Bug #3847
Rockets get stuck on the Launchpad (again).
100%
Description
First of, I think I remember that this was an Issue way back in a pre .20 version of KSP.
My rocket gets stuck on the Launchpad after Launching a vessel with a positive TWR (1.6) and standing on the Nozzle of a RT-10 Booster (no launchclamps).
The Craft finally lifts off after it tilted over by 5-10° to one side... if you are lucky
Craftfile and pictures attaches.
Pls check the category I 've put this in.
History
#1
Updated by Kerolyov almost 10 years ago
Updated by - Status changed from New to Confirmed
- % Done changed from 0 to 10
Confirmed for me too. For me it occurred with different rocket design on Tier 2 launchpad. Did you see this in career or sandbox game? If career what level was the pad upgraded to?
#2
Updated by Kerolyov almost 10 years ago
- File StuckOnPad.craft StuckOnPad.craft added
#3
Updated by RexKramer almost 10 years ago
Updated by I built a craft identical to the one in the pictures. It does not appear to have a TWR >1.
1. Launched as pictured. Ship did not move.
2. Launched with launch clamps. Ship slowly sank to the launch pad, as the thrust from the RT10 does not provide TWR > 1.
3. Removed 2/3 of the solid fuel from the large booster. Ship Launched normally.
#4
Updated by RexKramer almost 10 years ago
While the ship posted does not have a TWR>1, I was able to duplicate this with a ship that does have a TWR >1.
I built an identical ship, and removed some solid rocket fuel from the large booster, to get the mass down to 20, giving a TWR of about 1.3.
That ship did not lift off the pad alone. However, it did launch normally using launch clamps. That would confirm the rocket is sticking to the pad, and not simply underpowered.
I was using the Level 2 pad in career.
#5
Updated by MalfunctionM1Ke almost 10 years ago
Updated by Hi Rex,
please dont refer to replicated crafts. I did add the craft-file of the ship I used in the attachment above.
You might notice that the upper solid rocket booster is not completly filled with fuel...
name = SolidFuel
amount = 1000.00001490116
maxAmount = 2500
flowState = True
isTweakable = True
hideFlow = False
flowMode = BothPlease always refer to attached craftfiles rather than replicating.
#6
Updated by Katateochi almost 10 years ago
Updated by I have also had an issue of being stuck on the Tier 2 launch pad. I'd built a rocket while still on T1 launch pad and it launched fine. Same rocket on the tier 2 pad and it wouldn't lift off. As MalfunctionM1Ke says, tilting it managed to get it free. I also found that going to 4x physics warp could free it.
Some pics of my experience with this here -http://forum.kerbalspaceprogram.com/threads/103452-Stuck-on-the-2nd-tier-launch-pad
#7
Updated by Kerolyov almost 10 years ago
I've been playing around with this issue and have reported this issue to the testing team. I found the following things:-
1) Only seems to be a problem with the Tier 2 pad
2) Seems to be mass (~ 25-30t or more causes sticking) dependent but is not a TWR problem as all craft tested will launch if launch clamps used -> Maybe weight is pushing craft down into pad?
3) Sometimes if craft tilts over it can break free
4) Tested on mod free installation
5) Issue seen with various engines, T30, T45 and BACC & RT10 Boosters, so looks unlikely to be thrust transform issue
6) Position on pad seems to be important, with just off centre being worse
Most likely explanation is engines clipping into pad but taking Kerbal for EVA doesn't result in him apparently clipping into the pad.
Using launchclamps is a workaround for this issue
#8
Updated by matttherecluse almost 10 years ago
Updated by - File Orbital Science 1.craft Orbital Science 1.craft added
I have also just experienced this with multiple craft on the Tier 2 launch pad. I was working around it through using various means to break the craft free. I finally upgraded the launch pad to Tier 3 and was expecting the problem to go away, but the first craft I tried on it (attached) still experienced that problem. Just thought I would update this to add that I had experienced the bug with tier 3 launch pad as well.
#9
Updated by Squelch almost 10 years ago
Updated by - Status changed from Confirmed to Need More Info
- % Done changed from 10 to 0
matttherecluse wrote:
Just thought I would update this to add that I had experienced the bug with tier 3 launch pad as well.
I'm afraid your craft appears to be using mod parts, so won't load in a stock game. This is particularly important due to the possible cause of this issue, so your additional report for tier 3 pads must be treated with suspicion.
There is a possible link between certain rocket parts (engines) and potential clipping through the launch pad. This may be due to where the thrust transform is applied, so any clipping due to high mass may actually mean that the thrust is being applied below the surface and never able to break free under normal conditions. This is still a theory, but empirical tests seem to support this hypothesis. Launch clamps do alleviate the problem which further supports the clipping theory.
This problem only appears to affect vessels standing with the engines directly on the launchpad. Not all vessels are affected, and low mass vessels seem less likely to "stick"
To aid a better understanding of this issue, could we please try to identify which engines are affected?
This issue remains confirmed with the supplied craft, but I have marked it as needing more information so we can collate the affected part/mass/pad combinations.
#10
Updated by civil almost 10 years ago
Updated by - File 2015-01-06_00002.jpg 2015-01-06_00002.jpg added
- File 2015-01-06_00005.jpg 2015-01-06_00005.jpg added
- File 2015-01-06_00007.jpg 2015-01-06_00007.jpg added
Hi,
Confirmed for me too.
I have a very simple design, which was working on the un-upgraded launch pad but which refuses to launch after upgrading the pad.
While rocking to the side frees it from the ground, if I add a girder segment underneath (I don't have launch clamps yet) it remains stuck to the pad. (this actually seems to make it worse, remaining stuck until it falls almost the whole way over)
#11
Updated by Ape_Descendant almost 10 years ago
Updated by - File Double_T30_11_6t.craft Double_T30_11_6t.craft added
- File Double_T30_22_3t.craft Double_T30_22_3t.craft added
- File Double_T30_22_9t.craft Double_T30_22_9t.craft added
- File Double_T30_24_6t.craft Double_T30_24_6t.craft added
- File Double_T30_24_9t.craft Double_T30_24_9t.craft added
- File Double_T45_22_6t.craft Double_T45_22_6t.craft added
So I had a little play with this to see if rocket mass was the only factor, which i dont think it is. I tried various rockets from 11.6tonnes to 24.9tonnes (craft files attached, one of them may have accidentally still had the flight engineer chip attached but it donst seem to make a difference).
The results were:
11.6t - Normal lift-off
22.3t - Normal lift-off
22.9t - Normal lift-off (although there may have been a fraction of a second sticking but may have been my eyes playing tricks on me)
24.6t - Stuck to launch pad, could wiggle free
24.9t - Stuck to launch pad, could wiggle free
22.6t with T45 engines - Switched the engines and made it lighter again and this sticks to launchpad.
#12
Updated by Klox over 9 years ago
Updated by I see this problem often. Attached is my craft file and complete save.
I launched this craft last night without any problems. This morning, the craft is stuck. No changes except exiting the game and restarting.- KSP 1.0.2, No mods.
- Level 2 launch pad.
- Two T45 engines on the launch pad.
- 22.2t, 30 parts.
I tried launching at least 4 times and it was stuck every time. The last time I tipped the craft while under thrust and it finally broke free at about 45 degrees.
Finally, I exited KSP, restored my save, started KSP, loaded the craft, removed the T45s and re-added them, then launched without sticking.
#13
Updated by Ruedii over 9 years ago
Updated by I've encountered this bug several times as well. Usually I just add launch clamps to address the problem. However, it is a rather annoying collision map bug.
#14
Updated by Squelch over 9 years ago
- Platform Win32 added
- Platform deleted (
Windows)
#15
Updated by Rodhern over 8 years ago
Updated by I run a quite modded version 1.0.5. of the game, but it seems this problem can still happen from time to time. My example is the lowest level launch pad and a rocket with two T30s that unsticks/lifts off at TWR 1.6 instead of 1.0 as you would expect. I don't know if the rocket unsticks because of the TWR in itself or it is the decreased mass because of burned fuel.
#16
Updated by TriggerAu over 8 years ago
Updated by - Status changed from Need More Info to Needs Clarification
#17
Updated by just_jim over 5 years ago
Updated by - Status changed from Needs Clarification to Resolved
- % Done changed from 0 to 100
I tried this a dozen different ways in version 1.7.2, including using the attached vessels, and I cannot reproduce it. I suspect this is no longer an issue
#18
Updated by chris.fulton over 5 years ago
Updated by 
- Status changed from Resolved to Closed