We currently have: Cargo bays that protect their contents (in 1.0) Improved aerodynamics that will hopefully only cause drag-heat on parts with leading edges (in 1.0) Most of the stock parts tolerate temps of 3000 K+ (Including all stock wings at ~3400 K, structural panels at 3200 K and some parts up to 5000 K such as modular girders) While I can see that this may not be adequate if you want an impactor to hit Kerbal a multiple KM/sec, I do not see why this should not be sufficient for most other cases. From this page:http://en.wikipedia.org/wiki/Space_Shuttle_thermal_protection_system "The Space Shuttle thermal protection system (TPS) is the barrier that protected the Space Shuttle Orbiter during the searing 1,650 °C (3,000 °F) heat of atmospheric reentry. A secondary goal was to protect from the heat and cold of space while on orbit.[1]" So, that 3400 degrees for stock wings and 3000 degrees for stock MK2-3 parts seems like it already includes at least as much of a heat shield as is used by the space shuttle. So, if you find that your reentry vector is such that it could not be survived by the space shuttle, then I would agree that you probably need a dedicated heat-shield, but I also suspect that there is not really anything realistic that could help your craft survive in that situation. Add in that LKO is much slower than LEO(LEO is close to 8km/sec, while LKO seems to be a little above 2km/sec) and additional heat-shielding starts to seem pretty silly. Correction: I failed to notice that Kerbal part temps are in Kelvin, 3000 degrees kelvin is 2726.85c or 4940.33F As such the only stock parts I have found that do not make the space shuttle thermal protection system look like easily flammable kindling are the probe cores that can only withstand a measly 1200K (1700F or 926C)