Yes, convert your fuel into an ENTIRE HULL! I'm sure someone else has thought of this because its so damn simple a leap. In GURPS Spaceships you can make an ICE ship by making an entire vessel typically at the least SM+15 (700m x 160m x 160m) to SM+17 (1.5km x 300m x 300m) tanks and a hull of ICE! The way it works is that you have a Skeleton Ship (acts as a Spine and a rear module), one that is 1-2 sizes below this ship providing Thermo Nuclear Rockets to push the ship with relatively Low Accel. The Ice hull is held together with cables and material, with "Spiders" roughly SM+6 to SM+8 in size. These spiders dancing around provide repairs and maintenance around the ice hull to keep it intact and shoot at Small Debris that will damage the hull. The spiders provide manuver drives as well to allow for course adjustments.
In the rear is the Spin Gravity habitats for occupants and tech which still need some gravity.
These Ice Ships are the fuel but move the ice to cycle around the Star System. If you cycle between Mars and Earth (typically 1AU distance) and Ice ship will take 2 years to do the rounds... but if you have several Ice Ships you will have an Ice ship arriving pretty often, feeding the Economy with Reaction Fuel from Gas Giants. Travel within the system is hitching a ride on these ice ships. There is a bit of a steam punk feel to these Ice ships as they can be compared to Zeppelins with dangerous reaction matter all around the living compartments.
Basically to get the right amount of velocity (mps) to get anywhere in GURPS spaceships you need a ton of fuel... like an F*ton of fuel. While nuclear pulse is how we get there in the beginning to have an entire economy set up for continuous travel without using Reactionless drives look towards a larger energy source.
The same technology for space elevator, is used to suck up gasses from gas giants for processing (but gasses are easier to transport I'm guessing). So its pretty much converting these gasses into TNR fuel. Stations send the ICE where they can orbit and be guarded. Where tugboats move them towards Shipywards to equip the skeleton into the ICE hull. Gov't makes forcasts on the amount needed and what is cost efficient for the economy and they build as needed to spur the economy.
The Freighters have a path and schedule (ex Venus to Earth, then Earth to Mars, and mars to some major Rock on the belt, then Rock to Jupiter). They accelerate and decelerate to make their schedule and stops along Space Stations (slowing enough for Shuttles to match Velocities to unload/upload passengers or special cargo). Against pirates, warships follow a similar logistics system with ice being moved around along with them. Some Warships are very small relative to the ICE ships and are launched from the Ice ship to match velocities and create an Ice ship. Tethered sensor spin around the Ice ship to provide better resolution.
Still travel is slow, and there will be a particular Industry that is meant of Taking Care of Property and Assets while the owner is Away. Since they can be away in 5 years easily, its not your typical Financial Entity. They have to be really really stable.
Despite TL10 technology, TL9 is still the cheapest way to colonize a system because of the industrial base is easier to build. Its actually TL10 but its TL9 is effectivity, the same way a 747 is TL7 but with TL8 upgrades. TL10 is having a more self sufficient and portable TL9 for colonizing.
In my writing I tried to make a time line for developments of technology and how it changed the industry again and again. Thanks to the table and indexing tools in libreoffice lolz.
Gas Exaction Technology.Gas Extraction allows for Gas Giants to be skimmed safely with a advance super strong materials to extend a "hose" long and far enough to draw gasses. The technology is not just great for getting gas but also for terraforming! Guess where we are getting the initial gas??? Venus lolz.
imagine extracting the gass and letting some of it liquefy and crystallize. Set it down a path where the Ice is now a Ring around Venus. Design the ring to shade venus and you have a two fold method of cooling it while fueling your economy lolz. First stop is Venus to Earth Ice freighters.
Oh no Venus is running out of its super dense atmosphere, begin seeding with biotech meant to trap X chemicals into a solid harvest-able form lolz. In the end Venus has two wide band rings that shade some of it from the sun while providing skimmable fuel for travelling reaction drive ships. Eventually the rings will be sustained, until there is a way to balance the energy Venus is absorbing from the sun while making mostly habitable.