Rediscovering the wheel...McDonnell Douglas in the late '60s developed the MRS metal shingles to protect its prototype MDC 176 re-entering vehicle competing with the ceramic RCG-tiled Shuttle. The Reactive Cured Glass had been developed at NASA, and NASA eventually picked the Rocketdyne Shuttle over the Model 176 of MCD. The shingles bearing the highest heat fluxes were made of refractory metal and expensive, but they were very durable and did not need refurbishment after each flight. Space X stainless steel is cheaper but I doubt it will be durable because of oxidation over the long term, so I guess it will have to use one of the ceramic coatings (TBC) now available. Again, Space X did not invent anything new.
Rediscovering the wheel...McDonnell Douglas in the late '60s developed the MRS metal shingles to protect its prototype MDC 176 re-entering vehicle competing with the ceramic RCG-tiled Shuttle. The Reactive Cured Glass had been developed at NASA, and NASA eventually picked the Rocketdyne Shuttle over the Model 176 of MCD. The shingles bearing the highest heat fluxes were made of refractory metal and expensive, but they were very durable and did not need refurbishment after each flight. Space X stainless steel is cheaper but I doubt it will be durable because of oxidation over the long term, so I guess it will have to use one of the ceramic coatings (TBC) now available. Again, Space X did not invent anything new.