This related question asks about considerations for Santa's sleigh (particularly weight), but my question is more basic: how do you design a vehicle that satisfies Santa's design requirements, including the very tight schedule, in a way that doesn't turn Santa into a puddle of goo from high-Gs and vaporize the reindeer from wind-speed?
Key design requirements, as I understand them:
The vehicle must be able to support take-off and landing at the homes of all good children on Earth in a span of roughly 24 hours. (Good children on space colonies are excluded.) We can't afford a long pre-flight check; really, we probably don't even have time to open and close a hatch. (Art never shows a hatch anyway.)
Without knowing the number and distribution of stops we can only guess at the one-night mileage, but even at conservative estimates... mach-what? Gotta support super-high speed.
It's ok if maintenance and repairs take the next 363 days, but there's not going to be time on delivery night for pit stops and spot-repairs -- the vehicle needs to operate continuously during the delivery run. (Santa would probably prefer to be able to do a test-drive tuning check between deployments, however, so less-extensive maintenance is preferred.)
Santa, a well-padded humanoid, needs to survive the trip without long-term damage. As far as we know it's the same Santa every year.
The reindeer need to survive the trip. Santa is pretty cagey about the reindeer, though -- who'd know if Blitzen is the same Blitzen as last year? It's ok to assume that Santa runs a breeding program, though protections for the lead reindeer with the light-emitting mutation would be advisable.
There are no explicit requirements about materials or fuel sources.