Re-entry to earth from space question

[silverslith]

The main problem with passive cooling is that its only radiative at that altitude.
The atmosphere thins very gradually so it becomes a loading per sq area problem. Its not helpful to see it as skipping off the top of the atmosphere.
Craft like the space shuttle and rocket planes suffer from to little aerodynamic surface area to generate lift and control at altitude suitable for flying at 25000kmph.
When I checked wikipedia last week I found that the solution I've proposed for over a decade is being well advanced by a number of outfits. Numerous scenarios for transatmospheric airship like designs are proposed.
A craft off sufficiently low density to go from freefall to flying at lower air density is the answer.

[Tormod]

The problem is that you probably need multiple ways to reenter. As far as the capsule solution goes, it's a good choice if you're coming back from an out of orbit trip (like the moon). Since there currently is no waystation to dock at and change to a landing module, the landing module needs to be brought all the way from launch to target and back, and thus the spacecraft is designed so that the final module (descent module) is as basic as possible - therefore the capsule choice.

Space planes are very interesting, and for suborbital flights, and even for reaching space through multiple stage launches (ie, launch from the back of a plane) it should be feasible and perhaps cost effective.

The cost is the main issue, I think. Getting the price down to a practical level will ensure that private enterprises can get serious and do real business in the earth-to-orbit segment.

[silverslith]

Air breathing engines are a big impediment.
With superconductors well up to the task it would seem that even space elevators are well obsolete since no cable is actually required for efficient recyclic energy systems in the round trip. Quite a lot better than rockets that burn 100-1000 times the weight of their payload to get up there.

I don't at all accept the premise that a transorbital airship would be too light to handle near earth surface airshear stresses.
a 150m lifting body displaces ~1 million kg. Thats a lot to work with.