F=ma, so Acceleration is force divided by mass. We can't reach light speed because special relativity shows that mass increases with velocity. However it is not linear, and this effect is negligible at anything less than absurd velocities. For example relativistic mass at half the speed of light is still only an extra 15%. At 100 meters per second special relativity is not a factor and has nothing to do with the speed limits in Empyrion.