Sounds like you're remembering the Bussard Ramjet, which sucks up hydrogen from the interstellar medium to fuel a fusion reactor. It's technically possible on paper, but not even close to practical for a variety of reasons, among those being that the density of the interstellar medium is too low to provide enough fuel and fusion reactors aren't efficient enough.

https://en.wikipedia.org/wiki/Bussard_ramjet

The "Feasibility" section is pretty much a litany of big problems.

It works better if you have dedicated fuel collectors that act as refuel points

yeah it's called a water bottle rocket i think and i've seen one like 2 months ago.

also you can't reach orbit that way. the rocket equation says that you'd need exponentially more fuel the higher you want to go, simplified. precisely, it's a bit more like: m~0~ / m~f~ = exp(Δv/v~e~) where v~e~ is the effective exhaust velocity (how quickly the water is thrown out behind) and Δv is constant 7 km/s for going to orbit, so if v~e~ is sth like 20 m/s you can see how that's difficult. chemical fuel has v~e~ of 3 km/s so Δv/v~e~ is sth around 2.3 and exp(2.3) ≈ 10 so that's doable.

Is that Steve Spangler in the photo?

I think you'll like A Deepness in the Dark by Vernor Vinge. Published in 1999, and predominately features such technology.

Oh, you can do the math and make a more educated opinion than just pure guess. Find space "density", rocket size... figure out how much propellant you actually need and how many millenniums you need the get enough to keep your engines work for a few seconds. It actually might be a fun little article.