Science New Space Propulsion, using modern science.

[RisingFury]

How about photon pressure and tight beam lasers/mirrors as opposed to propellent?

It's been suggested before. The problem is that every beam of light except a perfect laser degrades as a c/r^2 with distance... Also, you need to input a huge amount of power to get even a few newtons of thrust.

I'm not quite familiar with the photon pressure concept, but wouldn't you end up not harnessing its energy if you reflect it?

Incorrect. By reflecting light you actually get twice the force.

Photons are generally regarded as waves, but imagine them as particles. They don't have mass, but because they have energy and because of their wave properties, they carry linear momentum.
If you hit an object with the photon and the photon gets absorbed, it will impart it's momentum onto the object, but if it gets reflected, it would double that momentum - kinda like bouncing the ball off the wall instead of just catching it.