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56 minutes ago, StrandedonEarth said:

They were planning on using the SDs for propulsive landing, so they should be able to throttle pretty deep 

Yes, you could not do hoverslam manned. The high g force is an requirement for abort at all situations especially max-q breakup 
However the superdrako is less efficient than the drako engines so you would want them for orbital operations. 

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18 minutes ago, CatastrophicFailure said:

Hey, remember that flap a while back where SpaceX had to cut the camera feed because reasons? The Gummint is actually close to a meaningful and reasonable change in regulation (shocking! :o).

 

Quote

 

Kelley alluded to that issue in her remarks. “SpaceX’s GoPro camera, that is used for marketing and shows customers that the payloads have successfully been separated, should not be treated in the same way as the highly technical camera that can see your shoelaces from space,” she said.

 

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IpEwSZ6.jpg

 

Also, RE: @tater's quoted tweet, I read recently that Crew Dragon flights will all be drone ship booster landings as opposed to RTLS, same reasoning as the dual-engine Centaur for those other guys<_<. Allows a flatter launch profile, thereby exposing the crew to lower G-loading in the event of an abort.

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5 hours ago, Xd the great said:

A question for the bfr: how do spaceX plan on keeping the cryo oxygen stored for months?

Vent the main tank to vacuum to thermus the header tanks with no solar irradiation. Any additional cooling will require bleedoff.

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58 minutes ago, kerbiloid said:

But the metal structure still keeps conducting the heat.

At a significantly reduced rate, especially if the ship stays nose on to the sun. And when that's not enough, I mentioned the solution in the part of the post you deleted.

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3 minutes ago, Rakaydos said:

I mentioned the solution in the part of the post you deleted.

I can't delete posts.
And my question post is not edited.
So, I don't understand this part.

4 minutes ago, Rakaydos said:

At a significantly reduced rate

Metal is a good conductor.

Buran had a small tank with a big mechanical skimmer inside to keep LOx liquid for 2-3 weeks.

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1 hour ago, kerbiloid said:

I can't delete posts.
And my question post is not edited.
So, I don't understand this part.

 

2 hours ago, Rakaydos said:

Vent the main tank to vacuum to thermus the header tanks with no solar irradiation. Any additional cooling will require bleedoff.

 

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10 hours ago, Rakaydos said:

Vent the main tank to vacuum to thermus the header tanks with no solar irradiation. Any additional cooling will require bleedoff.

Elon basically said this a year ago in a reddit AMA here. Granted that was the previous BFR design, but I doubt they've changed this. He did mention a cryocooler was an option down the road.

I recalled there was a section on space storable propellants in Ignition, the most relevant part is this:

"After all, the hard
vacuum of space is a pretty good insulator, and when you have, in
effect, a Dewar flask the size of the universe available, you can store a
low-boiling liquid a long time. An arbitrary upper limit (—150°) was
set for the boiling point of a space-storable, but the custom is to
stretch this limit to include the propellant you want to sell. OF2, boiling
at —144.8° is considered a space storable, but if you want to call
its ideal partner, methane, CH4, boiling at—161.5° one too, nobody is
going to complain too loudly."

Temperatures are in Celsius and this is from a time where OF2 is something people considered flying (wouldn't bet on it today). This does make things interesting though because LOX has a boiling point of -182.9 degrees, so we need to stretch the definition of space storable a little further.

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