Prerequisites:

Description:

    This is the adaptation of Fusion Rocketry to work without necessarily consuming onboard fuel.  This is done by, once the vessel is up to a minimum speed in interstellar space, arranging magnetic and electric fields such that the interstellar hydrogen medium is funneled into the ship, fused, and expelled from the rear of the craft faster than it entered.  This may well be impossible because (1) it may never be possible to fuse hydrogen-1 (which most of the interstellar medium will consist of) in small-scale craft (ie, less than planetary mass) and (2) it may not be possible to effectively move neutral hydrogen into a profitable configuration fast enough to power a vessel.

    Since this type of vessel uses the material available in front of it while traveling at relativistically high speeds, so this makes it far more vulnerable to both random junk in its path, and deliberately placed impediments (spacemines?) than would other interstellar craft.  This craft only travels for free above a certain minimum speed, so it must still carry some fuel for use in-system and accelerating to that speed.

    Each model of ramjet will have an inherent maximum velocity it can travel at while still fusing hydrogen from the interstellar medium.  This maximum will depend on the Ramjet Fusion Rocketry (dev), but will never get to light speed.  It can still accelerate to any speed while burning onboard fuel.