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SpaceX successfully launches two humans into orbit

nasa.gov

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Re: SpaceX successfully launches two humans into orbit

#821

Post by Kim_Bruning »

xjlin0 wrote: post #528
Rebelgecko wrote: post #363

Earlier quoted context omitted.

I don't know much about the intricacies of asteroid mining, but human beings are very capable entities. As great as machines like the Mars rovers are, there's no comparison. A human astronaut could probably accomplish as much in a week as a Mars rover can in a year. When I was reading the daily diaries of one of the rover drivers, it was incredible how much effort and thought went into the most trivial activities. A…

Once the job finished, the machine is dispensable, but the astronaut definitely wanna go home, which will cost much much more.

This is actually not so bad. Returning to earth is (relatively) cheap. Returning to earth from the moon is really cheap, so the extra fuel mass is affordable. From Mars you probably want to scavenge it.

https://en.wikipedia.org/wiki/In_situ_resource_utilization

https://www.reddit.com/r/space/comments/29cxi6/i_made_a_delt...

Re: SpaceX successfully launches two humans into orbit

#822

Post by Kim_Bruning »

giantrobot wrote: post #687
yellowapple wrote: post #663

Earlier quoted context omitted.

> I just don't see any commercial reason to launch people into space Asteroid mining comes to mind. And sure, we can do that with robots, but it's incredibly convenient to have actual sapient personnel in close proximity to coordinate things, perform repairs, etc. And Ceres is a reasonable choice for such a colony (more so than Mars, IMO, though I know plenty of people might disagree), given the low escape velocity a…

Asteroid mining is pointless for Earth-based industry. There's more of everything on Earth and it's orders of magnitude closer to processing and manufacturing infrastructure. The ISS in Earth orbit cost billions of dollars and was only possible because the Space Shuttle was an awesome utility vehicle that could act as an orbital work platform. Putting even trivial ore processing and refining infrastructure in a place…

I would like to take issue with your claim that it's closer to processing and manufacturing infrastructure. If expressed in km that is correct. It gets really interesting once you express it in Delta V.

It gets more interesting yet when you take into account things like linear accelerators which can launch things for pennies. They're not practical on earth, but somewhat practical on the moon. They might also be usable enough for asteroids.

I agree that the initial investment in the first space or moon settlement would be very, very expensive. On the other hand, once it is established it would be self sustaining, and even potentially competitive with earth.

Early on it could maintain itself by launching satellites to GEO and LEO. This is already a viable industry today.

It would also be much MUCH cheaper to source construction materials for further settlements from asteroids (or the moon, at a pinch)

https://www.reddit.com/r/space/comments/29cxi6/i_made_a_delt...

Re: SpaceX successfully launches two humans into orbit

#823

Post by m4rtink »

giantrobot wrote: post #750
QuesnayJr wrote: post #711

Earlier quoted context omitted.

I wonder if how hard it would be to build a space-only servicing vehicle that stays docked with the ISS.

The challenge is one of delta-v. To get from any orbit to any other orbit requires a change in velocity which requires propellant. Space is notably empty so you can't just go harvest yourself some propellant. The ISS is in a particularly crappy orbit with respect to servicing satellites so a repair ship docked there would require more propellant than one in a better orbit. The ISS is a nice destination for people bec…

Or possibly a dedicated servissing platform, say with ion engines or refueling capacity. It could do slow orbit changes unmanned with crew launched only for the actual servissing, or possibly dragging broken sats for repair to a manned station and back - could be pretty workable in GEO belt if you manage to get and sustain a crew there.

Re: SpaceX successfully launches two humans into orbit

#824

Post by m4rtink »

bouncycastle wrote: post #564
mikepurvis wrote: post #508

Earlier quoted context omitted.

There are plenty of inhospitable places here on earth where you could set up your anthropology experiment— deep under the ocean, for example, heck there was even a series of videogames made about this exact scenario. :)

That's right. I'd like to see that happen too. Although I'd argue that space has much more abundant materials & resources due to its vastness. Minus the geopolitical baggage. More importantly, there is a bootstrap problem. Where are the funds going to come from? There is no commercial benefit from such an experiment except perhaps tourism. On the other hand, a space colony could develop a self sustainable economy, de…

Yeah, the bootstrap funding is the main issue - other than that basically all available resources are out there in space, pretty much by definition. From that poikt of view it is a no brainer, once the initial cliff can be overcome.

Re: SpaceX successfully launches two humans into orbit

#825

Post by m4rtink »

TeMPOraL wrote: post #676
jacobush wrote: post #462

Earlier quoted context omitted.

They will of course invent a new racism, off-Worlders. But I'll take that as a slight improvement to our current situation anyways.

Look no further than to The Expanse, welwala[0]. It's all fun and games until (spoiler alert) someone decides to drop some space rocks on your home. That said, I think it's still worth the risk. -- [0] - A slur that roughly translates to "lover of planets and culture that comes from them".

I find it interesting that all the major powers in Expanse are in a realistic cold war & pretty nasty. You migh find one of them sympathetic for a while, only to find out it was all a construction hiding the horrendous deeds they did for political power. Only to find out the others did even worse thing. And agains this backdrop you have the heroes, trying to keep some sort of moral integrity & helping to save what they can, often derailing various grand schemes withou even realizing it.

Re: SpaceX successfully launches two humans into orbit

#826

Post by somebrody »

bolasanibk wrote: post #543
somebrody wrote: post #516

Earlier quoted context omitted.

https://www.space.com/bigelow-spacex-tourist-flights-space-s...

Bigelow Aerospace lays off entire workforce - Mar 23 2020 https://spacenews.com/bigelow-aerospace-lays-off-entire-work...

Thanks! Too bad for now

Re: SpaceX successfully launches two humans into orbit

#827

Post by ncmncm »

esmi wrote: post #805
andrepd wrote: post #699

Earlier quoted context omitted.

Eh, that's a really sad thing to optimise for, don't you think? Revealing of a broken incentive system. I'd prefer if HFT practices were banned.

Personally I waffle on this myself. My instinct tells me it’s bad but then I try to decide what trading cadence I would limit it to. Assume there is a CEO who wants to do something nefarious to manipulate the stock price. If they make a decision how fast can a company actually act on it? Would or could they make the company act on 1 hour boundaries? Even if we limited trades to once per week is that the long term we…

Don't limit cadence. Just tax transactions, and cadence will limit itself.

Re: SpaceX successfully launches two humans into orbit

#828

Post by 8bitsrule »

One of the first SF books I read as a young teen (and so don't recall the title) was about the pilot of an asteroid-miner. I was already intrigued by astronomy, and that got me interested in space travel. I don't really care what the excuse is to go.

There's a lot of intense interest in that idea, and yet so far we've barely gotten off the ground. Furthermore, unless some things change, our time window for being able to do that is growing shorter. Without a re-focus, it may not happen for a thousand years. And that'd be a shame. Dreams and stories that don't fuel action are wasted.

Lots of old books talked about 'Conquering Space'. Looks like we need to conquer ourselves first.

Re: SpaceX successfully launches two humans into orbit

#829

Post by dwd »

api wrote: post #680
dwd wrote: post #675

Earlier quoted context omitted.

Brunel would be my pick as a predecessor who Musk emulates. https://en.wikipedia.org/wiki/Isambard_Kingdom_Brunel Brunels' achievements spanned both civil and naval engineering projects, and much like Musk he didn't so much invent something completely new, but innovated on existing systems. His work on propeller screws is very much in the same vein as Musk and the Raptor engine. Probably fair to say he was a larger t…

Fascinating! He even helped get a pneumatic railway built, which failed, and reminds me a bit of hyperloop. If I had to bet on a Musk project that would fail it would be that one. Something about it just feels wrong to my engineering intuition... too tight of tolerances for a civil engineering project.

What the hyperloop set out to achieve was a worthy goal. The cost of high-speed rail in the US is astronomical so any solution that cuts that cost dramatically is a good thing. His plans for the LA-SF route was very much like what Brunel engineered for the GWR with a series of tunnels and bridges to minimise the gradient and allow for high speed and volume. I caught an InterCity125 a heap of times back in the early 80's while living near Chippenham running on the same line Brunel built.

I think with Musk, it's the lesser known achievements like the big battery in South Australia that elevate him to the level of Brunel.

https://reneweconomy.com.au/tesla-big-battery-outsmarts-lumb...

Re: SpaceX successfully launches two humans into orbit

#830

Post by esmi »

ncmncm wrote: post #827
esmi wrote: post #805

Earlier quoted context omitted.

Personally I waffle on this myself. My instinct tells me it’s bad but then I try to decide what trading cadence I would limit it to. Assume there is a CEO who wants to do something nefarious to manipulate the stock price. If they make a decision how fast can a company actually act on it? Would or could they make the company act on 1 hour boundaries? Even if we limited trades to once per week is that the long term we…

Don't limit cadence. Just tax transactions, and cadence will limit itself.

I waffle on this one too. Institutions that do HFT have a huge capital cost and pay large fees before they even make their first trade. They also employ programmers, traders, etc. Basically, these taxes are going to need to sum to something really big to dissuade them. Too small, they ignore it. Medium, the market will just consolidate. Large, you'll stop HFT, but at what consequence? The probability of unintended consequences is high.

This is when I decide I don't really understand the market as well as I think, and I should stop solving the world's problems, and go back to designing circuits.

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