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1 hour ago, CatastrophicFailure said:

 

some part of me wants to see this in a thrilling high-speed, very quiet chase around the Space Center grounds. :ph34r:

Security configuration: featuring a Tesla cannon and combat-ready AI.

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23 hours ago, sh1pman said:

Floating (or attached to seabed) launch platforms are going to be a thing when P2P BFR flights start happening. And according to Shotwell, they're definitely going to happen, within a decade or so.

I would not trust SpaceX staff's time estimations. Their boss has said himself that they may be a little "aspirational" (or word like that). It probably takes at least a decade before BFR makes first commercial unmanned space flights. Then they need much work and bureaucracy to get crew ratings and much more to get permissions to fly all countries near big cities. I would not say that it happens in foreseeable future.

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4 hours ago, Hannu2 said:

I would not trust SpaceX staff's time estimations. Their boss has said himself that they may be a little "aspirational" (or word like that). It probably takes at least a decade before BFR makes first commercial unmanned space flights. Then they need much work and bureaucracy to get crew ratings and much more to get permissions to fly all countries near big cities. I would not say that it happens in foreseeable future.

Meaning point to point, or flying at all (space flights)?

I think it will fly without crew well before 10 years. Crew is anyone's guess, I agree.

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11 minutes ago, tater said:

Meaning point to point, or flying at all (space flights)?

I think it will fly without crew well before 10 years. Crew is anyone's guess, I agree.

10 years is E2E BFR prediction by Shotwell. Elon time is half of that, I guess. So the first crew flights can be reasonably expected in 5 to 10 years time.

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5 hours ago, Hannu2 said:

Then they need much work and bureaucracy to get crew ratings and much more to get permissions to fly all countries near big cities.

Agree. Bureaucracy being the most complex... and twisted.

Another point I am curious about is the noise level, more precisely during the trans-sonic stage while descending. Obviously, weather conditions are playing a role in it, but as an example every single time a F9 first stage was landing back at the LZ1 it was more than possible to ear the so-call "sonic boom" pretty well, despite an horizontal separation of nearly 10 km (this, without counting the fact that the stage was still supersonic while being way farther)

When we knew it was (and still is) one of the "official" reasons against SST services or military maneuvers (apart from emergency) over some territories, I am wondering what they will find to fight against.

Edited by XB-70A
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30 minutes ago, XB-70A said:

Another point I am curious about is the noise level, more precisely during the trans-sonic stage while descending. Obviously, weather conditions are playing a role in it, but as an example every single time a F9 first stage was landing back at the LZ1 it was more than possible to ear the so-call "sonic boom" pretty well, despite an horizontal separation of nearly 10 km (this, without counting the fact that the stage was still supersonic while being way farther)

The incidence angle of a supersonic bow shock has a major impact on its ground effect. A supersonic vehicle overflying a populated area produces a sustained shockwave that travels linearly across the ground, with a sustained peak pressure. A vehicle descending almost straight down and going from supersonic through transonic to subsonic produces a toroidal region of shock which has a maximum only within a very small ring-shaped area on the ground.

If the shockwave from a supersonic overflight is like a tsunami scraping its way across the ground, the shockwave is like a sudden and severe but brief rainfall. 

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13 minutes ago, Nightfury said:

Regarding the legs:

no folding up on this one:(

Waaaaaaaaa??

:huh::huh::huh::huh::huh::huh:

I suppose that if they plan on taking this booster apart to nuts and bolts for inspection, it makes reasonable sense to take the legs off now and examine them separately.

leg_off.png

Odd. The old legs went on white and came off black. Now these go on black and come off sandblasted-white.

I wonder if the white is from ablation. 

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2 hours ago, sevenperforce said:

Waaaaaaaaa??

:huh::huh::huh::huh::huh::huh:

I suppose that if they plan on taking this booster apart to nuts and bolts for inspection, it makes reasonable sense to take the legs off now and examine them separately.

One would think that the quick-folding-after-launch thing is something they'd want to test before disassembly. I wonder if they had some kind of issue with it?

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8 minutes ago, CatastrophicFailure said:

One would think that the quick-folding-after-launch thing is something they'd want to test before disassembly. I wonder if they had some kind of issue with it?

Presumably they want to inspect for damage before refolding, which conceivably could cause additional damage that would obscure the source of the original damage.

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2 hours ago, sevenperforce said:

The incidence angle of a supersonic bow shock has a major impact on its ground effect. A supersonic vehicle overflying a populated area produces a sustained shockwave that travels linearly across the ground, with a sustained peak pressure. A vehicle descending almost straight down and going from supersonic through transonic to subsonic produces a toroidal region of shock which has a maximum only within a very small ring-shaped area on the ground.

 If the shockwave from a supersonic overflight is like a tsunami scraping its way across the ground, the shockwave is like a sudden and severe but brief rainfall. 

Still, it's not eliminating the problem (nothing to this date is), and I can't imagine one of their flight profile ending in a beautiful perpendicular trajectory.

Unless legal restrictions are softened, or reviewed, I guess it could lead to some "annoyance" to instance any port in an area close to a town.

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6 minutes ago, XB-70A said:

Still, it's not eliminating the problem (nothing to this date is), and I can't imagine one of their flight profile ending in a beautiful perpendicular trajectory.

Unless legal restrictions are softened, or reviewed, I guess it could lead to some "annoyance" to instance any port in an area close to a town.

It does eliminate the problem, to a degree. Their flight profiles do take a nearly perpendicular trajectory on landing, and the stage goes transonic at high enough altitude that the sonic boom is very muted. It's still audible from a great distance, but it's not the tooth-crunching, bone-shaking, window-shattering crack of a low-flying supersonic overflight.

Recall that sonic booms are directly analogous to the bow shock of a speedboat. If you are in the water and a speedboat passes nearby at high speed, it is going to produce a large wave that will very likely swamp you. However, if the speedboat is moving directly toward you and then stops before it reaches you, the bow shock will weaken and fade to nothing very rapidly.

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