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Blue Origin Thread (merged)


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1 hour ago, Elukka said:

I You keep repeating this claim but it's getting no less bizarre. I have no idea what this impression is based on - yes, things get reprioritized, put on the back burner, accelerated. They don't just haphazardly jump from project to project - maybe you're watching whatever they're publicizing most heavily at a time and making the assumption that that's all they're working on now? In particular the idea that they just go for Musk's silly pet projects until he has the next idea seems like something you invented, because I've seen nothing to indicate the company works like this. If it did, they would probably never accomplish anything.

  1. Company promotes technology as the next greatest thing
  2. Company finds out that next greatest thing can't be made to work / can't be scaled up / can't be made to work economically / doesn't fit with changing priorities and/or other technology they've developed in the meantime.
  3. Company puts once-greatest thing on the back burner.

Seems perfectly reasonable to me. Much better than pigheadedly insisting that your technology is the latest and greatest thing when faced with a mounting pile of evidence telling everyone else the exact opposite. It's also much more of a start-up / Silicon Valley approach to business, which is hardly surprising given Musk's background. Think how many projects Google started for example, only to abandon them later (often leaving an established user-base high and dry in the process).

Also - I think it works for them (SpaceX). It generates a buzz and gives them the aura of a company that's innovating and not afraid to try new things or even take a fresh look at old things that were previously deemed to be unworkable . Granted, it only gives them that aura because they've also been successful enough that that stream of ideas and 'pet projects' can't quite be dismissed as vaporware or marketing spin.

Either way as a non-industry outsider looking in, I find it refreshing to see a company essentially doing some of their brainstorming in public - and it's always interesting seeing what SpaceX are thinking of doing next, even if some it looks like a stretch goal (to put it mildly) when they announce it.

 

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5 hours ago, Lukaszenko said:

Is there any difference between pumping "uphill" and pumping to the bottom, but against the pressure of the "hill"? 

You assume that fuel is free to leave the core tanks while crossfeed is active. There is no reason to believe that - in all probability there would be valves that switch from taking fuel from the crossfeed to taking fuel from the core. If so, then there would be no pressure against which to pump the fuel.

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ok, it is true, Facon Heavy center core is more robust than the other two, it does not give much detail but spacex will limit production to 2 types of cores.

"Falcon Heavy is two different cores — the inner core and the two side sticks,” Shotwell said. “The new Falcon 9 will basically be a Falcon Heavy side booster. So we’re building [only two different] cores to make sure we don’t have a bunch of configurations around the factory so we can streamline operations and hit a launch cadence of one or two a month from every launch site we have."

http://spacenews.com/spacex-aims-to-debut-new-version-of-falcon-9-this-summer/

Well I was wrong on one single core to rule them all.

5 hours ago, kerbiloid said:

Probably, ~1 bar/10 m * 4 g, i.e. several bars of pressure.

Yeah, due lox density 1200kg/m3 and taking into account that the stage is 44 m tall, (lets rise the fuel 30 meters) at 4g it will be close to 15 bar (with 0 flow), so we need more than that.
I guess the tank pressure is much higher, but still not sure what we gain lifting the oxidant or fuel to the center core tank, if we can just feed the bottom connection before distribute that fuel to the engines.
In fact you dont even need different helium tanks, because those helium tanks are designed to keep the pressure constant even when the tanks are empty, the only that changes is that you need to release that helium 50% faster.

We can even let the center core tanks valves open with the center helium tank close, and you will consume the fuel of the other 2 boosters, but I think it will be more simple with the center core valve closed. 

Edited by AngelLestat
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4 hours ago, AngelLestat said:

ok, it is true, Facon Heavy center core is more robust than the other two, it does not give much detail but spacex will limit production to 2 types of cores.

"Falcon Heavy is two different cores — the inner core and the two side sticks,” Shotwell said. “The new Falcon 9 will basically be a Falcon Heavy side booster. So we’re building [only two different] cores to make sure we don’t have a bunch of configurations around the factory so we can streamline operations and hit a launch cadence of one or two a month from every launch site we have."

http://spacenews.com/spacex-aims-to-debut-new-version-of-falcon-9-this-summer/

Well I was wrong on one single core to rule them all.

Gracefully done. It's not much but have a 'like' for that.

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Here's my 5th SpaceX Mission Overview video, this time of JCSAT 14:

 

The landing was completely kOS controlled, I am currently trying to write a program doing a fully autonomous boostback, reentry and landing, here you can see it in action, performing pretty much flawless! Hope you like it! :)

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11 hours ago, Frozen_Heart said:

I always assumed that one day the Heavy would be replaced by a 9 Raptor, single stick rocket that looks like an up-scaled Falcon 9.

The Raptor has about 3 times the thrust of the Merlin so its liftoff thrust would be similar, but the much higher ISP and the Bigger second stage would make full recovery easier.

Then you stick three of those together into a single stage. :) Go big... and go anywhere!

11 hours ago, kerbiloid said:

27 single engines on start.
This begins to resemble N-1 with its 30.

Yep it does, although the N1 was hamstrung by being an all or nothing affair. The individual engines could be tested for sure but they were never tested together - other than building an actual rocket and lighting it.  Each of the three nine-engine cores in a Falcon Heavy has been pretty extensively tested - or rather the design has been extensively tested -  already. More importantly, computer control systems have moved on quite a bit from the KORD system used in the N1! Also (and I can't find a good source for this) but I've heard that the double ring of engines on the N1 1st stage caused problems with pressure waves and combustion instability, whereas the three Falcon Heavy cores should be independent of each other.

Edited by KSK
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1 hour ago, sojourner said:

JCSat launch delayed 24 hours due to weather.

Unfortunate. It would appear that... the fourth wath not with them.

I know, I know, I'll show myself out...

Actually I'm hoping it gets bumped just one more day so I can watch...

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2 hours ago, Kartoffelkuchen said:

Here's my 5th SpaceX Mission Overview video, this time of JCSAT 14.

The landing was completely kOS controlled, I am currently trying to write a program doing a fully autonomous boostback, reentry and landing, here you can see it in action, performing pretty much flawless! Hope you like it! :)

That was fantastic. I really need to learn KoS. Was the ballistic landing any harder then the boostback?

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1 hour ago, KSK said:

Then you stick three of those together into a single stage. :) Go big... and go anywhere!

Yep it does, although the N1 was hamstrung by being an all or nothing affair. The individual engines could be tested for sure but they were never tested together - other than building an actual rocket and lighting it.  Each of the three nine-engine cores in a Falcon Heavy has been pretty extensively tested - or rather the design has been extensively tested -  already. More importantly, computer control systems have moved on quite a bit from the KORD system used in the N1! Also (and I can't find a good source for this) but I've heard that the double ring of engines on the N1 1st stage caused problems with pressure waves and combustion instability, whereas the three Falcon Heavy cores should be independent of each other.

On that note, what are some of the advantages and disadvantages of different arrangements of engine clusters?

For a nine-engine cluster, you can do the 3x3 of the Falcon v1.0, or the 1+8 octaweb of the v1.1, or you could even do a 3+6 assessment with three triangles. For a four-engine cluster you can do 2x2 or 1+3.

I suppose that having a central engine and multiple planes of symmetry is nice, generally. 

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I'd bet the differences between the F9 and FH center core is the main reason for its delay. Not because it should take so long to develop, but because the F9 has been undergoing constant changes. Imagine if they had implemented the original 1.0 FH on time. They'd then have had two lines of rockets to keep up to date and upgraded to 1.1, Full Thrust, Even Fuller Thrust, etc. Some of those changes, especially 1.0 -> 1.1 were huge and would no doubt have resulted in pretty big changes in the hypothetical early FH too. My guess is they expected the F9 to mature much faster, but considering they've managed to more than double its original payload I can't really blame them for keeping on fiddling with it.

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19 hours ago, KSK said:

The individual engines could be tested for sure but they were never tested together - other than building an actual rocket and lighting it.

It was even more funny. Individual engines of original N-1 were single use. As in "one burn only". They had to test two engines from a batch, and mount other two. Falcons fly and will fly on tested, tested and tested again engines, no need to worry if some explode at the first run.

No testing stand for N-1 first stage was built too. So the stage had to explode not comfortably alone, but in flight, taking whole rocket and payload with her. Also ringed arrangement of engines on a wide-S stage somehow was bad for effective thrust, even with inner six.

About booster reusability and satellite costs. Modern satellites are so expensive partly because with prohibitevly expensive boosters they must be absolutely reliable and maximum light. If your craft fails, you will never afford to launch another, but you must use lightest and cheapest rocket available. In 1993 "designers spent up to $400,000 per kilogram in taking the last few kilograms out of a satellite so it could meet the selected launch vehicle’s lift weight-to-orbit capability". More affordable medium and heavy lift means you can make your payload cheaper. And instead doubling and tripling systems just plan to launch spare. More mass and more payloads means more launches and more launches mean less cost of launch. The idea is not new, but before Space X there were no means to make it true. Shuttle was overengineered before conception. Though Russians did made satellites heavy and mass produced simple modular rockets since forever.

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On 4/5/2016 at 3:39 PM, KSK said:

Gracefully done. It's not much but have a 'like' for that.

what I treasure most is the truth..  I don't like to maintain a wrong idea; or worst, spread it. 

On 4/5/2016 at 6:49 PM, sevenperforce said:

On that note, what are some of the advantages and disadvantages of different arrangements of engine clusters?

For a nine-engine cluster, you can do the 3x3 of the Falcon v1.0, or the 1+8 octaweb of the v1.1, or you could even do a 3+6 assessment with three triangles. For a four-engine cluster you can do 2x2 or 1+3.

I suppose that having a central engine and multiple planes of symmetry is nice, generally. 

the benefit of having many engines is that you reduce manufacture cost due quantity.. is also easier to design different launchers or stages changing the numbers of engines and in case one or two fails, you can still achieve your goal.

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Well, only 1:45 hrs left to launch... but I need to go to sleep, work tomorrow :(  

Edited by AngelLestat
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Its 1:15 for me on the East coast. I personally like the late launch, gives me lots of time to get home and get ready to watch after work. 

Plus the time lapses look really cool. 

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