First Falcon 9 Block 5 booster readying for static fire at McGregor

[Chris Bergin]

https://www.nasaspaceflight.com/2018/02/first-falcon-9-block-5-readying-static-fire-mcgregor-rapid-reuse/

- By Ian Atkinson (covering the evolution of Falcon 9 through to this first Block 5 arriving on the test stand). Photos by NSF's Gary Blair for L2 McGregor.

[speedevil]

the whole first stage will be covered in a thermal protection coating to help it better survive atmospheric reentry.

I'd missed, if that has not been revealed before.

I wonder how much higher energy FH centre-core entry that will permit reusably.

This could help fully recoverable payload quite a lot, as propulsive burns really hurt payload.
(through lower velocity at staging)

[Paul Howard]

Great work again NSF. Do we know more about the black interstage. Ian didn't seem to mention that visual addition.

[IanThePineapple]

Great work again NSF. Do we know more about the black interstage. Ian didn't seem to mention that visual addition.

Oh, I didn't talk about that.

I'll edit it once I get home

[Eerie]

And it's not octagonal. What the hell??? 8-P

[IanThePineapple]

And it's not octagonal. What the hell??? 8-P

I never understood why people thought was octagonal

[billh]

I don't see a photo credit on the aerial shot of the Block V on the test stand.

[Chris Bergin]

I don't see a photo credit on the aerial shot of the Block V on the test stand.

Shows it here:

[billh]

I don't see a photo credit on the aerial shot of the Block V on the test stand.

Shows it here:

Hmm. For some reason that doesn't show up in my browser. I've tried both Chrome and IE. The other picture credits do show up.

Edit: And Edge. All on Windows 10.
Edit2: Ah, I see. The picture directly below the title does not have a caption or credit. But the same picture does have the caption and credit when it appears in the body of the article.

[Herb Schaltegger]

And it's not octagonal. What the hell??? 8-P

I never understood why people thought was octagonal

Because people saw photos of the wrapped booster en route and it looked octagonal (due to the way the booster packaged/wrapped for the road) and because SpaceX boosters on the road is now so common in space-nerd circles, people haven't been paying attention to the road photos for a few years.

Eh, what can you do?

[abaddon]

Great to finally see that black interstage.  Should look quite dashing with the second stage on top.

I didn't know the raceway was going to be black, too.  That looks a little strange to my eyes, although I am sure after a few launches it will become the new normal.

[EngrDavid]

According to Wikipedia, the interstage is made from carbon fiber aluminum core composite.  Has this changed and its now purely carbon fiber and that explains the black color?  Or is the black color just because SpaceX decided not to paint it white.

[kevinof]

The new one is black, unpainted carbon.

According to Wikipedia, the interstage is made from carbon fiber aluminum core composite.  Has this changed and its now purely carbon fiber and that explains the black color?  Or is the black color just because SpaceX decided not to paint it white.

[JamesH65]

The new one is black, unpainted carbon.

According to Wikipedia, the interstage is made from carbon fiber aluminum core composite.  Has this changed and its now purely carbon fiber and that explains the black color?  Or is the black color just because SpaceX decided not to paint it white.

Purely for weight saving, or speed of manufacture? Presumably nothing heat critical inside. Or perhaps carbon just looks cooler....

[IanThePineapple]

The new one is black, unpainted carbon.

According to Wikipedia, the interstage is made from carbon fiber aluminum core composite.  Has this changed and its now purely carbon fiber and that explains the black color?  Or is the black color just because SpaceX decided not to paint it white.

Purely for weight saving, or speed of manufacture? Presumably nothing heat critical inside. Or perhaps carbon just looks cooler....

Probably unpainted to save weight, like what was done with the shuttle ET

[Nomadd]

 Presumably nothing heat critical inside. Or perhaps carbon just looks cooler....

It doesn't just look cooler. Black would radiate heat better.

[jpo234]

 Presumably nothing heat critical inside. Or perhaps carbon just looks cooler....

It doesn't just look cooler. Black would radiate heat better.

Does this matter? It will be in space for only a few minutes and inside the atmosphere other effects dominate...

[matthewkantar]

The leg attachments look unchanged. Excited too see what the bottom of the rocket looks like up close. Looks like a metal band around the bottom? Inconel or titanium heat shield?

Matthew

[neoforce]

the whole first stage will be covered in a thermal protection coating to help it better survive atmospheric reentry.

I'd missed, if that has not been revealed before.

I wonder how much higher energy FH centre-core entry that will permit reusably.

This could help fully recoverable payload quite a lot, as propulsive burns really hurt payload.
(through lower velocity at staging)

I also missed the thermal protection change until this article. Is there any additional information about this?  Is it a paint choice or some new material in the core?  Does the interstate have this change?  (Not sure if the interstate is considered part of the first stage or not)

[matthewkantar]

I also missed the thermal protection change until this article. Is there any additional information about this?  Is it a paint choice or some new material in the core?  Does the interstate have this change?  (Not sure if the interstate is considered part of the first stage or not)

The most surprising thing I noticed when I saw a used Falcon first stage in person was the use of cork as insulation. Amazing to me in 2017 the best product found for this application was tree bark. will be interesting to find out if the new protection includes cork.

Matthew

[envy887]

According to Wikipedia, the interstage is made from carbon fiber aluminum core composite.  Has this changed and its now purely carbon fiber and that explains the black color?  Or is the black color just because SpaceX decided not to paint it white.

Don't have to paint it, don't have to clean it. But I am curious what kind of TPS, if any, is on the interstage. That's going to get toasty on entry.

[sunbingfa]

Forgive my naive question, but does Stage1 also contains COPV in its LOX tank?

[cambrianera]

The leg attachments look unchanged. Excited too see what the bottom of the rocket looks like up close. Looks like a metal band around the bottom? Inconel or titanium heat shield?

Matthew

Pattern of latches seems different.

[Lars-J]

 Presumably nothing heat critical inside. Or perhaps carbon just looks cooler....

It doesn't just look cooler. Black would radiate heat better.

I think you are confused, black absorbs heat better. Not necessarily what you want. (which is why no fairings are painted black) But perhaps there are some other mitigating factors.

As for no paint, I certainly expect there to be some sort of coating over the carbon fiber to add some sort of protection.

[RotoSequence]

I think you are confused, black absorbs heat better. Not necessarily what you want. (which is why no fairings are painted black) But perhaps there are some other mitigating factors.

Black is simultaneously the best absorber and radiator of heat.

[docmordrid]

Forgive my naive question, but does Stage1 also contains COPV in its LOX tank?

Yes.

[meberbs]

 Presumably nothing heat critical inside. Or perhaps carbon just looks cooler....

It doesn't just look cooler. Black would radiate heat better.

I think you are confused, black absorbs heat better. Not necessarily what you want. (which is why no fairings are painted black) But perhaps there are some other mitigating factors.

How well something radiates heat is equal to how well it absorbs heat. If you are in a situation where your heat is not coming from radiation (e.g. contact from hot air) then black is the best color for cooling.

Most fairings don't worry about re-entry, and in the discussion of fairing re-use, I believe it has been stated their large ballistic coefficient means they should slow without much heating.

[cambrianera]

Emission or absorption is related to wavelenght.
Color is related to visible spectrum wavelenght.
You can have a white that has low emission (and low absorption) in visible and high emission (and absorption) in infrared.

[Lars-J]

I think you are confused, black absorbs heat better. Not necessarily what you want. (which is why no fairings are painted black) But perhaps there are some other mitigating factors.

Black is simultaneously the best absorber and radiator of heat.

Yes but only after absorbing a lot of heat. It has a high thermal equilibrium if that makes sense.

But the point about certain materials ptentially more emissive/absorbing in different wavelengths is a good one.

[cambrianera]

I think you are confused, black absorbs heat better. Not necessarily what you want. (which is why no fairings are painted black) But perhaps there are some other mitigating factors.

Black is simultaneously the best absorber and radiator of heat.

Yes but only after absorbing a lot of heat. It has a high thermal equilibrium of that makes sense.

But the point about certain materials ptentially more emissive/absorbing in different wavelengths is a good one.

That's it.
You want good emission in long infrared for low temperature.
For high temperature TP (shuttle belly) you want high emission in visible (red/orange, but obviously black is easier).
And high absorption in visible is not a problem on this kind of TP.

[abaddon]

Most fairings don't worry about re-entry

While that is true, we're currently talking about the interstage, which re-enters at a high velocity along with the rest of the first stage.

[EDIT] I see you were replying to a comment about the fairing, so I think we're all in agreement here.

[Elthiryel]

I've got some comments and questions regarding the article.

SpaceX developed the Full Thrust variant – sometimes incorrectly called “v1.2” – of the Falcon 9.

I don't think calling it v1.2 is actually incorrect. Some of the FT/v1.2 FAA launch licenses were certainly containing this name ("Falcon 9 Version 1.2", to be precise), I've attached the CRS-10 licence below.

Block 2 (B1021) was the first to be reused

I'm the one who tries to track which FT/v1.2 core was flying in which block version (I've even created an online spreadsheet to store this data ). For now, I presumed that the first Block 2 was 1021 (CRS-8), 1022 (JCSAT-14) or 1023 (THAICOM , but most probably 1021 or 1022. So, for me, this is a very interesting piece of information, can you confirm it is legitimate? It would allow me to update my spreadsheet.

[Tomness]

I hope the full static fire, meets or exceeds all thrust requirements and Block V is locked down and start on Block V Heavy Center core.

[RedSky]

The SPACE X name seems much higher on the stage.   Up in the frost LOX tank area...  to keep the name protected from the sooty lower section?

[joek]

The SPACE X name seems much higher on the stage.   Up in the frost LOX tank area...  to keep the name protected from the sooty lower section?

And possibly with the additional stage thermal protection it will not be obscured by condensation/ice during launch.  Will be interesting to see if there is a significant reduction.

[Lars-J]

The SPACE X name seems much higher on the stage.   Up in the frost LOX tank area...  to keep the name protected from the sooty lower section?

Nice catch, I was staring at it to see differences, but missed the most obvious. 

They have also moved the logos that used to be on the interstage (F9, US flag) down to just below the interstage.

[pargoo]

I think you are confused, black absorbs heat better. Not necessarily what you want.

Don't forget the Russian use black fairings on Proton: Kristall, Zarya, etc.

[Patchouli]

I also missed the thermal protection change until this article. Is there any additional information about this?  Is it a paint choice or some new material in the core?  Does the interstate have this change?  (Not sure if the interstate is considered part of the first stage or not)

The most surprising thing I noticed when I saw a used Falcon first stage in person was the use of cork as insulation. Amazing to me in 2017 the best product found for this application was tree bark. will be interesting to find out if the new protection includes cork.

Matthew

It's been used on a couple of other LVs such as the Delta II  though I wonder if parts of it on the Block 5 booster have been replaced with insulation similar to AFRSI  on the Shuttle?

[Elmar Moelzer]

I may have simply missed it on earlier first stage pictures (though looking through older pics, I cant seem to see them), or maybe it is not actually part of the stage but the crane, but there are some very visible "blocky things" on the top edge of the interstage. Are those part of the stage and if so, are they new additions?

Edit: Upon taking a closer look, I don't think they are actually part of the stage.

[Ugger55]

On the question of the back interstage and is it a good/bad thing for heat, are we all getting a little too far led down the garden path of reasons, beyond just the "rule of cool" and ease of manufacture.

Rocket lab's entire rocket is black including it's fairing. It will launch from the cape and currently launches from somewhere hot enough to invalidate range conditions. If that were a reason to stay clear of black I'm sure they would have. Conversely, we would see more black rockets too if it helped?

Also, how valid are the considerations about reenty heating. The interstage will be in the lee side of the booster for comprehensive and atmospheric heating, but will be exposed to the turbulent air from the grid fin shock boundary. We all saw the results on the precious TPS the first hot re-entrys but I don't recall anything similar since re gridfins. Have they found a way to stop that impingement on the interstage or designed around that?

[leetdan]

Have they found a way to stop that impingement on the interstage or designed around that?

The Ti grid fins don't have an ablative coating to shed.

[pospa]

NASA is requiring SpaceX to fly a “frozen” configuration of the Block 5 – meaning every vehicle is built the same way – successfully for at least 7 flights.

Q: Is it specified by NASA somewhere those 7 flights of F9 b5 must be always with new 1st stage, or can be "flight proven" block 5 booster?

[cambrianera]

Image scaled to get same diameter.

[niwax]

NASA is requiring SpaceX to fly a “frozen” configuration of the Block 5 – meaning every vehicle is built the same way – successfully for at least 7 flights.

Q: Is it specified by NASA somewhere those 7 flights of F9 b5 must be always with new 1st stage, or can be "flight proven" block 5 booster?

If they're going to fly crew in a used booster they might even have to. I doubt they have the capacity to fly new for every mission.

[Lars-J]

Image scaled to get same diameter.

Interesting, it certainly looks like the legs will be shorter, based on the leg latch points to the core. I guess they have stuck enough landings to save some weight with smaller legs.

[stcks]

Image scaled to get same diameter.

Nah, the legs look like they should be the same size.. your image is just scaled poorly. Look at the two bumbs on the raceway and how they correspond to the top attachment point. Its the same place.

[Joffan]

It looks like the securing mechanism for the legs may have changed, from clips round the edge to clips acting under the leg.

Image scaled to get same diameter.

Well, nearly, but what is still a little misleading there is that there is a black section at the bottom of the Block 5, so the base of the stage images are not aligned.

[cambrianera]

Image scaled to get same diameter.

Nah, the legs look like they should be the same size.. your image is just scaled poorly. Look at the two bumbs on the raceway and how they correspond to the top attachment point. Its the same place.

Really?
Diameter has not been modified.
As to the raceway I'm not that sure. Are you?
And I'm not saying legs are smaller.....

[stcks]

Image scaled to get same diameter.

Nah, the legs look like they should be the same size.. your image is just scaled poorly. Look at the two bumbs on the raceway and how they correspond to the top attachment point. Its the same place.

Really?
Diameter has not been modified.
As to the raceway I'm not that sure. Are you?
And I'm not saying legs are smaller.....

Its not the diameter, its where you have the base and the perspective of the two shots. Look again more closely, the top leg mounts are basically in the exact same place relative to the those two bumps on the raceways and those two bumps on the raceways have not moved.

[cambrianera]

Its not the diameter, its where you have the base and the perspective of the two shots. Look again more closely, the top leg mounts are basically in the exact same place relative to the those two bumps on the raceways and those two bumps on the raceways have not moved.

Again, are you sure?

[ugordan]

Its not the diameter, its where you have the base and the perspective of the two shots. Look again more closely, the top leg mounts are basically in the exact same place relative to the those two bumps on the raceways and those two bumps on the raceways have not moved.

Again, are you sure?

You are comparing two images from different vantage points that both have been taken so far from the stage that they can be considered orthographic projections, matching diameter alone will not match the height scale.

The leg length hasn't changed, neither has the location of tank relief vents. What *has* changed is that the 4 side hinges are closer in than they were before.

[gongora]

Its not the diameter, its where you have the base and the perspective of the two shots. Look again more closely, the top leg mounts are basically in the exact same place relative to the those two bumps on the raceways and those two bumps on the raceways have not moved.

Again, are you sure?

Yes.  There is a comparison pic in L2 that is lined up much better.  Your two boosters are not lined up vertically.

[cambrianera]

Thanks, waiting to see it!

[stcks]

Its not the diameter, its where you have the base and the perspective of the two shots. Look again more closely, the top leg mounts are basically in the exact same place relative to the those two bumps on the raceways and those two bumps on the raceways have not moved.

Again, are you sure?

As sure as I can be, yes. If there is any height difference between the top of the leg attachment points, its not noticeable in pictures. To be clear, I'm not claiming any special knowledge here, only pointing out that the picture evidence points much more strongly towards the legs being similar in length.

The main problem with your picture is that the bottom of the boosters are not even close to being properly aligned. Your Block 5 booster needs to come up a lot. Redo it and align the bumps on the raceways and the middle leg piston attachment and you'll see.

Edit: added image to illustrate just how far off your image is...

[cambrianera]

Its not the diameter, its where you have the base and the perspective of the two shots. Look again more closely, the top leg mounts are basically in the exact same place relative to the those two bumps on the raceways and those two bumps on the raceways have not moved.

Again, are you sure?

As sure as I can be, yes. If there is any height difference between the top of the leg attachment points, its not noticeable in pictures. To be clear, I'm not claiming any special knowledge here, only pointing out that the picture evidence points much more strongly towards the legs being similar in length.

The main problem with your picture is that the bottom of the boosters are not even close to being properly aligned. Your Block 5 booster needs to come up a lot. Redo it and align the bumps on the raceways and the middle leg piston attachment and you'll see.

Edit: added image to illustrate just how far off your image is...

Nice catch.
But reread my original post.
There was no claim of alignment, only that diameters were paired.
It was a quick job to get a first comparison, leaving to others (like you, now) the chance to contribute.
But alignment was wrong, not scaling...

[cambrianera]

It looks like the securing mechanism for the legs may have changed, from clips round the edge to clips acting under the leg.

Image scaled to get same diameter.

Well, nearly, but what is still a little misleading there is that there is a black section at the bottom of the Block 5, so the base of the stage images are not aligned.

You said it, I did not understand it immediately...
Well, thank you!

[Lars-J]

Yep, I see it now. The black section on the bottom of the Block 5 is much higher than the black section on the v1.2, which is what is creating the apparent difference. So the legs are basically the same size after all.

[cambrianera]

And here we are...

[CyndyC]

Oh look, payload already mated and ready to launch Hispasat 30W-6 on March 6th, courtesy of Space Coast Office of Tourism at https://spacecoastlaunches.com/blog/launch-list/

[stcks]

Oh look, payload already mated and ready to launch Hispasat 30W-6 on March 6th, courtesy of Space Coast Office of Tourism at https://spacecoastlaunches.com/blog/launch-list/

Wow its almost like SpaceX downgraded SLC-40, downgraded their F9, and built a time machine back to 2009.... /sarcasm

Sorry, that picture is from the original F9 user's guide from 2009 and shows a mockup vehicle that never flew. 

Sarcasm aside, it is very cool that we have come full circle with the appearance of the F9 block 5.

[oiorionsbelt]

Oh look, payload already mated and ready to launch Hispasat 30W-6 on March 6th, courtesy of Space Coast Office of Tourism at https://spacecoastlaunches.com/blog/launch-list/

Wow its almost like SpaceX downgraded SLC-40, downgraded their F9, and built a time machine back to 2009.... /sarcasm

Sorry, that picture is from the original F9 user's guide from 2009 and shows a mockup vehicle that never flew. 

Sarcasm aside, it is very cool that we have come full circle with the appearance of the F9 block 5.

Ha. Just spent 2 minutes searching for the 2009 photo because it looked so similar. Even the raceway on the side is black, very similar indeed in appearance to B5, sans legs.

[speedevil]

to 2009.... /sarcasm

Sorry, that picture is from the original F9 user's guide from 2009 and shows a mockup vehicle that never flew. 

It looks so stubby!

[Lars-J]

Sarcasm aside, it is very cool that we have come full circle with the appearance of the F9 block 5.

Yes, that is indeed very interesting. The first Block 5 vehicle on the pad will be an interesting side-by-side comparison. 

[rory]

NASA is requiring SpaceX to fly a “frozen” configuration of the Block 5 – meaning every vehicle is built the same way – successfully for at least 7 flights.

Q: Is it specified by NASA somewhere those 7 flights of F9 b5 must be always with new 1st stage, or can be "flight proven" block 5 booster?

If they're going to fly crew in a used booster they might even have to. I doubt they have the capacity to fly new for every mission.

At one flight per year, not having this capacity would mean shutting down Falcon 9 production entirely.