What did "mark" mean on Star Trek?

“Heading 315, mark 7”

“Heading 041, mark 319”

That sort of stuff. I used to think it was angle of inclination until I started noticing the really big numbers. Mark 7 would have the Enterprise flying(?) on a 7-degree incline. But that doesn’t explain the big numbers. “Heading 000, mark 90” would be elevating straight up, yes?

It must have been an elevation angle. In space, “straight up” doesn’t mean anything.

It’s elevation.

Except - “Straight up now tell me do you really want to love me forever, oh, oh, oh.”

It was a “Shout-Out” to Gene’s gay lover, Mark.

aka Mark Goddard the hunky stud on Trek’s bitter rival, Lost in Space.


Always elevation, never declination? Kirk boasts about being better than Khan, because he can comprehend three dimensions and Khan can’t…but the ship never goes toward Galactic South, only North?

Also, the Mark numbers are always small, usually single digit numbers. Nobody ever wants to travel anywhere close to true Galactic North?

Say I’m at Earth and want to visit Alpha Centauri: the direction would be 190 Mark negative 85.

(Is it still widely argued that Star Trek uses a 400 “grad” circle, instead of the 360 degree circle we use today?)

Yes! I noticed that, too. If the Enterprise were flying “downhill” wouldn’t the mark be a negative number?

I never remember hearing a negative mark and I’ve seen probably every episode of every Star Trek series.

319 degrees is equal to -41 degrees, so as long as they only use numbers between 0 and 90, and between 270 and 360, they are fine.

That is realistic. Most celestial bodies are going to be relatively well aligned with the galactic plane, so most of the places you’d want to go are also relatively well aligned with the galactic plane.

Whoa, no! The “galactic plane” is, on the average, some thousand light-years thick! There is absolutely no expectation that Earth, Vulcan, Romulus, Qo’noS, Bajor, Organia, Sherman’s Planet, et al are all in the same plane, or close to it.

(As noted, Alpha Centauri is almost directly “below” the Earth, at least when using standard astronomical coordinates – Right Ascension and Declination. I don’t know how to translate those to galactic coordinates.)

(Also, Star Trek is not consistent in how large the Federation is. Some of the time, they talk about “Quadrants of the Galaxy” implying a civilization that takes up a huge chunk of Galactic real estate – in which case, yes, most locations are in a relatively narrow plane – but even then, navigating between local sites – from Vulcan to Babel, for instance – might be at any angle whatever.)

(ST:TOS suggests that Warp Six is only 216 times the speed of light, so to travel from the center of one quadrant of the Galaxy to the center of another would take some 300 years or more. Since the Enterprise has gone from the center of the Federation to its borders in less than four years, the Federation takes up only a tiny fraction of the entire Galaxy.)

The episode with a guy who’s black on the right side has them fly to a planet “in the southernmost part of the galaxy, in an uncharted quarter,” because of course it was. And it lies “between four-oh-three mark seven and mark nine.”

I’m trying to remember what I read in “The Making of Star Trek” or some similar book back in the day.

My vague recollection is that they added the “mark” to coordinates to “sound futuristic and cool.”

I’ve always assumed that it meant ‘point’, and it sounded cooler than ‘decimal’.

Somebody PM robbie or one of the other submariners we have here and ask them. I’m sure Gene stole it from the Navy.

Not really relevant, but I thought it was interesting that the new Battlestar Galactica used “carom” the same way Star Trek used “mark”. I don’t recall them using it to give heading directions as much as to give the location of enemy ships. But I assumed it was about the same thing – some angles on an X-Y axis.

According to Roddenberry, “mark” was simply a way of separating the first heading in degrees from the second heading in degrees. The first was through the Galactic plane, the second at right angles to it (like using an altazimuth telescope mount).

I always though it odd that the second heading was never “up” or “down” (“north” or “south,” whatever). Otherwise, how the hell would the helmsman know which way to go?

The only time I can think of when “up” or “down” was used was in Wrath of Khan, when Kirk ordered “z minus 300” and the ship moved vertically downward relative to the Reliant, allowing it to sail overhead.

I believe the “400 degrees” bit originated in the original ST tech manual, back in the mid-70s. I always figured was just thrown in by someone who didn’t know what he was talking about.

Now that I think about it, though, it seems to me that in a third-season episode someone (Chekov? Uhura?) gave a heading that was more than 360 degrees. At the time, I thought it was weird, but it happened only once and they never did it again. Given the level of writing and story editing in the third season (“Tell me again what this transporter thing does, OK?”), it probably was just thrown in by someone who didn’t know what he (Freiberger? Singer?) was talking about.

Revision: There was some mention of a Galactic coordinate system, but more realistically everything would have been relative to the ship’s three-axis control system. In other words “Zero, mark zero” would have been dead ahead. “One-eighty, mark zero” would have been dead astern. And so on.

Actually, only two axes would be involved here: pitch and yaw. If you watch the show, though, there was a third axis (roll) in play, since the Enterprise continually banked like an airplane.

The way they use it, it seems more like they are giving yaw then (mark) pitch.
It would make more sense if it was roll mark pitch.

Using galactic coordinates would be a good idea, but it seems like they are navigating according to the position of the ship, not the galactic center.

That agrees with my memory (no, I’m not going to the basement, dig up the book and try to find it.) Roddenberry thought “mark” sounded sort of military and sort of navigational.

Did you read my revision above? :dubious:

There was a Galactic coordinate system mentioned; IIRC, their Galactic “prime meridian” ran through Sol in the Milky Way’s plane of rotation, while the Galactic “north pole” was marked by a distant galaxy dubbed “Polaris II,” to which the axis of rotation pointed.

How the hell you could navigate in a system like this (essentially inside a sphere of indefinite dimensions; there is no sharply defined boundary to the Galaxy) is beyond me, but I guess that’s what sensors and computers are for.