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This whole post excitingly reads like star wars. Can someone with an electrical or physics background help translate what this means "Our propulsion system use

by tevon 3y ago

This whole post excitingly reads like star wars. Can someone with an electrical or physics background help translate what this means "Our propulsion system uses a cathodic arc discharge powered by a capacitor bank"? I take it it uses capacitors to release larges amounts of electricity on a given period, thus producing plasma which creates propulsion?

blacksmith_tb 3y ago
That looks like it, I take it the "solid state" aspect of using a metal rod as the source of material to ionize is the main claim to fame here. It does mean 'refueling' is easy, just pop another rod in (easy if you happen to in orbit nearby, that is). The suggestion that you could make new rods from asteroids etc. is cool, but there's quite a gap between theory and practice still...
- imglorp 3y ago
  > make new rods from asteroids etc The Etc includes dead hardware in Earth orbit: that's a smaller gap than mining asteroids. Maybe not molybdenum but probably lots of magnesium, titanium and aluminum.
throwawaymaths 3y ago
It's like an ion drive. Here's the steps: 1. Start with a metal rod. 2. Remove one atom from the rod. 3. Remove electron from atom. 4. Now that the atom is charged, shoot it out the back of the engine really fast using electrical repulsion. 5. Shoot the electron out the back (using a different pipe) so that the exhaust doesn't come back at you due to electrostatic attraction. 6. Now you have the rod, with one less atom. Repeat. A whole ton of times. Steps 2&3 might happen simultaneously, not entirely sure the mechanism but generally an electrical arc is violent, it will spallate and ionize a few atoms here and there. Not having a tank is huge, and the first ionization energy of many metal ions is far far lower than noble gases, which are what is commonly used in normal ion drives
scld 3y ago
Yeah they'll use a capacitor to charge up and then dump high current quickly (that's what they're good at, as opposed to batteries which are better suited for a longer, steadier, lower current output).

by tevon 3y ago

blacksmith_tb 3y ago

That looks like it, I take it the "solid state" aspect of using a metal rod as the source of material to ionize is the main claim to fame here. It does mean 'refueling' is easy, just pop another rod in (easy if you happen to in orbit nearby, that is). The suggestion that you could make new rods from asteroids etc. is cool, but there's quite a gap between theory and practice still...

imglorp 3y ago
> make new rods from asteroids etc The Etc includes dead hardware in Earth orbit: that's a smaller gap than mining asteroids. Maybe not molybdenum but probably lots of magnesium, titanium and aluminum.

throwawaymaths 3y ago

It's like an ion drive. Here's the steps: 1. Start with a metal rod. 2. Remove one atom from the rod. 3. Remove electron from atom. 4. Now that the atom is charged, shoot it out the back of the engine really fast using electrical repulsion. 5. Shoot the electron out the back (using a different pipe) so that the exhaust doesn't come back at you due to electrostatic attraction. 6. Now you have the rod, with one less atom. Repeat. A whole ton of times. Steps 2&3 might happen simultaneously, not entirely sure the mechanism but generally an electrical arc is violent, it will spallate and ionize a few atoms here and there. Not having a tank is huge, and the first ionization energy of many metal ions is far far lower than noble gases, which are what is commonly used in normal ion drives

scld 3y ago

Yeah they'll use a capacitor to charge up and then dump high current quickly (that's what they're good at, as opposed to batteries which are better suited for a longer, steadier, lower current output).