As the late, great Douglas Adams wrote in Hitchhikers Guide to the Galaxy:
“Space is big. You just won’t believe how vastly hugely mind-bogglingly big it is. I mean you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.”
Author, Robert M. Campbell uses this theme to maximum affect in his debut series, Trajectory, which tells the tale of four ships being hunted by an unknown… thing as they return to Mars from the asteroid belt.
Today, Robert and I are going to discuss space and hopefully get across that no matter how big you think it is, it’s actually far, far bigger.
Hi Robert, thanks for joining me today. I recently read your Trajectory novels and was incredibly impressed by your depiction of the sheer distances involved in space flight. Let’s put this into a human scale context. If I wanted to drive to the moon (or Mars at closest approach), how long would it take me?
Hi Ralph. Thanks for the chat!
I’ve been thinking and dreaming about space for a long time now. The human brain is just incapable of dealing with the distances in any meaningful way, so we break it up into easily-digestible, logarithmic compartments whenever we make a visualization or simulation. Things at scale in our local, Earth-Moon environment are pretty big, but then you zoom out and see the Sun-Earth scale and you rope in the next two planets…
I like the Earth to the Moon example. I’ve been doing a lot of driving lately, and if you’ve ever traveled anywhere by car, or train, you know how incredibly tedious that is. If you spend enough time behind the wheel on Earth, you start to get a feel for just how big (and how small!) the Earth really is. You can drive across North America, from Prince Rupert in British Columbia to Miami, Florida in just a few days or a week if you’re really motivated. Three days if you don’t stop. That’s just six thousand, three hundred kilometers, the radius of the planet. Roughly six and a half more of those and you can drive around the Earth’s equator in an amphibian car-boat.
Six weeks to get around the planet with breaks for fuel and bathroom stops.
That’s roughly 1/10th the distance to the Moon nearly four hundred thousand kilometers away. The numbers are already starting to look large to us, but these are still manageable. This is the first big distance multiplier.
In a hypothetical space-car, traveling at Earth highway speeds, it would take over 160 days to get to the Moon from Earth. Nearly half a year, behind the wheel, without stopping. People do journeys like this all the time on Earth, but it’s gruelling, punishing travel. We have people in the Million Mile club on airlines. I wouldn’t want to live like that, but I could do it. For comparison, it took the Apollo astronauts about two-and-a-half days to make that same trip.
Let’s push the slider out. Looking at the slice of space between Earth and Mars during a close approach, you need to traverse around seventy five million kilometers. I’ve written it out, but let me put it into digits so you can see the zeroes: 75,000,000 kms. That is almost 200 times the distance from the Earth to the Moon. Two thousand times the radius of the Earth. And that’s still only half the distance between the Earth and our Sun at 152 million kilometers. This distance is convenient and will comes up as 1 Astronomical Unit (AU) when dealing with bodies in our system.
In a hypothetical space car, traveling at 100km/h, it would take over 85 years to span this distance.
Fortunately, we don’t drive cars in space or we’d never get anywhere.
So, if we want to get there, we need to travel fast. But, the distance isn’t going to be the only problem we face, is it?
No, it surely isn’t. It is a rich soup of complex equations and variables. It makes me giddy to think about it.
The first, and most difficult and expensive act of getting into space is leaving Earth’s gravity. You have to bring everything you need with you. You could have your supplies parked in space already, waiting for your arrival at the space station, but let’s use the Orion Multi-Purpose Crew Vehicle plans as our example and assume you have all the food and water you need already on board at launch.
So, you’re an astronaut. Congratulations! You’ve suffered through an extremely bumpy, two to two and a half gees with the occasional knock at much higher forces, aboard a heavy lift rocket like the SLS or Falcon Heavy, for several hours to make your Geo Transfer Orbit. Well done! You’ve detached from the last booster module and are sitting in a cramped container that will be your home for the next five months. You’re going to Mars in twenty-five tonnes of metal, fibreglass, water and rocket fuel.
The specialists on Earth have plotted a series of Earth to Moon orbital transfers with a final slingshot trajectory around the Earth that will fire your craft away at nearly forty thousand kilometers per hour. For most of this phase, you and your crew are weightless, except for the occasional burn from the ship’s rocket. These burns only last for about 10 to 20 seconds – just enough to kick the ship further out on its escape orbit.
On the last slingshot maneuver, the craft takes an extra half turn around the Moon and decelerates, bringing the ship inside on one half of a figure-eight in a low pass around the Earth. This is dangerous, as our ship is now moving in the opposite direction in it’s path through the Earth’s gravity well. Any contact with an orbiting body will have extremely unfortunate consequences! The crew did their homework however, and at closest approach, the pilot fires the ship’s engines in a prolonged burn that will accelerate your craft away from Earth and towards Mars.
These maneuvers are somewhat counter-intuitive: to reach an outer planet from an inner one, we need to slow our ship down with respect to Earth’s orbit, while also building up a vector that will take us further away from the Sun. To get to Mars, we need to shed approximately 5m/s of angular velocity about the Sun, while also covering the 75 million kilometers out to the next planet. The planets are not standing still while all this is going on. These rendezvous are further-complicated by Earth speeding away from Mars in its orbit, and Mars falling behind. This adds considerable distance to our journey. Roughly half-a-billion kilometers in the tangential direction to our orbit. 500,000,000kms to travel out 75 million. It no longer really makes sense to us the numbers have gotten so large.
There is no bailout on this trip. If we miss Mars, that’s it. You’re flying out into space.
Now we have to decelerate. In order to make orbit around Mars, we need to shed all this outward velocity we’ve accumulated and we have very limited fuel. If we burn too much decelerating, we won’t have enough to return home. We can use Mars’ gravity to some extent, but because it’s only 1/3rd the size of Earth, it’s not as useful for gravity assist maneuvers. Mars has a very thin atmosphere so we don’t get to slow ourselves down very much with that – it wouldn’t shave off enough speed to bring us into orbit on one pass, though we could use a series of long loops, dipping into the atmosphere to scrub speed over a longer period of time. I think Mariner and Pathfinder both did that. We have to use rockets to slow ourselves down in a prolonged burn, at a fraction of a G for over a day or several days.
Now that we’re here, we’re stuck on Mars until the next close-approach window in six months.
All in all, that’s a complex set of problems – the time it will take us, the difficulty in navigation and that’s before we throw in the human factor. What do you think are our challenges there?
Oh boy. We are just getting started there. Since the seventies, we’ve been putting humans into space on extended missions. Starting with Skylab, we put humans into orbit for 28 days, then 59 then 84 days at a time. Now on the ISS, we have humans in orbit pretty-much continuously for six months and more.
But even going into near space, human space travelers experience strange psychological effects.
I want to digress for a moment to talk about the kind of people we are still sending into space. With very few exceptions, these are people who are the best examples of human physiology and mental prowess. Most astronauts carry multiple advanced degrees. The pilots we train for space flight are invariably cut from the military with thousands of hours on the sticks of the most advanced aircraft we have in the world. For all intents and purposes, these people are exceptional humans.
They are not like us.
Now back in the ’50s and ’60s, when we started flying closer and closer to the edge of the atmosphere in U2 and then SR71 high altitude spy planes, some of the pilots returned home with strange feelings of separation. They described it as an anxiety at seeing the curve of the Earth from high altitude. I would love to know what Yuri Gagarin actually said during his debriefing as the first man in space, but Kruschev told his own version.
There’s a great quote from Joe Kittinger, the first man to ever do a space jump in 1960. I met him once at a balloon festival in Québec and he told us about the experience of freefall from one hundred thousand feet.
“There’s no way you can visualize the speed. There’s nothing you can see to see how fast you’re going. You have no depth perception. If you’re in a car driving down the road and you close your eyes, you have no idea what your speed is. It’s the same thing if you’re free falling from space. There are no signposts. You know you are going very fast, but you don’t feel it. You don’t have a 614-mph wind blowing on you. I could only hear myself breathing in the helmet.”
He nearly lost his hand because of a pressure breach on that jump. [https://en.wikipedia.org/wiki/Joseph_Kittinger]
The Apollo astronauts, still the only humans to ever truly leave Earth orbit were all profoundly affected by the experience. Dubbed the Lunar Effect, they all described powerful psychological experiences. I can’t imagine what that must have been like. All that training and work building up to the most extraordinary scientific and engineering accomplishment in human history, then taking a look back at the Earth over the Moon. It must have been staggering for primates evolved over millions of years of living on the ground, you know? We were never equipped for that.
Fifty years later, we have a new form of psychological phenomenon called the Overview Effect. Humans looking down at Earth from orbit describe the experience as a feeling of connectedness with everyone on the planet.
And that’s just the effect space has on the mind.
We’ve built up some pretty good science around bone density loss from extended trips into space. Muscle atrophy is extremely real and the astronauts have to spend a good chunk of their days just exercising so they can still function. The heart doesn’t have to work nearly as hard in space and like every other muscle, degrades with time. Astronauts returning to Earth have to work hard to build themselves back up to work in gravity. Conversely, humans living on Mars are going to go through some really interesting physiological changes over time — if they can survive there.
So all in all, it’s looking like we have huge challenges to overcome. But we might be coming across as pretty negative here. Let’s turn this around. I, for one think humanity’s destiny lies in space. You’ve clearly done a lot of research for the Trajectory novels, what kind of space craft do you think we’ll need, in the near and mid-term to explore and crucially exploit Mars and beyond?
Launch capability is an obvious first step. NASA’s SLS, SpaceX’ Falcon Heavy and other launch vehicles are the first step for launching vehicles into space. The harder problem for getting humans into space is making sure they have enough fuel and resources on board to keep everyone alive. It makes a lot of sense to have some kind of orbital way station around the Earth that we can stage all these supplies around.
The vehicles themselves are still using chemical rockets. Pound for pound, they’re still one of the most economical means of achieving high levels of specific impulse. In my Trajectory books, I describe fusion powered rockets that use modified tokamak reactors. We don’t have those yet, but we’re starting to make strides towards that technology. Dirty fission rockets have been explored as far back as the fifties by Freeman Dyson and could see a resurgence if we need to move anything really heavy.
But that’s all just propulsion. The really important question is how do we get the resources we need on Mars? Figuring out where to get Nitrogen on the surface or near surface is crucial for growing things and providing us with enough atmosphere to breathe. Potassium’s another problem, we need it to grow stuff. I think the raw materials for building things are all there, but getting at them is going to be challenging. All of that is going to require machinery which again, is expensive to move, but impossible to build without the raw materials.
One surprise is that actual structures may be really easy to build on Mars. Sulphur-based concrete seems possible and because the gravity is really light there, we can build things much larger than we can on Earth with comparatively fewer materials.
To get back to your question, I predict a big wave of robots being sent to Mars to get it ready for us over the next 50 years. Robots don’t care how long it takes to get to Mars so we can send them on slower, more economical transits. They also don’t feel the need to come home. They land, they do their work and wait for the humans to get there. Asteroid miners like the ones proposed by Deep Space Industries might be able to send raw materials back to Mars from the belt for construction.
In short, lots of robots.
We’ve kept our musings constrained to exploring the solar system here. Let’s expand this out. What if I wanted to go to the nearest star system, Alpha Centuri.
Oh, I’m not negative about any of this. It is extremely challenging science and engineering, and I think we’ll get there. Getting anywhere in space requires immense dedication and training, but humans are nothing if not resilient. And smart. I’ve also believed what Heinlein and Niven and Clarke have all said before, that the key to our survival — as a species — is to get off our comfy planet and force ourselves to colonize the solar system and wherever that leads us. It is essential.
But Alpha Centauri? That is a weird system, and it’s “close” to us! A binary star system, with a third, Proxima Centauri gravitationally linked to the alpha and beta pair. In the past month there were announcements about a potentially “Earth-like” planet orbiting Proxima,
Proxima orbits the main pair from very far out. Fifteen thousand AU. Because Proxima is a red dwarf, its habitable zone would be very close to the star, and probably suffer lots of radiation and plasma storms. It could be hellish. But there might be a safe band along the terminator if it’s tidally locked.
Anyway, to get to Proxima Centauri, that’s 4.25 Light Years away at its closest and that is a really big distance. 4.02 x 1013km. I could print out those thirteen zeroes, but you’d look at them and try to divide them into thousands and you’d still have too many zeroes. Forty million millions of kilometers. It is nearly 265 thousand Astronomical Units away.
The New Horizons probe, the fastest vehicle ever launched from Earth is now only about 30 AU from Earth having just passed Pluto last year. It took ten years to get there and has a current velocity of about 13m/s. If it were lined up to Alpha Centauri, and I don’t believe it is, it would take a very long time to reach its destination: One hundred million years.
Obviously, we don’t have that kind of time, so we would need something much, much faster. Our best theoretical propulsion systems, all of them nuclear, might be able to manage 10-20% light speed, accelerating over a span of decades. At that, we’re looking at 20-50 years taking into account the time it would take to accelerate to that speed, and a truly horrendous amount of heavy hydrogen fuel, or uranium or whatever material you chose. The ship would be almost entirely fuel when it started, and an empty husk on arrival. Shedding empty fuel pods would be an excellent way to drop mass (and probably heat) to go even faster! Almost manageable in a human lifetime, but certainly a one-way trip. When you start thinking about fifty years of supplies for a human crew, the mass involved starts to get quickly intractable. Fuel quantities go up, mass goes up, velocity goes down… You’d want to mitigate that by figuring out some form of stasis for your passengers or maybe even making the crew smaller. Once you start looking at a human in space, you have all of these appendages that aren’t that useful. Lots of mass in a human leg, for instance…
Ok, you can see where that’s going. I think, realistically, our best shot at extra solar exploration is going to be of the robotic probe variety. Circuitry is a million times smaller than biology, and we can probably get away with a fairly diminutive payload. That gives us the option of using lightsails and lasers to propel our ship across the vast distances. Small, limited powercells on board to drive a laser for deceleration at the target, or atmospheric braking if available could do the work to scrub off speed.
You can do a lot of science with a robot… but they make lousy travel companions.
Pay it Forward: Question from Peter Cawdron: Robert, what’s your favorite classic (20th century) science fiction story, and why?
That is not an easy question, Peter. Not at all. Obviously, I haven’t read everything from the 20th century, but I will pick two books that made a big impression on me. I can’t pick just one.
First is Huxley’s Brave New World. It’s almost a cliché now, it’s been so influential. You see it echoed in so much of our modern science/spec fiction and he wrote it in 1931. Huxley could see where we were going even then. It is still totally relevant.
The other book that made a big impression on me was Alfred Bester’s The Demolished Man. Written in the ‘50s, it was the first Hugo award winner and set the stage for cyberpunk and scifi noir. You can see his influence in Philip K. Dick, William Gibson, George Alec Effinger, and basically anything cyberpunk. What I really liked about Bester was his sociology background. He used his scifi as set pieces to study the human condition.
Paying it forward, it’s my turn to ask Isaac Hooke a question: What overused scifi trope really irks you off the most?
Robert, thanks for taking the time to answer a few questions, and writing those awesome books.
Thank you, Ralph. It’s been a real pleasure.
Robert Bio, including website & mailing list.
Robert M. Campbell hails from the east coast of Canada, having recently returned to New Brunswick after extended stays in Toronto and Ottawa. An early love of astronomy and technology eventually led him to a career in software engineering. Robert studied Computer Science and Anthropology at Acadia University in Nova Scotia.
After twenty years working in the aerospace, government and open source software sectors, he has written his first science fiction novels, Trajectory Book 1 and Book 2 – the first installments of a projected six in the New Providence Series. Book 3 is slated for release in early 2017.
Elevator pitches for Trajectory book one, two, three and links.
Buy book one for $0.99 between the 24th and 31st of October.
Set nearly 200 years in the future…
Four mining ships are making the slow return to Mars from operations in the asteroid belt. Back on the planet, a group of students discover a mysterious object in space in an impossible orbit. The crew of the Lighthouse space station are shocked by a devastating accident that throws their routine into chaos as they strive to get their ships safely home.
Cut off from Earth, the sub-surface Martian Colony of New Providence suddenly finds itself in peril from something hostile and unknown. Is it alien? Is it an AI from Old Earth? After five generations enduring the harsh conditions on Mars, will the 50,000 citizens of New Providence survive this new and terrifying threat?
In the second installment of this hard scifi thriller, the mysterious object is tracking the remaining mining ships through the asteroid belt as they desperately try to return to Mars. Lighthouse station enlists help from the colony, shrouded in spring dust storms, to devise a plan to get their ships safely home.
New Providence Series Book 3 (title tbd, expected release Early 2017)
After the events of Books 1 and 2, the story moves to the colony of New Providence beneath the surface of Mars. The Council convenes to discuss recent events. We are given a look at the efforts it takes to eke out an existence on the red planet as the last of humanity faces a new threat from space.
