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22 minutes ago, tater said:

Winds might be lower

That's what I was thinking, but if they are that sensitive to the local wind, then, um, did they really pick the right place for their spaceport?

Anyway, I've worked on tests at night, for multiple reasons (schedule, temperature requirement, low ambient noise, and even, yes, wind). But when doing something like this for the first time, typically you really would want to do it in the daylight if at all possible.

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26 minutes ago, mikegarrison said:

That's what I was thinking, but if they are that sensitive to the local wind, then, um, did they really pick the right place for their spaceport?

Anyway, I've worked on tests at night, for multiple reasons (schedule, temperature requirement, low ambient noise, and even, yes, wind). But when doing something like this for the first time, typically you really would want to do it in the daylight if at all possible.

Options there are pretty limited, places right on the coast tend to be windy… or hurricane-prone… or populated… it’s pick your poison. IIRC this whole system is supposed to be much more wind tolerant than a typical crane, but as this is the very first lift, they’re wisely using excessive caution. I reckon with all the lights they have there, wind is the greater concern. 

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31 minutes ago, mikegarrison said:

That's what I was thinking, but if they are that sensitive to the local wind, then, um, did they really pick the right place for their spaceport?

Anyway, I've worked on tests at night, for multiple reasons (schedule, temperature requirement, low ambient noise, and even, yes, wind). But when doing something like this for the first time, typically you really would want to do it in the daylight if at all possible.

They also have a finite number of closures available, so extending one they have and avoiding any other daytime beach interruptions might be an issue.

Not sure how day/night makes much of a difference here. The cameras they are using don't seem to care—they even turned the lights on inside the skirt I noticed.

Just now, kerbiloid said:

Nozzles are clipping the frame???

OMG, that's so Kerbal!

Yeah, Rvac don't gimbal, so they can be fixed to the body.

3 minutes ago, CatastrophicFailure said:

Options there are pretty limited, places right on the coast tend to be windy… or hurricane-prone… or populated… it’s pick your poison. IIRC this whole system is supposed to be much more wind tolerant than a typical crane, but as this is the very first lift, they’re wisely using excessive caution. I reckon with all the lights they have there, wind is the greater concern. 

Yeah, this is true as well. It is the very first try.

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9 minutes ago, tater said:

The Steel is only 4mm thick. There is a stiffening ring around the bottom, and the cut outs are in that.

 

9 minutes ago, CatastrophicFailure said:

It’s just a “rib,” and certainly braced as needed for the cutouts. Heck, having the engines fixed in place there might make the whole thing stronger

OK, but how were they designing both SS and SH, that in SS they have to cut out the ring instead of making a wider ring or place the engines closer by design, and in SH the engines do not fit the stage diameter and stick ou radially, requiring a skirt (exactly the reason of the skirt in N1)...

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Just now, kerbiloid said:

 

OK, but how were they designing both SS and SH, that in SS they have to cut out the ring instead of making a wider ring or place the engines closer by design, and in SH the engines do not fit the stage diameter and stick ou radially, requiring a skirt (exactly the reason of the skirt in N1)...

On the booster it doesn't matter. On the ship, it needs to meet the top of the interstage flat, and it needs the ring for latching hardware.

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1 hour ago, tater said:

On the booster it doesn't matter. On the ship, it needs to meet the top of the interstage flat, and it needs the ring for latching hardware.

On the first stage it tells that the required engine number was underestimated (possibly because the available engine thrust was overestimated, compared to the actual).
Otherwise they would just make the pencil a meter wider, and needed no skirt (which is additional air drag).

On the upper stage this in turn  is forced by the lower stage diameter (and probably by the fires in almost every test caused by the engines put too close to each other), as no engineer in clear mind would make these cutout willingly.
(Because they both weaken the constructon and complicate the production)

Edited by kerbiloid
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1 hour ago, CatastrophicFailure said:

having the engines fixed in place there might make the whole thing stronger

I highly doubt it. I would be really surprised if those engine nozzles actually touch that frame there. With all the different temperature extremes involved, I would be surprised if they wanted to induce any thermal stress due to differential expansion.

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2 minutes ago, mikegarrison said:

I highly doubt it. I would be really surprised if those engine nozzles actually touch that frame there. With all the different temperature extremes involved, I would be surprised if they wanted to induce any thermal stress due to differential expansion.

As I understand it, the arrangements is specifically so that the bells can be fixed to structure, details unknown, to help support them. Musk mentioned this in the past. 

4 minutes ago, kerbiloid said:

The next episode of the series will probably be caused by the first stage engines still put too close to each other like in the first versions of the second stage.

The engines on there now are likely as further developed and refined as S20 is to those older prototypes. And a full version 2.0 has already been spotted on site. Pretty sure there won’t be the same issues, if indeed they were issues. 

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Just now, CatastrophicFailure said:

As I understand it, the arrangements is specifically so that the bells can be fixed to structure, details unknown, to help support them. Musk mentioned this in the past. 

Sounds like a recipe for structural failure, but with these things details matter. So we'll see what happens.

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