>Only at extreme delta V levels do NTRs actually get better performance, but that's not a mission-to-Mars territory
Why is that not mission-to-Mars territory? You can shave months off the transit time with >15km/s delta-v.
Why is that not mission-to-Mars territory? You can shave months off the transit time with >15km/s delta-v.
2) Intercept velocities, on the other hand, are progressive -- pretty much for the same reason, combined with Pythagoras' theorem. At one point you stop being able to aerocapture, even with exerting downward lift in Martian atmosphere to prolong the braking phase.
Owing to these two things, I'm not quite sure that propelling yourself from LEO to Mars at 15 km/s would be a good idea, unless you intend to crash into the planet.
Using a Hohmann transfer orbit [1], you get from Earth to Mars in about 9 months.
Using an Aldrin Mars cycler [2], you can get in as little as 75 days. Of course, the Aldrin Mars cycler requires more delta-v, but that's the point, if you have more delta-v you get there sooner.