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SpaceX lands rocket at sea second time after satellite launch

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Re: SpaceX lands rocket at sea second time after satellite launch

#291

Post by rdancer »

lmm wrote: post #136
coralreef wrote: post #41

Earlier quoted context omitted.

Aren't they passing on the savings by bidding lower prices than their competitors?

Only marginally - if none of their competitors can reuse a rocket then they only need to undercut the cost of a non-reusable rocket. The reward for innovation is that you get a temporary monopoly on that innovation and so can extract something very like a monopoly rent.

The demand seems to be quite inelastic at the current price levels, but the comsat industry has been gearing up for reusability. It is possible that there will be some price elasticity at radically lower prices, and the increased demand makes up for the lower unit margin. SpaceX need to kickstart a whole new trans-lunar economy for the Mars colonisation project to work, so it is within their interest to stimulate long-term demand.

If Musk wanted to maximize his risk-adjusted profit, SpaceX would never have started. Remember, he financed the cashflow out of his own pocket, and went from a 100-millionaire to not being able to afford rent during the process. He himself said SpaceX had less than even chance of success, and he is known to be both very meticulous in preparation, and an incurable optimist.

Re: SpaceX lands rocket at sea second time after satellite launch

#292

Post by falsestprophet »

warrenmiller wrote: post #180
neals wrote: post #28

I always try to watch the webcasts and I can't help but cringe so hard when they start chanting 'USA USA USA', every single time. What is up with that?

Maybe they don't know their CEO is South African?

So you're telling Elon Musk he isn't an American?

He wouldn't pay you any mind.

I'm a other-than-singular national as well and I certainly don't care to hear I'm not American.

Re: SpaceX lands rocket at sea second time after satellite launch

#293

Post by skykooler »

fixermark wrote: post #133
sandworm101 wrote: post #90

Earlier quoted context omitted.

What numbers? Unsecured cargo is unsecured cargo. A metal object sitting on a flat metal deck gets tied/braced/chained.

By whom? The drone ship has no on-board crew. ... which means there's nobody around to be injured or killed if the rocket falls post-landing. Maybe it's a precaution worth taking when they intend these stages for commercial re-use; for now, the whole thing is one big experiment.

There is a ship a few miles away with engineers on it. Once the stage has vented all excess liquid oxygen and is safe to approach, they can return to the ASDS and secure it.

Re: SpaceX lands rocket at sea second time after satellite launch

#294

Post by falsestprophet »

vidarh wrote: post #75
TeMPOraL wrote: post #61

Earlier quoted context omitted.

You're thinking about SpaceX as just a random company in a random industry. It's not. SpaceX is the space company. On PR area they compete with NASA, the space agency. I can imagine that for many SpaceX employees, their work is synonymous with getting America back into space exploration game.

And I still think that is an American cultural quirk. To me that notion is bizarre.

What you people are missing is that Americans don't care what you think.

Re: SpaceX lands rocket at sea second time after satellite launch

#295

Post by api »

LocaX wrote: post #171
ino wrote: post #154

How are non-US space agencies and companies (like ESA, Russia, Japan, China, etc) reacting to the SpaceX and Blue Origin achievements? Are they also testing similar things but we aren't hearing? Or they aren't threatened by the advances?

I attended a conference from the head of the CNES (Centre National d'Etudes Spatiales, ~ French NASA) in Paris a week ago and he talked about that. Ariane 6 is going to be built with a cost effective approach and trying to focus on market needs (3D printing of parts, reusability of the first stage, etc.) At first, concerning SpaceX, his group of experts told him that the design of the rocket wasn't going to work and…

I'm kind of fascinated -- and not necessarily in a good sense -- with how unbelievably conservative the aerospace industry became right after its greatest moment of glory. That would have been Apollo in 1969. Seems like after the Moon landings everyone just said "welp, that's it, nothing else will ever be done."

Re: SpaceX lands rocket at sea second time after satellite launch

#296

Post by david-given »

fit2rule wrote: post #242
shiven wrote: post #108

Earlier quoted context omitted.

Yoo.Ess.Ae! Yoo.Ess.Ae! Yoo.Ess.Aeh! There. See. No harm, no foul. Anyways, as a non-American living in the US since 2001, I fail to see an issue with chanting USA, one way or another. It is an American company, with majority US employees, running this project (mainly) for an American entity (NASA), on US sovereign territory (or ocean?), using a significant chunk of US resources. So, it is their company and their cou…

I think its offensive to have nationalistic robot-like-chanting being defended as an okay thing. Its the sort of thing you expect people to do at rallies or cult gatherings, and from an outsider perspective it always tarnishes what is otherwise a very rational event, because its an implied irrational, collective mindset. As a non-American, I wish it'd stop - its a major turnoff for these events, and I switch away whe…

You're getting downvoted into oblivion, but yeah, that's basically how I feel. Cultural differences, I'm sure, because I'm not USian; but every time I see it on the youtube videos it makes me deeply uncomfortable.

Re: SpaceX lands rocket at sea second time after satellite launch

#297

Post by dzdt »

LocaX wrote: post #171
ino wrote: post #154

How are non-US space agencies and companies (like ESA, Russia, Japan, China, etc) reacting to the SpaceX and Blue Origin achievements? Are they also testing similar things but we aren't hearing? Or they aren't threatened by the advances?

I attended a conference from the head of the CNES (Centre National d'Etudes Spatiales, ~ French NASA) in Paris a week ago and he talked about that. Ariane 6 is going to be built with a cost effective approach and trying to focus on market needs (3D printing of parts, reusability of the first stage, etc.) At first, concerning SpaceX, his group of experts told him that the design of the rocket wasn't going to work and…

Newton's approximation for impact depth [1] gives a way to calculate how thick the barge deck would have to be to survive a high speed impact from the rocket stage. The impactor punches through until it has displaced an equal mass. An empty F9 stage masses about 23,100kg and has a diameter of 3.66m. [2] Steel has a density around 7,700 kg/m^3. Doing the math, the deck would need to be about 29 cm thick to survive a high speed impact. Estimates are the actual barge deck is 25-35 mm thick [3], so 1/10th that thickness. If the F9 stage came down onto the barge completely uncontrolled, it probably would punch through!

[1] https://en.wikipedia.org/wiki/Impact_depth

[2] http://spaceflight101.com/spacerockets/falcon-9-v1-1-f9r/

[3] http://space.stackexchange.com/questions/8842/what-is-the-sp...

Re: SpaceX lands rocket at sea second time after satellite launch

#298

Post by mikeash »

Tarrosion wrote: post #145
sandworm101 wrote: post #63

Earlier quoted context omitted.

12g but empty. A structure meant to survive being filled with 10+ times (fuel+upper stage) it's own weight will survive 10+Gs without effort. In other words, the stress of a 12g acceleration isn't much different than the stress of the stage sitting on the pad a few minutes previously. The overall structure actually goes through all sorts of stresses, not all of which are measured in G. The combination of push from th…

I am not a rocket scientist, but: I think this is only sort of true. Yes, the fueled rocket is much, much heavier. But not all parts of the rocket are load bearing as it sits on the pad waiting for launch. All parts of the rocket experience the 12g (or whatever it was) deceleration. Also, rocket skins are really, really thin (relative to their size, the forces they endure, etc.) I've read that without the fuel inside…

Regarding your last part, some rockets have balloon tanks, which means that the tank requires pressurization to keep its shape.

The Falcon 9 has a sort of partial balloon tank. It's strong enough for ground handling without pressurization, but it requires pressurization to handle flight loads.

Note however that it's pressure, not fuel, that provides the extra strength. These tanks are still pressurized even when almost empty.

Re: SpaceX lands rocket at sea second time after satellite launch

#299

Post by mattbeckman »

Kinnard wrote: post #244

I wonder if there's coordinate potential with seasteading? Astronauts are gonna want all sorts of goods and services upon landing I imagine. Having someone stationed nearby will mean swifter pickup of equipment and astronauts. And if there's someone stationed nearby they'll want goods and services as well.

I don't think astronauts would land on the droneship, as that's just for the first stage. When the Crew Dragon lands, it would be coming in from orbit, so I imagine they would just target the landing platform at the Cape as part of their de-orbiting plan.

That being said, would you want to be in the nearby path of the rockets if they were going to be ditched?

Re: SpaceX lands rocket at sea second time after satellite launch

#300

Post by Yhippa »

hoorayimhelping wrote: post #165

> P.S. Downvotes for this question? Really? There are always people on HN who love being contrarian and trying to diminish amazing things. It's like they hate seeing people excited for something and want to point out that this isn't that big of a deal. We're literally watching things happen for the first time ever, and this person's response is "what's so great about this?" while implying that people who are excited…

How do you even see downvotes?
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