A trip to Mars

Let's say you were to use a Nuclear Thermal Rocket for propulsion and a Nautilius X for habitation.

Speculative Specs:

Empty weight of Nautilus-X and propulsion: 220k lbs  ( 100k kg)
NTR rated 5000 MW, 250k lbs thrust, ISP 1000
Hydrogen fuel as reaction mass:   310k kg
delta-v for Mars insertion 6.6 km/sec, delta-v for Mars orbit 7.2 km/sec

Weight of Nautilus-X includes lander module and fuel.  It would have to fire for over 20 hours for delta v to Mars trajectory, and a little more than that for orbit.  You'd have to do that again to leave Mars, so the reactor would have to be able to fire for over 180 hours.

Total mass 410k kg. ( 902k lbs)

This does not include getting the Nautilus-X into orbit or its crew.  I am not assuming from LEO, but from a lunar-Earth Lagrangian point, like L2.  That may change delta-v numbers, come to think of it.

Gives you an idea of how hard this task would be.  Practically impossible.

Update:

Changed the link above to a better table.  It looks like an excursion from L2 would take much less delta-v.

From the table, it would take 16,540 to go from surface of Earth to the surface of Mars.  That includes getting off the surface of the Earth, inserting into trajectory towards Mars, going into Mars orbit, and then landing.  By starting from L2, you can subtract all but 5500 of it.  Seems like too much though.

You can still use the numbers above, but most of that velocity will cut travel time.  This could give a chance to lighten up on the fuel requirements, though.  It would come at the cost of a longer mission.

Update:

If you were to do a orbit to orbit trajectory, the delta v to Mars and back would be 5748 m/s each way.

Using the assumptions above, the weight can be cut down to 715k pounds.  Now, if you were to use the fuel available at Mars, say on one of the moons, the amount would be decreased dramatically.  Furthermore, if the moon was developed for fuel, that could pay for the fuel on the way down as well as the way back.