Quite true. We might do calculations on the velocity the divers have when they hit the upper fringes of the atmosphere, based on how much time passes - but that'd probably be futile considering the amount of cuts.
Let's take the opposite approach. This has actually already been done, on paper: NASA seriously studied various means of returning astronauts to Earth without the benefit of a space capsule. Or more accurately, by using an entry aid that would easily fit inside a Mercury capsule, which is basically as good as none at all...
One major issue was getting the astronaut to fall: a rocket of some sort was needed, plus a targeting aid. Our STXI heroes would need none of that, since the shuttle was the aiming device, and may also have given them an initial boost with artificial gravity (although the pull of Vulcan at that altitude would have been almost the same as the pull of Vulcan at sand level). So that leaves the "entry device" angle.
Subcontractors to NASA considered two main possibilities. One was to erect a parachute or skirt of sorts to significantly increase the surface area of the astronaut (tenfold or more), so that air resistance would be high and velocity and acceleration low. No real heat shielding was included in that package. Another was based on the idea of expanding a bit of foam around the astronaut, only increasing his area fivefold or less, and using some ablative heat shielding in addition; this became the MOOSE, a system proposed for NASA use (perhaps on Gemini) or for USAF (for Dynasoar), but never adopted.
Apparently, the biggest heat concern with the MOOSE was whether the exothermic deployment of the polyurethane foam would fry the astronaut... Friction heat loads were low.
Now, our heroes minimized their surface area and maximized their speed. I could see an order of magnitude of difference in heat load there - but I'm not sure heat dissipation would be an issue as such. A bow shock of some sort would quickly emerge, and that's where we'd see ionization glow, not necessarily on the helmet itself. With the angles we were given, we might well miss the glow: it would be behind the camera in the forward shots, the possible "comet tail" would be hidden behind the heroes, and we didn't get good side views at the period of maximum deceleration.
Of course, a high tech stealth skydive exploiting ST tech to the fullest would probably feature some sort of a "trailblazer" that moved the bow shock forward and dissipated it as much as possible. A projectile flying ahead of the heroes, perhaps. Or a long but thin rod with a properly shaped tip (these are being used to modify the bow shock in planned supersonic and hypersonic aircraft). Or a forcefield version of the same.
But if we go high tech, then we have to wonder why our heroes used a parachute. Shouldn't they just have used some sort of gravity belts?
(Also, if the parachute, the harness and the suit withstood the deceleration from terminal velocity to very low touchdown speed within just a few dozen meters, why did Kirk's parachute fail on the second try? Was it due to battle damage, or was this particular chute faulty? It did appear the chute was designed for repeated use, as it had that reeling mechanism...)
Timo Saloniemi
