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Interesting read. I've wondered about their use of big touchscreen interfaces having heard a friend's experience with the similar setup in a Model 3. On multip

Interesting read. I've wondered about their use of big touchscreen interfaces having heard a friend's experience with the similar setup in a Model 3. 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.

theanirudh 6y ago
They have physical buttons Incase the touch functionality misbehaves.
- remarkEon 6y ago
  But there’s only a handful of buttons, no? Unless I’m missing something. Might be a dumb question but the Apollo control panels had hundreds. How would you manually fly the Dragon in the event of a screen failure? I’m assuming this question was answered somewhere, since the thing was certified to fly, but I must’ve missed it. Edit: Is the answer simply "it doesn't, it gets flown remotely from Mission Control"?
  - NikolaeVarius 6y ago
    You don't manually fly it? The physical buttons correspond to pre-programmed procedures/abort modes. 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.
  - theanirudh 6y ago
    Im not sure, even I would like to know the answer to this.
  - SiempreViernes 6y ago
    Well, Apollo did a lot of complicated stuff in space and on the moon, while the spacex capsule just goes up and then down. Only questionable bit is how they do the docking without the screens.
    - Aperocky 6y ago
      with a rusty script that succeed 99% of the time.
    - servercobra 6y ago
      The docking is automated as well.
    - jaywalk 6y ago
      The docking is automated.
      - mnd999 6y ago
        There is a manual option if there is a crew onboard. I can’t really think of any reason outside of a dire emergency to use it though.
  - deleted 6y ago
    [deleted]
  - garaetjjte 6y ago
    You probably don't fly manually, just use predefined abort procedure or receive configuration from ground control. It looks humans now are just another cargo and screens are only for non-critical flight information purpose (in other case I cannot see how they would get away with touchscreen only and software running on Chromium). It's interesting to wonder whether if Apollo 13 style fault happened, modern ships would be easier to reconfigure and rescue or harder?
  - johntb86 6y ago
    They have 3 screens. If one screen fails, they can probably continue using the others.
  - jon-wood 6y ago
    Give their docking simulator[1] a go on a phone or tablet - I was dubious at first, but even on an iPhone I managed to complete manual docking on the first attempt. It turns out flying a spaceship is very different to flying a plane, and rapid inputs just aren't massively important. Generally your edit is probably true as well - in standard flight everything is meant to be on autopilot using predefined routines for the mission, computers are just significantly better at performing a 16 second burn at 82% thrust at precisely T+12:48:16.
    - JoeAltmaier 6y ago
      That makes sense. Flying a plane is all about responding to perturbations to keep on an even course. A spaceship has literally zero perturbations. It goes exactly as you direct it to go, within the precision of your burns. So its all about carefully issuing bang-bang control signals (burn for 2 seconds) then measuring the response against expectations.
      - e_y_ 6y ago
        It's close to zero over short distances (ignoring solar wind and LEO atmosphere), although you're still trying to dock with a moving target. 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.
    - 0xffff2 6y ago
      You managed to dock in a simulation in which it's guaranteed that nothing goes wrong. Most of the switches and buttons are there for when something does go wrong. 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.
rootusrootus 6y ago
> On multiple occasions they've had to pull off the highway to turn their car off and on again to get the screen working. 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.
- wlesieutre 6y ago
  I'm not suggesting it had any function on that automotive functions, but I was also not aware of the media center reboot with steering wheel buttons. From what he described to me I don't think he was either, I'd have to check and will pass that along if not! 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.
  - mav3rick 6y ago
    It's called a watchdog. And it's 99% running Android and should have that.
    - comboy 6y ago
      Last time I've heard they were using Ruby on Rails.. https://news.ycombinator.com/item?id=17835760&p=2 https://news.ycombinator.com/item?id=17835760&p=2
  - extrapickles 6y ago
    It probably does, but you always have issues where the task that feeds the watchdog works fine, but another does not (eg: GPU gets in an odd state). 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.
modeless 6y ago
Your friend is dangerously misinformed. There is no need to pull off the road to fix any problem with the screen. There are physical controls for everything essential to driving and they work independently of the screen. Dragon is reportedly the same.
Diederich 6y ago
> On multiple occasions they've had to pull off the highway to turn their car off and on again to get the screen working. 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.
- wlesieutre 6y ago
  I'm aware there are two computers and the UI crashing has no impact on the basic function of the car, but turning the car off and on makes the media computer restart. Not sure if he was aware about the steering wheel reset function, it was a while ago that he told me that story. Also possible I've misremembered it.
  - Diederich 6y ago
    I should not have said 'this is false'; the story very well could be accurate. Please pardon the harsh tone. 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.
- vonseel 6y ago
  Makes you wonder if the software for media computer is simply less rigorously tested since it’s less critical, kind of sad if that is the case.

theanirudh 6y ago

They have physical buttons Incase the touch functionality misbehaves.

remarkEon 6y ago
But there’s only a handful of buttons, no? Unless I’m missing something. Might be a dumb question but the Apollo control panels had hundreds. How would you manually fly the Dragon in the event of a screen failure? I’m assuming this question was answered somewhere, since the thing was certified to fly, but I must’ve missed it. Edit: Is the answer simply "it doesn't, it gets flown remotely from Mission Control"?
- NikolaeVarius 6y ago
  You don't manually fly it? The physical buttons correspond to pre-programmed procedures/abort modes. 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.
- theanirudh 6y ago
  Im not sure, even I would like to know the answer to this.
- SiempreViernes 6y ago
  Well, Apollo did a lot of complicated stuff in space and on the moon, while the spacex capsule just goes up and then down. Only questionable bit is how they do the docking without the screens.
  - Aperocky 6y ago
    with a rusty script that succeed 99% of the time.
  - servercobra 6y ago
    The docking is automated as well.
  - jaywalk 6y ago
    The docking is automated.
    - mnd999 6y ago
      There is a manual option if there is a crew onboard. I can’t really think of any reason outside of a dire emergency to use it though.
- deleted 6y ago
  [deleted]
- garaetjjte 6y ago
  You probably don't fly manually, just use predefined abort procedure or receive configuration from ground control. It looks humans now are just another cargo and screens are only for non-critical flight information purpose (in other case I cannot see how they would get away with touchscreen only and software running on Chromium). It's interesting to wonder whether if Apollo 13 style fault happened, modern ships would be easier to reconfigure and rescue or harder?
- johntb86 6y ago
  They have 3 screens. If one screen fails, they can probably continue using the others.
- jon-wood 6y ago
  Give their docking simulator[1] a go on a phone or tablet - I was dubious at first, but even on an iPhone I managed to complete manual docking on the first attempt. It turns out flying a spaceship is very different to flying a plane, and rapid inputs just aren't massively important. Generally your edit is probably true as well - in standard flight everything is meant to be on autopilot using predefined routines for the mission, computers are just significantly better at performing a 16 second burn at 82% thrust at precisely T+12:48:16.
  - JoeAltmaier 6y ago
    That makes sense. Flying a plane is all about responding to perturbations to keep on an even course. A spaceship has literally zero perturbations. It goes exactly as you direct it to go, within the precision of your burns. So its all about carefully issuing bang-bang control signals (burn for 2 seconds) then measuring the response against expectations.
    - e_y_ 6y ago
      It's close to zero over short distances (ignoring solar wind and LEO atmosphere), although you're still trying to dock with a moving target. 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.
  - 0xffff2 6y ago
    You managed to dock in a simulation in which it's guaranteed that nothing goes wrong. Most of the switches and buttons are there for when something does go wrong. 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.

rootusrootus 6y ago

> On multiple occasions they've had to pull off the highway to turn their car off and on again to get the screen working. 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.

wlesieutre 6y ago
I'm not suggesting it had any function on that automotive functions, but I was also not aware of the media center reboot with steering wheel buttons. From what he described to me I don't think he was either, I'd have to check and will pass that along if not! 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.
- mav3rick 6y ago
  It's called a watchdog. And it's 99% running Android and should have that.
  - comboy 6y ago
    Last time I've heard they were using Ruby on Rails.. https://news.ycombinator.com/item?id=17835760&p=2 https://news.ycombinator.com/item?id=17835760&p=2
- extrapickles 6y ago
  It probably does, but you always have issues where the task that feeds the watchdog works fine, but another does not (eg: GPU gets in an odd state). 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.

modeless 6y ago

Your friend is dangerously misinformed. There is no need to pull off the road to fix any problem with the screen. There are physical controls for everything essential to driving and they work independently of the screen. Dragon is reportedly the same.

Diederich 6y ago

> On multiple occasions they've had to pull off the highway to turn their car off and on again to get the screen working. 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.

wlesieutre 6y ago
I'm aware there are two computers and the UI crashing has no impact on the basic function of the car, but turning the car off and on makes the media computer restart. Not sure if he was aware about the steering wheel reset function, it was a while ago that he told me that story. Also possible I've misremembered it.
- Diederich 6y ago
  I should not have said 'this is false'; the story very well could be accurate. Please pardon the harsh tone. 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.
vonseel 6y ago
Makes you wonder if the software for media computer is simply less rigorously tested since it’s less critical, kind of sad if that is the case.