Bearing in mind that all this is just a fun exercise, and there's no reason to believe that the 1.2 mN/kW thrust will scale to megawatts of power, here's how long it would take to get to Mars if this finding scales to a practical spaceship drive:
- Assume solar panels in space can give you 2.5kW per square meter, and a hypothetical spacecraft has a 20 x 40 meter solar array giving 2 MW
- 1.2 mN/kW == 1.2 N/MW, so at 2MW you're getting 2.4 Newtons of thrust.
- Let's say that the craft weighs 100 tonnes, that gives an acceleration of 0.000024 meters per second squared, or about 20 hours to get to walking speed.
- Mars is 225 million km away.
- Putting those numbers into this nifty space travel calculator, it'll take 6 years to get to mars, including acceleration and deceleration. Or 2 years if you can get the craft mass down to 10 tonnes.