Assume you have a thing: rocket, satellite, probe, etc, and you’re pushing it to mars or whatever, and you have an engine that, based on the comment states in consumer noble gasses as fuel, one would assume you have to provide the noble gas, correct?
So after you falcon9 the thing into orbit, and push it along, and it then uses this engine to go the distance, will it constantly increase or hit a max terminal velocity. In either case, would that not tell you how much fuel to give it; which comes down to “if it is powered by helium and we are supposedly running out of helium, how much helium would it use vs how much helium is available?”
Is that not a sound question?
The second part of the question is “if we give it one ton of fuel, how far can it get?”
There are a lot of variable not accounted for, like the mass of the ship(and cargo) you are going to attach it to. In theory it can keep accelerating as long as it has fuel, and the maximum speed would be related to the speed of the exhaust. At very high velocity we would have to account for friction with the interstellar medium, space isn't entirely empty just the density is very (very) low.
In the real world you probably have a destination in mind... and maybe want to come back. For one way mission, accelerate till half your fuel is gone, perhaps coast for a bit, then decelerate with the remaining fuel (maybe keep some reserves for maneuvering).
So basically, step two of getting to Mars is to setup interstellar refulling stations.
Once you get to mars, or any destination, you need fuel to get back/other things...
So assuming we have an engine that can deliver us back and forth in a reasonable time, then we need to think about deploying intermediate refueling drones... and then drones to refill them... and then how to manufacture and deliver that fuel to the various nodes...
And if we are running out of helium, on earth, we need to find the most harvestable noble gas we can in the solar system...
What are the atmospheres of the other planets made up of, specifically Jupiter, how could we slurp off its atmosphere to Bush is around the solar system?
The parameter you are looking for is delta-V, the total change in velocity that the craft can accelerate to. It relates to inverse specific thrust, which is the parameter discussed earlier, comparing slow heavy exhaust to fast light exhaust.
So after you falcon9 the thing into orbit, and push it along, and it then uses this engine to go the distance, will it constantly increase or hit a max terminal velocity. In either case, would that not tell you how much fuel to give it; which comes down to “if it is powered by helium and we are supposedly running out of helium, how much helium would it use vs how much helium is available?”
Is that not a sound question?
The second part of the question is “if we give it one ton of fuel, how far can it get?”
Pretty simple MPG question in my mind...