Booster Cleaning?

[brettreds2k]

I have noticed tonight’s launch, the the previous launch looked like new first stages but of course tonight’s 6th landing and the previous launch I believe was a 10th landing.

I guess SpaceX is now cleaning the first stages between flights?? They have done this in quite a while.

[brettreds2k]

I thought someone in here would know lol

[Alexphysics]

I have noticed tonight’s launch, the the previous launch looked like new first stages but of course tonight’s 6th landing and the previous launch I believe was a 10th landing.

I guess SpaceX is now cleaning the first stages between flights?? They have done this in quite a while.

They don't clean first stages between flights. What you might have seen is the soot getting covered in ice and thinking it is whitier than usual which is only an illusion of the ice being there in the first place, not because of any cleaning at all.

[oldAtlas_Eguy]

I have noticed tonight’s launch, the the previous launch looked like new first stages but of course tonight’s 6th landing and the previous launch I believe was a 10th landing.

I guess SpaceX is now cleaning the first stages between flights?? They have done this in quite a while.

They don't clean first stages between flights. What you might have seen is the soot getting covered in ice and thinking it is whitier than usual which is only an illusion of the ice being there in the first place, not because of any cleaning at all.

The amount of ice is a matter of atmospherics. Humidity level, air temp, wind speeds, direction, and sun angle as well.

[brettreds2k]

That makes sense. I knew they stopped cleaning them after the first few reused launches but these last 2 looked super clean which is why I was wondering. Thanks everyone!!

[king1999]

They don't clean first stages between flights. What you might have seen is the soot getting covered in ice and thinking it is whitier than usual which is only an illusion of the ice being there in the first place, not because of any cleaning at all.

The black streaks on the reused rockets are not soot but scorch marks. Soot can be washed off to reduce weight but scorch marks can't be removed without replacing the coating.

[Redclaws]

They don't clean first stages between flights. What you might have seen is the soot getting covered in ice and thinking it is whitier than usual which is only an illusion of the ice being there in the first place, not because of any cleaning at all.

The black streaks on the reused rockets are not soot but scorch marks. Soot can be washed off to reduce weight but scorch marks can't be removed without replacing the coating.

Source for this?

[darkenfast]

They don't clean first stages between flights. What you might have seen is the soot getting covered in ice and thinking it is whitier than usual which is only an illusion of the ice being there in the first place, not because of any cleaning at all.

The black streaks on the reused rockets are not soot but scorch marks. Soot can be washed off to reduce weight but scorch marks can't be removed without replacing the coating.

How are Dragon crews able to sign their names on F9 Boosters with their fingers then? SpaceX launch commentators have repeatedly told us that the black deposits on the first stages are soot from the Merlin engines firing into the air-stream during re-entry and landing.

[king1999]

Source for this?

https://twitter.com/elonmusk/status/1068940024136126464

[whitelancer64]

https://www.reddit.com/r/spacex/comments/ovesbd/the_inspiration4_crew_holds_up_sooty_fingers/

[whitelancer64]

SOOTY FINGERS The astronauts of SpaceX's Crew-2 mission to the International Space Station pause for a picture after writing their initials in the soot on the used Falcon 9 rocket they will ride to orbit. From left to right: Thomas Pesquet (ESA), Shane Kimbrough (NASA), Akihiko Hoshide (JAXA), and Megan McArthur (NASA).

https://www.planetary.org/space-images/sooty-fingers

[AC in NC]

It's obviously BOTH notwithstanding Elon's tweet.  RP-1 is going to produce soot and re-entry is going to scorch.  [deleted]

[Redclaws]

I think it was an interesting question and I like the “both” answer.  It makes sense and fits the facts.

[deleted]

[Alexphysics]

Yes, boosters get covered in soot, and yes they also have scorch marks. Soot can be removed a bit but not entirely and specially at the scale of the whole booster. I know they tried cleaning up soot entirely from boosters with all possible ways but all you can do at most is removing the upper layer, there's a deeper layer that is extremely complicated to remove so they just resorted to painting over. In the end they realized how suboptimal this was and they stopped doing it altogether

[alugobi]

They do, however, clean off the weld lines for inspection.  We occasionally see a booster with cross-hatch clean lines on it.

[jon.amos]

They do, however, clean off the weld lines for inspection.  We occasionally see a booster with cross-hatch clean lines on it.

Cleaned for this inspection or cleaned by this inspection.  Ultrasonic inspection would be pretty good as cleaning process depending on the coupling media.