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I suppose it has to do with how many frames of reference you're juggling in a task/profession. With boats, others mentioned that wind provides its own frame, and there are separate words still for "left" and "right" in that frame.

Then there's space, where it gets even more fun, as the relevant frames - the ship, the orbit (or the "centre of gravity" of everything pulling on you) - are completely independent. That is, your orientation doesn't matter for the travel direction. Now, not only "right" and "left" are ambiguous - but also "up", "down", "forward" and "backward".

When in orbit, you have "prograde" and "retrograde" to refer to the velocity vector's direction and its opposite; if we dub that "forward" and "backward", then "radial" and "antiradial" are "down" and "up" (i.e. towards / away from the center of orbited body), and then "normal", "antinormal" for "left" and "right", which you can get from the cross product of "forward" and "up".

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> With boats, others mentioned that wind provides its own frame, and there are separate words still for "left" and "right" in that frame.

There's windward (towards/upwind) and leeward (away/downwind).

Are there left and right too?

https://en.m.wikipedia.org/wiki/Windward_and_leeward

There's port/starboard tack, where the wind is coming from the port/starboard side of the vessel. It can be confusing because, for example, if a boat on a port tack tacks to port, the result is a starboard tack (once the bow crosses the direction from which the wind is blowing).

That has another ambiguity: in wind, directions are presumed to be naming the source of the wind, not the sink.

After your first few hours on deck in foul weather, that one will seem obvious.

For wind, you have “lifted” (wind shift that takes you closer to your destination) and “headed” (similar but away) when going to weather. Downwind, it’s a little different as the wind just “shifts” and you trim sails or steer to take advantage.

And the wind itself backs (anti-clockwise) and veers (clockwise) with height.

What matters to sailors with respect to the wind is the angle which it meets the boat or the orientation of the boat with regard to the direction of the wind. For that there are dedicated names known as the points of sail which include: close hauled, close reach, beam reach, broad reach, run, and in irons.

https://en.m.wikipedia.org/wiki/Point_of_sail

Good point! :)

But points of sail don't have any handedness, correct? I.e. they're mirrored on both sides of the wind.

As mentioned in another comment, tacking (with its active directionality) is probably the closest to handed-terminology.

>But points of sail don't have any handedness, correct? I.e. they're mirrored on both sides of the wind.

The right-of-way rules in sailboat racing depend on who is on 'port tack' or 'starboard tack' (ie, they differentiate those mirrored halves). There's nothing physically special, though.

Even without the wind, the separate words help. In crew (rowed) boats, people sit backwards. And then boats are stored on racks upside-down. It can get complicated!

And the British decide to make things more confusing by referring to the sides of the boat as strokeside and bowside.

Strokeside is always port, even if in that particular boat stroke's oar is actually on the starboard side- and even in a sculling boat!

And for some reason half of the world have port and starboard channel markers as red and green, and the other are green and red. I don't know who's fault that is!

Windward and upwind are different in my book: windward is anything to the side of the boat opposite the main boom, whereas upwind is you draw a line perpendicular to the wind direction and anything toward the wind from that line is upwind. You could have a mark downwind of you on the windward side if you overshot the last tack before a mark.

The convention for orbital spacecraft is that the local coordinate system has +z facing whatever it is orbiting and +x facing travel direction. Then you can refer to directions relative to the spacecraft such as "+x", "-y", etc.

The space shuttle normally orbited with it's payload bay, opposite of the landing gear facing Earth. The payload bay was +z direction. From the layperson's point of view, the shuttle orbited upside down, but from an aerospace engineer's point of view it orbited right side up and landed upside down.

That's a convention, but hardly the convention.

I used to work satellite navigation for NOAA. For the GOES sats we often used Intrack (Prograde/Retrograde), Crosstrack (Normal/Anti-normal), and Radial (Towards planet/away from). I don't think anyone really referred to any directions as "plus x" or "minus y"

There are different conventions, yes. Even for the shuttle I've seen +z point in the opposite direction in some documents. I work in systems engineering so I'm less exposed to terms used in operations and more in discussions about which part of the spacecraft things are located.

Actually I work on rovers and it's a perennial debate whether to follow spacecraft convention (+z is down) or automotive convention (+z is up). Then mechanical engineers will usually follow what is intuitive on the screen (+z is forward). This is because computer graphics convention is +z facing out of the screen.

Yeah, operations is kind of where engineering's best practices go out the window for practicality haha.

We used to tilt the spacecraft when doing inclination burns so that we could get a little bit of intrack delta-v to even out our orbit. I always thought that was delightfully janky.

>> The space shuttle normally orbited with it's payload bay, opposite of the landing gear facing Earth

That wasn't a choice. The doors had to remain open and pointing away from the earth so that the radiators could properly dissipate heat. It also, in theory, kept the most important thermal tiles pointing away from incoming space rocks.

> The doors had to remain open and pointing away from the earth

It's the opposite. The orbiter usually kept it doors pointed toward Earth and the "bottom" tiles pointed away from Earth, and orbited with its engines pointed prograde. (Upside-down and backward relative to the atmospheric flight people are familiar with)

https://space.stackexchange.com/questions/12321/why-did-the-...

As I suspected from seeing your username over the years, you really are knowledgeable on the topic of temporal space and orientation :)

https://en.m.wikipedia.org/wiki/Deep_temporal_space

I’m curious, have you ever played Kerbal Space Program? Or, are you familiar with orbital mechanics for a different reason? KSP taught me about those terms and familiarized me with the concept.

KSP mostly. I did have an interest in the topic since childhood, but KSP is for me what really made the concepts and terminology stick.

Interesting: once you nail down any two axises, the third follows.

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