In more realistic scenarios, "down" is just defined by the direction of thrust. So approaching a ship, they will be down assuming you are decelerating to match their velocity, but they will be up if you are still thrusting towards them.

But all of that has almost nothing to do with how people will think of orientation to other ships since generally speaking you won't be using eye sight to communicate ship to ship. At that point an agreed upon down will be needed. Probably aligned with galactic or star system to establish a plane, and probably right hand rule to establish up and down. In general given that space is big and ships are small they will just be points on each others radar until they need to dock with each other so it doesn't really matter how people are actually oriented, as long as when they communicate what they say makes sense to the other side.

edit: or maybe down is towards the currently orbitted gravity well, like towards a planet/moon/star.

Space shuttles would typically orbit with their top side facing towards Earth. Probably because the bottom is completely covered with ceramic tiles.

And if you're a Romulan, especially your allies.

And whatever that shape from Picard was.

Not a trekkie, do they ever land in atmosphere on these ships? You would want aerodynamics for that to reduce drag and thus heat, but I'm not familiar enough to know.

I guess they probably have good thermal protections with their future tech, though.

They don't even need to fly nose-forward. The Enterprise could exit warp at any damn orientation it wanted. Blasting across the alpha quadrant nacelles-first, like Powdered Toast Man.

Isn’t this due to the warp field? They ummm, have less warp drag?

Depends on the distance being traveled by both ships. The Milky Way is 1000 light years deep, so there's a lot of vertical room to maneuver. Mentioned locations at real star systems, like Wolf 359, are definitely not all on the same plane in any way. Possibly more relevant, though, is that 'up' isn't really much of a thing. Star systems can (and do) have their axis tilted significantly off of the galactic axis, so even if you define 'up' within a star system and orient your ship that way, you may wind up tilted weird when you arrive at the next system due to it having a different 'up'. You could define 'up' by the galactic axis, but that would still only apply to the one organization; there's no reason for the UFP, Romulans, Klingons, Cardassians, and Dominion to all agree that one side of the galaxy is the top and the other is the bottom, but they do anyway. Humans couldn't even agree on which way to orient maps of our own planet for centuries.

Sure but there are star systems that are above and below the exact ecliptic of the galactic plane. We're not on the ecliptic that's why you can't see the milky way as well in the southern hemisphere because we're kind of below it.

If a ship was travelling from Sol to Arcturus it would travel up (relative to the galactic plane) because we're slightly below it and it's considerably above it. The galaxy is very thin compared to its width, but it's still of thousands of light years high.

I can travel the galactic plane with my spaceship oriented any of 360°. Straight is straight.

What I don't understand is why they were even close enough for the image. If subspace comms are a thing, a solar system length may be just fine.

Don't forget about orbital mechanics. For a rendez vous between two ships you need a lot of maneuvers in opposite directions, it's not like shown in movies where the fly like airplanes. If two ships are close to each other they will likely be in different orientations and it would be a waste of energy to face each other since communications still happen at thens of thousands of kilometers of distance

Bingo, ships travel in a specific way so their paths are more or less predictable.

You beat me to it.

I knew this would be here

It's to reduce the profile they expose to the planetary defenses.

• Star Trek Production Excuses Intern, probably

KSP taught me what orbits are and Star Trek taught me that they are just not that important

do it right and it could even look very good and immersive. But at least with the skills, technology and budget of a 1966 TV show, and especially with certain wack ship designs it's far easier to just have everything oriented the same way