Refurbishment of Used Stages/Vehicles

[Jcc]

a few months back I toyed with the idea of using the legs to generate lift and control...

Mechanically, current legs are a non-starter on this. I don't know whether Block 5 will have automatically retractable legs, but probably not.

And aerodynamically...no, I don't think this works. Even with the COM being so far forward, the drag on those legs at anything over a few km/s would flip the stage like a shuttlecock.

Elon Musk has just said, the gridfins become a lot larger and provide more drag. That could counter some more drag of the legs. Or just one leg. He did announce too that the rocket can do some more lift as well. I don't believe that helps on ascent but can increase drag on the way down. The increase of capability must come from somewhere and not from more engine thrust alone.

I think he said the larger grid fins will provide more control authority, besides being able to handle the heat. Obviously, they would produce more drag also, and reduce terminal velocity a bit. One thing I interpreted was that perhaps with better lift characteristics it can go through the thinner atmosphere at a shallower angle, and therefor enter at a higher velocity, requiring less of a reentry burn, ultimately saving fuel.

[FutureSpaceTourist]

Copying here as more appropriate on this thread:

They might switch to an ablative coat that can be quickly applied and removed. Something that provides good thermal insulation, and protects the core from re-entry heating. Better ablative paint would allow them to try even hotter landing which use shorter re-entry burns, and in turn with the stronger titanium grid-fins allow them to glide and aerobrake.

Surely to get very rapid re-use there needs to be less use of ablative coatings? How else are 10 re-uses without refurbishment, and a potential 24 hrs between flights, going to be achieved?

[Kaputnik]

Copying here as more appropriate on this thread:

They might switch to an ablative coat that can be quickly applied and removed. Something that provides good thermal insulation, and protects the core from re-entry heating. Better ablative paint would allow them to try even hotter landing which use shorter re-entry burns, and in turn with the stronger titanium grid-fins allow them to glide and aerobrake.

Surely to get very rapid re-use there needs to be less use of ablative coatings? How else are 10 re-uses without refurbishment, and a potential 24 hrs between flights, going to be achieved?

I agree. But perhaps the TPS will have enough margin on it for multiple flights. And some materials do not start ablating until beyond a certain exposure level, so it is conceivable that the refurbishment perid would depend on what flight profile had been flown?

[sevenperforce]

Does anyone happen to know whether COTS spray-on ablative materials are even available? Washing the soot off the stage and spraying on a fresh coat of ablative protection probably wouldn't count as a full "refurb" and could be done after each flight.

[Kabloona]

Does anyone happen to know whether COTS spray-on ablative materials are even available? Washing the soot off the stage and spraying on a fresh coat of ablative protection probably wouldn't count as a full "refurb" and could be done after each flight.

LockMart sells several.

https://tinyurl.com/l3h89nu

[Norm38]

@jeff_foust on Twiiter currently reporting on Shotwell's talk at 33SS.

https://twitter.com/jeff_foust

From the tweet:  "Shotwell:  Refurbishment cost is substantially less than half of a new one, and will get better"

What is substantially less? Is that 40%, 30%?

[AncientU]

@jeff_foust on Twiiter currently reporting on Shotwell's talk at 33SS.

https://twitter.com/jeff_foust

From the tweet:  "Shotwell:  Refurbishment cost is substantially less than half of a new one, and will get better"

What is substantially less? Is that 40%, 30%?

Sure, pick one.  40% is correct order of magnitude -- best we'll ever know.

[pb2000]

@jeff_foust on Twiiter currently reporting on Shotwell's talk at 33SS.

https://twitter.com/jeff_foust

From the tweet:  "Shotwell:  Refurbishment cost is substantially less than half of a new one, and will get better"

What is substantially less? Is that 40%, 30%?

I doubt SpaceX will release exact figures, or give reference to what half they are referring to (internal cost or sticker price). In any event this is the very first reflown booster so, lets wait for block 5 (and knowing Elon block 5.001, 5.002, etc) before counting nickels and dimes.

[guckyfan]

I find it astounding that going through that stage with a fine comb, doing things that have never been done, and finding out all that needed finding out was done with less than 50% of the cost of building a new one.

It can only go way down from there.

[JamesH65]

I find it astounding that going through that stage with a fine comb, doing things that have never been done, and finding out all that needed finding out was done with less than 50% of the cost of building a new one.

It can only go way down from there.

Materials cost? Labour to make the big tanks and engines? Both very time consuming I assume.

[Lars-J]

I find it astounding that going through that stage with a fine comb, doing things that have never been done, and finding out all that needed finding out was done with less than 50% of the cost of building a new one.

It can only go way down from there.

Materials cost? Labour to make the big tanks and engines? Both very time consuming I assume.

The by far biggest component of the cost is labor. Material costs are lower than most people think.

[Endeavour126]

Is there an official statement about the reasons not to refly again the SES-10 first stage?

[Elmar Moelzer]

Is there an official statement about the reasons not to refly again the SES-10 first stage?

Elon Musk thinks it is of historic value and wants to donate it to the cape as a display piece of sorts.

[Endeavour126]

Thank you.

[rsdavis9]

Is there an official statement about the reasons not to refly again the SES-10 first stage?

Elon Musk thinks it is of historic value and wants to donate it to the cape as a display piece of sorts.

And maybe limited value to refly because of age and better candidates coming in all the time.

[FutureSpaceTourist]

At about 10:30 in the video Gwynne says something about future refurbishment cost that I can't quite make out. There's a "10" and "labour" but I'm not sure what else.

Don't know where else to post this. Gwynne Shotwell's talk at the 33rd Space Symposium shot on someone's mobile:



Seems to include most of the Q&A too.

[RedLineTrain]

At about 10:30 in the video Gwynne says something about future refurbishment cost that I can't quite make out. There's a "10" and "labour" but I'm not sure what else.

Don't know where else to post this. Gwynne Shotwell's talk at the 33rd Space Symposium shot on someone's mobile:



Seems to include most of the Q&A too.

"It will be on the order of a tenth the work, the labor."

[Wolfram66]

You could always have a door in the top of the core storage facility and install a rack system like fridge soda can dispenser... 

[rsdavis9]

You could always have a door in the top of the core storage facility and install a rack system like fridge soda can dispenser... 

That sure beats the size of the HUGE sodas they serve at the movie theater.

[AncientU]

I find it astounding that going through that stage with a fine comb, doing things that have never been done, and finding out all that needed finding out was done with less than 50% of the cost of building a new one.

It can only go way down from there.

Sounds like down to 10%, in fact.

...
"It will be on the order of a tenth the work, the labor."