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Making Humans a Multiplanetary Species [video]

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Re: Making Humans a Multiplanetary Species [video]

#681

Post by nickik »

giarc wrote: post #315

I've never listened/watched the Q/A session from any of his talks, are the questions from the audience usually better?

Yes. Far better. Usually it seems to by mostly journalists.

This is conference everybody can go to, and it seems the people who really wanted to ask questions were not the space nerds.

To compensate he made a Q&A with journalist right after, he answered some great questions that the community was already wildly speculating about, I don't have a very good link, see: https://www.reddit.com/r/spacex/comments/54j2y4/rspacex_offi...

Re: Making Humans a Multiplanetary Species [video]

#682

Post by kijin »

mikeash wrote: post #434
ythl wrote: post #411

Earlier quoted context omitted.

I still think it's many, many orders of magnitude easier to survive on a messed up earth than on a fresh Mars or Venus.

Depends on how messed up it is. Earth ravaged by global warming and pollution? Yeah, still a lot easier than Mars. Earth ravaged by a strike from a gigantic asteroid that sterilizes the crust to a depth of three meters? Mars is probably easier. The chances of the second one are pretty low, but some people think that any chance is too high.

As far as we're aware of, the crust of Mars is even more sterile.

I'm pretty sure humanity currently possesses the knowledge and resources to build multiple underground shelters around the Earth (as seen in Hollywood movies) that can sustain a population of at least one million indefinitely. Food can be grown with artificial lighting. Air and water can be brought in from outside, purified and recycled. If you need anything else, send robots (or people in protective suits) to scavenge the surface. The only thing we lack is political will.

Re: Making Humans a Multiplanetary Species [video]

#683

Post by wyager »

jack9 wrote: post #671
wyager wrote: post #395

Earlier quoted context omitted.

I don't understand the abject lack of imagination, or optimism, or whatever it is, that makes some people believe that mildly complicated engineering challenges are somehow impossible. Do you think no one in SpaceX has thought about this for more than five seconds? Obviously it's not completely trivial to sustain humans on Mars, but there is literally no reason to believe we couldn't accomplish it using current level…

> Keeping humans alive on THE MOON starting from now is vastly easier to comprehend than putting a man on the moon starting from 1950 Fixed. Mars is impossible, for now. We haven't kept someone in space long enough to reach mars nor have we developed a sustainable model that's extraterrestrially tested. Mars has more problems than a moon base, not significantly less (there's a few small pros and cons but being so far…

Nope, I meant what I said. The moon was impossible in 1950. Actually impossible, not just expensive like getting someone to Mars in the very near future. The tech didn't exist.

> We haven't kept someone in space long enough to reach mars nor have we developed a sustainable model that's extraterrestrially tested

SpaceX claims to be able to do it in as little as 90 days. You can go a lot faster with more free fuel. We've kept someone in space for 4 times that.

> Mars has more problems than a moon base, not significantly less

What are you referring to? Mars has available gasses, water, and more easily accessible useful solids than the moon. It will be easier to get radiation shielding on Mars, as the surface is more amenable to building underground structures.

> Except that we have no demonstrable way to do it

You are aware that we have sent probes to Mars, yes? The only difference between that and the human is how much money you're willing to spend to increase the chances of the journey being survivable.

Re: Making Humans a Multiplanetary Species [video]

#684

Post by slededit »

jack9 wrote: post #671
wyager wrote: post #395

Earlier quoted context omitted.

I don't understand the abject lack of imagination, or optimism, or whatever it is, that makes some people believe that mildly complicated engineering challenges are somehow impossible. Do you think no one in SpaceX has thought about this for more than five seconds? Obviously it's not completely trivial to sustain humans on Mars, but there is literally no reason to believe we couldn't accomplish it using current level…

> Keeping humans alive on THE MOON starting from now is vastly easier to comprehend than putting a man on the moon starting from 1950 Fixed. Mars is impossible, for now. We haven't kept someone in space long enough to reach mars nor have we developed a sustainable model that's extraterrestrially tested. Mars has more problems than a moon base, not significantly less (there's a few small pros and cons but being so far…

> We haven't kept someone in space long enough to reach mars

A quick google search says a trip to mars varies between 150-300 days. The longest human spaceflight exceeds that at 438 days aboard the Mir space station [1] from 1994-1995.

1. http://www.space.com/11337-human-spaceflight-records-50th-an...

Re: Making Humans a Multiplanetary Species [video]

#685

Post by Pinckney »

shuntress wrote: post #369
ElComradio wrote: post #311

Earlier quoted context omitted.

In the same way nerds got beat up because the jocks are just jealous of their brains? There can be criticisms of a plan to send a few people to die in a metal box millions of miles away at incredible cost that do not require jealousy as a motivator.

This (almost) as accurately describes the Apollo program. Are you saying we should not have gone to the moon? *There's criticism: "Maybe it would work better with Type A rather than Type B" and there's _criticism_: "Thats stupid and you are stupid for thinking its not stupid"

I'll say it, sure.

Apollo was dangerous, expensive, and didn't accomplish anything that couldn't have been done more safely and cheaply with probes. It was cool as shit too, but I'm not going to pretend that 'cool' is a real basis for public policy.

Mr Musk is welcome to spend his money as he wants, of course.

Re: Making Humans a Multiplanetary Species [video]

#686

Post by nickik »

grkvlt wrote: post #590
codeulike wrote: post #136

The Mars colonial fleet would depart en-masse - about 1000 ships

> As of 17 September 2016, there have been 310 manned spaceflights [...] 8 of which were sub-orbital [1] There have been 302 manned orbital launches according to [1] and from adding up the successful launches in [2] there seem to have been a total of 5057 orbital launches so far, in the 70 or so years of spaceflight. Apparently the Mars fleet needs from 3 to 5 tanker launches per manned craft, so this program will re…

> Assuming one in five are crewed, with 100 crew per vehicle, that means 3000 deaths over the life of the program.

A failure in the rocket does not mean everybody dies. There is a launch abort system for that. Musk has confirmed this after the presentation.

Re: Making Humans a Multiplanetary Species [video]

#687

Post by jotato »

sailingparrot wrote: post #591
jotato wrote: post #475

Any reason why you couldn't put a tanker in geo-sync orbit connected to a very (very) long fuel pipe somewhere on earth? The idea being you can pump fuel up instead of launching it? Kind of like a space elevator for fuel! :)

Probably the same reason we can't build a space elevator :)

In didnt say it would be easy, but neither is sending 100 people to mars.

I'm not engineer, but wouldn't a pipe be easier to build than an elevator?

Re: Making Humans a Multiplanetary Species [video]

#688

Post by mikeash »

bjelkeman-again wrote: post #511
lisper wrote: post #496

Earlier quoted context omitted.

> Some of the comments here make me think of crabs in a pot pulling down the ones who try to climb out. It's fine with me if some of my fellow crabs climb out, but it is very important not to lose sight of the fact (and to his credit, Musk gets this right) that unless all of us climb out (and we won't) then conditions in the pot are still going to matter to those -- almost certainly the vast majority -- who are left…

Yes, but there is more than enough effort/energy/enthusiasm available to do both things. Both things are valuable and we need them both. And we can afford them. What Musk presented costs about as much as an Olympic game.

Probably not even close to that cost. I think he said something like $10 billion to get it up and running. How much did Rio cost? Even if that estimate is way too low, I think it's a lot more money poured into people running around in tight clothing.

Re: Making Humans a Multiplanetary Species [video]

#689

Post by stepanhruda »

bsdetector wrote: post #47

We won't really be an interplanetary species until we can get back from Mars. Imagine being colonists on Mars without the ability to be totally self-sustaining without technology and supplies from Earth and nuclear war breaks out. It's going to be a long time before any Mars colony can survive on its own.

The point of being multiplanetary is if there is an extinction event on Earth, people survive on Mars. You don't need to _immediately_ be able to come back, although you need to be able to move off Mars at some point.

Re: Making Humans a Multiplanetary Species [video]

#690

Post by Pinckney »

deftnerd wrote: post #572
Grishnakh wrote: post #498

Earlier quoted context omitted.

Why not just save a bunch of time and use new boosters? Then reuse those boosters for other missions? Reusing rockets is great for saving money, but that doesn't mean you need to reuse the same rocket for this one mission; if you have a business going with, say, 30 missions over the next year, you're probably going to need a lot more than one booster in stock anyway. Or, instead of new boosters, use a bunch of reused…

I personally think it makes sense for SpaceX to offer to take over Tiangong I, the Chinese space station that's going to be deorbited soon. It's older and not suitable for safe habitation anymore. If SpaceX could use their launch capacity to bring up fuel tanks and to boost the orbit, it could do well as an orbiting fueling station. Just launch tankers and fill up tanks on Tiangong and then the space craft with passe…

What would they use it for?

If you're going to Mars, your vessel has a reasonable crew habitat, so you don't need Tiangong I for that.

Tiangong I is more payload than spaceship. Its tanks can only hold about 1000kg of propellant. Mr. Musk's proposed transfer stage has a propellant budget that's nearly 2,000,000kg.

Having to maintain compatibility with it may be hard (comms, docking, etc). There might be some hardware you could loot off it, but it's not worth flying a mission just for that, and launch windows mean visiting on a trip somewhere else would be prohibitively expensive.

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