Psychological Problems of Interplanetary Travel (1975) | Hacker News Reader

Psychological Problems of Interplanetary Travel (1975)

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57 pointsthe-mitr27 comments

I'm not saying it would be the most pleasant thing in the world, but a 6-month interplanetary trip on Starship (with iPads, unlimited entertainment, a variety of food, video games, and even almost real-time communication with Earth) doesn't seem anywhere near as unpleasant as a 3-month trip on the Mayflower. People seemed to handle that OK though.

Notwithstanding Musk's continuous lying about it, Starship would take nine months to get there, not six.

Once there, of course, after a single trip around the hab can (can hab?), you would start counting days ... sols ... until you could go home. Presuming it would be possible and permitted. If not, sucks to be you. Mars is a frozen wasteland with nothing of enduring interest.

The only export of any value conceivable would be excess Raptor engines taken off of landers, with their bells cut off.

I wonder if they'd have some pseudo-restaurants in the habitation area, to help simulate some sense of normalcy.

If they do, and if you then saw one of your fellow travelers eating an interesting-looking sandwich, and you wanted to find out what it was, you would have the rare perk of walking up and dropping a pun that's been decades in the making:

"Can hab cheeseburger?"

Nine months is the duration of a Hohmann transfer to mars, not necessarily the shortest possible for starship - since starship has ~6900 m/s delta v ( https://twitter.com/elonmusk/status/1151300180148252674 ) and an earth-mars transfer only requires 3900m/s I think 6 months is well within the realm of plausible.

There is no possibility of a lone can blasting out there, whatever the delta-V it could muster.

You need, at least, two cans to swing at ends of a boom so your crew does not arrive unable to walk. You might want something attached at the axis, besides. That thing might do all the boosting, with the cans' Raptors used just to land with. ISRU fantasies notwithstanding, they need to carry enough fuel to blast off again, come time to go home.

The cans get benefit of aerobraking on the way down. The mainframe will need to shed its excess velocity some other way. There's nothing else near enough by to swing around. It will need to have brought along enough fuel to boost home, besides. Maybe it used ion thrusters all the way out, and can use them to creep back to Mars in time to pick up the cans and head home.

An alternative is that there is no mainframe, just the boom, and you re-fold and stow it before arrival. Somebody else would have boosted your cans out there, maybe a pair of Superheavys, so your cans won't have to arrive empty.

I wonder if a Superheavy with no can stacked on could make it to orbit in one stage. Probably you would unship their engines on orbit, and install a couple of vacuum Raptors in their place before sending them careering out of the solar system.

I don’t know the numbers for Starship specifically, but this is a matter of how much fuel you have available to burn, and six months has long been considered reasonable.

For a free-return trajectory (end up back at Earth if you’re not willing or able to conduct a Mars entry burn), the minimum-energy trajectory takes 250 days (8.3 months) and requires 3.34 km/s delta-V. Getting it down to 180 days takes 5.08 km/s, so about 50% more delta-V (and fuel). Getting there faster is possible but starts to run into diminishing returns, especially because it makes aerobraking at Mars more and more difficult, requiring even more fuel for slowing down on arrival.

These numbers are from Robert Zubrin’s “The Case for Mars” (1996) which assumed a six-month transit time would be the norm for human missions.

Fantasies of moving to Mars to escape climate change are stupid—even under the best terraforming projections and the worst climate change projections, Earth will be several orders of magnitude more habitable for centuries at least. But the scientific return from a once-warm-and-wet world is more than enough reason to go. Someone like NASA’s Jessica Watkins, who did her dissertation on Martian geology at Caltech, certainly would not be counting down the sols.

Whaling ships could spend years out in the ocean (although I guess they must have hit ports along the way).

The main problem of Mars is that there's nothing on it. If you have a ship that can get you to Mars, you might as well stay on it: the view is better, you don't have to live like a mole person, and you aren't at the bottom of a giant gravity well. Go checkout some asteriods or something.

I think for an average Martian Joe any type of outdoor recreation would be a rare thing. Rip your suit in this rugged rocky landscape and almost immediately you start to develop serious injuries, pass out and die. And what if you vomit? How do you pee? Cheaply protecting someone from radiation, near-vacuum, and below freezing temperatures while keeping them comfortable is way beyond our current level of tech.

Most likely if we actually built a city of people on Mars, life would be similar to living on an earth city but with low-G and you never go outdoors. We'd replicate typical earth city attractions and add a low-G spin where it was appropriate. Access to nature would be a problem (expensive fake Earth hab dome, dangerous outdoor games, no unfiltered sunlight on your skin, etc.)

Elon's ravings notwithstanding, what makes sense to me is extensive robotic exploration of Mars, perhaps operated by a skeleton crew of people who don't need quite the extensive training and qualifications of an astronaut. With enough exploring, experimenting and digging and we're likely to find something very exciting.

I feel like it doesn't make sense to colonize Mars while we have any unused land on this planet. The worst deserts on this rock still have gravity and oxygen, and they aren't a rocket trip away.

If you'd have to recycle your water and raw materials anyways, why not do it someplace where a dome crack won't kill everybody?

Interesting, I hadn't actually thought of this.

I think we should go to space (in O'Neil cylinders), but I'm going to spend some time thinking about desert wasteland arcologies.

The worst deserts on Earth are still the sovereign territory of other governments, and if you do anything to make them not deserts there'll be a lot of people interested in the environmental impact or planning to come and take/ruin it.

Mars is appealing partly because it'll be a long time before it's crowded enough for any of that to matter.

It makes sense from the point of acquiring the expertise to build and essentially building an outer world haven in case a global catastrophe takes place.

If we stick around on Earth only, eventually something will wipe us out. Asteroids hit roughly every 60 million years (we are already overdue on this one), super-volcanoes can be much more frequent, ie once every million years. There are cosmic events that we have no clue about, ie some hypermassive gamma ray burst cone sterilizing Earth (and probably rest of solar system, but most probably not hitting nearby stars). Or we will just fuckup environment so much we will make it completely unlivable for higher life, ie runaway greenhouse effect.

Even if mankind is quite resilient, our current society is super fragile to much smaller catastrophe, and we may actually loose the ability for inter-planetary travel easily.

We really need to diversify our location. That's not the goal of this century, and probably not even the next one, but to have some skeleton seed of civilization elsewhere than here is a logical must, and Mars is easiest and closest one. So better start doing some baby steps towards that direction immediately when we can, rather than pour trillions into more than useless warfare.

I used to think we should fix issues here on Earth before moving elsewhere, but the problem is, we won't. Its dangerously naive idea. Rather we should accept that mankind is flawed and accept and work with flaws, compared to wait for some utopia to happen here and then expand.

Just to note, despite the media hyperbole they get, a stray gamma ray burst directly bathing our earth would probably not do anything close to what you described. Probably worst case scenario: total ozone layer depletion. Bad, very bad for the food chain and for a large part of photosynthesis, but not cataclysmic in the sense of being a sterilizing event.

https://www.cambridge.org/core/journals/international-journa...

I may still cause human extinction, even if life as a whole survives

Extinction, no. Gamma ray bursts last for anything from a few seconds to a couple minutes or so. This means that it would only saturate one side of the world with its own direct ionizing radiation. This would severely harm or kill most plants on that side along with many other thin-skinned organisms, but it wouldn't outright kill larger animals and large plants and it wouldn't directly do anything to lifeforms on the opposite side of the planet.

The ozone layer would then of course shrink worldwide, yes, and this would collapse a large part of photosynthesis, causing a probable food chain collapse, but we're impressively adaptable and at the very least, millions of human beings would stay alive sustaining themselves with food grown or raised under adaptive conditions. The rest of nature would also adapt based on what survives, as it always has with previous cataclysms. This would probably help us too.

In other words, humanity would suffer terribly and billions would probably die, especially since this kind of event would be so sudden and unstoppable, but we wouldn't all die and the many survivors would repopulate as the ozone layer regrows too (which would happen over a few decades since it regenerates itself from solar radiation). But yes, bad. There is a theory that a gamma ray burst caused the Permian-Triassic event, the Great Dying, and 95% of life on Earth was extinguished during that time, though much of it was much less adapted to unexpected radiation than many lifeforms on Earth are now, so things could be less severe next time.

> unused land

In reality, there is no 'unused' land on Earth, because we share the planet with other living beings. Earth has a biosphere that is already severely degraded by humanity's destruction of natural habitats

Hmm. I’ve mused about this before. Right now my thought is this: the Earth is like our home. Sounds, smells, gravity, light, and proximity to other living things is all familiar to our bodies.

Put a human in the alien landscape of space (not to mention far away planets) and you may discover new (maddening) sensations. Like being heavily dosed on a narcotic cocktail. Disorientation. Detachment.

Oh wait. That’s Burning Man. Haha

We have had people spend more time in space stations than it would take to go on a trip to mars. The biggest problem is that space radiation and hazardous dust are far more dangerous than psychology.

This was depicted in "Hi, Bob" (FAM) [1]. And perhaps "Bring it Down" [2] too, somewhat.

[1] https://nerdsthatgeek.com/television/for-all-mankind-recap-h...

[2] https://nerdsthatgeek.com/television/for-all-mankind-recap-b...

This is a deep topic that depends on how future spaceships are designed. That in turn depends on technology.

For example, if propulsion and fuel are cheap (eg fusion) you may accelerate constantly, flip around and then decelerate constantly. Do this at 1G and you will avoid problems of prolonged zero-G. If fuel is a significant part of your mass (as it is with all current rockets) then doing that will be prohibitively expensive if not impossible. That means either zero-G or spin gravity. Spin gravity necessitates a certain minimum diameter. The travel time will be much longer so you then have different psychology to deal with.

The size of the engine in each case may dictate a certain ship size. This entails different dynamics based on group size.

If you need spin gravity, you put a pair of cans at the ends of a cable. Or truss if you are being extravagant.

Boosting at 1G the whole way would take a hell of a lot of fuel just for reaction mass, even with fusion. Producing enough 3He to do that with a crewed spacecraft would take a long, long time. Typically, you have to make 3H, tritium, and wait for that to decay at a half-life of 12 years.

The old two spinning cans on a cable idea. When you drill into it you find that the stabilisation required for the cable is much heavier and more complex then a long rigid pole.

Extravagant truss it is, then.

That is, presuming stabilization is needed. Is this about keeping your solar panels pointed at the sun?

If we could travel to Mars continuously thrusting at 1g the entire way, we would basically have solved most of our major problems. That would get us to Mars in days, would allow asteroid mining, would allow colonies all over the solar system with frequent restocking of supplies, O'Neil colonies, and so on. It'd be The Expanse.

Unfortunately, cheap and continuous thrust like that doesn't look like it'll be available anytime soon. It would be a total gamechanger, though.

The pandemic provided a perfect filtering mechanism for those who thrive in isolation.

I love this and I want a physical copy.

This is no great revelation but if anyones into this sort of scenario and hasn't come across it you gotta get elbow deep in the Remembrance of Earths Past trilogy.

https://en.m.wikipedia.org/wiki/Remembrance_of_Earth's_Past

Once you get a few hundred pages in it explores the social / cultural horrors of interplanetary / interstellar/ multigenerational space travel time in the juiciest possible way. So juicy...

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