Elon Musk says one heat shield problem could kill Starship's reusability for years. Starship is the most complicated machine humans have ever built. The hardest part isn't the engines. It isn't the steel. It isn't even the explosion margin on liftoff. Musk named the one remaining bottleneck. "It's having... the heat shield be reusable. No one's ever made a reusable orbital heat shield." The shield does two impossible jobs. "It's gotta make it through the ascent phase without shucking a bunch of tiles, and then it's gotta come back in and also not lose a bunch of tiles or overheat the main airframe." 40,000 tiles per ship. Musk reframed the consumable problem through brake pads: "Your brake pads in your car are also consumable, but they last a very long time." The shield must consume slowly. It must not require inspection between launches. Musk on the current state: "We have brought the ship back and had it do a soft landing in the ocean. But it lost a lot of tiles." A soft landing is not reusability. The bar is daily launches. One ship. Many flights. Musk, on the gap that's left: "You can't do this laborious inspection of 40,000 tiles type of thing." The first reusable heat shield in history is the last gate to Mars. If you're new here, GeniusThinking is a gallery for the greatest minds in economics, psychology, and history. Follow along for more similar content. — Elon Musk ( Elon Musk ), CEO of Tesla and SpaceX, on Dwarkesh Patel's ( Dwarkesh Patel ) podcastshow more

High-cycle, reliable engine reflight without replacement, refurbishment or laborious inspection is about the same degree of difficulty as a rapidly reusable heat shield. And then there are thousands of smaller challenges throughout the primary structure. This is a crazy hard problem.

Maybe it would be cheaper to figure out how to slow the vehicle down to subsonic before crashing into the atmosphere at orbital velocity. I don't have that solution but I bet there's one out there.

Rather than tiles, try a pearlite silica based spray on surface. Something like a lightweight pool marcite or spraycrete. Sprayon before launch, scrape off after landing, grind it up, and spray on again for next launch.

P.S. If you want to support us to keep our content free and accessible... Grab a free copy of our 100+ best mental models, cognitive biases, and fallacies below. The Ultimate Mental Models Playbook ❤️

@grok pls can you compare "Starship is the most complicated machine humans have ever built." to one human cell? what is more "complicated" and pls compare it in words we could understand.

Instead of consuming heat it needs to repel it. Frequency(sound) can put out a fire. It should also be able to repel heat.

Why couldn’t robots do the inspection in an hour or so? Just a bunch of drones flying around the ship with special equipment.

Tell him to give me a call.

The problem is simple, the solution not so simple. Either create a Reusable heat shield(do the materials exist today) or create an easily replaceable shield or.. and this is outside of my knowledge. Is there a way to slowly Deorbit a ship without the extreme heat

Well I disagree that Starship is the most complex machine humans have ever built. That prize currently goes to ASML Holding N.V. It is the Dutch company, and the only company in the world, that designs and manufactures extreme ultraviolet (EUV) lithography machines used to produce advanced semiconductor wafers. Operationalized, volume production-capable EUV lithography at 13.5 micron beam wavelength is the confluence of so many advanced physics innovations, patented and proprietary, that it is an amazing creation.

NO heat shield is the key to re usability. The solution is access to enough energy to slow from orbital speed to MACH 2 BEFORE entering the atmosphere. Reusability will never be achieved so long as going to space is a death-defying stunt.

So rebuilding the heat shield is the biggest bottleneck I didn’t realize that. I wonder if 3D printing like the kind @RocketLab is doing has a role here

If anyone can solve it, it is Elon and his team. They figured out how to create an Aluminum alloy that does not fatigue fracture from cyclic loads. Now in 1978, that was not considered possible at all. Heat shield - going to have to create a new alloy that can withstand the temperatures of reentry. Ceramic/Glass does not seem to be the solution as it is not robust enough. Part of the solution perhaps.

graphene should take care of that....

What could be used to expand the crushed air in front of the falling object instead of protecting it from the heat? Perhaps Moses’ staff and focused intention to “part the seas” as it were? Instead of attached to the ship, conditions applied from outside the ship sourced from space or grounded on Earth? More musing required on this.

@grok Which is more complex: Starship or the Hedron Collider?

No it's not, the Hadron collider or I.T.E.R currently being built pisses all over your little chemical rocket. Get a grip sometimes your so full of shit 🤣

Springtime is my favorite season of the year!

@ManuLionCrypto Agreed. It’s a difficult item to design. I think the shield should be either self repairing or actually self replacing. Difficult yes but impossible no

-heatshield structure has to be secured with elastic some with... -reusable or remade..

Ok. So make a spray on that hardens. Use a polymer that conducts no heat and can handle the vibration and friction. Becomes solid and expands when not under pressure and you can carry several canisters aboard for emergency repairs. Now have a quantum Ai create it.

No one has made a reusable heatshield? Umm,

People see Starship explosions and think the challenge is simply “making a rocket work.” But the real breakthrough SpaceX is chasing is airline-like reusability at orbital scale. Launching to orbit is already hard. Returning safely is harder. Doing it rapidly, repeatedly, cheaply, with minimal inspection between flights has never been achieved in human history. That’s why the heat shield matters so much. A truly reusable orbital heat shield is one of the final missing technologies needed to make Mars transportation economically possible at scale 🚀

Ok follow me here - you launch starship naked and fabricate shield tiles on the moon. You pick up an extra few tons of payload capacity which is nothing to sneeze at. Can be that much harder than orbital data centers.

What about truck spray on bed liner material ??? It seems to survive nearly anything !!! But these ships are not airliners … you will never see a one- or single-day turnaround time …

It’s too bad we haven’t yet discovered a way to capture all that dispensed energy on reentry for relaunch.

Heat shield failure has resulted in the death of more than one astronaut. Increase reliability and survivability as simply as possible. I for one wouldn’t bet against SpaceX succeeding in that effort.

Why can’t they cache fuel in orbit and use that fuel to slow Starship using re-entry burns ? Then land it like the boosters.

Если вы потеряли обшивку,часть плитки во время полета,может имеет смысл рассмотреть другой материал обшивки-более легкий, цельный,обхватывающий ракету более плотно,обволакивающий по максимуму,но одновременно выдерживающий большие температуры.Например,силикон.Или что-то подобное.

Well, hopefully XAI comes up with new material soon. Just have Optimus inspect tiles all day long 😁

You can have reusable tiles. ~ The thickness and weight, will eat up the payload. ~ Auto brake pads are more than a few mm thick.

Liquid cooled heat shield? More complexity but maybe higher reliability

Surely a circular laser device could inspect the craft for missing tiles or tiles with excessive scorch marks. Shouldn’t take that long. Haste makes waste.

Would it make safety and economic sense to add extra fuel and utilized braking thrusters to minimize de-orbit velocity?

👍