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Comment by TeMPOraL | Hacker News Reader

And "just" 24 years over radio if there's anyone there to talk with ;).

I doubt I'm alone in this, but I do find it simultaneously amusing and depressing how mind bogglingly big the universe (or even the galaxy) is. It's clear that discovering entirely new levels of physics will be necessary to stand a chance of going anywhere.

I've read that most of Lovecraft's is derived from the horror at realizing how insanely large in both space and time the universe is.

The unspeakable horrors and mind defying deities in his oeuvre are effectively just reiteration of the "the human race is an irrelevant blip on the universe's radar" concept.

Well that just cries out for a quote :)

"We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far. The sciences, each straining in its own direction, have hitherto harmed us little; but some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the deadly light into the peace and safety of a new dark age." - H.P. Lovecraft "The Call of Cthulhu"

beautiful, thank you!

You're not alone.

I grew up reading and watching a lot of sci-fi. Today I recognize that most of it was garbage in terms of physics, but I'm still saddened that the universe isn't that easy - we can't just hop on a space cruise ship and do a tour of a nearby nebula...

Going to Mars may be routine some day, though!

Just going to Mars will significantly increase your risk of cancer, unless we find smart ways to repair our genetic material as we go.

Well, for the journey itself the problem has a simple solution - more shielding. Then of course we have to answer the question of how can we get ships into orbit when they are full of shielding, but that's not insurmountable.

The bigger issue is actually living on mars - as romantic as that idea is, human habitation on the surface is really dumb, the radiation level is not insignificant, so anything long term would either have to be shielded or be under ground. And if we are going to build an underground colony....then why not start with one here on Earth?

Then of course we have to answer the question of how can we get ships into orbit when they are full of shielding, but that's not insurmountable.

If regular travel becomes a reality, you wouldn't shield the launch vehicle, but the cycler[1].

[1] https://en.wikipedia.org/wiki/Mars_cycler

The benefit of using a cycler rather than a ship that travels orbit-to-orbit is that there is no need to accelerate/decelerate the mass of the ship, just the perishables (people and provisions for the voyage)

You would accelerate a small vessel (like a crew dragon or orion), intercept and dock with the much larger cycler, then enter the ship for your x-month trip.

When you near mars, you get back into your dragon, and burn away from the cycler, entering into martian approach.

7 people in a Crew Dragon for 18-24 months would not be pleasant. 7 people in a flying space hotel would be far nicer.

You could presumably look at using a small asteroid to provide the bulk of the "cycler", offering plenty of shielding for the trip, you'd only have to get it into position once - far less fuel requirement.

My understanding though is Musk is planning on using BFR to go surface-to-surface, with maybe a refuel in earth orbit. I believe this is because of the amount of material that needs transporting to Mars for the first 20 years or so, and that mass can be used as useful shielding. Even if Mars becomes self sustaining and doesn't require a large amount of cargo:people ratio, I believe Musk is aiming for a much shorter transit time than 2 years.

> You could presumably look at using a small asteroid to provide the bulk of the "cycler", offering plenty of shielding for the trip, you'd only have to get it into position once - far less fuel requirement.

Or maybe even something like, as some have suggested (not me!), Phobos:

http://enterprisemission.com/Phobos.html

Warning: it's kind of out there. At the very least, it's perhaps interesting as speculative sci-fi.

Grand theft moon? That's as crazy as Space 1999.

Not as crazy as claiming Phobos is an alien spaceship though, with highly places ESA sources due to announce it soon (article date 2010)

> And if we are going to build an underground colony....then why not start with one here on Earth?

Because if an asteroid hits Earth or if the world superpowers decide to go full nuclear, the underground colony in Mars will survive (unless superpowers decide to nuke that from here as well...)

I'd argue that a colony at the bottom of our own ocean would survive literally any event of any magnitude, maybe except for a direct asteroid strike. In terms of survivability of the human race, that's a better project to start with - and of course then move on to other planets, but underwater/underground colonies would give us lots of insights into living in such environments permanently.

The pressure range range between vacuum, mars atmosphere and earth atmosphere is 10⁵Pa. The pressure at the bottom of the ocean is 10⁸Pa. Humans can survive the former with little more than strong tensile garment and a breathing apparatus, the latter requires massive, crumple-resistant pressure vessels around everything.

Finally someone with the sense to realize what difference an order of magnitude can make to a decision. Now lets compute how likely we are to die by an asteroid vs how likely we are to die being stranded on a barren, frozen rock 60M Km away from the nearest source of critical supplies.

That depends on your time horizon. Probabilities of catastrophic events tend towards 1.0 individually. But within the same time horizon you can keep it close to 0 with sufficient redundancy and recovery.

So the tradeoff would be risking a finite amount of human lives in the short term to reduce the risk of a total loss in the long term. I.e. over time it becomes fixed vs. fractional cost.

Fair point, but then we forgo learning how to build a rocket to leave this rock should there ever be a need.

Just....do both? Have a proper, city-size, self-sustaining colony on the bottom of the ocean, and at the same time keep developing rockets and vehicles to bring as much material and and many robots over to Mars as physically possible. Like, I don't think getting to Mars is an issue - we probably could send and even land someone on Mars within a couple years if we absolutely had to. But then the question is - what then? That's the hard problem.

The good thing is that Mars is chock full of dormant lava tubes[1]. That provides a solution to the problem you propose assuming we figure out how to seal them and make them habitable for human life. It is an exceptionally difficult, but tractable problem. FTL travel however, is not tractable at all with our current tech and (lack of) understanding of physics.

[1] https://en.wikipedia.org/wiki/Martian_lava_tube

Count your blessings. The vast separation between stars means that star systems can have stable planetary orbits for billions of years, which is important for life to develop.

Or extreme life extension, or fully digital AI. Life span is a big part of the problem.

Personally I doubt that meat will go to the stars. Planets, sure, and maybe bases or settlements. The stars take too long.

Or entirely new levels of lifespan. Just upload yourself to the grid and boot up in a few million years.

you are not alone

To me this sounds feasible.

We already organize space missions over the 20 year mark. Communicating effectively with another civilization could be taken just as seriously and done in an organized and effective manner.

It would take a while to get going but once the sharing starts it would be immensely productive.

Why 24 years? Radio travels at the speed of light, not half the speed of light, right?

Any response would take 12 years as well.

Roundtrip time.

HAHA! Thanks, sometimes I need a kick in the rear. I was thinking one way.

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