One heat-shielding method suggested was almost "science-fictionish".
It involved using superconducting magnets, on the nose-cone & leading-edges of a spacecraft to deflect the ionized-air and superheated plasma
generated by re-entry speeds.

That theoretical concept has and had obvious drawbacks and flaws. Notably? What happens if the electric-current involved in generating the magnetic-field fizzles?
Ain't a pretty picture.

Another method hinted at was the
concept of circulating refrigerant
coolant-fluids between a double-shelled
outer-skin of a re-entering spacecraft.
Obvious drawbacks?
>Extra [unwelcome] weight.
>Refrigerant coolant would probably
absorb too much heat-energy and result in either a chemical explosion [2NH3 -> 3H2 + N2] or a mechanical explosion [flashing into vapor]
Bad news both ways.

And the final obvious drawback:
What if the coolant-pumps broke down?

Jacob Samorodin