Incidentally, regarding meta materials. Since we apparently have some semblance of space infrastructure. Has anyone tried to sonically agitate molten titanium in near 0 as it cools? I think I recall some speculation that the n0 molten titanium could crystalize if sonically agitated while cooling. Which would give it some extra rigidity per volume; meaning less needed titanium for the same tensile strength in construction.
I... really don't remember where I... recall (?) it from. Though I do recollect something about someone calling it out as Gundam Lunar Titanium for some reason. 🤷♂️
[X] A teardrop-shaped hull (Starting Weight: 600 dTons).
Much as I'd like to get a headstart on deploying orbital infrastructure over our target with the wheel, slightly simpler novelty is the order of the day.
[X] A teardrop-shaped hull (Starting weight: 600 dTons)
While the merits of each hull type are many and varied, a singular approach is, at last, championed. Though not as simple as the cylinder, a teardrop-shaped vessel will nonetheless remain a simple shape, but explore the bounds of spacefaring shapes for future vessels.
The shape that the designers lay in has a rounded face as the front of the ship, narrowing to a flat point on the back. The dimensions, along with the detailing for the necessary oxygen systems, vital electrical systems, thermal radiators, and vital armoring against micrometeorites and background radiation, bring the design very nearly to 600 dTons, exiting the Small weight category and breaking into the Medium. However, the dimensions make it a very compact in-between that only out-measures the largest cargo aircraft your world employs by a few meters in all three dimensions.
With the shape of the craft drawn out, the next step is the engine assembly that will drive the ship, both in power and propulsion. The assembly is split into two parts; the power plant and the propulsion systems, and while there are tried and tested methods for accomplishing both tasks, one company of engineers and scientists has come forward to you with intriguing propositions.
In terms of power plants, one could traditionally install either a conventional fuel cell system or a fission generator that would slim down the fuel supply needed, but carry with it the risk, small though it might be with the automatic safety measures that are required to be put in place, of dangerous radioactivity. However, scientists and engineers, representing a private company known as Maesanthi Fusion Dynamics, propose installing a well-tested, but still largely prototype fusion reactor. It's bulkier, certainly, but it also seems to deliver half again as much power as a tried and true fission pile of the same scale, and a field test like this would allow for potential scaledown of the setup in the future. At least, so the engineers pitching the idea tell you.
In other news, it would be a trivial task to put on a series of typical bell-shaped main thrusters to accompany your RCS thruster array. Such thrusters have been the main method of propulsion into and through space for the better part of a century. However, the chance at a new spacecraft design with no small amount of funding thrown at it has also encouraged the engineers at MFD to dig up drafts and begin seriously testing a thruster that utilizes a somewhat smaller fusion generator, if not connected to the larger main generator, to ignite hydrogen in order to achieve direct thrust through an aerospike assembly. It shares its bulkiness with its power plant cousin, but thrust tests have been remarkably promising thus far, and the cost might be worth it to shave time off of what is currently a 5-and-a-half-day trip, one way, to Husena.
Finally, there comes the question of solar arrays. Being able to passively generate energy from background solar radiation has been floated since the beginning for ships that do not intend to stray far from their main sources of this energy. However, the bulk that they add to the ship, and thus the time they add to construction, may not fully be worth the amount of power that they would generate. As it stands, proposals for two solar arrays placed abeam on either side of the ship compete with slightly more extensive plans for adding two more, one on the ventral hull and one on the dorsal, to the mix. Though, with power generation being what it could be, it's not an unpopular idea to nix solar arrays entirely and simply depend on the power plant. The extra power from the solar arrays, however, might allow you to have just enough for an extra module.
Leaning toward Fusion + Fusion Aerospike + no solar.
Fuel cells put us firmly back in "tyranny of the rocket equation" territory. Fission is well-understood, but not only are its failure states frankly horrifying, it also adds "persistent radiological hazard, possibly across wide area" to the failure state of nearly every other component. Fusion is the future, and we can only benefit from developing institutional expertise with it ASAP.
The fusion aerospike is a tougher call; we don't really need the extra thrust, and it's less mass-efficient...but that includes its own dedicated fusion plant, and the text explicitly calls out the possibility of tying it into the main fusion reactor instead (if one exists), which should drastically reduce its mass and bulk and- if we're willing to depower other systems while under thrust- might also increase its power. Since I'm going for the fusion powerplant anyway, I think the fusion aerospike is worth a shot.
Finally, I just don't think we need the extra power from solar if we're going for fusion power. Not for this ship, at least; it's still good for stations and great for inner-system exploration where the square-cube law means exponentially higher power generation per square meter as distance to the nearest sun shrinks. This far out, however, it's merely decent- useful if we need more power or more unresupplied endurance, but not especially compelling in a vacuum (if you'll forgive the pun).
[ ] 0: Fusion Reactor (Test Phase [Roll for Efficiency])
[ ] 1: Fusion Powered Aerospike Array (Prototype [Rolls for Efficiency, Thrust Power])
[ ] 2: No Solar Arrays
...Are write-ins allowed?
[ ] 2: No Solar Arrays
-[ ] 2: Mounts and power connections for 1 pair Solar Arrays (0.5-1 dTon)
Would let us add the solar arrays easily later:
later in this project if it turns out we can afford the mass and could use the power
if we're building a one-off individual ship intended for long-duration and/or inner-system missions (such as a survey cruise of the inner system)
or for future tranches of the same design as tech advances and module power needs grow , without the near-total redesign required to upgrade the fusion reactor and its hopefully-integrated aerospike.
I am leaning towards fusion + fusion aerospike + 4 solar arrays.
This is the appropriate time to test bed these kinds of technology especially since this will become the model for future ships. The sails are an excellent redundant system to take the strain off the prototype fusion systems should problems start to occur with them. Not to mention the power gathered by the sails do not necessarily have to go into propulsion but can be instead used to power various other systems and gear on the ship. One thing no one wants is to be stranded in space or to have a prototype fusion reactor collapse. So I vote going all in on sails.
It is always important to have redundant and backup systems. With the fusion systems and sails we will have at minimum 58 P.U. for Project Lunar Seer and the ships would be able to go up to 16 KPS with the only cost being 102 tons. Well worth it in my book especially since some bloat is to be expected for largely experimental ships.
[X] 0: Fission Reactor
[X] 1: Fusion Powered Aerospike Array (Prototype [Rolls for Efficiency, Thrust Power])
[X] 2: No Solar Arrays
I think the radiological fears of the fission plant aren't much of an issue. If we're playing around with viable fusion plants we likely have a wealth of experience do drawn on for operating fission generators without them melting down.
New thrusters on the other hand, are much more directly relevant to spacecraft with increasing the efficiency with which you can expend reaction mass being pretty much the way to try to get around the rocket equation problem of trying to haul more fuel to improve whatever meaning you also need to haul more fuel to move that fuel. Also I think it's probably a good idea to try out at least some new technologies on this ship, and this still lets us mess around with fusion.
As for solar panels, if this was the generalist ship I might include them for the power for extra modules to cover everything, but we're trying to make these more focused so I don't think we'll need the extra module power as much.
[X] 0: Fusion Reactor (Test Phase [Roll for Efficiency])
[X] 1: Fusion Powered Aerospike Array (Prototype [Rolls for Efficiency, Thrust Power])
[X] 2: 2 Solar Arrays
I want the two experimentals on this ship for one very simple reason - it's going to be smol because it's single task, which means any errors will be more easily and more cheaply fixed, with fewer consequences if it goes completely tits up.
I want 2 solar arrays so that in the event the reactor has to go low power or be completely shut down, the ship isn't completely helpless. When we've worked out the kinks and made the fusion stuff a mature technology we can consider doing away with it, but for now keep it.
Y'know what... I'll call it now, I'll state plainly if write-ins for a vote are specifically not allowed. Write-ins can allow for creativity, and if they get enough traction, more power to them.
Y'know what... I'll call it now, I'll state plainly if write-ins for a vote are specifically not allowed. Write-ins can allow for creativity, and if they get enough traction, more power to them.
[X] 0: Fusion Reactor (Test Phase [Roll for Efficiency])
[X] 1: Fusion Powered Aerospike Array (Prototype [Rolls for Efficiency, Thrust Power])
[X] 2: No Solar Arrays
-[X] 2: Write-In: Mounts and power connections for 2 Solar Arrays (0.5-1 dTon)
The fusion plant is explicitly "well-tested", if we go fusion+fusion aerospike and don't get to integrate it into the main powerplant then we've got two fusion plants onboard anyway, and if we do integrate then we'll probably have the mass budget to add the solar arrays later.
In any case I don't think it'll be an issue- the test roll is for efficiency, after all, not reliability. Redundancy is great for long missions, big ships, and small systems; I'm not sure if the moon counts as a long mission for us at this point, but power generation is a big system and this is a small ship. I think it'd use too much of our mass budget for too little gain to be worthwhile at this scale.
I think the radiological fears of the fission plant aren't much of an issue. If we're playing around with viable fusion plants we likely have a wealth of experience do drawn on for operating fission generators without them melting down.
Oh, for sure; I'm basically not at all concerned with "the fission plant itself goes catastrophically haywire and melts down", but I am somewhat concerned with adding radiological contamination to, say, "a micrometeorite impact/turbulence in the fusion aerospike/CYOcatastrophe detonates the aft end of the ship all over <insert general location here>".
Y'know what... I'll call it now, I'll state plainly if write-ins for a vote are specifically not allowed. Write-ins can allow for creativity, and if they get enough traction, more power to them.
[X] 0: Fusion Reactor (Test Phase [Roll for Efficiency])
[X] 1: Fusion Powered Aerospike Array (Prototype [Rolls for Efficiency, Thrust Power])
[X] 2: No Solar Arrays
-[X] 2: Write-In: Mounts and power connections for 2 Solar Arrays (0.5-1 dTon)
[X] 0: Fusion Reactor (Test Phase [Roll for Efficiency])
[X] 1: Fusion Powered Aerospike Array (Prototype [Rolls for Efficiency, Thrust Power])
[X] 2: No Solar Arrays
-[X] 2: Write-In: Mounts and power connections for 2 Solar Arrays (0.5-1 dTon)
This *sounds* good, but could the ship run on minimal power with 2 solar arrays?
Oh, for sure; I'm basically not at all concerned with "the fission plant itself goes catastrophically haywire and melts down", but I am somewhat concerned with adding radiological contamination to, say, "a micrometeorite impact/turbulence in the fusion aerospike/CYOcatastrophe detonates the aft end of the ship all over <insert general location here>".
Personally, if we have manned ships undergoing rapid unplanned disassembly far away from our planet, I think we have bigger issues to worry about than fission fuel chunks being scattered about. And I'm not sure that's something the fusion plant can entirely avoid either. It's not going to have radioactive fuel rods, but fusion power is still going to be producing significant amounts of radiation when operating as a result of, well, nuclear fusion. So you could likely still see irradiated fusion reactor fragment contamination as a minor side issue to the "back of the ship just blew up" problem.
Sure, but nothing like the heavy elements from fission byproducts, not in any significant quantity.
Anyway- yeah, even in the absolute worst case it's probably not a big deal, it's not like we're launching from downtown Metropolis, and there's nobody (that we know of) on the moon to care about getting irradiated.
Wanting to start getting experience with fusion ASAP was by far my bigger motivation, though.
[X] 0: Fusion Reactor (Test Phase [Roll for Efficiency])
[X] 1: Fusion Powered Aerospike Array (Prototype [Rolls for Efficiency, Thrust Power])
[X] 2: No Solar Arrays
-[X] 2: Write-In: Mounts and power connections for 2 Solar Arrays (0.5-1 dTon)
