disappearing encounter nodes.

[miklkit]

I'm new to interplanetary travel and have run into a problem that is messing me up.  I'm going to Duna now and when I get close the encounter nodes disappear, then reappear when I go to normal time.  This was on my last trip. 

Other trips they disappear and stay gone until I redo the encounter and correct for any errors. 

Is this normal?

[king of nowhere]

it's happened to me too, it's probably a bug of the latest version.

however, if you were in an intercept course with duna, you will stay in an intercept course, whether the game realizes it or not. so don't worry, just keep going until you get in duna's SoI

[miklkit]

That is another can of worms.  On one trip I had to make 3 corrective burns to get the encounter again, only to have them disappear again. 

[king of nowhere]

12 hours ago, miklkit said:

That is another can of worms.  On one trip I had to make 3 corrective burns to get the encounter again, only to have them disappear again. 

oh, wait, there is another issue: sometimes when you time warp your trajectory gets slightly shifted, so that may be why you're losing encounters and need corrections.

to counter that, two things:

1) always save before time warping, and check for minute changes in trajectory

2) first accelerate manually to 10x, and only then give the command "accelerate time to this position"

Edited June 16, 2022 by king of nowhere

[miklkit]

This happens about 15-20% of the time and it happened again last night.  Two more burns were needed.  I can only see well enough to make corrections when I get pretty close, so have gotten into the habit of over engineering the craft so they can make many burns. 

2)  just might be my problem as I always go straight to the big warps.  MechJeb goes up and down the warp speeds slowly, so maybe this is a well known bug, except to Noobs like me. 

[18Watt]

14 hours ago, king of nowhere said:

2) first accelerate manually to 10x, and only then give the command "accelerate time to this position"

That seems to be very helpful, ‘easing in’ to warp, instead of going straight to full blast.

 

On 6/15/2022 at 5:29 PM, miklkit said:

I'm going to Duna now and when I get close the encounter nodes disappear, then reappear when I go to normal time.  

That has been a problem as long as I can remember.  It has changed a little with different versions of the game, but still happens.   @king of nowhere’s suggestion of easing into time warp seems to be a common way to limit the effect.

On 6/15/2022 at 7:47 PM, king of nowhere said:

however, if you were in an intercept course with duna, you will stay in an intercept course, whether the game realizes it or not.

That is correct.  Unfortunately, if you needed to do a course correction, that becomes impossible to plan.  For example, you have a Duna encounter, but want to adjust your trajectory mid-course to get an Ike encounter.  

[miklkit]

That last one sounds like it is true, except when it is not.   I can not trust it to be true based on past experience.  Burns of over 1 minute when only 5 days out have happened just to get the encounter to Duna back.

[king of nowhere]

4 hours ago, miklkit said:

  Burns of over 1 minute

this culd mean everything and nothing. 1 minute could be 2000 m/s with a high thrust lander, or a small correction burn with ion engines

[miklkit]

Trudat!  This particular example was this MK1 spaceplane traveling from Minmus to Ike.  It actually needed 3 big burns to get the encounter to stick.  I forget how much it weighs, 70 tons?, with 3 Rapiers and 2 NERVs.

 

I made a return trip from Ike to Kerbin in a MK3 and used the slow up and down with the warp method and it still needed 1 small correction burn.  Just under 200 tons and 5 NERVs.  I guess this is just something I'm going to have to live with.

 

 

[king of nowhere]

damn, I just got stuck with that bug, and it's not one of the other well-known issues I knew, it's worse.

So I was planning a trajectory to Ceres, and I got a close approach at 500k km. Then I set up another node further ahead, and the close approach disappeared. I didn't do anything with the new node, it just disappeared. And then I deleted it, and still there was no approach. I fiddled a bit with prograde/retrograde, and I got again a close approach... at 2 million km.

I even got an encounter, which disappered as soon as I tried to set a new node in front of it. And then, even though my original node hadn't moved at all, I could not make the game see the encounter again.

i saved the game when I had the encounter planned. I reloaded the game, the encounter is not there anymore.

Unfortunately, while I can confirm that there's a very annoying bug here besides the rounding error, I have no idea how to account for it.

[miklkit]

Uh ohh.  You too?  It is becoming more and more common to me, to the point that I expect it now and start making course corrections at least a week before hand.  It really slows things down when I have to sneak up on it with a new burn every day. 

EDIT:  I just went from Minmus to Ike and never had a problem.  The encounter nodes stayed put even when warping.  It didn't end up where predicted, but the flight went off without a hitch.  More testing needed.

Edited June 19, 2022 by miklkit
more info

[miklkit]

It happened again.  I use MechJeb and this time on a trip to Duna no encounter was generated.  Ok fine, I'll get an encounter when I get close.  silly me............never happened.  Used MJ again and again.  It took 3 tries to actually get an encounter, but did eventually get to Duna orbit.  Was getting low on gas so went for Ike Base.  again the encounter disappeared but I was able to manually find an encounter and landed at Ike Base.  It took 8 years and 276 days to make the trip.  Woopee.

[king of nowhere]

I don't know mechjeb, but the fact that it cannot make an encounter does not necessarily mean anything. If you are passing close to the planet, you can make a correction manuever to get there, always.

perhaps you should just get reasonably close and use the navisphere to finish the encounter - do you know how to use the navsphere to make a rendez-vous? if not, i can explain.

 

By the way, in part 26 of my caveman jool 5 challenge I explain how to get an interplanetary encounter in a couple orbits without using manuever nodes at all - because in caveman you cannot use them. you may find it useful as an alternative

[miklkit]

I've gotten to the point where I plan on doing corrective burns, but this time there was just no way.  I tried prograde, retrograde, radial in, and radial out.  No way.  It had way more fuel than needed normally, but this time it didn't have nearly enough.

MJ is slightly better than the built in thingy and way better than me.  It usually saves a lot of time to just let MJ do everything with just some fine tuning by me.  All i get on my own are flickering and disappearing lines.

[imcute]

kraken sucks

[king of nowhere]

Just a few minutes ago, I time-warped past an encounter, and I thought maybe the same thing is happening to you. I knew I was close to the encounter, and the encounter disappeared. I did time warp carelessly, and I found myself having passed my target (vesta). I actually got the encounter - kerbalism science activates authomatically if it is set so, and I did get science from vesta. but I did not get anything else because the time warp was high. It stops authomatically when you change SoI, but it had enough delay that i found myself out of time warp but already out of vesta.

By the way, I was in a collision course, but i did not explode because the game didn't have time to register that.

Anyway, my point is that when you KNOW you have an encounter because you had performed your burn correctly, perhaps you still have an encounter, and you just need to time warp more carefully. if you don't time warp to max, maybe the game will finally see you are on an encounter when you enter duna's SoI

[miklkit]

I have become far more careful than that and always sneak up on the encounter at normal speed.   I get close to it by warping slowly (warp 4) then stopping and checking because the encounter disappears when warping.  Sometimes.  Sometime it doesn't.  And sometimes it is just gone and I can't find one.  It is different every trip and is taking all the fun out of it. 

I have heard some opinions that it is Steam that is messing up KSP.  Dunno about that, but am thinking about creating a non Steam install and trying it out.

[king of nowhere]

6 hours ago, miklkit said:

I have heard some opinions that it is Steam that is messing up KSP.  Dunno about that, but am thinking about creating a non Steam install and trying it out.

my install is not in steam, and i have the same problem.

I do believe it's a mixture of rounding errors and encounters disappearing. when you set the encounter right, it will still be there, and you'll meet the planet if you time warp carefully. if there is a rounding error, then the encounter truly disappeared, but you can avoid that by starting time warp to 10x manually

regading manual confirmation of the encounter using the navisphere...

look at the navisphere, the prograde marker is straight over the target. this means you are moving exactly towards the target, so you have an encounter (notice that you have to set the navball on "target")

Here the prograde marker is not exactly on target, so you're going to miss (in this case the target is another ship, but the principle is the same). But you can adjust your trajectory. see where I am pointing my ship? this will both slow down compared to the target, and move prograde towards it.

I also recommend saving the game before time warping, and checking that your apoapsis and periapsis remain the same.

 

Ultimately, I suffer the same bug as you, but it never had a significant impact on my mission. You can mitigate it.

[miklkit]

I'm not having any luck with careful warping either.  That 8 year flight was done by carefully going up and down warp speeds.  This is just something I'm going to have to deal with then.  Sigh.  Taking 6000 m/s for a 2000 m/s flight is now SOP.