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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

#371

Am i missing something, is the need to land vertically a requirement of a fragile fuselage? Seems wasteful to carry extra anything (in this case rocket propellant) to space, just to avoid having to re-right the rocket when you get it back on earth for a subsequent launch. Is extra fuel payload < landing gear or parachutes?

Elon intends to land rockets on Mars and return them to Earth. Mars is light on facilities for refurbishing rockets.

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

#372
post #201

Am i missing something, is the need to land vertically a requirement of a fragile fuselage? Seems wasteful to carry extra anything (in this case rocket propellant) to space, just to avoid having to re-right the rocket when you get it back on earth for a subsequent launch. Is extra fuel payload < landing gear or parachutes?

Lack of wings. (That's obviously for the landing gear part of the question) But fragile fuselage is certainly spot on. Parachute-landings still have quite some impact velocity. Strengthening an object the size of a Falcon 9 first stage to survive that impact would require a much stronger and thus prohibitively heavy structure, even if the parachute itself was free. The nice thing about powered upright landing is that…

Even if you were sure the engines would survive impact, you wouldn't want your expensive, complex rocket engine to take a dunk in salt water.

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

#373
post #260

Earlier quoted context omitted.

Ariane 6 looks like it will be a fine rocket. Should be quite competitive if they can get it to market before, say, 2010, and if SpaceX's reusability efforts come to naught. Otherwise, I fear it'll be much too little, much t0o late.

I've got $10,000 says they do not get it to market before 2010. :) (ITYM 2020)

I think he is saying it is already too late as spacex has hit both those milestones.

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

#374
post #295
post #171

Earlier quoted context omitted.

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."

NASA didn't become boring because of internal culture. They were planning all sorts of crazy stuff:

http://www.wired.com/2014/10/dreamingadifferentapollo/

NASA became boring because they were ordered to become boring and were defunded.

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

#375
post #136

Earlier quoted context omitted.

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.

Its more favorable for SpaceX to lower prices as much as possible to crush incumbents (ULA). Extracting maximum profits just gives time for other competitors to catch up.

That may be favourable in the short term but a monopoly position stagnates R&D due to lack of need. Plus Elon Musk doesn't strike me as the type to avoid innovating.

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

#376

Earlier quoted context omitted.

Thank you - how does the barge communicate with the falcon? And what types of comminucations are they having. I assume the barge is stating its GPS location, but does it also communicate things like sea conditions - and its elevation (what is it called to describe the condition of the sea), as well as wind, north-south orientation, etc... I am impressed - but I want to know how this works.

Rumor is ( https://www.reddit.com/r/spacex/comments/3b0stk/falcon_9_wha... ) that the barge does not communicate any information to the booster. Instead, it uses GPS and some ingenious motors to maintain position and orientation, and the Falcon booster uses a radar altimeter to judge accurate vertical distance.

Thats just fucking awesome if true. Its like "how can we maximize the use of some 'cheaper' technology and a shit-ton of math to accomplish this in the technologically simplest way?"

Wow.

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

#377

Hosted webcast: https://youtu.be/L0bMeDj76ig Landing at 38:18mins https://youtu.be/L0bMeDj76ig#t=38m18s Great info on the thrusters on the first stage at 19:37. https://youtu.be/L0bMeDj76ig#t=19m37s Edit: Thank you and sorry about the time stamp link, I posted quickly from my phone. Hopefully it works on shortlinks.

Seems like the landing is now around 29min: https://youtu.be/L0bMeDj76ig?t=28m58s

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

#379

Earlier quoted context omitted.

Say what you want about SpaceX's plans for re-usability, nobody can deny they are making progress at an incredible pace. I've just checked on Wikipedia and apparently the first flight of the Falcon was in 2010. That's six years ago. Compared to that, Arianeespace's target of 2025 (in nine years!) for Adeline is almost ridiculous. Just checked: Stephane Israël just raised concerned after SpaceX's latest success: http:…

Could you copy-paste his comments? Google translate worked OK, but the site has a paywall.

Pre paywall ""Europe must take stock of what is happening in the United States , because if nothing is done , in ten years, our launcher sector will be in big trouble. " Faced with the offensive for two and a half years in the space by Elon Musk , who breaks the prices of commercial satellite launches, Arianespace boss Stephane Israel sounds alarm . The distortion of competition will intensify as the founder of SpaceX was awarded on April 28 , its first contract with"

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

#380
post #26

Earlier quoted context omitted.

Do customers get a discount for launching on a used rocket?

The first one definitely will (unless negotiations break down and they decide to launch without a customer, but that seems unlikely). Eventually when it becomes routine maybe not.

"This ones been up and back, it works. This one hasn't flow yet but we think it's good"
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