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I am totally with you on this - I just can't get over how utterly rudimentary and basic this thing looks! I can't wait to see it fly! I am so used to seeing s

I am totally with you on this - I just can't get over how utterly rudimentary and basic this thing looks! I can't wait to see it fly! I am so used to seeing space stuff done in clean rooms, and things taking years and years to come to fruition (e.g. hearing about and seeing NASA or ESA probes etc getting made) that to see what is essentially a bunch of guys in a field just welding something together blows my mind. I mean, is it just the outside that looks like that and inside it is ultra-exotic materials and tanks? Of course the engines are sophisticated machinery, but what about the insides? Are we just seeing the outer shell and it's all unobtanium nano-tube composite on the inside?

extrapickles 7y ago
I suspect most of the structure that gets really hot or cold is steel. To save weight, they are probably also letting more of the rocket get colder/hotter than normal, thanks to the wider temperature range of steel. Once the temperatures get reasonable, it might be aluminum or or carbon fiber. The passenger/cargo/avionics section are probably the only areas where this would be true, so a bulk of the rocket will be steel.
- hinkley 7y ago
  Steel can tolerate a lot more deflection before it bends, and much more stress before it cracks. And while I would never expect a space craft mechanic to employ this technique, any bike mechanic will happily offer to bend steel back into shape for you, but bent aluminum or carbon fiber is scrap. Bending it back will fracture it, if it hasn't already. When Canondale hit the big time, they had one model year where they made the dropouts out of solid aluminum and in the next model year the derailleur hanger was bolted on. It's the easiest part to bend and there's no repairing it. Bad enough for road bikes, spectacularly dumb for mountain bikes.
balfirevic 7y ago
> Are we just seeing the outer shell and it's all unobtanium nano-tube composite on the inside? Nope, it's just steel. Outside shell is the tank.
- hinkley 7y ago
  I recall quite a while back, when titanium started first showing up outside of aerospace, that someone had created a titanium-titanium composite by layering plate titanium with titanium cloth and welding it together somehow. Was supposed to be stronger. Wonder if there's a steel equivalent possible. I think the military was looking at a similar material to replace depleted uranium with something non-radioactive (depleted uranium still experiences alpha particle decay, which is fine if you don't aspirate or ingest it, but a shell can pulverize on impact with a target. Also it's still a heavy metal even if you don't take rads from it).
  - balfirevic 7y ago
    > I think the military was looking at a similar material to replace depleted uranium with something non-radioactive I thought the point of depleted uranium projectiles was simply the density of uranium, giving them large impact energy for a given volume. If that's the case, titanium (4.5 g/cm^3) will not even be as good as steel (8 g/cm^3), let alone uranium (19 g/cm^3).
    - MR4D 7y ago
      Tungsten. https://www.military.com/dodbuzz/2018/05/14/air-force-debates-replacing-depleted-uranium-rounds-10.html https://www.military.com/dodbuzz/2018/05/14/air-force-debate...
      - nitrogen 7y ago
        I hope I am never in a position to hear that sound in person.
wuunderbar 7y ago
Yea it's pretty wild. Although I am certain this is just for a prototype. I think the actual ones that will be sent to the Moon & Mars will be done in a clean room.

extrapickles 7y ago

I suspect most of the structure that gets really hot or cold is steel. To save weight, they are probably also letting more of the rocket get colder/hotter than normal, thanks to the wider temperature range of steel. Once the temperatures get reasonable, it might be aluminum or or carbon fiber. The passenger/cargo/avionics section are probably the only areas where this would be true, so a bulk of the rocket will be steel.

hinkley 7y ago
Steel can tolerate a lot more deflection before it bends, and much more stress before it cracks. And while I would never expect a space craft mechanic to employ this technique, any bike mechanic will happily offer to bend steel back into shape for you, but bent aluminum or carbon fiber is scrap. Bending it back will fracture it, if it hasn't already. When Canondale hit the big time, they had one model year where they made the dropouts out of solid aluminum and in the next model year the derailleur hanger was bolted on. It's the easiest part to bend and there's no repairing it. Bad enough for road bikes, spectacularly dumb for mountain bikes.

balfirevic 7y ago

> Are we just seeing the outer shell and it's all unobtanium nano-tube composite on the inside? Nope, it's just steel. Outside shell is the tank.

hinkley 7y ago
I recall quite a while back, when titanium started first showing up outside of aerospace, that someone had created a titanium-titanium composite by layering plate titanium with titanium cloth and welding it together somehow. Was supposed to be stronger. Wonder if there's a steel equivalent possible. I think the military was looking at a similar material to replace depleted uranium with something non-radioactive (depleted uranium still experiences alpha particle decay, which is fine if you don't aspirate or ingest it, but a shell can pulverize on impact with a target. Also it's still a heavy metal even if you don't take rads from it).
- balfirevic 7y ago
  > I think the military was looking at a similar material to replace depleted uranium with something non-radioactive I thought the point of depleted uranium projectiles was simply the density of uranium, giving them large impact energy for a given volume. If that's the case, titanium (4.5 g/cm^3) will not even be as good as steel (8 g/cm^3), let alone uranium (19 g/cm^3).
  - MR4D 7y ago
    Tungsten. https://www.military.com/dodbuzz/2018/05/14/air-force-debates-replacing-depleted-uranium-rounds-10.html https://www.military.com/dodbuzz/2018/05/14/air-force-debate...
    - nitrogen 7y ago
      I hope I am never in a position to hear that sound in person.

wuunderbar 7y ago

Yea it's pretty wild. Although I am certain this is just for a prototype. I think the actual ones that will be sent to the Moon & Mars will be done in a clean room.