Burn timer = Perfect.

[Stoup]

Yeah, but what if people want to actually watch their rocket fly, instead of watching a circle slowly grow larger? It'd be nice to be able to trust the system

[JoeSchmuckatelli]

3 minutes ago, Stoup said:

Yeah, but what if people want to actually watch their rocket fly, instead of watching a circle slowly grow larger? It'd be nice to be able to trust the system

What circumstances are you finding it doesn't work (watching the ship)?

I've tested it pure w/r/t Mun and it was fine.  For Duna I kept switching back and forth.

I will say I do have some concern with precision when there is a noticeable delay between Flight and Map -but it hasn't been terrible.

• Contrast to the preceding 3 weeks where watching the timer got very odd, seemingly random results.  Further the bar and number countdown never seemed to agree with each other.  That's gone with the patch, as far as I can see - but Mun/Duna is as far as I have tested.

[The Aziz]

12 minutes ago, Stoup said:

Yeah, but what if people want to actually watch their rocket fly, instead of watching a circle slowly grow larger? It'd be nice to be able to trust the system

If it was any interesting. In any case, you can watch your rocket fly and switch to map view on the last 7 seconds. 

You'd still most likely switch afterwards anyway to make further maneuvers or just to see if your new trajectory is satisfying because the readouts you have in flight are far from complete.

[CashedOut]

On 3/16/2023 at 7:22 PM, Fullmetal Analyst said:

yeah its much more accurate now, though i would prefer a readout for dV to reach node 

^This 

Hadn't realized just how much I relied in KSP1 on knowing the exact amount of dV remaining - dead useful for very fine maneuvers, especially with orbital rendezvous when you want to dock with something. This is one of the top items on my KSP2 wishlist. 

However, for myself I don't think the countdown/ burn timer is a big issue - I think it's still useful in itself, but it does require a lot more micromanaging through map view and is less scientific - it's more about reaction time than anything. And I agree with The Aziz on the big picture - unless you are insanely hardcore, you should be doing maneuvers in map view anyway

[Ravlain]

I'm finding that frequently the DV and numeric burn time show 50% of the correct figures, while the bar at the bottom is correct, so remaining time 0 is when half the bar is empty. This doesn't happen all the time though.

[Tazooka]

14 minutes ago, Ravlain said:

I'm finding that frequently the DV and numeric burn time show 50% of the correct figures, while the bar at the bottom is correct, so remaining time 0 is when half the bar is empty. This doesn't happen all the time though.

One time my bar started going red from the left side. Even though I was not even close to completing my burn. I didn't understand why it did that

[JoeSchmuckatelli]

Full disclosure - the more I play the more I find things that may indicate erratic behavior.  Notably after separation of a stage, the bar and timer got misaligned. 

 

Wish we knew if they were drawing from different resources to show the respective data 

[Tazooka]

28 minutes ago, JoeSchmuckatelli said:

Full disclosure - the more I play the more I find things that may indicate erratic behavior.  Notably after separation of a stage, the bar and timer got misaligned. 

Same, sometimes its perfect, other times its short and then it can also be way too generous

29 minutes ago, JoeSchmuckatelli said:

Wish we knew if they were drawing from different resources to show the respective data 

I've only really used Metholox fuel

[JoeSchmuckatelli]

7 minutes ago, Tazooka said:

Same, sometimes its perfect, other times its short and then it can also be way too generous

I've only really used Metholox fuel

I'm not thinking about fuel types.  I'm trying to figure out why the bar and the numbers would behave differently - only solution is that the timing of each is drawn from a different process. 

Like these are calculated differently for some reason 

Edited March 20, 2023 by JoeSchmuckatelli

[Scarecrow71]

I'm still trying to figure out why the actual Ap of a burn during LKO circularization is higher than what I plot.  I always start with a Pe in the neighborhood of 100km, and I set up the burn to have an Ap in the neighborhood of 105-110km.  But when I finish with the burn, stopping short of when the timer says I should, I end up with an Ap of about 150km.  Not sure why this is?

[Tazooka]

Just now, JoeSchmuckatelli said:

I'm not thinking about fuel types.  I'm trying to figure out why the bar and the numbers would behave differently - only solution is that the timing of each is drawn from a different process. 

Like these are calculated differently for some reason 

Ah okay
Could it be something to do with the nodes maybe?

I say this as usually the burns that are accurate are Prograde/Retrograde
But Radial/Anti-Radial and Normal/Anti-normal burns don't tend to be as precise

Or maybe it doesn't like a mix of calculations?

[JoeSchmuckatelli]

17 minutes ago, Tazooka said:

Ah okay
Could it be something to do with the nodes maybe?

I say this as usually the burns that are accurate are Prograde/Retrograde
But Radial/Anti-Radial and Normal/Anti-normal burns don't tend to be as precise

Or maybe it doesn't like a mix of calculations?

I think this will be something good to figure out.  

For now I'm defaulting to the numbers - but pre-patch that was the bad strategy. 

Thing is - it is so rare for them to be off this build I haven't spotted a trend. 

[LameLefty]

For any vehicle with a reasonably-good TWR  and where orbital altitude isn’t changing rapidly, I’ve found the burn timer to be pretty accurate. 

But those caveats above matter: if you’re burning out of an already-eccentric orbit, especially down low near the foci of the conic, the timer isn’t very good. Similarly, if you’ve got a low TWR and you’re in a low orbit where the burn time takes more than a small fraction of your orbital period, it’s not very accurate.

I haven’t noticed any particular issues with radial-antiradial/normal-anti normal burns at all.

For me, the single biggest issue I have is when I’m burning to leave an SOI. The resulting trajectory after leaving the SOI just seems wrong. It’s usually not completely off for me leaving Kerbin’s SOI for Jool or Duna, for example, but it’s TERRIBLE leaving an outer system for a body closer in. Kerbin to Eve, Duna to Kerbin, or Jool to Kerbin burns have all just been flat wrong once leaving the initial SOI. 

[JoeSchmuckatelli]

10 minutes ago, LameLefty said:

Kerbin to Eve

My one trip to Eve worked well,with some eyeball adjustment and a mid course plane change.   Would have to attempt more to be sure. 

[LameLefty]

24 minutes ago, JoeSchmuckatelli said:

My one trip to Eve worked well,with some eyeball adjustment and a mid course plane change.   Would have to attempt more to be sure. 

I haven’t been to Eve since before Patch 1. But I’ve returned from Jool and the final trajectory after leaving Jool’s SOI was absolutely nothing like it should have been, as it was depicted post-burn but before leaving the SOI. As in, I needed to add over 1,100 m/s dV in subsequent burns to get the same Kerbin encounter I should have had after the initial burn. 

[JoeSchmuckatelli]

7 minutes ago, LameLefty said:

I haven’t been to Eve since before Patch 1. But I’ve returned from Jool and the final trajectory after leaving Jool’s SOI was absolutely nothing like it should have been, as it was depicted post-burn but before leaving the SOI. As in, I needed to add over 1,100 m/s dV in subsequent burns to get the same Kerbin encounter I should have had after the initial burn. 

Jool is on my to do list.  I'll keep an eye out! 

[The Aziz]

just focus on correct escape vector until that's fixed.

(Yes this was taken from very old KSP1 tutorial)

[LameLefty]

This is the mess when you try to return from someplace as far away as Jool back in-system:

Here's my trajectory AFTER my escape burn but before leaving the Jool SOI. Background: I was in a near-circular high Jool orbit (221,000km or so) after leaving orbit around Pol. FWIW, this was a near-pefect "canonical" departure burn of about 1,200 m/s.

Yet somehow, after leaving Jool's SOI, and despite burning entirely retrograde to Jool's own orbital velocity around Kerbol, this is what I ended up with.

I was able to salvage this one with about 700 m/s a few hours after leaving the SOI, followed by a ~30 m/s midcourse correction about halfway home to get a close Kerbin periapsis and better inclination for the entry.