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Interesting. 10 sides, with 2 pillars per side—this is related to the SH outer ring of engines, clearly.

2 minutes ago, cubinator said:

Ok I gotta ask...I don't suppose there's an elevator in there yet, so do the workers ride up on the crane? Or do they have to take the stairs?

Actually, there is an elevator visible. Goes to the 4th or 5th segment.

 

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1 hour ago, tater said:

 

Worth noting that 378 isp is already the isp they were targeting for it, and that in 2019 he said it would be later possible for the rVac to reach 385 isp albeit very difficult
Edit: old video (9 months ago), but this is how the static fire of a rVac looks like

and this the comparison between normal raptors and vac ones

 

Edited by Beccab
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33 minutes ago, sevenperforce said:

Okay, nice. That helps with some of the speculative maths....

Yeah, I've been using 380 until now.

Would be interesting to see what parameters are required for a LSS to be propulsively staged from LEO. I still like "tug" architecture, myself, but I think it might well be possible to run the whole thing from LEO/MEO as any refilling ops around the Moon don't really save anything (you have to get those props there regardless, might as well take them in the LSS itself).

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22 minutes ago, tater said:

Yeah, I've been using 380 until now.

Would be interesting to see what parameters are required for a LSS to be propulsively staged from LEO. I still like "tug" architecture, myself, but I think it might well be possible to run the whole thing from LEO/MEO as any refilling ops around the Moon don't really save anything (you have to get those props there regardless, might as well take them in the LSS itself).

The problem is that LSS can not aerobrake into LEO, the tankers can as they have heat shield and flaps. 
And if the aerobrake fails you only loose a tanker. 

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15 minutes ago, Beccab said:

Do we have any info regarding the isp of sea level raptors?

350s

6 minutes ago, magnemoe said:

The problem is that LSS can not aerobrake into LEO, the tankers can as they have heat shield and flaps. 
And if the aerobrake fails you only loose a tanker. 

Propulsively.

Musk said tank could be stretched for 1600t of propellants. A 60t SS could then leave LEO, land on the Moon, and return to LEO with no aerobraking at all (using 378s Isp). That's a fast transit. Assuming the crew is not taking SS from LEO (Orion/whatever), they can reduce the dv requirements slightly with a slower transfer. Assuming an 80t LSS, it's slightly low on dv for this, but the retanking ops could simply be in a higher orbit.

The bottom line is LSS can certainly function from an Earth orbit, it's just a matter of where.

Tanker 1 goes to LEO and gets filled. Tanker 2 goes to LEO and is partially filled. LSS is sent to MEO and is met by tanker 1 and 2, and topped off completely. Does complete lunar mission, and returns to MEO.

 

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Alternately make a SS that sheds the nose as a fairing, and what would be the payload adapter is just a match for the base. You now have a SS tug that has engines on the bottom, and a "bottom" for docking also on the top. Fill that. Fill LSS. Dock tug to LSS, give LSS 2.3 to 2.5km/s with tug. Tug propulsively returns to LEO. 80t LSS with normal 1200t props can fly to lunar surface and back to LEO using engines, no aerobraking.

The special sauce with SS is refilling. If they can land stage 2 just for uncrewed tankers and do the refilling ops... SS changes literally everything.

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I think it’s worth noting that all Starship variants including Lunar will be stainless steel, as far as we know. As such, they should be able to take a fair amount of aerobrake without any extra thermal protection, especially if there are leftover props to act as a heat sink. And when crew is not involved and time is less of an issue, then the aerobrake passes can be as shallow as they need to be 

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54 minutes ago, StrandedonEarth said:

I think it’s worth noting that all Starship variants including Lunar will be stainless steel, as far as we know. As such, they should be able to take a fair amount of aerobrake without any extra thermal protection, especially if there are leftover props to act as a heat sink. And when crew is not involved and time is less of an issue, then the aerobrake passes can be as shallow as they need to be 

Yeah, for any uncrewed variant, they can make as many passes as needed.

 

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