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Design of a rapid transit to Mars mission using laser-thermal propulsion

arxiv.org

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Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#41

Post by ericmay »

jmyeet wrote: post #23
kilroy123 wrote: post #20

Earlier quoted context omitted.

I strongly disagree and I dare say this is an incredibly short sighted view. Pushing forward to living on Mars will unlock tons of technological and scientific advances that will only help us better live here on Earth, and Mars. The mother of invention will always been necessity. We simply don't need a lot of the tech that will be created, until we try to live off-world. So much technology and scientific know-how, ca…

Let's accept this premise (which amounts to essentially "we don't know what we don't know") and I'll ask a natural follow up question: what is the difference between colonizing the Moon and colonizing Mars in terms of problems we'd need to solve and thus technology we'd likely gain?

I think it really comes down to the distance. Mars is much further away. I believe the shortest one-way trip is 9 months (or maybe it's 2 years?) which means the colony/outpost must be 100% self-sustaining for at least that period of time. It will also require new technologies to make sure that humans can make the trip (sane and healthy) and that engineer products to last for that trip. Also, communication. We'll have to invent different communication procedures and technologies to support a colony on Mars. I think it'll also lead to new propulsion methods because eventually humans will want to make that trip go much faster. Of course the same can be said for the moon, but if the trip currently takes a few days you can only do it so much faster compared to how much more quickly you might be able to shorten a trip to Mars.

To summarize, many of the problems are similar but at much greater scales. I mean, hell we actually put people on the moon. No human has set foot on Mars.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#42

Post by bayesian_horse »

ben_w wrote: post #11
0_____0 wrote: post #10

Earlier quoted context omitted.

This doesn't answer the question of why you'd want to put people on Mars in the first place.

Disaster recovery, the penultimate in off-site backups of humanity itself.

We're better off riding it out in a bunker or something on earth. It's easier to build something self sustaining on earth that can survive anything, than build the same thing anywhere else.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#43

Post by atonalfreerider »

jmyeet wrote: post #2

Sure let's continue unmanned exploration of Mars but manned exploration let alone colonization makes absolutely zero sense. mars is nothing more than a further, more annoying version of the Moon. Similar gravity, less sunlight (ie further from the Sun), communication latency (~10 minutes vs 1.5 seconds), no magnetosphere (just like the Moon so you'll probably need to live underground) and just enough atmosphere to pr…

There is a future where some scarcely few people set foot on Mars and survive with a fleet of robots. The rest of us can experience Mars through virtually reality. I think this is a likely outcome.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#44

Post by ben_w »

jmyeet wrote: post #23
kilroy123 wrote: post #20

Earlier quoted context omitted.

I strongly disagree and I dare say this is an incredibly short sighted view. Pushing forward to living on Mars will unlock tons of technological and scientific advances that will only help us better live here on Earth, and Mars. The mother of invention will always been necessity. We simply don't need a lot of the tech that will be created, until we try to live off-world. So much technology and scientific know-how, ca…

Let's accept this premise (which amounts to essentially "we don't know what we don't know") and I'll ask a natural follow up question: what is the difference between colonizing the Moon and colonizing Mars in terms of problems we'd need to solve and thus technology we'd likely gain?

My guess (and possibly hope) is cheap industrial scale deployments of Sabatier carbon capture.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#45

Post by bayesian_horse »

jmyeet wrote: post #2

Sure let's continue unmanned exploration of Mars but manned exploration let alone colonization makes absolutely zero sense. mars is nothing more than a further, more annoying version of the Moon. Similar gravity, less sunlight (ie further from the Sun), communication latency (~10 minutes vs 1.5 seconds), no magnetosphere (just like the Moon so you'll probably need to live underground) and just enough atmosphere to pr…

Gravity is higher, which is important for Humans. Also the resources are more diverse. And you can study Mars better from the surface of Mars than from the surface of the Moon (duh...).

I'm not a massive fan of Mars colonization. But I do get the appeal of getting manned missions there. Some science really can't be done as well or cheaply by robots alone. Though even with Humans on board, much of the work will be done by robots anyway.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#46

Post by ben_w »

0_____0 wrote: post #12
slothtrop wrote: post #9

Earlier quoted context omitted.

If terraforming is in the cards, stands to reason it would be first tried in our own backyard. Mars is the best contender for it. Actually it might be useful in other respects than being livable. The vision is far less romantic if you consider it a distant future project.

At least Venus has a magnetosphere. How are you going to terraform a planet that can't retain more than 6.5 millibars worth of atmosphere? Build a big-ass bubble around the planet to deflect solar wind? Nuke the core of the planet to re-melt it and get a magnetic field back?

Nuking the core is neither sufficient nor necessary for the magnetosphere. Not sufficient because all of the nukes together are orders of magnitude too little to melt it, not necessary because a spinning ball of liquid metal is a really inefficient way to make a magnet.

IIRC one of the plans for an artificial magnetosphere for Mars only needed a 1 GW supply to the magnetic coil.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#47

Post by gambiting »

dahfizz wrote: post #31
0_____0 wrote: post #10

Earlier quoted context omitted.

This doesn't answer the question of why you'd want to put people on Mars in the first place.

Why did Homo Erectus leave Africa? Why did early humans cross the land bring into the Americas? What could have possibly possessed the aborigines to cross the ocean to Australia? Because its cool. Because its interesting. Because it is baked into our monkey brains to want to explore. If people want to push the frontier, why are you such a grump about it?

I'm positively certain that in all of your examples people have pushed into new areas because of food, to find new land to live on, to find riches, to find the promised land or other mythological reasons. Somehow I don't imagine aborigines crossing the ocean because "it's cool".

You know what we're going to find on Mars? Rocks. A whole lot of radiation. No breathable atmosphere and freezing temperatures.

Imagine the most hellish place on Earth - that's still better for humans than the most pleasant place on Mars.

Would it be "cool" to stand on Mars? To stand on another planet? Of course it would. And I firmly believe that we should continue our planetary explanation - but making plans for human habitation on Mars when we haven't even been back to the Moon in 50+ years is literally just stupid. Put a base there, learn how to make it self sufficient and then let's talk about Mars.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#48

Post by maxerickson »

gambiting wrote: post #47
dahfizz wrote: post #31

Earlier quoted context omitted.

Why did Homo Erectus leave Africa? Why did early humans cross the land bring into the Americas? What could have possibly possessed the aborigines to cross the ocean to Australia? Because its cool. Because its interesting. Because it is baked into our monkey brains to want to explore. If people want to push the frontier, why are you such a grump about it?

I'm positively certain that in all of your examples people have pushed into new areas because of food, to find new land to live on, to find riches, to find the promised land or other mythological reasons. Somehow I don't imagine aborigines crossing the ocean because "it's cool". You know what we're going to find on Mars? Rocks. A whole lot of radiation. No breathable atmosphere and freezing temperatures. Imagine the…

Like if you could build something awesome on Mars it would pretty much universally be easier to build it in North Dakota.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#49

Post by gambiting »

ericmay wrote: post #29
0_____0 wrote: post #10

Earlier quoted context omitted.

This doesn't answer the question of why you'd want to put people on Mars in the first place.

Why do anything?

This is a very flippant comment, but I will try to respond anyway - we simply haven't achieved a post scarcity society yet. Maybe we will at some point, but we just aren't there yet. So right now our time, money and natural resources are quite simply limited. So maybe it's not that we shouldn't have a base on Mars - it's just that maybe that shouldn't be the first step in human habitation in space.

Re: Design of a rapid transit to Mars mission using laser-thermal propulsion

#50

Post by gambiting »

merpnderp wrote: post #24
gambiting wrote: post #14

Earlier quoted context omitted.

If that really is your goal then build a colony at the bottom of the ocean or deep under ground here on Earth - at sufficient depth there is literally nothing that could endanger such colony, it's functionally equivalent to being on mars without the idiotic travel cost.

Except 8 billion starving desperate people trying to get it. For instance if people were starving or hiding from fallout, those doomsday shelters the rich are building for themselves would likely be overran by the locals who helped build them or heard all about them from town gossip.

How are those 8 billion starving people getting into a base 10km below the surface of the ocean which requires a specialized submarine to get to? How is this any more realistic than 8 billion starving people getting to Mars?

And finally - I hope you aren't suggesting that the base on Mars is a way to escape "8 billion starving people".

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