The Space Shuttle was both designed to be reusable and only to return from low earth orbit so, as TBB (Yes, she is a rocket scientist) can tell you, NASA chose a ceramic tile system as a heat shield to shed the energy from the friction of entry into the atmosphere.
The new Orion crew capsule is designed for higher orbits and deep space, returning at much higher speeds and therefore much higher temperatures than the Shuttle. In addition, Orion is not reusable, so the heat shield only needs to work once and can be lower cost.
It must work or the heat caused by atmospheric resistance will destroy the structural integrity of the vehicle, as happened as on Columbia when the shield was damaged by debris.
NASA has gone back to the Apollo style heat shield, made of a honeycomb structure filled with resin that burns away in layers to take heat away from the vehicle, keeping the inhabitants and cargo safe.
This destructive process is called ablation. It is designed to burn off energy that is turned into heat on deceleration.
The spacecraft is going as fast as it needs to go to do what it needs to do in space, but that speed is just too high for earth’s atmosphere, at least with the materials we have today. The heat limits of materials is one of the key reasons we won’t be seeing hypersonic flight anytime soon.
My brain, I have found, tends to run fast and to run hot.
This blog reveals that I have a relentless, fierce, and driven creativity, grounded in both deep thought and passionate emotion, enough to offer new day after day after day after day. It also reveals an odd capacity to keep standing up even when battered and lonely, a kind of toughness that keeps my spine intact even as my organs start to fail. I am what I am, as TBB as affirmed.
This intensity means that when I attempt to enter conventional human space, I have to struggle to slow down, to match my energy to the group.
I was never very good at that process. Small talk escaped me. What I offered instead often overloaded other people’s circuits and blew out their fuses.
There is always a cost in to me in shedding energy, burning off my essence in appropriately directed heat in order to try and sync up with others who have no interest or capability to match my speed.
This is one reason I often resist relationships, not because of the work involved but rather because of the cost of the waiting involved, the requirement to trip myself up, modulate myself down, attenuate my energy to keep pace with the group. There is always a cost in heat and waste to burn off that energy.
There is only so much ablation one person can stand. You lose too much momentum, the shields get too thin and pretty soon you have the structural damage which allows that destruction to reach into vital places.
I have already lost so much energy that losing more feels impossible. Instead of replenishing my protection, I continue to burn it away, to ablate it, layer by layer.
The thought of having to start over with a new team, to patiently offer myself in tiny spoonfuls, waiting between drops to let them heal, catch up, or just do what they need to do, seems like an interminable and ultimately futile game. Do I search for medications that offer some anæsthesia, or do I just miss the point, staying away from the price?
I have spent a lifetime burning away energy, possibility and heat in order to stay connected to the other people around me. That may not have been the optimum way to use that energy, but it made sense at the time, in a challenged family and a world full of stigma. Now, my shields are ablated, scorched, parched and thin.
Going slow to make connections just doesn’t feel like good or possible advice right at the moment. Ablation has just gone too far.