Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

SpaceX successfully launches two humans into orbit

nasa.gov

Post reply on HN
Print view View original

631–640 of 839 posts

Re: SpaceX successfully launches two humans into orbit

#631

Post by lutorm »

chipsa wrote: post #309
avmich wrote: post #52

Earlier quoted context omitted.

> What would be the options? Soyuz uses straight hydrogen peroxide, I believe, 82% concentration. For 3 tons capsule it takes 30 kg of peroxide - monopropellant - to land. Buran is still the example of a high tech option - it used LOX and kerosene for RCS, the biggest trick was to keep LOX liquid for a month-long missions. It was done with mid-1980 technologies. Kliper planned to use LOX and ethanol. The craft wasn't…

Crew Dragon carries 3 klbs, or 1.4 tons of hypergols. It doesn't just use those tanks for RCS, but also for the abort system. Also, Crew Dragon is closer to 14 tons at landing.

Indeed. If you want to switch to a less efficient propellant, you also have to explain how to make the launch escape system work with it, otherwise you've traded the extra safety of not having to handle hypergols for a massive extra risk in a less capable escape system.

Re: SpaceX successfully launches two humans into orbit

#632

Post by borosT »

mumblemumble wrote: post #558
wongarsu wrote: post #511

Earlier quoted context omitted.

On the ISS you can produce higher quality optical fiber than on earth [1]. A demonstration fabrication unit is already on the ISS, and NASA has recently published prices for using the ISS for commercial tasks such as this. I suspect many other manufacturing methods can also benefit from zero gravity, and as launch costs drop more of these will be explored. 1: https://upward.issnationallab.org/the-race-to-manufacture-…

It's interesting to think about that from the other side, too. Just delivering the raw materials to the manufacturing facility would cost ~$3000/kg (assuming rock bottom SpaceX prices). Based on some loose googling, I think that 1kg of raw material would yield only something on the order of 100m of cable. It looks like a typical 100m fiber optic patch cable retails for about $60. So, there's clearly a lot of value to…

is asteroid mining viable compare to shipping raw material up the earth gravity well?

Re: SpaceX successfully launches two humans into orbit

#633

Post by dannyw »

mumblemumble wrote: post #558
wongarsu wrote: post #511

Earlier quoted context omitted.

On the ISS you can produce higher quality optical fiber than on earth [1]. A demonstration fabrication unit is already on the ISS, and NASA has recently published prices for using the ISS for commercial tasks such as this. I suspect many other manufacturing methods can also benefit from zero gravity, and as launch costs drop more of these will be explored. 1: https://upward.issnationallab.org/the-race-to-manufacture-…

It's interesting to think about that from the other side, too. Just delivering the raw materials to the manufacturing facility would cost ~$3000/kg (assuming rock bottom SpaceX prices). Based on some loose googling, I think that 1kg of raw material would yield only something on the order of 100m of cable. It looks like a typical 100m fiber optic patch cable retails for about $60. So, there's clearly a lot of value to…

High frequency traders will want the best connectivity humanely possible. It’s a zero sum game. If they can beat a competitor firm’s signals by the smallest fraction of a second, even a nanosecond, they reaps in the profits. So $100m for some better fibre? Go nuts!

Re: SpaceX successfully launches two humans into orbit

#634

Post by 101404 »

dingaling wrote: post #559
101404 wrote: post #188

Loved the SpaceX guy on handover to NASA: "... and thank you for flying on Falcon today!" Private space flight started with this flight.

> Private space flight started with this flight. 21 June 2004

That's wasn't private, that was on a government space ship.

Re: SpaceX successfully launches two humans into orbit

#635

Post by 101404 »

avmich wrote: post #201
101404 wrote: post #188

Loved the SpaceX guy on handover to NASA: "... and thank you for flying on Falcon today!" Private space flight started with this flight.

> Private space flight started with this flight. I hear Dennis Tito and Mike Melvill sighed.

That was both on government capsules.

Re: SpaceX successfully launches two humans into orbit

#636

Post by borosT »

frakkingcylons wrote: post #152
jl6 wrote: post #131

Earlier quoted context omitted.

Not to detract one iota from this amazing achievement, but what definition of sustainable are you thinking of? This was still paid for by the government.

The sheer cost of launches is much lower on a Falcon 9 and Crew Dragon versus the Shuttle. Amortized per-launch cost for the Shuttle was about $1.5B [0]. The cost of the Demo-2 mission today with 2 astronauts costs $110M [1]. [0]: https://en.wikipedia.org/wiki/Space_Shuttle_program#Budget [1]: This article states the per-astronaut cost paid by NASA on a Crew Dragon mission is $55M, compared to $86M on Soyuz: https://…

does anyone know why it took so long for us to develop resuable rocket? Isn't reusable rocket the natural next step for space launching capabilities?

Re: SpaceX successfully launches two humans into orbit

#637

Post by jerome-jh »

The first man in space was launched by the russians almost _60_ years ago. That was history.

Then the americans sent men to the moon, that was history too, and _50_ years ago.

We realized sending human into space was not really useful, so that more or less stopped. The ISS was an international endeavor with questionable scientific goals, but still it was fun and an unprecedented global collaboration. The Mars rovers and some other space probes (Viking, Venera) were true scientific achievements too.

What we see here is a private company re-learning how to send men in space and calling this "history". No doubt it will be used to send highest paying customers in space. It will also be used to send a large, low orbit satellite constellation without the slightest amount of collaboration or concerting with other space users. Other companies will compete to send their own constellations, some of them will certainly fail in a few years and leave their junk in space for tens of years. It has even been used to send a car into space, although many scientists would have loved to send a useful payload even in a test flight.

All this is financed by investors lured by the "dream" of sending men die on Mars, and by a government that has lost the sense of reality. How great.

Re: SpaceX successfully launches two humans into orbit

#638

Post by lazyjones »

nutjob2 wrote: post #393
lazyjones wrote: post #328

Earlier quoted context omitted.

> I hope we can move away from the "elon sucks" v.s. "elon is a genius" dichotomy and into a culture of acknowledging accomplishment while insisting claims in other areas be fully justified. Until then, I'll happily consider Elon's or even John Carmack's opinion over those of Elon's numerous, noisy but otherwise uninteresting critics on the Internet and elsewhere.

How much weight should I give the opinion of someone who calls someone who disagrees with him "the pedo guy"? It's a serious question. Elon may run some successful companies, but beyond that his credibility has taken a beating on any number of fronts. How much credit should Elon get for heading companies full of other people who do the actual work? Could another leader do a better job, given Elons unsteady behaviour?

> It's a serious question. Elon may run some successful companies, but beyond that his credibility has taken a beating on any number of fronts.

People are seriously confused these days. It's like doubting Einstein's famous statement about the importance of bees and his credibility in general because there's a photo of him sticking out his tongue.

> How much credit should Elon get for heading companies full of other people who do the actual work? Could another leader do a better job, given Elons unsteady behaviour?

He should get full credit for what he does, not minus "Internet bad points" because someone somewhere didn't like something he said.

Re: SpaceX successfully launches two humans into orbit

#639

Post by BorisTheBrave »

greeneggs wrote: post #504
pmorici wrote: post #200

Earlier quoted context omitted.

They said during the launch live broadcast that SpaceX intends to fly paying tourists by next year. Apparently many tourists have also visited the space station. https://www.space.com/spacex-crew-dragon-will-fly-space-tour...

Space tourism to the ISS is just US taxpayers paying for billionaires' vacations. Yes, NASA charges a fee, but it is tiny relative to the cost of the service. If somebody develops a private space station, great. Until then, this isn't an industry that deserves any support.

Is that true? Most of the cost of rockets seems to be the r&d, there's economies of scale to doing more launches.

I'd have hoped nasa is smart enough to charge more than the marginal cost of one more launch.

Re: SpaceX successfully launches two humans into orbit

#640

Post by isatty »

unixhero wrote: post #630
fasteddie31003 wrote: post #569

Earlier quoted context omitted.

I think it's hilarious how HN dislikes Elon. Elon is edgy, non-pc, and speaks his mind. All traits I see looked down upon in Silicon Valley.

What's non-pc?

Maybe non politically correct.
Post reply on HN