Gas-giant aided interplanetary transfer system, ring vs laser

Question

As I mentioned in previous questions, my story takes place within a star system featuring several gas giants.

I have been wondering how they could be exploited to make interplanetary travel more practical, besides the obvious utility as gravitational breaks and slingshots, and I think I came up with two strategies:

1. Building an orbital ring around the gas giant (at an altitude that would allow for liveable gravity, which would be a radius of several hundreds of thousands of kilometres) serving as a space station and a launch system (following the principle of the mass driver). By the calculation I ran a space craft launched by the ring could reach up to 100 km/s before the centripetal force became problematic and that is without taking into account the craft’s own propulsion. (Meaning the craft would be fast enough to reach the equivalent of mars in a few weeks and without expending fuel)
2. Placing a fusion-powered laser on the gas giant’s surface using balloons and some form of anchoring, fitting the crafts with retractable laser sails and then using the laser to provide initial acceleration.

For additional context, the gas giants in my system are all pretty big, as in having more than 5 Jupiter masses. And of course the civilisation that would develop the systems originated from the moons of the gas giant in the habitable zone.

For the first idea I have pretty solid data about how helpful it would be, however for the second I don’t have much certainty as most of the research I could find is for solar sails.

I’ll be honest, I am much more partial towards the giant ring solution. However considering the promise of solar/laser sail technology I feel I cannot fully dismiss the other option either. Can you help me figure out which one of the two provides the best advantages compared to the drawbacks, especially when it comes to helping massive ships achieve interplanetary speed without requiring enormous fuel/propellant to payload ratios?

Also if you have other suggestions feel free to mention them in the answers.

Answer 1

Pick option 3

There are significant problems with both suggested approaches:

1. The orbital ring will kick spacecraft out at considerable speed, but it is a very high risk option for trying to decelerate incoming spacecraft. Alternatively, spacecraft have to decelerate using conventional rockets/solar sails/ion thrusters etc when arriving at their destination. It can also only launch in the plane that it is rotating in - which admittedly may not be a huge issue if all the bodies in the system are in the ecliptic.
2. The laser cannon has the advantage that it can be used to both accelerate departing spacecraft and declerate arriving spacecraft, albeit at much lower accelerations due to material limits, meaning that spacecraft need highly durable solar sails but practically no fuel except for minor course corrections. However, the "surface" of the gas giant, supported by balloons, is a frankly appalling location. It means that it is limited in its arc of fire as the planet rotates and it has to punch its laser through all the atmosphere above it - the thickness of which will increase dramatically as the angle shifts from directly vertical. (There must be atmosphere above it or balloons could not support it.) That's without even considering how it can be "anchored" in any way to the solid core of what is basically a proto-star.
3. Putting multiple laser cannon evenly spaced around the orbital ring with a modest launch catapault is the best of both worlds. The spacecraft are thrown off with some initial velocity, then get lit up by a laser once they are at a safe distance that won't melt their solar/laser sails. The lasers can switch from accelerating outgoing spacecraft to decelerating incoming spacecraft as required, with no losses to beaming through an atmosphere. Where appropriate (eg at very long distances from any planet with a laser-equipped ring and/or close to the primary) the ships can switch to using their sails as purely solar sails. The only disadvantage of option 3 vs 2 is that there is no virtually unlimited fuel supply for fusion plants to power the lasers - but the orbital rings are in space, just add an array of solar panels as large as required.

Note that option 3 will not allow for transits as rapid as option 1 + serious thrusters - the upper limit of acceleration is determined by how much light heats up the solar sail vs the ability to radiate the received heat into space. However, it is a model which is sustainable for as long as the sun keeps shining.