[hunterp]

“Long-distance travel takes months or years because the specific impulse of chemical rocket engines is very low, so the craft takes a while to get up to speed,” she said. “But if we make thrusters based on magnetic reconnection, then we could conceivably complete long-distance missions in a shorter period of time.”

[unchocked]

I strongly doubt she said this, as it is factually incorrect. While the specific impulse of chemical engines is low, their thrust is high so they get up to what speed almost instantly.

[tuatoru]

And there's a catch with increasing specific impulse. Specific impulse is proportional to exhaust velocity. The energy required to expel the exhaust is proportional to the square of exhaust velocity.

Because nothing is 100% efficient, high specific impulse means dissipating a lot of waste heat. Increase the thrust too much and you melt your vehicle.

[T-A]

> they get up to what speed

That looks like a Freudian typo. They get up to their top speed faster, but that top speed is lower. Their high thrust comes from spewing out lots of mass at relatively low exhaust velocity, i.e. low specific impulse. And delta-v is directly proportional to specific impulse:

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

The lady's quote may have been a reference to gravitational assist, which must currently be used to get planetary probes to destination with puny chemical rockets:

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

It gets the job done... eventually, after long detours around another planet or two than the one you actually want to reach.