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A good update from SpaceXcentric on Starship and other Space X activity...
https://www.youtube.com/watch?v=w-jd1Cd4Taw
Hoping we can all get back on track in 2020!
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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SpaceX is continuing its test launch activities throughout 2020.
Cameron County Judge Eddie Trevino Jr. has ordered a temporary closure of State Highway Four near the entrance of Boca Chica Beach.
The closure is taking place on January 6th, 2020 between 3 P.M. to 4 P.M.
Law enforcement along with SpaceX will be monitoring the area and will only allow individuals who provide proof of residence.
“Why should anybody in the United States have to be forced off their property for a private individual,” said Terry Heaton, a Boca Chica Village resident.
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Musk has been tweeting and this brings us up to date:
https://www.youtube.com/watch?v=Miw6KDHuphs
A flight in 2 to 3 months if all goes well.
From 9:25 onwards - Musk claiming Starship will be launched for $2 million per mission. So you could get a Starship in LEO ready for flight to Mars for less than $15million! That would be $150 per kg...Even if you double that for getting to Mars, that's still only $300 per kg... Of course human flight will require more expensive fitting out of the Starship, so maybe double again for $600 per kg. Still incredibly cheap. If one person needs a ton of stuff to get them to Mars, that would be only $600,000 total.
If you could pack 100 people on a Starship that would be a cost of $80,000 on the ticket...but I guess higher to account for staffing, health care and all the other add ons. Call it $100,000. If it carried 50 people then the ticket price would be $200,000.
Very encouraging if true!
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...and an update from SpaceXcentric .
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Test tank ready for pressure test?
https://www.youtube.com/watch?v=TPcTf1NWAJA
Is this a test for part of the Starship...trying to avoid the previous catastrophic testing??
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Seems like the test was a failure...or not...the pressure was beyond what will be required but not by a sufficient margin...
https://www.youtube.com/watch?v=Yz9g3ZRHxrg
Test tank ready for pressure test?
https://www.youtube.com/watch?v=TPcTf1NWAJA
Is this a test for part of the Starship...trying to avoid the previous catastrophic testing??
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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A video from Mic of Orion...Musk and Space X are pressing ahead, no let up in the Starship programme.
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SpaceX is using the old-timey method of testing; to point of failure! If ya don't break it--ya can't fix it!
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There is always a strain mismatch at a cylinder-dome joint that induces localized bending stresses. Anyone who has ever actually designed pressure vessels knows this, and what to do about it. You thicken the wall at the weld joint by about a factor of 2, and for 5-6 thicknesses either side of it.
The failure was at this joint. Actually, 2 of them. Not surprising at all that there were 2 of them, given how fundamentally-variable welding really is.
Once they fix this, the next failure zone is at the larger conical-spherical joint, and for exactly the same reasons as the cylinder-dome joint. You avoid this by not changing the dome radius of curvature. Rather fundamental error in vessel design.
Spacex REALLY needs to talk to someone who designed boilers or solid rocket motors, in order to get their designs through testing faster.
As Oldfart 1939 says, you want to test it to destruction. But you want that destruction to occur just where you expected, and at the pressure you expected. THAT hasn't happened yet for Spacex.
Which means they have yet to consult a real pressure vessel expert. Simple as that.
GW
Last edited by GW Johnson (2020-01-14 13:18:47)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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They are on the learning curve: They know not that they know not. Soon they will move to phase 2: They will know that they know not. Whether they skip stage 3, where they know not that the know, is moot. Probably will know when they know.
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Next best is a submarine builder as there welds are tested to ensure they do not fail.
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Yes. But as GW has suggested, having input from someone who has previously dealt with this problem professionally would accelerate the learning curve. It's very basic as to why there needs be thicker stock at the weldment joints, since there will be substantially larger surface butt-welded between the tank segments. I was going to joke about "it doesn't take a rocket scientist to understand this problem." No. It takes a pressure vessel engineer.
Last edited by Oldfart1939 (2020-01-17 14:38:45)
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I'm surprised if they haven't. Seems odd. But the evidence is they haven't!!
Yes. But as GW has suggested, having input from someone who has previously dealt with this problem professionally would accelerate the learning curve. It's very basic as to why there needs be thicker stock at the weldment joints, since there will be substantially larger surface butt-welded between the tank segments. I was going to joke about "it doesn't take a rocket scientist to understand this problem." No. It takes a pressure vessel engineer.
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Musk has not done a lot of different things which could cause loss of life in many of his projects...
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Interesting video from SpaceXcentric
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The starships moving targets payload to orbit has to due with a ship that has not been built to know the mass fraction, engine performance that is only partically tested, changes now a dual inner tank fuel using all of its fuel to get all the payload to orbit and being empty unable to do anything until refueled. It takes 6 to 7 starship fuel payloads to get it topped off to be able to even move from LEO.
Musk has only an estimate for what his ship will charge let alone how much it will take to make the real deal to launch.
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Mic of Orion looks at Starship/Super Heavy launch costs.
https://www.youtube.com/watch?v=bK1BNfh0kFE
$2 million a bit ambitious but he thinks $7 million possible in the future. That's about $70 per kg.
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If a Falcon 9 is launching for 10 million then there is no way the starship is doing a cost of less per launch as the ship itself is 7 times larger if not more costly to operate as the fuels are not as cheap. Now cost per kg will be lower for sure.
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This cost estimate is based on Starships being used for everything from satellite launchs, Earth to Earth transport, lunar trips, ISS supply, Starlink deployment, orbital tourism and Mars colonisation. So you would be looking at hundreds, perhaps thousands being built every year.
That will bring the cost down substantially.
If a Falcon 9 is launching for 10 million then there is no way the starship is doing a cost of less per launch as the ship itself is 7 times larger if not more costly to operate as the fuels are not as cheap. Now cost per kg will be lower for sure.
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What is a said to be a good test of the prototype Starship tank...details a little sparse.
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What will be Recent SpaceX Super Heavy Starship Summary
Stability is going to be a problem with the leg location...
Comparison of developement costs...
agressive timeline to push build developement but not all testing....
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Well...if they can keep to that schedule...double wow!!
Where it says "first flight" of Mk 1 - presumably that's Mk1 Starship and Superheavy together. My understanding is we might see first flight of the Starship Mk 1 end of this month/March this year.
What will be Recent SpaceX Super Heavy Starship Summary
https://www.nextbigfuture.com/wp-conten … 30x430.jpg
Stability is going to be a problem with the leg location...
Comparison of developement costs...
https://www.nextbigfuture.com/wp-conten … .54-PM.jpgagressive timeline to push build developement but not all testing....
https://www.nextbigfuture.com/wp-conten … .47-PM.jpg
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Cost comparison graphic show in post #496 isn't quite accurate. Technically it is, but cost per launch dropped dramatically after the first launch. Then it rose steadily. It rose to 1/2 billion before the Colombia disaster, then 3/4 billion right after, then continued to rise until it was $1 billion per launch.
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The current play toys are labled MK# but we have seen no building of the bottom of this monsters first stage. So far we have a single stage that will see a limited payload mass to LEO in its current configuration.
GW I am sure has looked at this ability but its still a moving target of assumptions.
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I've seen Mk 1 versions referred to as SN1 etc - does SN denote Serial Number? I think we are expecting the first Mk1 SN1 Starship launch in late Feb/early March this year.
The current play toys are labled MK# but we have seen no building of the bottom of this monsters first stage. So far we have a single stage that will see a limited payload mass to LEO in its current configuration.
GW I am sure has looked at this ability but its still a moving target of assumptions.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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