Unlimited mass? Yes, you adjust the speed of 300,000 km/s

not mass, i mean the ships rooms for stuff

What stuff?

fuel, equipment

and in what ship can i get to the speed of light?

How many tons?

Eran100, you can go to data/ships and open the ships' lua files with a text editor and look at and change the specs. Keep in mind that they're all interrelated. More mass will mean lower speed, etc. The speed of light in Pioneer is not a limit. The game uses Newtonian physics so if you can carry enough fuel you can exceed light speed. Well actually, in Pioneer the speed of light is infinite. You can't travel between star systems that way though because the game only generates one star system at a time.

@Eran100

The old Frontier bug where you could have as much capacity as you wanted thanks to a bug doesn't exist in Pioneer.

If you have a huge amount of cargo capacity then it affects the total weight on the ship so the handling and control of the ship changes, acceleration becomes rubbish and you'll have to change the values for the thrusters for turning, rolling, yawing etc so that it will compensate for the extra weight/mass.

Andy