SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year • Hacker News Board

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#501

Post by Mithaldu » Wed, Mar 01, 2017, 11:43 AM UTC

mikestew wrote: post #205

Mithaldu wrote: post #183

Earlier quoted context omitted.

I'm happy to be corrected if you know more.

You're the one that made the claim, it not up to the rest of us to post links refuting it.

Yes, i made the claim, however i don't stand by it. I was challenged, realized my knowledge may not be up to snuff and asked that someone more knowledgable than me be nice enough to share, and i meant that earnestly. I'm not interested in winning contests, i just want to have good knowledge.

clock_tower did so here, very excellently: https://news.ycombinator.com/item?id=13749603

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#502

Post by andygates » Wed, Mar 01, 2017, 12:22 PM UTC

misnome wrote: post #297

Gravityloss wrote: post #233

I find this schedule very very unlikely. No humans have flown in the Dragon at all yet. Also none on any of SpaceX:s rockets. There have been lots of launch and pad failures. I'm cheering for SpaceX for doing more towards spacefaring, but I'm very skeptical and think this will, at least, end up being negative PR to them, and, at worst, a lot more.

I'm glad to see somebody questioning the timescale. There is definitely a huge blind spot around Musk around here.

"We'll do amazing things tomorrow!" and "We'll do amazing things the day after tomorrow!" are still amazing things; Musk timelines just come pre-Hofstadter'd.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

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Post by JshWright » Wed, Mar 01, 2017, 1:31 PM UTC

nojvek wrote: post #376

Retric wrote: post #331

Earlier quoted context omitted.

Sorry, butchered that. I was trying to say the figures are less exact depending on how hard you want to hit the earths upper atmosphere. ~8.2km/s if you want to end up in earth LEO ~8km/s if you want to get back to the earth. You can also save a little if your sending an unmanned craft and don't care how long it takes or skip low moon orbit.

I wonder if spaceX is going to send a permanent colony of bots on moon to make a base there. The latency is a lot lower than Mars and would make a good start. Sending a couple of humans around moon for tourism is a waste of resources.

The Moon is a terrible "start" for Mars. They are very different places, and require solving very different problems. In many ways, Mars is a lot easier (the atmosphere can do a lot of the work of slowing you down, you have the raw materials to make methane (the rocket fuel SpaceX will be using), etc).

People tend to think of the Moon as a "staging point" on the way to Mars, but in reality, it would be a significant detour.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

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Post by Retric » Wed, Mar 01, 2017, 1:55 PM UTC

bdamm wrote: post #495

gozur88 wrote: post #483

Earlier quoted context omitted.

There was never any reason to spend that kind of money. It was worth going to the moon once to see what was there, but I have yet to see anybody articulate a reason to go back that doesn't rely on soaring rhetoric and implausible money-making schemes.

Rare-earth mineral security?

Rare-earth means low concentrations. There is still a lot of this stuff in the darts crust an it's not destroyed with use.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

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Post by Symmetry » Wed, Mar 01, 2017, 3:14 PM UTC

palunon wrote: post #497

Symmetry wrote: post #449

Earlier quoted context omitted.

No. The Moon is in orbit around the Earth and both the Earth and Mars are in orbit around the sun. The Moon varies between 360,000 and 400,000 km away and the closest Mars gets to us is 54,600,000 kilometers. Those numbers are a bit of an exaggeration because how much fuel you need is just as important as absolute distance/time to travel and for that you need 4 km/s of delta-v to get from Earth orbit to Moon orbit an…

I meant that the Earth is closer to Mars than the Moon is, not that Mars is closer to Earth than the Moon is (of course it isn't, that would make for a big, big blood moon)

Oh, in that case then the relevant metric is probably delta-v in which case the Moon is always a lot closer to Mars than th Earth is. See here:

http://i.imgur.com/SqdzxzF.png

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

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Post by logfromblammo » Wed, Mar 01, 2017, 3:44 PM UTC

sandworm101 wrote: post #493

logfromblammo wrote: post #474

Earlier quoted context omitted.

There is the possibility that the wealth of an individual was acquired through voluntary trade. In that case, the person has already done so much good for other people that asking them for philanthropy instead of self-indulgence is renegotiating a deal that has already closed. In contrast, most governments have acquired massive wealth through taxation of their subjects. Those subjects are less likely to tolerate the…

Nobody can make billions through work. There are no billion-dollar medical doctors or even lawyers. Billions can only come through passive income, through owning shares of a growing company rather than hard graft.

I consider working in a leadership role, for a company you have a significant share of ownership in, to be active income.

There are billion-dollar founder-managers. There are billion-dollar investor-board members. People like Carl Icahn blur a bit of the line between passive and active income, but changing the direction of a company via votes and proxies is work, too. Even managing a hedge fund involves some work, as it involves calculating alpha, beta, and correlation rather than direct management of one company, but that's applying a lot of information-leverage to a little bit of work, and I consider that to be mostly passive income. The work itself is worth maybe $100k to $500k/year for the financial analysis, and any excess is passively gathered as dividends from the portfolio companies and as fees from the fund's investors.

It isn't a binary "good rich" and "bad rich". There is a continuous spectrum from not a dime that wasn't earned to not a dime that was. The tech company tycoons fall mostly on one end of that, and the Saudi princes fall mostly on the other.

I think that as a gross generalization, those who have had to earn some of their wealth have a greater right to spend what they have as they please, without consideration for societal expectations. There's no noblesse oblige for the person who does not passively benefit from the collection of the taxes.

But if you're a wealthy monarch, or a trust fund baby, you had damned well better think of the children before you try to go to space.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#507

Post by euyyn » Wed, Mar 01, 2017, 5:08 PM UTC

jessaustin wrote: post #492

euyyn wrote: post #196

Earlier quoted context omitted.

If something bad happens, you don't want to say "oh well, guess I should have sent an expert with them after all."

Why do we expect that an "expert" could do anything for an automated craft? Will there be soldering involved? Changing batteries? Rather than allowing for such things, just build more redundancy. Unlike Apollo, this program will have access to powerful computers and other electronic components. Where would one find an expert in lunar circumnavigation?

Planes can take off, fly, and land themselves. Do you expect that a pilot can do anything for it? They don't solder anything, nor change batteries.

> Where would one find an expert in lunar circumnavigation?

The branch of astronautics that deals with navigation in space is called Astrodynamics. It is taught at universities across the world. You can find experts among the astronauts of the various space agencies. Or you can train your own, the same way those agencies do.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

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Post by gozur88 » Wed, Mar 01, 2017, 6:13 PM UTC

bdamm wrote: post #496

gozur88 wrote: post #485

Earlier quoted context omitted.

The military is something like 20% of the budget. That's not where most of your money is going.

You're including social security and medicare/aid, which is not entirely money that can be easily diverted. Especially social security. Without those, defense is the lion's share of the budget, and with Trump's new proposal, even more so.

Sure... if you wall off most of the budget and then look at the rest, defense is the lion's share.

But that makes no sense.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

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Post by gozur88 » Wed, Mar 01, 2017, 6:17 PM UTC

bdamm wrote: post #495

gozur88 wrote: post #483

Earlier quoted context omitted.

There was never any reason to spend that kind of money. It was worth going to the moon once to see what was there, but I have yet to see anybody articulate a reason to go back that doesn't rely on soaring rhetoric and implausible money-making schemes.

Rare-earth mineral security?

Rare-earth minerals aren't actually rare. The name comes from the relatively low concentrations in which you find them naturally. But we won't run out; they're just more expensive to refine as we tap lower concentration sources. Even poor sources are going to yeild minerals at a cost that's a few orders of magnitude less than a what you'd get on the moon.

Re: SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

#510

Post by effie » Thu, Mar 02, 2017, 12:49 AM UTC

gozur88 wrote: post #484

whyenot wrote: post #308

Earlier quoted context omitted.

Why is it so important to send people on these missions outside of some 21st century version of manifest destiny? NASA could do so much more with its limited funding if it just cut out all the humans.

Carl Sagan used to make that point. From a science perspective, you get a much, much better bang for your buck sending robots. But as Larry Niven pointed out to Sagan, every time you convince someone that manned space doesn't make sense you convince them there's no reason to go into space at all. Yes, NASA could do a lot more with its budget if it didn't do manned space, but if it didn't do manned space NASA might no…

  > every time you convince someone that manned space doesn't make sense you convince them there's no reason to go into space at all

That's just well-sounding nonsense. People can appreciate science and exploration even if it does not involve video of humans in outer space. Video or photos of celestial objects are enough reason for the laic public and there are many physical measurements that should be done to advance our knowledge. All this can be done very well and cheaper without humans onboard.