[The E]

It shouldn't be too hard to work out the Indus' distance from the sun from one's fov settings and a little trig. However, that scene is already inaccurate: you can't be in a "decaying orbit" unless you're actually inside the atmosphere of the thing you're orbiting, and the Indus would be slag long before getting that close.

This is patently wrong. You are in a decaying orbit as soon as your angular velocity is below the velocity required to counteract the gravity (or if your angular velocity is higher, see for example the Moon). In both cases, you're changing altitude relative to the thing you're orbiting.

In the Indus' case, they came out of subspace with damaged engines and probably at a suboptimal vector to get into a stable orbit around the sun; they're trying to generate angular velocity, but the engines are not capable of doing more than prolonging the inevitable.

[Phantom Hoover]

Decaying and stable have nothing to do with altitude, they refer to the long-term behaviour of a system. You seem to be confusing "circular" and "stable".

[headdie]

Orbit is when your forward velocity is balanced with the drop caused by gravity.  if your forward velocity is below this rate of altitude loss then you will spiral into the gravity generating object.  what you are thinking of is that when in a atmosphere you have to continually generate forward velocity to counteract the loss of velocity cause by friction

[The E]

Decaying and stable have nothing to do with altitude, they refer to the long-term behaviour of a system. You seem to be confusing "circular" and "stable".

Actually, no.

The Indus' orbit is shaped so that its Apoapsis is too close to the sun for Indus to survive. Indus' engines are not capable of generating enough thrust to alter that orbit in any meaningful way. I do realize that "decaying orbit" may be the wrong term for this, but you know what? I don't care. It's a simple sentence that gets the point across without having to explain terms like Apoapsis. So, after careful examination of your nitpicks, I have determined that they are just that.

So even if Indus' orbit was stable in some way, it simply does not matter. Just as it doesn't matter for a satellite if its orbit is stable but has an apoapsis somewhere within the thing that it is orbiting.

[Phantom Hoover]

Ah, headdie. Nothing like someone helpfully explaining something they clearly don't understand.

E, regardless of understandability it's still an abuse of notation, which is not what you were saying earlier.

[The E]

Ah, headdie. Nothing like someone helpfully explaining something they clearly don't understand.

E, regardless of understandability it's still an abuse of notation, which is not what you were saying earlier.

Oh, right, I probably should have included a bit about me reading up a bit and realizing that your nitpick was true. Sorry.

Nevertheless, a nitpick it is. And "abuse of notation"? Really? What would you have written instead?

[Phantom Hoover]

I think "collision course" would convey the same meaning without being outright inaccurate. It's not important, I onl mentioned it because discussion already went that way.

[Aesaar]

Phantom: It already gets the point across.  A change isn't needed because, simply put, no one cares.

[Buckshee Rounds]

Ah, headdie. Nothing like someone helpfully explaining something they clearly don't understand.

E, regardless of understandability it's still an abuse of notation, which is not what you were saying earlier.

A decay is when an orbit gets smaller, simple as. Doesn't matter if the force doing it is atmospheric friction, particles smacking the orbiter, a retrograde burn or whatever, if the orbit is becoming smaller then it is in decay. Technically you are right in that the Indus' orbit wasn't getting any smaller at the point in which we see her (since she can't possibly be in the atmosphere), but her Periapsis was at a point where the Indus would presumably encounter the atmosphere at some point and therefore would be subject to friction which would cause her orbit to become smaller (which is just semantics at this point since the ship would be long gone). If I remember right the exact quote was "we are in a decaying orbit" or something like that, which in the context of being on a ship whose orbit is not currently getting smaller, but will eventually, sort of makes sense.

I believe I've worded that right, if not then I hope you catch my meaning. "Collision course" just doesn't have the same dramatic effect unfortunately so I think you can forgive the very slight inaccuracy here.

Headdie's explanation was perfectly fine btw.

[Phantom Hoover]

Headdie was completely wrong: you can't spiral in towards anything without an external force.

[General Battuta]

I like decaying orbit because it succinctly conveys that they're ****ed. Nothing about FreeSpace orbital mechanics ever makes any sense, it's important to remain consistent on that point!

[General Battuta]

Their orbit is decaying because the free space drag that makes ships slow down when they're disabled is constantly killing their velocity.

[Buckshee Rounds]

Replace the word "spiral" with "be pulled towards" and he's essentially right. Talk about nitpicking...

Decaying and stable have nothing to do with altitude, they refer to the long-term behaviour of a system. You seem to be confusing "circular" and "stable".

Something else I've realised:- I'm not actually sure if decay is used to refer to the orbit becoming smaller at one specific moment in time, or over a specified period of time as you suggested. From the moment the Indus exits subspace to the moment where she encounters the Sun's atmosphere, she would be in an orbit that would *eventually* become smaller. If we take your meaning of decay (long-term behaviour of a system) to be true, then saying the Indus is in a decaying orbit is actually a completely accurate description.

[General Battuta]

SPACE FRICTION

[Buckshee Rounds]

Their orbit is decaying because the free space drag that makes ships slow down when they're disabled is constantly killing their velocity.

Totally, I mean it's like they've never heard of hitting Alt-G before, noobs...

[Phantom Hoover]

science friction

[headdie]

science friction

your getting it

as a side though what is the particle density between the sun and Mercury's orbit?

[-Norbert-]

If I have the choice between "decaying orbit", "we are getting closer and closer to the sun" and some word I never heard before, I pick decaying orbit.

It might not be a 100% accurate, but it's easy to understand what is meant. And if that's not enough for you, think of the poor guy who said it.
He just fled a killingfield that saw his entire battlegroup torn to pieces. As he said, he's the last conscious member of the bridge crew, probably a bit woozy too from all the radiation and at the very least close to panicking.
If you were in his situation, would you go to find a dictionary to find out what the perfect term for that screwup up position you are in is, before setting of the emergency call? Would you spend even half a second thinking about it, as long as any potential listener get's the general meaning?

[Phantom Hoover]

That explanation doesn't extend to the cutscenes though; you'd have to grasp at straws to come up with a diegetic explanation for them.

[QuakeIV]

I just assumed that it meant they were colliding with the far upper atmosphere of the sun.  Depending on how much stuff they were hitting this could mess them up fairly rapidly.  Before anyone else says the Indus would be hosed if it contacted the atmosphere of the sun, the SURFACE of the sun isn't physically that hot (5,778 Kelvin (5505 °C) by google's numbers). I sincerely doubt the atmospheric particles of the sun are hotter than its surface.  wait never mind

Whats going to doom them to doomy doom is the amount of electromagnetic radiation as they get closer, again if I had to hazard a guess.  The atmosphere is likely to do jack and [expletive redacted] beyond slowing them down.  Considering the fact that (as put elsewhere) they have nuke-soaking armor I think they could handle the actual heat from good ol' Sol's atmosphere for a while, as well as the radiation up to a point. derp

Not deleting this because that helps me learn to actually check my facts first.  With that said, the suns 'atmosphere' is weird if you read the linked wikipedia article.