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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

#31

Post by dahfizz »

0_____0 wrote: post #10
ericmay wrote: post #3

Earlier quoted context omitted.

Mars has water and more “acceptable” temperatures, I believe. This doesn’t have to be a mutually exclusive endeavor. We can put a base on Luna and colonize Mars. Maybe the Moon is the stepping stone to Mars?

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?

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

#32

Post by jmyeet »

mchusma wrote: post #27
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…

I also think Dyson swarms are the future. But I think the Mars effort is helpful towards getting there. Elon's public motivation for Mars is basically a human backup plan. And for that, it probably may be the best shot of the next 100 years. It seems like a million people living and working on Mars is more likely to survive a worst case scenario that a million people in rotating space habitats.

But how is the Moon not a sufficicent backup plan?

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

#33

Post by ben_w »

gambiting wrote: post #22
ben_w wrote: post #17

Earlier quoted context omitted.

Plausible, but I remember when I did my degree, one of the examples given about the importance of choosing a good site for “off site backups” was a company whose main site was one of the WTO twin towers, whose off site was the the other tower on the grounds that they couldn’t conceive of anything that would affect both without also destroying civilisation as a whole.

Well sure, but that's always a question of what are you trying to defend yourself against(what kind of scenario is the backup helping with). Twin towers are probably good enough for any kind of fire/electrical failure/theft/vandalism, but not for a meteor strike, war or as we've seen - terrorism. It's not that people in your example were stupid and didn't see it - just that most likely they didn't consider those dang…

> don't start with Mars first

On that part we definitely both agree :)

Although, I would say that developing the tech to colonise Mars can be a useful rallying point for tech useful to Earth (if you can put a city of a million on the red planet, you can also put it in the middle of the Himalayas or Antarctica or the Sahara), in the same way that Tesla is useful as a rallying point for electric cars despite all the people I hear complaining about the build quality.

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

#34

Post by finnh »

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.

What's the ultimate, then?

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

#35

Post by gambiting »

rthomas6 wrote: post #28
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.

I can think of some things that would require them to stay there, unable to surface, for thousands of years. Having the ability to mine asteroids and create additional colonies and space stations seems better to me.

....just mine around your base? Create tunnels that span the entire planet if you must? How is all of this not easier than something as exotic as asteroid mining?

Even if the entire surface is irradiated(somehow) you can still launch things into space with underground railguns. It's not what we currently use, but it's easier to imagine this than building a base on Mars with current(or near future) technology.

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

#36

Post by mrfusion »

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…

No post body was provided.

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

#38

Post by jeffreygoesto »

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.

With a "humanity" like this, maybe a bad idea... Maybe fix some of the bugs first with that money? Mars does not run away, you know...

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

#39

Post by ceejayoz »

revicon wrote: post #18
bbojan wrote: post #5

Earlier quoted context omitted.

The Moon has very little hydrogen, carbon and nitrogen, which Mars has in abundance. These are very important elements both for biology and chemistry. E.g. if you want to have a self-sufficient colony outside Earth, you could do it on Mars but not on the Moon. Mars could be terraformed (in theory); the Moon never could.

With no magnetosphere would there even be a point to terraforming?

Terraforming is an engineering project on such a scale it's probably reasonable to assume advancements like radiation resistance/repair in humans and artificial magnetic fields. For example, this apparently feasible (but currently batshit crazy) proposal: https://www.universetoday.com/153368/an-absolutely-bonkers-p...

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

#40

Post by politician »

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?

The ISRU profiles of both bodies are significantly different and Mars has much higher gravity.

The Moon is, first and foremost, a weapons platform, and any every competent military sees it as such. There will never be a functioning colony on the Moon until the Earth is unified under a single government.

Mars is far enough away that colonization is possible, and the technology needs are so dramatic that we’ll have to develop a comprehensive deployment plan to bootstrap self-sufficiency from the start. Despite 150 years of industrialization on Earth, we still lack an experimentally tested plan to reboot.

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