salt (especially if they get hyper specific about what we’re going to do and by what date we’re going to do it).

But even if it turns out I got specific details about the future wrong, I still believe the general ideas expressed in these A to Z posts will be right. Human civilization is going through a tough time right now, but will come out of this, we will learn from our mistakes, and we will build a better future for ourselves, both here on Earth and out there among the stars.

Want to Learn More?

Here’s an infographic from Space.com about the Z-1 spacesuit, and here’s their infographic about the Z-2.

Also, here’s a short video from NASA about the xEMU spacesuit, which borrows that super convenient hatchback design from the Z-series suits.

Our Place in Space: Yestersol

April 29, 2022April 28, 2022 ~ J.S. Pailly ~ 17 Comments

YESTERSOL

Do you ever feel like there just isn’t enough time in your day? Like you just cannot get everything you need to do in a day done in a day? Do you wish your day could be just a little bit longer? If so, moving to Mars might be a good solution for you! A day on Mars is nearly 40 minutes longer than a day on Earth! Scientists call this slightly longer Martian day a “sol,” and several cute and clever new words have been introduced related to Martian timekeeping: words like yestersol, tosol, and solorrow.

As of yet, there are no humans on Mars ^{(citation needed)}, but there are humans here on Earth who have to live and work and plan their whole schedules according to Mars time. You see, the Mars rovers can only operate during Martian daylight hours. Therefore, everyone back at mission control for those rovers needs to be awake, alert, at their desks and ready to go when it’s daytime on Mars (regardless of what time it is here on Earth).

Sometimes the discrepancy between a Martian sol and an Earthly day isn’t so bad. Sometimes, when it’s daytime at Jezero Crater (current location of the Perseverance rover), it’s also daytime in southern California (where Perseverance mission control is headquartered). But day after day, sol after sol, that forty minute difference adds up. At some point, high noon at Jezero crater will be the middle of the night in southern California.

It’s important that the same crew of people always works with the same rover. Therefore, NASA has had special clocks and watches made to help people keep track of what time it is on Mars. NASA scientists and engineers associated with various Mars missions set their work schedules, meal schedules, and sleep schedules according to Mars time. As a result, there is a small community of “Martians” here on Earth, living their lives about forty minutes out of sync from the rest of us. And quite naturally, certain colloquial terms have developed within this little community of Mars researchers.

Yestersol refers to the sol before the current sol. Tosol is the current sol. And solorrow is the next sol, after the current sol. Making a clear distinction between “yesterday” and “yestersol” is especially important for people who live on Earth and still have to deal with many Earthly concerns, but who also, in a very real way, need to think and act as if they’re living on Mars.

I like to think of the whole “yestersol, tosol, solorrow” phenomenon as a little preview of the future. It’s one thing to think about big picture futuristic stuff, like space elevators and planetary protection laws; but it’s little bits of culture and daily life (sorry, sol-ly life) that help make the future feel like a real place.

Want to Learn More?

NASA spacecraft engineer Nagin Cox gave a really neat TED Talk about what it’s like living on Mars time. Click here to watch it.

Our Place in Space: Xanadu

April 28, 2022April 26, 2022 ~ J.S. Pailly ~ 4 Comments

XANADU

`Titan is the largest moon of Saturn. It’s a very cold place. It’s so cold on Titan that water is basically a kind of rock, and certain chemicals that we typically think of as gases (i.e.: methane and ethane) flow freely as liquids. As a result, the surface of Titan looks surprisingly similar to some regions on Earth: a rocky landscape eroded by rain and rivers. Except the “rock” is frozen water, and the rain and rivers are a mix of liquified methane and ethane. One of the most curiously familiar “rock” formations on Titan lies near the equator. It’s called Xanadu.

Xanadu is an Australia-sized region of craggy hills and mountains. Due to Titan’s thick, hazy atmosphere, it’s impossible to see Xanadu (or any other surface feature on Titan) except in certain specific wavelengths, such as certain wavelengths of infrared. When Xanadu is visible, it appears as a bright splotch on Titan’s surface, surrounded by much darker desert terrain.

It’s unclear how Xanadu came to be. One hypothesis I read argues that Xanadu could be associated with some sort of giant impact event. Perhaps a large asteroid or comet smashed into Titan, disrupting the icy crust, which then refroze as this jagged and craggy terrain. Another hypothesis suggests that Xanadu was created by some sort of tectonic activity—a fascinating possibility. At this point, Earth is the only world confirmed to have plate tectonics.

In this Our Place in Space series, I’ve tried to emphasize all the cool and exciting things humans could do in the distant future. I have also mentioned, from time to time, my belief that humans in the distant future will learn to be good stewards of the Earth. Space exploration can help us do that. Titan is so curiously familiar, yet also so weirdly different from Earth. Trying to understand why Titan is so different-yet-similar can teach us much about our own world—which, in turn, will help us figure out how to take better care of our planet.

But there’s a catch. Just as we have a responsibility to take better care of Earth, we also have a moral responsibility to not mess up Titan. Remember Titan’s thick, hazy atmosphere? There are some weird chemicals forming in that atmosphere. Organic chemicals. Could those organic chemicals be associated, in one way or another, with biological activity? Maybe. Maybe not. No one can say at this point.

In the next few years, NASA will be sending a robotic helicopter to explore Titan’s Shangri-La region, one of the dark-colored regions directly adjacent to Xanadu. If we’re lucky, maybe that robo-helicopter will venture into Xanadu at some point. I have confidence that NASA will thoroughly sterilize all of their equipment before sending it to Titan to ensure that we do not contaminate Titan with our Earth germs.

There will be many more missions to Titan in the future. Just as Mars is crawling with Mars rovers today, Titan will be covered in Titan rovers, Titan helicopters, and Titan submarines in the future. The place has too much in common with Earth, and we simply cannot leave it unexplored. But humans in the distant future will not only be good stewards of the Earth; they’ll be good stewards of the Solar System. And so, whether we’re exploring Xanadu or Kraken Mare or Shangri-La, or any other region on Titan that has a super cool name, strict safety precautions will always be a must.

Want to Learn More?

I had a really hard time finding information about Xanadu for this post. I’m guessing that’s because very little information is available at this time. More exploring needs to be done! What I did find came from these three scientific papers:

Our Place in Space: The Wilderness

April 27, 2022April 26, 2022 ~ J.S. Pailly ~ 8 Comments

THE WILDERNESS

All month long, I’ve been telling you about how, in the distant future, human civilization will spread out far and wide across the Solar System. At the same time, I have rather casually been declaring various places in the Solar System should be off limits to humans. I feel perfectly justified in doing that after reading a certain research paper titled “How much of the Solar System should we leave as wilderness?”

I’m not going to summarize that paper in its entirety. If you want to learn more, you can check out the links in the “Want to Learn More?” section below. The main point I want to talk about, based on what that “wilderness” paper said, is that the Solar System is absolutely ginormous. You may think you understand how big the Solar System is. However big you think it is, it’s probably bigger than that.

As a result, we can declare insanely large swaths of territory and resources “protected wilderness” without inconveniencing ourselves. The paper advocates for establishing a one-eighth principle, meaning that our future space economy should be restricted to using only one-eighth of the resources in our Solar System. The remaining seven-eighths would be off limits. To quote from the paper:

We are required, as a point of social ethics, to accept reasonable constraints upon our self-interest in order to meet basic standards of justice between one another and (arguably) between ourselves and future generations. This is a precondition of having any sort of stable and lasting human society. However, we will take it that a livable ethic for society at large cannot ask for too much. More precisely, a reasonable social ethic cannot ask for anything so demanding that it is impossible, inconsistent with what we know about human psychology, or otherwise so demanding that it belongs only in the domain of private sacrificial commitment of a sort associated with political and religious ideals. The one-eighth restriction may seem to fall foul of this constraint.

Yes, the one-eighth principle sounds very demanding and restrictive at first glance. But, as the authors of that paper go on to explain, the Solar System is really big. Even if we make some highly optimistic assumptions about how fast the future space economy might grow, it would still take centuries to use up a full eighth of the Solar System.

This wilderness paper is now one of my all time favorite scientific research papers. It does make some important warnings for the future, though, and if you’re a fan of the kind of futurism I’ve been touting in this Our Place in Space series, I’d encourage you to check out the links below.

In the meantime, I declare that the rings of Saturn should be off limits to mining operations. Let’s preserve the natural beauty of those rings. Parts of Mars should be off limits as well—if we find alien life on Mars, perhaps the whole planet should be off limits. Same for many of the icy moons of Jupiter, Saturn, Uranus, and Neptune—especially Titan, Enceladus, and Ganymede—and most extra especially, Europa. Seriously, nobody mess with Europa!

Want to Learn More?

Click here to read “How much of the Solar System should we leave as wilderness?”

Or click here to read an article from Live Science summarizing the paper’s main points in less technical language.

Our Place in Space: VASIMR

April 26, 2022April 24, 2022 ~ J.S. Pailly ~ 17 Comments

VASIMR

For space enthusiasts and people directly involved in space exploration, VASIMR can be a highly controversial subject. In some circles, mentioning VASIMR is almost like bringing up abortion or gun control. VASIMR supporters will tell you that this technology could radically reduce the fuel costs associated with space travel and also cut down the transit times for interplanetary journeys. The anti-VASIMR crowd will tell you that this technology has been stuck in the research and development phase for four decades now and that it’s time we cut our losses and spend all that R&D money on something else.

VASIMR stands for VAriable Specific Impulse Magnetoplasma Rocket. Rather than generating thrust through controlled chemical explosions (as traditional rockets do), a VASIMR engine heats up a neutral gas (typically argon or xenon), ionizes that gas, then accelerates the gas using super powerful magnetic fields. The magnetically accelerated gas shooting out the back of your spaceship will propel your spaceship forward.

The weight of your argon or xenon fuel would be far less than the weight of the liquid oxygen/liquid hydrogen fuel used in most rockets today. And in theory, VASIMR powered rockets could travel faster than chemically propelled rockets. We could get to Mars in a matter of weeks rather than months, or get to Jupiter in a matter of months rather than years! So why aren’t we already using this technology?

The problem, as I understand it, is that it takes a lot of power to ionize argon or xenon gas. It takes even more power to generate those super powerful magnetic fields. All the equipment needed to generate that much power is heavy. Prohibitively heavy. Whatever advantage VASIMR might offer in terms fuel weight is thoroughly negated by the weight of all the extra equipment you’d need to make the engine work.

The idea for VASIMR was originally pitched in 1977. The first laboratory experiment was conducted in 1983. This technology really has been in development now for four decades, and it’s still not ready to fly.

I’m not going to advocate for cutting funding on this research. Progress has been made over the last forty years. It’s slow progress, to be sure, but slow progress is still progress, and if VASIMR ever does work as intended, it would be a huge, huge breakthrough for space exploration. Many things that are not possible for us right now would suddenly become possible.

If it ever works as intended….

Want to Learn More?

As I said, VASIMR can be pretty controversial. To give you a better sense of that controversy, I’m going to recommend this article by Robert Zubrin (President of the Mars Society), titled “The VASIMR Hoax.” I’m also going to recommend this response to Zubrin from Ad Astra Rocket Company (the company currently working on VASIMR), titled “Facts About the VASIMR Engine and Its Development.”

Our Place in Space: Utopia Planitia

April 25, 2022April 24, 2022 ~ J.S. Pailly ~ 12 Comments

UTOPIA PLANITIA

Earlier this month, we talked about Jezero Crater on Mars. There’s strong and compelling evidence to suggest that Jezero Crater was once filled with liquid water. In other words, Jezero Crater used to be a lake. If Jezero Crater used to be a Martian lake, then the nearby region of Utopia Planitia was probably once a Martian ocean.

As you can see in the highly technical diagram above, much of Mars’s northern hemisphere was once covered in water. Probably. Okay, as a responsible science blogger who wouldn’t want to make you think there’s scientific consensus about a topic when there is not scientific consensus about a topic, I should make it clear to you that the topic of ancient Martian oceans is somewhat controversial in the scientific community. Scientists are still arguing over what may or may not be ancient Martian shorelines, among other things.

But let’s assume that ancient Mars did have oceans of liquid water on its surface (that seems like a safe assumption to me, but I’m not a scientist—I’m just a guy with a blog). If so, those oceans would have covered much of Mars’s northern hemisphere. Today, Mars is sort of a lopsided planet, with generally low elevation terrain in the north and generally higher elevation terrain in the south. So if ancient Mars did have large amounts of liquid water on its surface, common sense tells us that that water would have accumulated in the low elevation regions (i.e., the northern hemisphere).

Utopia Planitia is one of those low elevation regions in the northern hemisphere. The terrain is also relatively flat, making Utopia Planitia a fairly easy place to land a spacecraft. Several robotic missions to Mars have already landed there, the most recent being China’s Zhurong Rover. And as if all that weren’t enticing enough, ground penetrating RADAR has detected frozen water underground in the southwestern portion of Utopia Planitia.

In the distant future, Utopia Planitia may end up being the site of a major human colony on Mars. It’s a safe place to land, there’s a supply of water nearby, and it’s a scientifically interesting region.

On the other hand, if plans to terraform Mars ever come to fruition, Utopia Planitia may end up being part of a Martian ocean once again. As I said before, it’s a low elevation region. As we transform Mars into a more Earth-like world, water will start to accumulate in places like Utopia Planitia first, at which point we’d probably have to change the name from Utopia Planitia (plains of Utopia) to Utopia Mare (sea of Utopia).

Want to Learn More?

Here’s an article about the Zhurong Rover and the science it can do in the Utopia Planitia Region.
And here’s an article about the discovery of all that frozen water beneath the surface of southwestern Utopia Planitia.
Lastly, Utopia Planitia is on SpaceX’s list of potential landing sites for a future Mars mission. Here’s an article about that.

P.S.: As a Star Trek fanatic, I’d be remiss if I didn’t mention this. Many of the ships from Star Trek were built at the Utopia Planitia shipyards on Mars, according to Star Trek lore.

Our Place in Space: Tolkien Crater

April 23, 2022April 22, 2022 ~ J.S. Pailly ~ 11 Comments

TOLKIEN CRATER

You would not expect to find water on Mercury. If there ever was water on Mercury, you’d expect it to boil away into space pretty quickly. I said the exact same thing about water on the Moon yesterday, and yet it turns out there is water on the Moon, trapped in ice form at the bottom of craters near the Moon’s north and south poles. The same is true for craters near the north and south poles of Mercury. To my eternal delight, one of those water-filled craters is named after fantasy author J.R.R. Tolkien.

By longstanding tradition, craters on Mercury are named after historically important artists, authors, and musicians. There are a few exceptions, because a few craters were named before that tradition was established, but the vast majority follow the rule. And so there’s a crater named after Shakespeare, and a crater named after Van Gogh, and a crater named after Mozart. John Lennon has a crater named after him. Walt Disney has a crater. And so does J.R.R. Tolkien.

Tolkien Crater happens to be located near Mercury’s north pole. As a result, the bottom of Tolkien Crater is perpetually shielded from sunlight by the crater walls. It’s extremely dark and extremely cold—cold enough for frozen water to remain stable over cosmic time scales, despite Mercury’s lack of any significant atmosphere or Mercury’s proximity to the Sun.

In the distant future, as humanity spreads out across the Solar System, we may end up deciding to colonize Mercury. Mercury has resources humans in the future may need: large quantities of metal and perhaps, also, large quantities of helium-3 (necessary for powering nuclear fusion reactors, assuming we ever figure out how to make nuclear fusion reactors work). If humans do colonize Mercury, places like Tolkien Crater will be valuable real estate.

Most likely, human habitats on Mercury will be built underground. It’s easier and safer to live underground than to live on Mercury’s surface. As a result, I like to imagine that people living in and around Tolkien Crater will refer to their subsurface dwellings as “Hobbit holes.” However, considering how important mining operations would be for a successful Mercury Colony, some sort of reference to the Mines of Moria might be more appropriate.

Let’s just hope those Mercury colonists do not delve too greedily or too deep, lest they awaken something slumbering in the darkness.

Want to Learn More?

Universe Today has an article on how and why we might colonize Mercury. And here’s an article from Wired.com about the naming of Tolkien Crater.

Lastly, I feel that I have to mention this: if you haven’t seen a picture of Disney Crater, you really need to click here and see a picture of Disney Crater.

Our Place in Space: Shackleton Crater

April 22, 2022 ~ J.S. Pailly ~ 14 Comments

SHACKLETON CRATER

You would not expect to find water on the Moon. If there ever was water on the Moon, you’d expect it to boil away into the vacuum of space pretty quickly. And yet there is growing scientific evidence suggesting that craters near the Moon’s north and south poles are full of frozen water. In the distant future, the most important and famous of these water-filled craters will be Shackleton Crater.

Shackleton Crater is about 21 kilometers across and 4 kilometers deep. For the sake of comparison, the Grand Canyon is just shy of 2 kilometers deep. What’s really important, though, is that Shackleton Crater is located almost perfectly at the Moon’s south pole. As a result, it doesn’t matter what time it is—it doesn’t matter what part of the lunar day/night cycle it it—the bottom of Shackleton Crater is always shielded from sunlight by those 4 kilometer tall crater walls. Always.

That makes the bottom of Shackleton Crater extremely dark. More importantly, it makes the bottom of the crater extremely cold—cold enough to overcome water’s natural tendency to boil (or sublimate) in a vacuum.

Shackleton Crater is not unique in that respect. There are over three hundred craters around the Moon’s north and south poles that are in a state of perpetual darkness. Any or all of these eternally dark craters could have frozen water inside them. So what makes Shackleton Crater so extra special? Well, once again, the crater is located almost perfectly at the Moon’s south pole. As a result, while the bottom of the crater is always in darkness, sections of the crater rim are always in sunlight.

This combination of perpetual sunlight up here and perpetual darkness down there makes Shackleton Crater the #1 most valuable piece of real estate on the Moon. If you built a moon base at Shackleton Crater, you could set up solar panels along the crater rim while also having easy access to all that frozen water at the bottom of the crater.

I don’t generally like making “in the next twenty years” predictions, but in the next twenty years, there’s a good chance that somebody will land at Shackleton Crater and build some sort of scientific research station. Perhaps there will be several research stations, clustered together, almost village-like.

In time, that village on the Moon will grow. And it will keep growing. In the distant future, it would not surprise me if Shackleton Crater eventually became one of humanity’s first off-world metropolises.

Want to Learn More?

Check out these links:

“Meet Shackleton Crater: Future Moon Landing Site,” from Sky & Telescope.
“Moon Village: Humanity’s First Step Toward a Lunar Colony?” from Astronomy.com
“Searching for Ice in the Moon’s Shadowed Craters,” from Fraser Cain’s vlog.

Our Place in Space: The Rocket Equation

April 21, 2022April 20, 2022 ~ J.S. Pailly ~ 9 Comments

THE ROCKET EQUATION

Are you bad at math? That’s okay. I’m bad at math too. I try to avoid talking about math on this blog because I know a lot of my readers are still traumatized by high school math classes, but also because I don’t feel I’m qualified to explain math anyway. So in today’s post, we’re going to talk about what the rocket equation means and why it’s so important without talking about what the rocket equation actually is or how it works.

As you know, you need fuel to go to space. If you’re a rocket scientist, the rocket equation tells you how much fuel you need to reach any specific destination in space. You want to travel from Earth to the Moon? Plug some numbers into the rocket equation, and the equation will tell you how much fuel you need. Want to go from the Moon to Jupiter? Plug new numbers into the equation, and it’ll tell you how much fuel you need for that trip. It always ends up being an absolutely ridiculous amount of fuel.

When you see space vehicles sitting on the launch pad, something like 85% to 90% of the mass of that space vehicle is fuel. The rocket equation demands that it be so. For the sake of comparison, fuel makes up about 30% to 40% of the mass of an airplane, or about 4% of the mass of a car. NASA famously refers to this as “the tyranny of the rocket equation,” because NASA is the American space agency, and whenever Americans don’t like something that call it tyranny.

With a little creative engineering, rocket scientists can make marginal improvements to a rocket’s fuel efficiency—a 1% or 2% improvement, perhaps! But that’s about it. The rocket equation is unforgiving, and it offers very little wiggle room. In other words, the rocket equation means that space exploration is super expensive, and it always will be, unless and until we invent some totally new Sci-Fi propulsion system that no longer requires rocket engines.

As a science fiction writer, I’m perfectly happy to dream up propulsion systems that ignore the rocket equation. But for the purposes of this “Our Place in Space” series, I’m trying to stick to more realistic science, which means that the distant future we’ve been exploring in these blog posts is still very much constrained by the rocket equation.

We humans can still do a lot under those constraints. We can get to the Moon (we’ve done it before!), and we can get to Mars and the asteroid belt as well. Most of the outer Solar System is within our reach—in time, perhaps the entire outer Solar System could be ours. But there are limits. So long as we’re still using rockets for space travel, there will always be limits on how far humans can go.

Want to Learn More?

Check out NASA’s “The Tyranny of the Rocket Equation” article, which goes into more detail about why the rocket equation matters. There’s also some colorful language in there about “revolting against tyranny.”

And for those of you who do want to see the math, here you go. Enjoy!