Why do sci-fi artists design aerodynamic spaceships like mother ships that are never going to land? Aerodynamics really doesn't matter a whole lot in space.
Also, why would these ships need a discernable top and bottom? There is no real up or down for most of your interstellar travel.
Personally, I blame Flash Gordon and Buck Rogers
Theory: aerodynamic-appearing is strongly correlated with "visually attractive".
It's visual language for "we can spend money on excitingly curved hull plates and unnecessary fairings, etc., just so we don't have to look at a starship that looks like a boiler factory had a terrible accident when attempting to mate with a steamroller".
(Which in turn is symbolic language for "we are rich and have a high culture, unlike you primitive savages from beyond the Marches".)
Side note: one factor in naval architecture is trying to minimize the number of curved hull plates needed, because they're more expensive than flat, and increasing the number of curve dimensions increases the cost disproportionately.
In the #eldraeverse, the IN uses sweepingly curved hulls and elaborate brightwork to make a deliberate statement of "If we had budget to spare for *this*, just imagine what the working parts are like."
Naked frames and greebles look cheap.
@cerebrate @nyrath @JeremyMallin
Of course, any spacecraft that is serious about spending time in outer space has external Whipple shield plates to protect against micrometeoroid impacts...
@isaackuo @nyrath @JeremyMallin
It's so nice when technical requirements also give you a great opportunity for branding! 😊
@cerebrate @nyrath @JeremyMallin thinking back to wooden ships, straight beams and planks are a lot easier to cut from a tree than curved ones.
@SkipHuffman @nyrath @JeremyMallin
Same with steel ships. I believe the current standard is to try to keep the percentage of curved hull plates required down to 15% of the total or less; and within that percentage, to strongly prefer simple curves (i.e., those which can be made through line heating and rolling) over complex, multi-dimensional curves, which are much harder technically to achieve.
@SkipHuffman @nyrath @JeremyMallin
(Sadly for those of us who prefer spheres to cylinders in spaceship designs. Teardrops are right out!)
@cerebrate @SkipHuffman @nyrath @JeremyMallin
I wonder if the Holy Hand-grenade of Antioch would make a decent ship design?
@cerebrate @SkipHuffman @nyrath @JeremyMallin
OTOH, for a spacecraft using Whipple shielding, you can make pretty much any shape you like using overlapping "fish scale" plates. The individual plates are just flat squares, attached to the mounting poles at the corner.
@cerebrate @nyrath @JeremyMallin At this point we don't really know what the economics of space/microgravity industry will be. I suspect "optimize for low mass" is going to be an overwhelming consideration.
@SkipHuffman @nyrath @JeremyMallin
On the one hand, in the near-future with current-type drives, that's certainly true; on the other hand, as drives get more and more SFnal, it becomes less of a consideration.
On the gripping hand, though, I observe that _even though_ painting an airliner imposes real additional fuel costs to operations, airlines don't choose to save money by flying naked hulls. Even freight-only lines like Amazon Air. Evidently branding gains outweigh fuel costs.
@SkipHuffman @nyrath @JeremyMallin
So I wouldn't be at all surprised to see that not-all-that-far-into-the-future Interplanetary Express will happily eat the resulting fuel costs of shaping their Whipple shields into a fastest-rocket-in-space look and painting racing stripes on them _if_ it makes them stand out to people looking out hab windows, standing in boarding galleries, shipspotters, people looking at their brag sheets, etc., etc.
Branders gonna brand.
@cerebrate @nyrath @JeremyMallin at that scale and range, yes. But we don't see a lot of branding (other than painted names) on large freighters. Cruise ships yes, but not 20k TEU container ships.
Maybe local ships will have enormous inflatable outer mylar hulls at .01PSI pressure
@cerebrate @SkipHuffman @nyrath @JeremyMallin
One argument for sleek ships is the amount of matter like free hydrogen taking up interstellar space. This could be a problem especially at speed
@olav @cerebrate @nyrath @JeremyMallin How shallow an angle would a .1c hydrogen atom need to strike the prow for it to be deflected?
@SkipHuffman @cerebrate @JeremyMallin
Optimize for low mass because with rocket propulsion Every Gram Counts
(Aka The Tyranny of the Rocket Equation)
https://www.projectrho.com/public_html/rocket/basicdesign.php#everygramcounts
@nyrath @cerebrate @JeremyMallin
Also energy is cheap (inside the orbit of Jupiter). Just hang panels out to collect more.
Mass is expensive. You have to get it from somewhere, take it where you need it, and once you throw it away its gone.
@SkipHuffman @cerebrate @JeremyMallin
Note that RocketCat is holding a Parker Atomic Pen from 2001 A Space Odyssey
https://spectrum.ieee.org/a-radioactive-pen-in-your-pocket-sure
@nyrath @cerebrate @JeremyMallin is it wise to trust cats with nuclear technology? Sometimes they seem kind of iffy on gravity.
@SkipHuffman @cerebrate @JeremyMallin
Well, RocketCat has *already* been entrusted with a nuclear-salt-water powered torchship armed with casaba howitzer weapons. So an atomic pen is negligible.
@SkipHuffman @nyrath @cerebrate @JeremyMallin I’d guess that “optimize for durability/reusability” will be the priority — new ships are costly, and propellant should be relatively cheap. (This is an extension of the SpaceX strategy — their launchers aren’t optimized for mass, but for reusability.)
@michaelgemar @nyrath @cerebrate @JeremyMallin
Launchers/landers are a special category. They need to operate in several environments and all the transition points in between.
@SkipHuffman @nyrath @cerebrate @JeremyMallin Good point, but generally any vehicle that is reused is going to prioritize durability (especially in an environment where breakdowns can be fatal). Cars are not as light as they can be, they are light while prioritizing durability and safety.
@michaelgemar @SkipHuffman @nyrath @JeremyMallin
Or aircraft, for that matter.
But also, not all optimizations are orthogonal. You can optimize for mass by making a nice aerogel outer hull that is also near-optimal as Whipple shielding, and then using patterned variants of it in your company livery need not add more'n a few grams here and there (molecular weight of dye may vary, but probably not *that* much).
@michaelgemar @nyrath @cerebrate @JeremyMallin that also depends on how much "vehicle" you need. The purpose of a vehicle is to deliver a cargo to a destination and protect it in route. On earth your cargo needs protection from a variety of elements and continuous thrust and course correction. Orbital transfer can be mostly one big shove and the environment is constant. Volatiles could be shipped in little more than a slowly spinning bag with a transponder.
@SkipHuffman @cerebrate @nyrath @JeremyMallin Conditional disagreement: "optimize for low mass" will be a consideration for structures that need to be moved between orbits with differing momentum relative to their primary. For stuff not intended to move (eg. construction in situ on asteroids) optimizing mass may be a non-issue.
@nyrath @JeremyMallin
Today, for example, we put curved, as anti-industrial/functional-as-possible-looking cases on all manner of things that aren't intended to ever move, because good-looking can sell a million units.
Apple spent _decades_ beating the entire market and turning Everything Is An iPod In The Future into a trope by turning "humans are basically magpies where sleek, shiny things are concerned" into their core marketing strategy.