totm nov 2023 SpaceX Discussion Thread

[Beccab]

 

[Deddly]

Has anyone done the calculation to see how much heavier Starship is because Elon wanted it to be more pointy? 

[magnemoe]

9 hours ago, mikegarrison said:

This is part of the reason why welds are not traditionally used on airplanes.

These days welds are done by machine and are extremely consistent. If you use friction stir welding, it's not even an additive process.

Thought it was more with problem welding thin aluminum plates. 
Ships got lighter then they shifted from rivets to welding  during WW 2, think it was as much as 5% 

[Alyx0304]

How do y'all think Starship's landing legs are gonna look like? I heard someone say they were gonna use ones similar to the ones on the SNs but stronger

 

Also, do you think it's still gonna land on Mars?

 

[Beccab]

52 minutes ago, Alyx0304 said:

How do y'all think Starship's landing legs are gonna look like? I heard someone say they were gonna use ones similar to the ones on the SNs but stronger

 

Also, do you think it's still gonna land on Mars?

 

The landing legs will be a lot different between variants for sure; for earth landings, something the old ones seem pretty decent, considering it's a concrete landing pad with a flat surface. For moon and mars landing you need a wider base though, as well as some degree of levelling in the landing gear.

As for mars, it's still a bit too far to go beyond personal opinions for now. Imho, there will likely be at least some cargo landings; it's too early to speculate much about crewed mars trips though. I'm tending toward yes on both parts, but who knows

[tater]

[CatastrophicFailure]

And here we are on the KSP forum SpaceX thread, now devolved into literally arguing about watching paint dry. 

[JoeSchmuckatelli]

1 hour ago, CatastrophicFailure said:

And here we are on the KSP forum SpaceX thread, now devolved into literally arguing about watching paint dry. 

IKR?  What did I start? 

... 

Of course, when I quip about paint drying on the KSP2 sub, bad things happen 

Edited June 29, 2022 by JoeSchmuckatelli

[tater]

Live

[tater]

Another routine flight to space so far. MECO, sep, SES-1, fairing.

Entry burn

Greased it. Dead center.

[Beccab]

Landed!

[tater]

 

[sh1pman]

Was thinking about Moonship lander. Is there any info about how SpaceX is going to deal with heating issues? The ship is going to be sitting in constant sunlight for weeks. In a vacuum. Without some kind of active cooling the cabin will turn into a hot sauna very quickly. 

[StrandedonEarth]

8 minutes ago, sh1pman said:

Was thinking about Moonship lander. Is there any info about how SpaceX is going to deal with heating issues? The ship is going to be sitting in constant sunlight for weeks. In a vacuum. Without some kind of active cooling the cabin will turn into a hot sauna very quickly. 

There’s really no info at all about the habitable space. Presumably a cooling system will be part of that. I suppose they could lay out some ground loops to radiate away heat in whatever direction is away from the Sun, or even have them  in on or under the skin of the vehicle  

And then there’s the matter of keeping warm during the lunar night, but at least there will probably be some waste heat to help with that 

 

[Ultimate Steve]

Just now, StrandedonEarth said:

There’s really no info at all about the habitable space. Presumably a cooling system will be part of that. I suppose they could lay out some ground loops to radiate away heat in whatever direction is away from the Sun, or even have them  in on or under the skin of the vehicle  

And then there’s the matter of keeping warm during the lunar night, but at least there will probably be some waste heat to help with that 

 

Correct me if I'm wrong, but IIRC Artemis plans to land at places where the nights are either short or non existent. Depending on how short, they might be able to get away with burning some of their propellant for heat (and power) although that may not be trivial to plumb.

[sh1pman]

Just now, StrandedonEarth said:

I suppose they could lay out some ground loops to radiate away heat in whatever direction is away from the Sun, or even have them  in on or under the skin of the vehicle

Also, the ground itself gets boiling hot during the lunar day, so the radiators will need to be properly insulated. Does it make sense to find a permanently shaded ditch nearby and bury the coolant pipes underground there? 

[StrandedonEarth]

14 minutes ago, sh1pman said:

Also, the ground itself gets boiling hot during the lunar day, so the radiators will need to be properly insulated. Does it make sense to find a permanently shaded ditch nearby and bury the coolant pipes underground there? 

I was thinking have the coolant loops under a reflective Mylar canopy of some sort, keeping the ground underneath cool, and radiate out the sides. 

But they probably have completely different ideas. I’m just spitballing here. 

[JoeSchmuckatelli]

38 minutes ago, sh1pman said:

Also, the ground itself gets boiling hot during the lunar day, so the radiators will need to be properly insulated. Does it make sense to find a permanently shaded ditch nearby and bury the coolant pipes underground there? 

 

18 minutes ago, StrandedonEarth said:

I was thinking have the coolant loops under a reflective Mylar canopy of some sort, keeping the ground underneath cool, and radiate out the sides. 

But they probably have completely different ideas. I’m just spitballing here. 

How much lateral conduction would actually occur through regolith without atmosphere / water?   Simple shading should be generally sufficient I'd think. 

[Ultimate Steve]

They could have the loops raised slightly up off the ground with specially designed posts to minimize heat transfer.

Edited June 29, 2022 by Ultimate Steve

[tater]

https://riograndeguardian.com/trevino-i-expect-starship-to-launch-from-boca-chica-within-next-90-days/

Quote

“I could accurately say that if it was up to SpaceX it would have been today or yesterday. I can say that with a 100 percent degree of certainty,” Treviño responded. 

“But, I think on the real aggressive side, we are probably talking 30 days. On the more moderate side, probably 60 and more realistically 90. But, it could be anywhere in that ballpark.”

 

[CatastrophicFailure]

Race is still on. 

[sh1pman]

12 hours ago, JoeSchmuckatelli said:

 

How much lateral conduction would actually occur through regolith without atmosphere / water?   Simple shading should be generally sufficient I'd think. 

Shading of what, the ship? Like with a giant sun umbrella?

[Pthigrivi]

Long term a good solution might be digging trenches for a geothermal heat pump loop, essentially turning the regolith into a thermal battery to store heat during the day for use at night. On earth you have to dig down 1.2m or so, but soil on earth generally has quite a bit of conductive moisture so the heat pulse might not go so deep on on the moon.

Edit: Oh duh just dig a series of bore holes:

https://denning.atmos.colostate.edu/readings/lunar.regolith.heat.transfer.pdf

Edited June 30, 2022 by Pthigrivi

[StrandedonEarth]

3 hours ago, Pthigrivi said:

Long term a good solution might be digging trenches for a geothermal heat pump loop, essentially turning the regolith into a thermal battery to store heat during the day for use at night. On earth you have to dig down 1.2m or so, but soil on earth generally has quite a bit of conductive moisture so the heat pulse might not go so deep on on the moon.

Edit: Oh duh just dig a series of bore holes:

https://denning.atmos.colostate.edu/readings/lunar.regolith.heat.transfer.pdf

I was thinking boreholes too. Thx for finding a relevant document 

[Beccab]