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2 hours ago, Wjolcz said:

More than 1.

If they want to go all the way to the full launch weight including all the margins, it will be exactly 1 at the point of launch. It might not get all the way to orbit that way, though.

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2 hours ago, ThatGuyWithALongUsername said:

Didn't Elon say something about "aiming for about 1.5" at one point?

they have 35/27 raptors for a 5000tons ships, so 7-7.4 Meganewton of thrust, 1.5 is correct

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On 3/23/2020 at 3:08 PM, ThatGuyWithALongUsername said:

Didn't Elon say something about "aiming for about 1.5" at one point?

Think its 1.5 to 1.6 TWR, unlike an disposable rocket there you tend to go for low TWR as tanks and fuel is cheaper than engines, with an reusable stage especially with boost back you want an high TWR to get second stage up to speed fast so you can drop second stage early and go back. 

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31 minutes ago, CatastrophicFailure said:

Aaaaaand more meh news: 

 

Hope they didn't just bomb somebody's house!

SpaceX is planning to launch astronauts on unused, new boosters. At least at first.

I wonder if they will eventually reach a point where it is considered safer to launch on a "flight-proven" booster?

I've only been on the very first flight of an airplane one time, because those are usually very highly restricted. Usually just two pilots and a flight test engineer. (The one I was on was because we really needed some data on an ECS noise issue, and that was the only flight available to get it on.)

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7 hours ago, mikegarrison said:

I wonder if they will eventually reach a point where it is considered safer to launch on a "flight-proven" booster?

Think so, were there any mission failures with reused boosters yet? (Excluding landings)

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8 hours ago, mikegarrison said:

Hope they didn't just bomb somebody's house!

SpaceX is planning to launch astronauts on unused, new boosters. At least at first.

I wonder if they will eventually reach a point where it is considered safer to launch on a "flight-proven" booster?

I've only been on the very first flight of an airplane one time, because those are usually very highly restricted. Usually just two pilots and a flight test engineer. (The one I was on was because we really needed some data on an ECS noise issue, and that was the only flight available to get it on.)

I assume they was afraid the parachutes could open during flight who would be bad. 

I wonder if an booster used one or two times is safer than an new, more than that and you probably get some wear who reduce relability.

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2 hours ago, Xd the great said:

Think so, were there any mission failures with reused boosters yet? (Excluding landings)

The recent Starlink mission was definitely a close call although it was a primary mission success.

Falcon9's two mission failures were with new boosters due to design flaws. There's never a good time to discover a design flaw, but it does make sense that if there are any they're more likely to show up on the first flight as opposed to the second or later.

Also worth noting - Falcon9's one secondary payload failure was that after an engine failure there wasn't enough margin left to make the secondary orbit with the required level of confidence. Now that most flights are recovered they fly with a huge landing margin. If you have an engine out you just sacrifice the landing and use your full expendable performance to acheive the mission. It's a double level of mission security in addition to engine-out capability.

Edited by RCgothic
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1 hour ago, RCgothic said:

Has anyone ever seen any internal baffles go into these tanks? What's to stop the fuel sloshing around during throttle events and manoeuvring?

Not much. But that's probably desirable actually. When Starship goes belly first into the atmosphere the fuel should collect in its 'belly part' moving the centre of mass away from the centre of pressure making it more shuttlecocky.

Unless it's designed to reenter with all tanks but the header ones empty. But then they are still talking about transpirational cooling and can't imagine they want to use precious header tank fuel for that.

BTW did Saturn V have any anti-sloshing mechanisms?

Edited by Wjolcz
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38 minutes ago, sevenperforce said:

Yep. Slosh baffles and rings in the first stage RP-1 tank:

That's the Saturn 1 though, a much smaller rocket than the Saturn V. I wasn't able to find anything about Saturn V baffles.

I know there were ullage motors on the third stage.

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