I don't see any need for structural integrity fields in a low-sublight spacecraft, nor for deflectors. Those are only necessary for vessels that engage in high speeds vs. the space medium or in high acceleration, and the solar sail would do neither.
Nor do I think that wood would be a particularly poor material for building spacecraft. Not in the sense of structural strength, at least. Launching by a rocket should only create stresses on the order of one to ten gees, which a wooden structure might withstand better than a metallic one. "Wood" is just one specific type of composite, after all, and those are characteristically lightweight and strong for their weight. Wood would also be a nice radiation protection material.
The problem with wood would be that it typically encases a lot of water, which would cause problems in the harsh sunlight, extreme cold and low pressure of space. It would have to be very dense and dry wood to work in that environment.
Launching from a space station should be no different from launching from orbit, so Sisko didn't invalidate that part of his experiment at all. We don't know how Bajorans launched their vessels from surface to orbit, but we have no reason to think they couldn't have done that. Perhaps they used ballistic rockets, perhaps they used transatmospheric aeroplanes, perhaps they used airships, perhaps they used big guns or other accelerators, perhaps they used ascent chutes, perhaps they used antigravity. All of those are technologies that a typical "21st century Earth" level culture ought to have in abundance - and Bajorans are consistently described as an advanced and ancient civilization. They might have reached "21st century Earth" technology levels tens of thousands of years ago, and then stagnated. Or then merely 800 years prior to "Explorers", which would make the ascent technologies relatively new but still perfectly extant.
The one thing that's counterfactual about Sisko's replica is that it had too little sail surface area in relation to payload mass to be workable. The sail should have been several kilometers per side at the very least.
However, if Bajorans had antigravity (and perhaps used that for going from surface to orbit), then the smaller sail area would work just fine. The craft's mass would simply be reduced, while sunlight would produce the propulsion. Yet one wonders why Bajorans wouldn't have used their gravity control tech to create internal gravity for the craft, then. Unless they simply liked zero gee?
Let's also remember that we don't know what these craft were built for. Akorem Laam used his for contemplation in solitude. Perhaps he chose a lightsail because he found the usual impulse cruisers noisy and unromantic? Bajor might well have had plenty of "traditional" space tech in addition to the lightsails, just like we today have plenty of naval technology that does not involve sails.
Timo Saloniemi
