Starship heat shield

[OTV Booster]

Those are likely not tiles at all, but antenna (or other instrumentation) covers for a ship which according to rumors it's not going to have a heatshield at all. Installing such stuff paints the said rumors more likely.

   
 
Would someone please provide a summary of the rumours? I looked back a few pages and didn't find anything. Cheers!

Don't know if you know about it but this site has some useful articles 

https://www.nasaspaceflight.com/2022/09/starship-next-phase-of-testing/

As previously reported, Ship 26 and Ship 27 may be undergoing a radical change in plans, omitting thermal protection system (TPS) tiles and not installing aerodynamic flaps. So far, this seems to be holding true with parts of Ship 26 seen now bare of tiles and on stand-by at Starbase’s ring yard for stacking.

Ship 27 parts are also proceeding similarly to Ship 26 parts. In some cases, there seems to be a strange mix-match of parts for these vehicles.

https://www.nasaspaceflight.com/2022/08/booster-7-additional-tests/

While all of this is happening, workers have been seen doing unusual work on future Starship vehicles and more concretely on Ship 26.

Workers were seen removing Thermal Protection System (TPS) tiles and blankets from Ship 26’s nosecone, while some of its barrel sections, which were supposed to receive the installation pins for the TPS tiles, are already staged outside in the ring yard ready for stacking.

While there has not been any official reason provided, some indications point to SpaceX trying to fast-track Ship 26 and Ship 27 builds by not installing TPS tiles or even flaps in order to quickly deliver Starlink v2 satellites into orbit, which the company may need in order to accelerate deployment once Starship proves itself worthy of going into orbit.

Hmmm. Maybe I'll have to eat my words. Low throttle well before MaxQ. Maybe even for a while after MaxQ. No fins. No tiles. Lots of margin. And ammo in their FCC arguments about bandwidth.


No attempt at EDL makes no sense from a testing perspective but it ties the whole thing up with a bow from a StarLink perspective. 

[Keldor]

Remember it's not a case of not installing tiles on the pins on S26, they were installed (on the nose at least) and later removed...

The question is why?

Hmm...  Another possibility is that S26 is in the process of being scrapped, similar to what they did with S16 after S15 flew.  In this case, they might just have to strip the TPS for environmental reasons, since we can probably expect it to have a lot of the same potential health issues from exposure as asbestos.

[sebk]

No. They proceeded with the construction, but stripped of tiles.

[John-H]

My fearless prediction is that they will launch at least a few expendable, much lighter Starships.

John

[darkenfast]

Forgive if this has been mentioned above and I missed it, but could the "tileless" Ships be scheduled for shipment to KSC, for fit-checks, tile installation practice or whatever? It might make sense to do the tiles there, especially if shipping involves laying the Ship down on its side. I know it seems a little early, but it was just a thought.

[Nightstalker89]

Until they catch a booster, why expend resources on putting tiles on the ships, just expend them and move on.  Once they catch a few boosters then concentrate on ship reuse.  Classic agile development technique.  Only work on what you need today to get the fastest viable product to market.  After that refine.  The current ships with tiles are just development lead products to see where the team working on that in parallel may need to refine their portion of the product.

[JamesH65]

In this case, they might just have to strip the TPS for environmental reasons, since we can probably expect it to have a lot of the same potential health issues from exposure as asbestos.

I don't think we have seen evidence for that, have we? Asbestos has a very specific hook like shape which makes it nasty, does the material used for the tiles have the same structure?

[DanClemmensen]

Until they catch a booster, why expend resources on putting tiles on the ships, just expend them and move on.  Once they catch a few boosters then concentrate on ship reuse.  Classic agile development technique.  Only work on what you need today to get the fastest viable product to market.  After that refine.  The current ships with tiles are just development lead products to see where the team working on that in parallel may need to refine their portion of the product.

It's a tradeoff. They have a limited number of approved launches, so they need to test the TPS on every launch. The resources needed to test EDL are different than the resources to test launch, and except for the very first launch the EDL test can be deferred for days or weeks, so there is not even a short-term resource allocation problem.

[eriblo]

Until they catch a booster, why expend resources on putting tiles on the ships, just expend them and move on.  Once they catch a few boosters then concentrate on ship reuse.  Classic agile development technique.  Only work on what you need today to get the fastest viable product to market.  After that refine.  The current ships with tiles are just development lead products to see where the team working on that in parallel may need to refine their portion of the product.

They explicitly started with the Starship part of the system because that was going to take the most effort and the whole reusable system was the minimum viable product - they already had unrivaled launch capabilities.

Now with Starlink V2 needing launches ASAP they might have a reason for a few expendable launches but I highly doubt it would have anything to do with speeding up the rest of the program.

[robot_enthusiast]

Until they catch a booster, why expend resources on putting tiles on the ships, just expend them and move on.  Once they catch a few boosters then concentrate on ship reuse.  Classic agile development technique.  Only work on what you need today to get the fastest viable product to market.  After that refine.  The current ships with tiles are just development lead products to see where the team working on that in parallel may need to refine their portion of the product.

They explicitly started with the Starship part of the system because that was going to take the most effort and the whole reusable system was the minimum viable product - they already had unrivaled launch capabilities.

Now with Starlink V2 needing launches ASAP they might have a reason for a few expendable launches but I highly doubt it would have anything to do with speeding up the rest of the program.

I would have to disagree with the sentiment that it will not speed up the rest of the program. They appear to have paused further development of the heat shield until they get flight data to work off of to continue improving the design. Because of this it appears that their choices are to pause production for months after the first flight while improvements are implemented, or continue production without heat shields and continue developing SH and stage 0. Going to the effort of installing a heat shield on S26 & 27 would only give them redundant data at the cost of pulling resources from other areas and extending the production timeline.

[edzieba]

On the subject of the tiles themselves: can anyone remember the last time tiles were installed on any vehicle?
Looking back over the archived photos, S25 appears to have been fully tiles (prior to stacking) in late July, and S26 had been partially tiled for some time before the tiles were removed in August.

I'm going to place my bet as: Tile block upgrade is occurring, S26 and later will receive new tiles (which may be visually identical) before flight if tile production has restarted in time to provide full tile coverage, and ships will only launch untiled if there are not sufficient tiles available to complete coverage in time (rather than launching partially tiled, those tiles can be 'stolen' to more rapidly complete tiling of the next ship).

[StarshipTrooper]

It could be that they can build a Superheavy quicker than they can a fully tiled and finned Starship. So to get up to pace for launching StarLinks they needed to speed up the upper stage production.

[ppb]

It could be that they can build a Superheavy quicker than they can a fully tiled and finned Starship. So to get up to pace for launching StarLinks they needed to speed up the upper stage production.

And they may still get valuable data that anchors their aero heating and structural models for a bare SS on reentry. They may even have enough torque authority from ACS only and no flaps to trim their preferred attitude during the critical phase of reentry.

Minimum viable product includes a minimum viable heat shield.

[OTV Booster]

It could be that they can build a Superheavy quicker than they can a fully tiled and finned Starship. So to get up to pace for launching StarLinks they needed to speed up the upper stage production.

As an alternative, put more resources into SS and build fewer boosters. The last Elon mentioned long term SS to booster ratio it was 10:1.


Edit to add: until they can grab a booster they'll need one per launch. Even then the changes will come so thick and fast they may not bother (StarLink being the joker). It may be a year or two before we see a full stack launched with already flown stages.


Time, time, time See what's become of me
While I looked around for my possibilities
I was so hard to please...
     Simon & Garfunkel

[john smith 19]

Hmm...  Another possibility is that S26 is in the process of being scrapped, similar to what they did with S16 after S15 flew.  In this case, they might just have to strip the TPS for environmental reasons, since we can probably expect it to have a lot of the same potential health issues from exposure as asbestos.

Highly unlikely.

The well known safety issues around Asbestos would force similar safety requirements around stuff that was even similar to it in structure.

That said most of this stuff is dangerous if it's finely powdered and get airborn. Asbestos OTOH is naturally fibrous, so it's difficult to process without it getting airborn.

[InterestedEngineer]

Zack Golden reasonably arrives at the conclusion that the tile damage from the 6 engine Raptor test was caused by debris from the test stand.

Implications for taking off from Mars, but not for taking off from Earth.

[john smith 19]

Zack Golden reasonably arrives at the conclusion that the tile damage from the 6 engine Raptor test was caused by debris from the test stand.

Implications for taking off from Mars, but not for taking off from Earth.

Which suggests that there should be action around the base to either strengthen the concrete or overlay it with steel plate preping for the next flight.

That should be pretty visible. Has anyone seen this?

[oiorionsbelt]

Zack Golden reasonably arrives at the conclusion that the tile damage from the 6 engine Raptor test was caused by debris from the test stand.

Implications for taking off from Mars, but not for taking off from Earth.

Which suggests that there should be action around the base to either strengthen the concrete or overlay it with steel plate preping for the next flight.

That should be pretty visible. Has anyone seen this?

  "the next flight" will see Starship atop the booster not on the suborbital pad. Static fires of course.....

[RamsesBic]

Zack Golden reasonably arrives at the conclusion that the tile damage from the 6 engine Raptor test was caused by debris from the test stand.

Implications for taking off from Mars, but not for taking off from Earth.

Which suggests that there should be action around the base to either strengthen the concrete or overlay it with steel plate preping for the next flight.

That should be pretty visible. Has anyone seen this?

  "the next flight" will see Starship atop the booster not on the suborbital pad. Static fires of course.....

Don't forget S25. It has to go through ambient, cryo, thrust and static fire tests too. The sub-orbital pads need an upgrade if they want to SF 6 Raptors again.

[john smith 19]

  "the next flight" will see Starship atop the booster not on the suborbital pad. Static fires of course.....

Then I guess the question becomes "Does the launch pad differ from the static fire pad?" IE Heavier concrete layers, steel plates laid down etc.

That would suggest that unexpected high levels of pad debris was the issue with the missing tiles.