On multiple occasions they've had to pull off the highway to turn their car off and on again to get the screen working. Not really an option on your way to space.
Surely not? The touchscreen is run by the media computer which does not control the car. You can reboot it with the 'two finger salute' while you are driving down the highway. Some things will be unavailable (you cannot, for example, engage autopilot while it is rebooting), but the car still runs & drives.
I hope they just miscommunicated the situation to you, otherwise they are really working too hard just to fix a touchscreen. Turning the entire car off is kind of a pain in the ass. I've never done it. And I have only rebooted the touchscreen a couple times ever. Your friend may want to schedule a service appointment if they really do have to power cycle the whole car, because that is super abnormal.
I'm a little surprised that the media computer doesn't have a built-in heartbeat check and know to reboot itself if it stops responding. I've heard of other cars and embedded systems doing that.
EDIT - asked him about reboot via steerling wheel:
> It’s not great because you lose lots of feedback. No speedometer, no sound from turn signals, etc. But it does work.
In single core systems its somewhat solvable, but in multicore and if you want to include multiple chips in the crash domain it gets very hard with off the shelf chips.
> It’s not great because you lose lots of feedback. No speedometer, no sound from turn signals, etc. But it does work.
Yep, this is very true. You are driving blind, as it were, because the touchscreen is the dash. Fortunately it doesn't take long to reboot, but it is still much less than ideal.
This is false. Teslas have, roughly speaking, two computers. One drives the big touch screen, and the other manages the core automotive functions.
The media computer sometimes hangs/crashes; this has no impact whatsoever on the basic function of the car.
When that happens, it's an easy matter to reset it while the car is in motion; one just holds one button under each thumb on the steering wheel for a few seconds. The big screen will come back within a couple of minutes.
It's more correct to say that stopping and re-starting the whole car is not the easiest way to restart the MMU. It's quite possible there are people who aren't aware of the 'two thumb salute' method.
Edit: Is the answer simply "it doesn't, it gets flown remotely from Mission Control"?
I think the main reason there are so few buttons on Dragon is that it evolved from an uncrewed vehicle that was designed to be flown from the ground, so everything is much more connected and software controlled than was even practical in the shuttle era.
If you've played KSP or read about Gemini 4, the relative motion can be unintuitive due to orbital mechanics. The SpaceX docking simulator puts you right next to the ISS with low relative velocity -- as it would be in real life if everything went as planned -- but it would be much more challenging if you needed to do it manually from a greater distance and relative velocity.
They use a touchscreen so they don't need to have hundreds of buttons for things that aren't necessary to have around all the time.
It's interesting to wonder whether if Apollo 13 style fault happened, modern ships would be easier to reconfigure and rescue or harder?
Only questionable bit is how they do the docking without the screens.