Why Not Space? [Op-Ed]

[Zaune]

Do The Math, a blog written by Tom Murphy, associate professor of physics at the University of California.

Ask a random sampling of people if they think we will have colonized space in 500 years, and I expect it will be a while before you run into someone who says it’s unlikely. Our migration from this planet is a seductive vision of the future that has been given almost tangible reality by our entertainment industry. We are attracted to the narrative that our primitive progenitors crawled out of the ocean, just as we’ll crawl off our home planet (en masse) some day.

I’m not going to claim that this vision is false: how could I know that? But I will point out a few of the unappreciated difficulties with this view. The subtext is that space fantasies can prevent us from tackling mundane problems whose denial could result in a backward slide. When driving, fixing your gaze on the gleaming horizon is likely to result in your crashing into a stopped car ahead of you, so that your car is no longer capable of reaching the promised land ahead. We have to pay attention to the stupid stuff right in front of us, as it might well stand between us and a smart future.

I was completely astonished by the prevalence of the “space” reaction to the inaugural Do the Math post on galactic-scale energy. The post illustrated that continuing growth of our physical scale (energy) is not viable on a number of fronts—not the least of which is that Earth’s surface would reach the boiling point of water in a mere 400 years, based purely on thermodynamic arguments, and independent of which energy technology is employed. Many comments on the internets chided this view as being hopelessly unrealistic in its willful ignorance of the great space migration to come.

The connotation is that we should not heed repeated warnings about our current collision course with a finite world when—by some clairvoyant means that eludes me—we know we are destined to colonize the infinite void beyond. Space is therefore seen as an escape hatch for the human endeavor and from our arguably botched track record on Earth. Escapism may be more accurate.
Survey Says…

Before we get going on practical matters, let me share the results of a survey question I have posed to college students in my classes. Let’s see how you fare, imagining yourself to be in the same age bracket of 18–22:

Approximately how far have humans traveled from the surface of the Earth in your lifetime? [e.g., since 1980 or so]

a) 600 km (low Earth orbit, 0.1 times the Earth radius)
b) 6,000 km (about the radius of the Earth)
c) 36,000 km (geosynchronous orbit; about 6 Earth radii)
d) 385,000 km (about the distance to the Moon; 60 Earth radii)
e) beyond the Moon

I make the question visual, which you can do as well. Start with a standard Earth globe (12 inch or 30 cm diameter). The first answer is 0.6 inches (1.5 cm) from the surface, followed by 6 inches (15 cm), then a yard (meter), then 30 feet (9 m) for the Moon. Take a minute to picture this.

Earth-Moon system to scale, with response distances indicated

Out of a total of 109 students responding (one group in 2006, another in 2010), only 11% got the right answer: low Earth orbit. 52% thought humans had been as far as the Moon since the 1980′s, and 20% thought we had been farther than the Moon. Some were indignant on learning the truth: “What do we use the space shuttle for, if not to go to the Moon?!” I can only guess that some students imagined the International Space Station as a remote outpost, certainly beyond the Moon, and likely strategically located next to a wormhole. How disappointing it must be to learn that it merely hugs the globe.

I could easily get sidetracked on this astounding result. But I’ll just point out that the idea that we are no longer able to accomplish feats we once could do (like travel to the Moon) clashes with the prevailing narrative that we march forever forward. Not only can’t we get to the Moon at present, but the U.S. no longer has a space shuttle program—originally envisioned to make space travel as routine as air travel. And for that matter, I no longer have the option to purchase a ticket to fly trans-Atlantic at supersonic speeds on the Concorde. Narratives can break. I’ll leave it at that.
A Moment of Silence

A recent article in the Economist about the end of the space age—besides generating howls of protest—noted that, short of signs of life turning up on Mars, public interest in the surviving unmanned space program will wane. I think this is especially insightful given my survey of what young folks assume we’re already doing. It would be hard to sell this upcoming generation on an expensive plan to return to the Moon when the act of announcing the plan will backfire in angst that lunar trips are not already a routine part of NASA’s activities. Travel to Mars, carrying a multi-hundred-billion dollar price tag, is even less likely to see support.

John Michael Greer followed this piece with a delightfully well-written elegy lamenting the end of our space ambitions. Many of my sentiments are perfectly captured in this article, and I highly recommend the read.

Surely the termination of the NASA shuttle program has forced us to accept setbacks in our dreams of space. But this does not have to be a predictor of the future. After all, we could have decided to keep the shuttle program alive if economic and political winds had favored doing so, and we do not lack the know-how for going back to the Moon if it became a priority. Perhaps, then, we are looking at only a temporary bump in the road.
Down to Brass Tacks

However, there are practical realities to consider. If we extend our solar system model using the standard-size Earth globe as our reference, the Moon is 30 ft (9 m) away, and is about the size of an apple. The sun is 2.2 miles (3.6 km) away. Mars is sometimes as close as 0.8 mi (1.3 km) and sometimes as far as 6 mi (10 km). Light travels at a sprinting speed of 16 m.p.h. (26 kph) in this scale, but an energetically feasible transfer orbit to Mars would take 8.5 months, effectively traveling slower than a snail.

First, reflect on the vastly different scale in travel to the Moon vs. Mars. In our model, you could toss a rock to the Moon. But getting something to Mars is a whole different ballgame. Not even a slingshot would be up to the task. In practical terms, a three-day lunar journey becomes 260 days to Mars: almost 100 times as long. The closest star to the Sun, in this model, is about a million kilometers distant: 2.5 times farther than the actual Earth-Moon distance. On a separate model scale—compressed 17,000 times compared to our previous model scale—the density of stars in the local Milky Way (one star per 100 cubic light years) is analogous to grains of sand 50 km apart! Can you imagine this? Mostly empty, empty space, folks.

I often travel to the Apache Point Observatory in southern New Mexico to tend to my lunar ranging experiment. On a recent trip, I was excited to find a newly-installed solar system model consisting of planet signs positioned along highway 6563 (named by nerds after the wavelength of the hydrogen-alpha emission line of great importance in solar, stellar, and galactic astronomy). Even traveling at 15 times the speed of light, or 40 m.p.h., the scale is daunting (although, considering relativistic time dilation, a traveler would experience this pace if traveling at 0.998 times the speed of light). If you’ll forgive me, it really drives home the isolation even within the local oasis we call the solar system.

Space is no Luxury Cruise

Space is a hostile place for humans. It’s mostly empty, though not lacking in deadly ionizing radiation and cosmic rays. What few resources exist are so mind-blowingly scattered that they would seem to be utterly absent to the casual observer. Some point out that the open ocean is also hostile to human life, and conjure the image of a luxury ocean liner placidly plying the waters, oblivious to the surrounding harshness. If we can picture that, why is it such a stretch to imagine a luxury liner in space? It’s a gripping image, and would seem to counter worries about the cruelty of space. But let’s look at the oh-so-many ways the two situations cannot compare.

If the ship sinks, and you have a life raft, you stand some chance of rescue. The ocean is vast, but it’s a two-dimensional vastness teeming with human activity (compared to any realistic vision of 3-d space inhabitation even within the confines of our solar system). People have survived for months on the open ocean, subsisting on the elements around them. Running out of air is not a problem. Fresh water falls out of the sky as rain. Critters that are attracted to the cover of your life raft provide a source of food. I recommend the book 117 Days Adrift for a gripping account of a British couple who survived such an ordeal. Sometimes edible fish would actually jump into their dinghy. By contrast, a hamburger has never slammed into the side of the space shuttle in orbit, and I very much doubt that chicken nuggets are going to float up seeking the shelter of your space rescue pod!

If you fall overboard in the ocean, you can conceivably survive for a day or more depending on water temperature. I have actually met a guy who twice survived being stranded overnight treading water in the ocean—once in Indonesia and another time in Australia! In space, you’re dealing with a life expectancy of about one minute, unless you’re lucky enough to be suited up for the unexpected accident—in which case you have a perhaps a few hours to enjoy the view.

If the ship springs a leak, you can pump out water indefinitely, and that magical, life-supporting air fills in the void: it surrounds the ship, which is open to the air above. In space, a leak must be replaced with air brought on board (presumably in pressurized containers), but cannot be counted on to last indefinitely. A submarine is therefore a more apt analogy, but even then, the safety of the surface is never more than “walking distance” away.

And let’s not forget: ships take us to places that are naturally habitable. Where are the space versions of cruise-ship submarines going to take us? I, for one, would hope back to Earth!

No, the ability to picture a luxury liner in the hostile open ocean is hopelessly insufficient for me to extend the analogy to space. We’ll see our oceans teeming with people-laden vessels or inhabitation of the ocean floor before we see a population explode into space. These options are just so much easier, and carry some hope of acquiring vital resources.
Failure of a Narrative

This brings us back to the compelling narrative that our evolutionary ancestors finned their way out of the water, so it is only natural—nay, inevitable—that we will wing our way off the planet. When creatures crawled out of the water to inhabit the land, it was to reap the unbelievable vegetative bounty of the land, free of the threat of predation. No bounty of food or sense of safety tugs us into space. It’s quite the opposite on both fronts, in fact. We live on the bounty right now.

Ideas of terraforming Mars must be seen in a new light given the challenge revealed by global warming. Compared to pre-industrial levels, we have a 100 part-per-million (0.01%) CO2 problem in our atmosphere that has us completely stymied. Crudely speaking, Mars has a one-million part-per-million (100%) problem with its atmosphere. As much trouble as we are having mitigating climate change with unfettered access to all the resources on Earth, what hope would we have of turning around a place like Mars with no infrastructure to rely upon?

Likewise, attempts to create a self-contained biosphere to support human life have so far been failures—despite having the overwhelming advantage of being set up in an otherwise habitable environment with unencumbered access for construction and provisioning efforts. Making something work in the harshness of space, far from any Home Depot, would represent a challenge many orders-of-magnitude harder still.

Despite this, and the winding-down of the NASA shuttle program, the optimism of many space enthusiasts is not fazed. They look forward to future mining operations on asteroids and on the Moon. I would think we would tear up the much closer ocean floor first, given the comparative convenience and cheapness of such operations.
Insider Out!

Having said all of this, it may come as a surprise when I say that I am a proponent of the space program. As a teenager, I fell in love with the movie The Right Stuff. I cherished visits to the nearby space museum in Huntsville, Alabama, and was thrilled to see Chuck Yeager in person at the National Air and Space Museum. Inspired by the passage of Halley’s Comet, I built a telescope and through it saw all nine planets in one night—when there were nine!. I saw a quasar over 2 billion light years away, and a supernova rivaling the brightness of its host galaxy 36 million light years away in Leo. My eyes have been out there, in some sense (and I never saw any food).

Just after college, I worked on analysis of a ring-laser gyroscope camera that flew on the space shuttle, and learned in the process that I was better at identifying stars than were the astronauts. I shot lasers at satellites (with permission!). I witnessed a shuttle launch and felt the percussion on my proud chest. I was supported by NASA during part of my graduate school days to study merging galaxies. My current project uses the reflectors left on the Moon by the Apollo astronauts: I feel I have touched the reflectors on my own (and discovered them to be dusty). My team and I found the reflector on the lost Soviet Lunokhod 1 rover after forty years of silence. Half of my project funding comes from NASA (they won’t read this, will they?).

APOLLO in action. Credit: Dan Long

In other words, I’m an insider—and a supporter. I whole-heartedly believe that space offers tremendous scientific promise. If we decide to return to the Moon (with or without people), I am enthusiastic about placing next-generation reflectors on the lunar surface, allowing us to drill deeper into the mysteries of gravity. Radio observations from the quiet far side can peer into the “dark ages” of the universe as the very first stars were forming. I am super-excited about the LISA gravitational wave observatory that I hope someday will get the funding and the green light to launch, assuredly revolutionizing our view of the universe. And to the extent that human spaceflight inspires youngsters to pursue a career of exploration and science, I’m all for it.

But I want to caution against harboring illusions of space as the answer to our collision course of growth on a finite planet. We live at a special time. We have enjoyed spending our inheritance of fossil fuels, and are feeling rather heady about our technological prowess. For many generations now, we have ridden an exponential growth track, conditioning ourselves to believe that our upward trajectory is an eternal constant of our existence. We’ll see. When we cross to the down-slope of fossil fuel availability—beginning with oil—we’ll see how timeless the growth phase seems to be, and whether we can afford a continued presence in space. We should be mature enough to admit that we have no context in which to evaluate how successfully the human race will navigate this unprecedented transition.

Some professional athletes are smart about their earnings. They know that they will long outlive their athletic prowess, spending and investing modestly and smartly in preparation for the long haul. Others live large, assuming that the future will always be bigger—as has so far been true for their whole lives. We have not yet known a modern existence without an ever greater scale of fossil fuels, and it is their availability that has catalyzed our progress. This century, we will enter a new phase, untested by humanity. Dismissing the challenge this presents by looking beyond to a future in space is one of the best ways to ensure that such a future never comes to pass. All athletes know better than to take their eye off the ball.

Pessimist, pragmatist or both? Either way, he makes some good points about just how big a challenge space colonisation will really be.

[Guardsman Bass]

He's pessimistic, mostly pointing out the difficulties (but with some good points about the difficulties). I think the main problem is that his argument is essentially that space colonization is a question mark because of Peak Oil, which I don't find quite as convincing.

[Guardsman Bass]

The editing window closed before I could edit my post again, but I wonder if Apollo gave us an unfair expectation of what manned spaceflight -ought- to be capable of doing right now. How might it have progressed if Kennedy and Johnson hadn't been pushing hard for the moonshot?

[Simon_Jester]

More like the Soviet program.

Seriously, while the Russians had plans for lunar missions, there was never a serious, systemic effort by the USSR to put a man on, or even near, the moon. Instead, they had a long string of relatively lightweight space stations, a continuous shuttling of manned capsules up into space and back down, which was done for scientific purposes and national prestige. This culminated in the construction of Mir, which (unfortunately for Russians In Space) came at the same time the USSR was falling apart and the country was being dismantled and sold to oligarchs, thus contracting the definition of "possible" by Russian standards.

Would there be a space shuttle? I'm not sure. We might still be flying a distant descendant of a Gemini capsule, something comparable to the Russian Soyuz.

[Guardsman Bass]

I think that would be a good thing, since Soyuz is proven technology. Possibly cheaper as well, although I haven't been able to find figures on how much it costs the Russian to launch a Soyuz capsule these days. Re-usable capsules/spaceplanes have been a disappointment anyways - by the time you finish re-furbishing it and getting it ready for another launch, you haven't saved much money (if any).

Same for the space stations, which would give us more space infrastructure in Earth orbit. Our attitude on manned space exploration might be different, as well. Instead of triumphant victory and disappointing anti-climax, we might have more of a sense of steady progress. Of course, the downside is that we might also simply end up with no manned space program if or when Congress slashes its funding, although I don't think that would happen if the Soviets are also sending people into space.

[PainRack]

He's pessimistic, mostly pointing out the difficulties (but with some good points about the difficulties). I think the main problem is that his argument is essentially that space colonization is a question mark because of Peak Oil, which I don't find quite as convincing.

Why not? Space colonisation as a private enterprise could only be done if its "cheap". In an era of expensive resources, its easy to predict that this would not come about.

[Guardsman Bass]

He's pessimistic, mostly pointing out the difficulties (but with some good points about the difficulties). I think the main problem is that his argument is essentially that space colonization is a question mark because of Peak Oil, which I don't find quite as convincing.

Why not? Space colonisation as a private enterprise could only be done if its "cheap". In an era of expensive resources, its easy to predict that this would not come about.

His point is that expensive energy is a big question mark for space colonization, mostly because of Peak Oil. I'm skeptical of that, both in terms of the speed of its impact (he thinks that it will be a sudden thing, with drastically rising prices leading to national hoarding, leading to energy shortages), and in terms of what we can substitute. You don't need cheap oil to run a manned space program.

[K. A. Pital]

I think that would be a good thing, since Soyuz is proven technology. Possibly cheaper as well, although I haven't been able to find figures on how much it costs the Russian to launch a Soyuz capsule these days. Re-usable capsules/spaceplanes have been a disappointment anyways - by the time you finish re-furbishing it and getting it ready for another launch, you haven't saved much money (if any).

Same for the space stations, which would give us more space infrastructure in Earth orbit. Our attitude on manned space exploration might be different, as well. Instead of triumphant victory and disappointing anti-climax, we might have more of a sense of steady progress. Of course, the downside is that we might also simply end up with no manned space program if or when Congress slashes its funding, although I don't think that would happen if the Soviets are also sending people into space.

Soyuz is very cheap actually (80 million USD is the figure I've heard).

And manned programs... that's not the future. The future is mechanisms controlled from Earth by steady uplinks (and yes, it becomes harder and harder the farther we progress into the Solar system, but it is still way more reliable than meaty humans).

Mars radiation and non-breathable atmosphere? Not a big deal for robots; big deal for humans, which is why we're looking for a cave on Mars to hide a possible human base and make construction easier. Same for many other planets.

Human presence in space is going to be limited; but his automatic hands, feet and eyes - the robots - shall be working in the farthest points on many bodies. And, of course, we'll have to make nuclear pulse propulsion ships, otherwise moving bulk cargo between planets is going to take too long.

[Simon_Jester]

I find the premise that it's all going to be about teleoperations and robotics in space depressing- I doubt anyone will have trouble understanding why. I'm still cautiously optimistic about the alternatives, mostly because I choose not to make strong assumptions about what "the Singularity" will look like before I've lived through it. People who do that always strike me as having missed the point.

As to the specifics- nuclear pulse makes far more sense for liftoff than for interplanetary journeys. It would be a great way to get hundred thousand ton payloads off the surface of the moon, where no one cares about the fallout. It would be a good way to get huge payloads off the Earth if no one cared about fallout. But there are better (if less glamorous) options for a bulk freighter that never needs to land anywhere.

[K. A. Pital]

I find the premise that it's all going to be about teleoperations and robotics in space depressing- I doubt anyone will have trouble understanding why.

Why? I could understand why one could make a large colony on Mars - the prospects of terraforming are non-zero, after all. I could hardly understand the reason not to send hordes of Earth-controlled semi-autonomous robots to mine lunar regolith and keep human presence on the Moon to a few scientific exploration outposts with minimal crew. The Moon's hostile. Venus even more so. The other ones are just very far (=uncontrollable aspects increase), and this poses huge issues for human colonization until we can radically expand the human lifetime and resilience.

Robotics controlled from Earth will allow humans to engineer and construct massive infrastructure across the entire Solar system without actually having to get out of their comfortable habitats (be it Earth or reasonably massive Orion ships with BIOS-like fully enclosed environments) to build it. And then travel across the system at will if human presence is ever needed here or there.

As to the specifics- nuclear pulse makes far more sense for liftoff than for interplanetary journeys. It would be a great way to get hundred thousand ton payloads off the surface of the moon, where no one cares about the fallout. It would be a good way to get huge payloads off the Earth if no one cared about fallout. But there are better (if less glamorous) options for a bulk freighter that never needs to land anywhere.

Which, though? As far as I gathered, nuclear pulse is the best realistic shot (feasible with today's science and materials) we have for interstellar travel too (with the exception of SR being flawed and physics discovering the FTL Holy Grail). That says a lot - pulse propulsion must be rather efficient per unit of consumed fuel mass.

Moon/Mars, etc. weak-gravity planets would be much better served by space elevators that could be constructed even with modern materials, not even speaking of the recently created stuff like graphene. Which is something I'm considering in the story I'm writing now.

[someone_else]

short of signs of life turning up on Mars, public interest in the surviving unmanned space program will wane.

That's why I'd say fuck science (temporarily) and start prospecting stuff we can theoretically reach, hoping to find something cool.
In the meantime focusing on orbital matters like on-orbit refuelling or satellite servicing isn't so wrong. We need those skills anyway, and they can turn some kind of profit, i.e. giving motivation for doing more.

I wonder if Apollo gave us an unfair expectation of what manned spaceflight -ought- to be capable of doing right now.

I tend to agree.

Which, (better alternatives than Orion Boom Boom Drive) though?

Since it's a freighter, it can be handled like a SPACE TRAIN!!!!! without much problems. Won't be fucking glorious like riding nuclear fire, but will beat the crap out of Orion anytime performance and cost-wise. Without so mindboggingly dangerous fuel (tiny nukes) in the hands of anyone with a craft.

You can leave Orion Drives to military vessels, that may need the flexibility of a self-powered engine (or not).

Beamed-power's often-ignored brother could offer its help: solar sailing kinetic impactors. a paper. other reference material

You send solar sails on a solar orbit, and then they maneuver to get a retrograde orbit. Poof, you get impactors at 30 km/s or more. It's a relatively slow process to wound up (takes 4-5 years for them to do the trick), but once they are in such retrograde orbit you will only have to book the flight a year or so before the sails arrive to push your freighter around.

I've seen people claim they were able to do a similar trick with a rocket-powered critter and jupiter's gravity assists to boost stuff in Earth orbit (on a sub-orbital craft) to orbital speed, which can be useful to do the same things as well. Here and here, but I don't know enough myself to say if it's bullshit or not.

To avoid blowing up your craft you just make fucktons of very small sails, that will have a "sandblasting" effect on a solid pusher plate.

It also has the significant benefit that it's completely harmless for any celestial body with any kind of atmosphere (they blow up too high to be more dangerous than fireworks).

Of course it may be a bitch to aim the critters to a ship at above 40 km/s, but hey, Orion drives were not exactly ready-to-go nor fully safe affairs either.

If you scale this thing up to relativistic impactors and use magnetic nozzles you can go interstellar as well. Will look like crap, but will still beat hands down any other mildly realistic way.

[Skgoa]

[Skgoa]

ghetto edit: this was meant as a comment on the blog post in the OP but after reading the comments that followed it... wow, just wow.

- Space travel is cheaper than ever and will only get cheaper.
- Space travel takes such a tiny portion of our ressources (especially compared to the non-materiell costs like salaries) nowadays, that it won't be hurt by peak-whatever nearly as much as any other aspect of modern life.
- Dwindling ressources would actually make the case of space colonization much stronger, since there is plenty of ressource UP THERE.
- The era of only robots going BEO is going to end soon, with many a space agency planning big manned missions in the near future.
- The soviets had a moon program, they might even have made it there first, if Apollo 11 had failed. (Though at a rather high chance of killing the soviet astronauts in the process.)
- I am not even going to comment on "nuclear pulse" AGAIN. This video is an accurate representation of my reaction: http://www.youtube.com/watch?v=9zSHz7Thvbc
- Reusable is great, cheaper, and the future. The problem dragging the shuttle down was a (as it turned out unnecessary) fear of thermal tiles breaking. Other types of heat shielding or less violent re-entries would require much less maintenance.
- It's Hohmann Transfer Orbit, not Hofmann.

[Sky Captain]

A space freighter probably would use slow hofmann transfer orbits to get to destination so there is no need for high performance engines. A cheap relatively crude solar thermal rocket could be all that is required to go from Earth orbit to near Earth asteorids (if/when space resource extraction takes off that is most likely where we will begin) or from Earth orbit to Lunar orbit if you are not in a hurry.
Expensive high performance engines likely will be used only on manned craft where living cargo don't want to spend years in transit.

[PeZook]

- The soviets had a moon program, they might even have made it there first, if Apollo 11 had failed. (Though at a rather high chance of killing the soviet astronauts in the process.)

Really?

This is so ridiculous that I don't know what to say. The first test launches of the N-1 rocket occured in January and June 1969, and they both failed miserably. Had Apollo 11 failed, the Russians would still not have a freakin' rocket,and the LK lander was still untested (first unmanned test flight in NOVEMBER 1970). In contrast, all Apollo hardware was fully tested and flight ready, so the only scenario where the Soviets get to the Moon first would possible only if the American public decided to scrap Apollo altogether (for example, if Apollo 11 failed, 12's hardware was taken apart in search of problems, then 12 launched with 13's hardware and blew up in space).

[K. A. Pital]

Since it's a freighter, it can be handled like a SPACE TRAIN!!!!! without much problems. Won't be fucking glorious like riding nuclear fire, but will beat the crap out of Orion anytime performance and cost-wise. Without so mindboggingly dangerous fuel (tiny nukes) in the hands of anyone with a craft.

I understand the danger (hell, it forms a major plot point ). I'm just curious as to the numbers. You can't beat nuclear pulse with liquid or solid fuels, so what sort of a propulsion system will the "space train" use? Any calculations? I couldn't find this shit in "Atomic Rockets", sadly, since they're focusing too much on Grand Sci-Fi and not just Solar system colonization.

Expensive high performance engines likely will be used only on manned craft where living cargo don't want to spend years in transit.

Yeah, I was thinking more about passenger ships than about cargo ships, I guess. Orion could make it to Mars in what, four weeks? That's quite reasonable for a human, instead of the year that it would take with the current projects.

[cosmicalstorm]

I used to think that huge tin cans full of plumbing and life support to make room for sacks of meat using 1 % of their body weight for their actual minds was the definitive future. But these days I do believe the "lol singularity" have a much better version, unless we self destruct before we go there, which is definetly a possibility.

[CaptainChewbacca]

I remember seeing a proposal for an interesting kind of permanent 'mars shuttle'. It would be a large vessel permanently cycling back and forth between Earth and Mars, using fuel just to maintain its' route, and then ships would fly from earth to dock with it, ride it to mars, and then disengage when they arrived at their 'stop'.

Wish I could find that paper.

[Guardsman Bass]

Robotics controlled from Earth will allow humans to engineer and construct massive infrastructure across the entire Solar system without actually having to get out of their comfortable habitats (be it Earth or reasonably massive Orion ships with BIOS-like fully enclosed environments) to build it. And then travel across the system at will if human presence is ever needed here or there.

I agree, and that's actually what I think will happen. Our robots in space (controlled from Earth in Earth orbit, autonomous farther out) will become so good that we'll use them for everything . . . including the potential assembly of space colonies. Humans won't be necessary in space, although you could have humans choosing to live in space if they get the robots to do the work, and if they can afford the costs of getting there.

The other possible way is tourism. If you can get launch costs down far enough, then you could have a company/organization launch a space station where space tourists can hang out for a while. It's not a huge jump from there to having a handful of permanent residents who can afford to get re-supplied from earth, provided the zero-g doesn't kill them.

As for propulsion, I've heard some good arguments for Solar-Electric Propulsion. It's not super-fast, and not so great in the outer solar system, but it would let you move stuff around without some of the political and engineering difficulties of using nukes in space.

- Reusable is great, cheaper, and the future. The problem dragging the shuttle down was a (as it turned out unnecessary) fear of thermal tiles breaking. Other types of heat shielding or less violent re-entries would require much less maintenance.

Less violent re-entry also means you need the fuel to slow-down your spaceship, which in practice means in-orbit re-fueling. Until that's in place, my opinion on re-usables is that I'll believe it's cheaper when I actually see it happen, since we've had a fair number of reusable vehicle projects that came to nothing.

- The era of only robots going BEO is going to end soon, with many a space agency planning big manned missions in the near future.

Who is planning that? The Chinese, who may or may not go back to the Moon? The US, which doesn't have plans to send astronauts beyond LEO until sometime in the 2030s? In the latter's case, even that's vague.

[PeZook]

Actually, studies done by the Soviets on the Vostok capsules indicated they could feasibly be refurbished and reused. They decided against this for safety reasons, but it shows you DON'T actually need any softer re-entry to accomplish reuseability or semi-reuseability for capsules since, you know, the Vostoks didn't even have parachutes.

[Guardsman Bass]

Actually, studies done by the Soviets on the Vostok capsules indicated they could feasibly be refurbished and reused. They decided against this for safety reasons, but it shows you DON'T actually need any softer re-entry to accomplish reuseability or semi-reuseability for capsules since, you know, the Vostoks didn't even have parachutes.

What's the cost of doing that, though? That's my main concern, particularly if you end up having to bring it to a certain safety standard.

[K. A. Pital]

The other possible way is tourism. If you can get launch costs down far enough, then you could have a company/organization launch a space station where space tourists can hang out for a while. It's not a huge jump from there to having a handful of permanent residents who can afford to get re-supplied from earth, provided the zero-g doesn't kill them.

It is a freaking huge jump. Like I said, I'm writing sort of a novel about the early days of an Earth-based spacefaring civilization (yup, the Commune, for those who know), and the amount of scary shit you run into with space colonies is just immense.

1. Zero-g. The humans permanently living off-world will have to exercise all the time, unless they're on Venus. In which case they're probably stuck on a small exploring station at the lower end of a skyhook and the population is pathetic at best, at worst just a pair of guys. Moon and Mars bases (which are the most feasible ones, fairly easy to resupply too) will have to have dedicated teams of specialists ready to train every day, and spend quite a lot on the training.

2. No slackers. The remaining hours will be spent on scientific activities, which is also nothing to scoff at. The prospect of do-nothings off-world is pretty much nil. Only as visitors, and even then: if you can, say, grab an HMD over your head and control a robot rover on Mars or Moon, why on Earth would you even want to get up a rocket and risk dying somewhere in extremely hostile environments? Tourists will also use robots; the people actually present on a world in person will be the ones operating the most critical elements of the robotic infrastructure.

That makes it fair to assume that no "tourist" will ever get much further than Moon and Mars, and even there he's unlikely to turn up in person.

3. Radiation. It never goes away no matter how much you want it to. Hormesis or anything like it is as of yet unproven, so quite probably humans will just experience huge issues when subjected to long-term radiation influence. Shielding is expensive. Mars dwellings will be completely sub-surface. Anything moving on the surface will have to be heavily shielded.

I sort of circumvented it with a 'deepscraper' like that and heavily shielded plastic for the transparent cells at the top:

That would allow a colony with at least a hundred thousand men to exist on Mars, but that will probably be it. Having a satellite constellation around Mars, they'd be able to explore the world and mine hematite and niobium if they so need with nothing but good old robots.

4. Terms of transit. Mars, even with an imagined Orion express, will be almost a month away. Other planets are even further away. Humans need jolly good reasons to spend so much time in transit. And if there are none except exploration, only few explorers shall go.

5. Resupply. That's the Queen Bitch of human sublight colonization, even in the Solar system. Robots on the plains of dead worlds of Enceladus, Titan or wherever else don't need much. If they are really super-valuable, just deliver a party of RITEGs and allow the robots to charge up their batteries, if they are themselves huge enough, outfit them with RITEGs. It doesn't matter. Humans require non-irradiated food and vitamin supplements, water (solvable for Mars and a few ice worlds, but elsewhere no) and oxygen atmosphere.

Even if you build a fully enclosed biosphere that's large enough (see BIOS-3 or the Biosphere-2 dome, for a more extreme example), why'd you ever want to drop them on planets? Makes much more sense to let these enclosed biospheres, with enough radiation shielding, to travel from one planet to the other, drop robots, perhaps landing craft if humans want to come down, then pick it up and carry on. Once you decide for a permanent base instead, you're basically squandering all that enclosed biosphere which probably costs shitloads of manhours and precious materials and advanced knowledge to build (!) on a single point in the Solar system, and on a single point on the planet of choice as well. There's gotta be a very serious reason for doing that.


So I think that spacefaring humans are likely, but humans as "millions of colonists"? Not before we learn to terraform world properly. Before that a dozen or a hundred thousand meaty bodies on Mars is our ceiling.

[Guardsman Bass]

I'm not talking about a full-blown, self-sustaining space colony. I'm thinking a handful of people living more or less permanently on a space station in LEO, since they're rich enough to pay for supplies to be occasionally brought up from Earth (or rich enough to stay up there permanently on what is otherwise just a place where space tourists hang out for a few days). All of which, of course, is dependent on there being enough space tourists so that you can find a few eccentrics who want to stay up there for good (meaning that launch costs are a big question mark).

On other point about the Moon and Mars colonies that you could make is that we have no data on how merely "low" gravity by Earth standards (such as Mars' 0.38 g) affects human beings over the long term. We know how micro-gravity affects people, and obviously how Earth's surface gravity affects them, but nothing on what's in-between. That's a plus for the free-standing space colonies, since you could rotate them to get Earth-standard gravity, allowing people to move between them and Earth.

[K. A. Pital]

Technically we already have that. People who spend lots of time on the ISS between crew rotation launches. If they were "rich nuff" they could probably finance the space agencies' shit and thereby get a "permanent ISS citizen" card simply cause they give so much money. However, they can't. There are some "space home" ideas, but a permanent one is problematic due to long-term microgravity. Nobody's going to build a special space gym with all the necessary equipment for the lone dweller.

Psych and health effects of cramped zero-g environments are known to be bad. I doubt even the most eccentric rich guys would subject themselves to that. Though you can never know.

we have no data on how merely "low" gravity by Earth standards (such as Mars' 0.38 g) affects human beings over the long term

That's only because we haven't been there. But we can make a reasonable guess - that's not gonna be good for your health. Like long-term sitting and laying is not good, and causes muscle atrophy. We already know muscle atrophy will follow without exercise. The question is only "how bad will it be" and "how intensive the exercise regime should be", not whether it will occur. It will.

[Simon_Jester]

I find the premise that it's all going to be about teleoperations and robotics in space depressing- I doubt anyone will have trouble understanding why.

Why? I could understand why one could make a large colony on Mars - the prospects of terraforming are non-zero, after all. I could hardly understand the reason not to send hordes of Earth-controlled semi-autonomous robots to mine lunar regolith and keep human presence on the Moon to a few scientific exploration outposts with minimal crew.

It's not that I'm opposed to doing it, it's that I, personally, am happier with the idea of large scale human settlement. Which I think would seem understandable, even if it isn't necessarily logical.

It's not as if it would be the only logical thing that I find depressing.

As to the specifics- nuclear pulse makes far more sense for liftoff than for interplanetary journeys. It would be a great way to get hundred thousand ton payloads off the surface of the moon, where no one cares about the fallout. It would be a good way to get huge payloads off the Earth if no one cared about fallout. But there are better (if less glamorous) options for a bulk freighter that never needs to land anywhere.

Which, though? As far as I gathered, nuclear pulse is the best realistic shot (feasible with today's science and materials) we have for interstellar travel too (with the exception of SR being flawed and physics discovering the FTL Holy Grail). That says a lot - pulse propulsion must be rather efficient per unit of consumed fuel mass.

Pulse propulsion has the advantage that it requires no fundamentally unsolved engineering problems, except possibly the creation of nuclear shaped charges, which do not now exist.

However, there are other drives that provide higher mass efficiency, and/or which are more versatile (i.e. they scale well, which Orion drives do not).

- The soviets had a moon program, they might even have made it there first, if Apollo 11 had failed. (Though at a rather high chance of killing the soviet astronauts in the process.)...

- I am not even going to comment on "nuclear pulse" AGAIN. This video is an accurate representation of my reaction: http://www.youtube.com/watch?v=9zSHz7Thvbc ...

- Reusable is great, cheaper, and the future. The problem dragging the shuttle down was a (as it turned out unnecessary) fear of thermal tiles breaking. Other types of heat shielding or less violent re-entries would require much less maintenance.

I won't speak to the rest of this, but regarding these three things:

1) The Soviets had designs for 'moon shot' hardware, but none of it was ever close to a manned flight. They might have gambled on a Zond flight in 1968-70, but based on the performance of the unmanned Zond capsule tests, it would have been hellaciously risky. To actually put a man on the moon, as opposed to just circling around it and coming back a la Zond, they would have had to build and develop a lot of stuff that historically, they never got the budget for. It's not that the Soviets couldn't have gone to the Moon, it's that the Soviet government never committed the huge scale of funds and resources it would take to make it happen, so most of the hardware never got beyond the prototype/blueprints phase and the missions were never planned beyond the 'rough sketch' level.

2) I'm not a big fan of nuclear pulse propulsion, since its most obvious application is the same one it will most likely never be used for. No one would let anyone take off from Earth in an Orion-drive ship, and for most other purposes something else would work better anyway.

3) The Shuttle's thermal protection system was mostly a constraint of the era- at the time, the options for making the thing able to survive reentry boiled down to "metallic shield" or "tiles." A metallic heat shield would have been a lot heavier and cut into payload, especially given the big wings the Shuttle got saddled with. The ceramic shield they actually used was lighter but much more fragile.

Today, we might be able to do better- but in the 1970s, the Shuttle as designed and any similar reusable spacecraft of similar design was something of a boondoggle.

- The soviets had a moon program, they might even have made it there first, if Apollo 11 had failed. (Though at a rather high chance of killing the soviet astronauts in the process.)

Really?

This is so ridiculous that I don't know what to say. The first test launches of the N-1 rocket occured in January and June 1969, and they both failed miserably. Had Apollo 11 failed, the Russians would still not have a freakin' rocket,and the LK lander was still untested (first unmanned test flight in NOVEMBER 1970). In contrast, all Apollo hardware was fully tested and flight ready, so the only scenario where the Soviets get to the Moon first would possible only if the American public decided to scrap Apollo altogether (for example, if Apollo 11 failed, 12's hardware was taken apart in search of problems, then 12 launched with 13's hardware and blew up in space).

The most plausible scenario I've read (not saying it's likely, just that it's got the veneer of plausibility that allows suspension of disbelief) was based on a 'narrowly alternate' version in which Apollo 11 is a partial failure (they get to the moon but never come back). Apollo 12 aborts after the lightning strike (as historical), because NASA has gotten twitchy, and 13 is cancelled. The Soviets carry on, and the Soviet landing takes place in April 1972, although their first lunar mission encounters several extremely dangerous points where hardware failures nearly get them all killed.