5 ms·

Did they need to modify the Tesla to make it vacuum worthy? Like, remove any fluids, remove any parts that might explode in the hot or cold of space, deflate t

Did they need to modify the Tesla to make it vacuum worthy? Like, remove any fluids, remove any parts that might explode in the hot or cold of space, deflate the tires, etc. Note: I'm more interested in a scientific answer, as opposed to casual conjectures. Preferably from an engineer knowledgeable of such things. And specifically, the materials sciences aspect of how materials will survive in a vacuum.

jacquesm 9y ago
They have a bigass vacuum test chamber, you can bet they did their homework and every container that might end up pressurized had a hole in it to allow the leveling of the pressure. No point taking chances with something like this, it only has to look good, it doesn't have to drive.
- urda 9y ago
  > it only has to look good, it doesn't have to drive. After all, where it's going it won't need roads.
lmm 9y ago
It's not like they're trying to keep it driveable? I would guess they'll have drained any fluids but I don't expect it to be fully operational after the van allen belts, for example.
- Retra 9y ago
  How would the Van Allen belts disable a car?
  - jacquesm 9y ago
    Non radiation hardened electronics will likely die.
mike741 9y ago
the car is not actually in the vacuum AFAI can tell from their GIF: https://tctechcrunch2011.files.wordpress.com/2018/02/spaceroadster.gif?w=800&h=415 https://tctechcrunch2011.files.wordpress.com/2018/02/spacero... id imagine a 360-camera is projected onto the inside of the sphere/case the car is actually inside of.
- gliptic 9y ago
  What are you talking about. That gif is showing the fairing separation. There's no sphere.
  - mike741 9y ago
    amazing, is the car strapped to the outside of the rest of the ship? how does it remain so stable after the separation? by "sphere" i just meant the case it is shown inside of at the start, since the markings on the wall resemble motion tracking panels used for 3d projection. perhaps I just underestimate the precision and smoothness of the fairing separation, or am misunderstanding how the car is rigged so as to remain so stable.
    - deleted 9y ago
      [deleted]
    - jotm 9y ago
      It's like putting a satellite into orbit, right? Up until the rocket stops burning, it's held in place by something, then it's released, then enclosure opens with minimal/nonexistent effect on the payload, leaving it out there... In this case, the car has enough velocity to float to it's Sun orbit, I guess.
      - jeroen 9y ago
        No, the 3rd burn took it from earth orbit to sun orbit.
    - jeroen 9y ago
NamTaf 9y ago
As a mechanical design engineer (not of cars, of other vehicles) I can't think of any systems that you'd need to modify if you don't plan on driving the car again. This is all off-the-top-of-my-head theorycrafting, so I could be wrong. Space is only -1 atmosphere and even then, it only affects sealed systems. For the rest, they'd equalise. Also, cooling in in space is actually fairly gradual as there's only radiation, not convection or conduction. Let's go through the systems and evaluate what that means: For structural components, nothing will really change. After all, we built spacecraft out of aluminium before. The ISS has to cope with this more, as it goes in and out of sunlight every 90 mins, so it gets something like 15 cycles of high/low temperature a day. The thermal shock of going from darkness to sunlight is the main issue, but this won't be passing through the earth's shadow constantly since it'll be orbiting the sun, so changes will be far more gradual. Bigger issues come from different materials joined together, such as steel to aluminium, since they expand at different rates, but that's not really a problem here and even if it is, it'll just crack a bit at the seam. That's not going to cause the car to explode into little fragments. For unsealed systems with fluids, they'd just boil away in the vacuum before desubliminating into little frozen droplets and bounce around or whatnot. The only sealed systems with fluids in them that I can think of are tyres and brake lines. Tyres tend to sit at about 30-35 PSI, which is ~2 atmospheres. They then have to endure significant heating/cooling, dynamic pressures of spinning, etc. so an extra atmosphere wouldn't cause issue from a pressure point of view. Ditto brake lines - you stomp on them with a mechanical advantage and they never rupture. I think you'll find the worst damage will be to the paint over time, which will fade more aggressively since it's not protected from UV sunlight any more. edit: I forgot the batteries, which I believe are a sealed unit. They might have just dropped the battery pack from the car. Not sure what a vacuum would do to them as I don't know enough about Li-Ion battery design to comment.
CmdrKrool 9y ago
Elon says, albeit casually, here in the press conference at 5m36s: https://youtu.be/sytrrdOPYzA?t=5m36s https://youtu.be/sytrrdOPYzA?t=5m36s "We didn't really test any of those materials [...] it's just literally a normal car in space"
- jotm 9y ago
  It would be pretty cool if they retrieve it later, replace the batteries... and it still works :D
  - k_lander 9y ago
    i think its expected to next swing past earth in 2030
astronautjones 9y ago
Musk basically said "not really" in the press conference
mr_toad 9y ago
The metals in the are likely to sublimate significantly over the course of tens of thousands of years. Plastics and rubber might only last decades. Painted surfaces might survive longer than exposed metals. The glass will eventually become clouded and discoloured due to radiation damage and scoring by micrometeorites. Some plastics can rapidly deteriorate in sunlight. Erosion from micrometeoroids (dust) and larger impacts is also a factor over timescales of thousands of years. I doubt it will last the millions of years that is suggested. http://www.dtic.mil/dtic/tr/fulltext/u2/266548.pdf http://www.dtic.mil/dtic/tr/fulltext/u2/266548.pdf

jacquesm 9y ago

They have a bigass vacuum test chamber, you can bet they did their homework and every container that might end up pressurized had a hole in it to allow the leveling of the pressure. No point taking chances with something like this, it only has to look good, it doesn't have to drive.

urda 9y ago
> it only has to look good, it doesn't have to drive. After all, where it's going it won't need roads.

lmm 9y ago

It's not like they're trying to keep it driveable? I would guess they'll have drained any fluids but I don't expect it to be fully operational after the van allen belts, for example.

Retra 9y ago
How would the Van Allen belts disable a car?
- jacquesm 9y ago
  Non radiation hardened electronics will likely die.

mike741 9y ago

the car is not actually in the vacuum AFAI can tell from their GIF: https://tctechcrunch2011.files.wordpress.com/2018/02/spaceroadster.gif?w=800&h=415 https://tctechcrunch2011.files.wordpress.com/2018/02/spacero... id imagine a 360-camera is projected onto the inside of the sphere/case the car is actually inside of.

gliptic 9y ago
What are you talking about. That gif is showing the fairing separation. There's no sphere.
- mike741 9y ago
  amazing, is the car strapped to the outside of the rest of the ship? how does it remain so stable after the separation? by "sphere" i just meant the case it is shown inside of at the start, since the markings on the wall resemble motion tracking panels used for 3d projection. perhaps I just underestimate the precision and smoothness of the fairing separation, or am misunderstanding how the car is rigged so as to remain so stable.
  - deleted 9y ago
    [deleted]
  - jotm 9y ago
    It's like putting a satellite into orbit, right? Up until the rocket stops burning, it's held in place by something, then it's released, then enclosure opens with minimal/nonexistent effect on the payload, leaving it out there... In this case, the car has enough velocity to float to it's Sun orbit, I guess.
    - jeroen 9y ago
      No, the 3rd burn took it from earth orbit to sun orbit.
  - jeroen 9y ago

NamTaf 9y ago

As a mechanical design engineer (not of cars, of other vehicles) I can't think of any systems that you'd need to modify if you don't plan on driving the car again. This is all off-the-top-of-my-head theorycrafting, so I could be wrong. Space is only -1 atmosphere and even then, it only affects sealed systems. For the rest, they'd equalise. Also, cooling in in space is actually fairly gradual as there's only radiation, not convection or conduction. Let's go through the systems and evaluate what that means: For structural components, nothing will really change. After all, we built spacecraft out of aluminium before. The ISS has to cope with this more, as it goes in and out of sunlight every 90 mins, so it gets something like 15 cycles of high/low temperature a day. The thermal shock of going from darkness to sunlight is the main issue, but this won't be passing through the earth's shadow constantly since it'll be orbiting the sun, so changes will be far more gradual. Bigger issues come from different materials joined together, such as steel to aluminium, since they expand at different rates, but that's not really a problem here and even if it is, it'll just crack a bit at the seam. That's not going to cause the car to explode into little fragments. For unsealed systems with fluids, they'd just boil away in the vacuum before desubliminating into little frozen droplets and bounce around or whatnot. The only sealed systems with fluids in them that I can think of are tyres and brake lines. Tyres tend to sit at about 30-35 PSI, which is ~2 atmospheres. They then have to endure significant heating/cooling, dynamic pressures of spinning, etc. so an extra atmosphere wouldn't cause issue from a pressure point of view. Ditto brake lines - you stomp on them with a mechanical advantage and they never rupture. I think you'll find the worst damage will be to the paint over time, which will fade more aggressively since it's not protected from UV sunlight any more. edit: I forgot the batteries, which I believe are a sealed unit. They might have just dropped the battery pack from the car. Not sure what a vacuum would do to them as I don't know enough about Li-Ion battery design to comment.

CmdrKrool 9y ago

Elon says, albeit casually, here in the press conference at 5m36s: https://youtu.be/sytrrdOPYzA?t=5m36s https://youtu.be/sytrrdOPYzA?t=5m36s "We didn't really test any of those materials [...] it's just literally a normal car in space"

jotm 9y ago
It would be pretty cool if they retrieve it later, replace the batteries... and it still works :D
- k_lander 9y ago
  i think its expected to next swing past earth in 2030

astronautjones 9y ago

Musk basically said "not really" in the press conference

mr_toad 9y ago

The metals in the are likely to sublimate significantly over the course of tens of thousands of years. Plastics and rubber might only last decades. Painted surfaces might survive longer than exposed metals. The glass will eventually become clouded and discoloured due to radiation damage and scoring by micrometeorites. Some plastics can rapidly deteriorate in sunlight. Erosion from micrometeoroids (dust) and larger impacts is also a factor over timescales of thousands of years. I doubt it will last the millions of years that is suggested. http://www.dtic.mil/dtic/tr/fulltext/u2/266548.pdf http://www.dtic.mil/dtic/tr/fulltext/u2/266548.pdf