Help me solve a disaster(possible bug)

[wolfedg]

Story Version

Incident Report

The csm was in the process of orbital rendezvous with the lunar module. Remote command (read:the player-me) observed the landing legs mysteriously jettison from the lm upon visual acquisition of the target. They determined the incident was not an issue at the time and proceeded to switch control to the lm to line up the docking port. After aligning the lm docking port, control was switched back to the csm. This was the point of sudden catastrophic failure of the stack separator between the cm and sm. Mission result- 3 astronauts stranded in lunar orbit.

So what happened?

Remote command operators swear they never touched the keyboard and the stage indicator screen in the mission control center still showed the stage as not having been activated.

TLDR Non story version

I was attempting lunar rendezvous and parts were mysteriously jettisoning from my ships causing me to not be able to complete my mission.

[Voidryder]

Story version (Kerbal Style)

You have three choices Director Wolfedg. First, leave that crew stranded awaiting death as your engineers race to determine what went wrong before launching a rescue mission. Second, launch a rescue mission now and hope the next remote-op is a better pilot. Or third, celebrate the successful establishment of Mun Orbit One, the first extra-Kerbin space station around another body!! Champagne for everyone!!

[Stealth2668]

Story version (Kerbal Style)

You have three choices Director Wolfedg. First, leave that crew stranded awaiting death as your engineers race to determine what went wrong before launching a rescue mission. Second, launch a rescue mission now and hope the next remote-op is a better pilot. Or third, celebrate the successful establishment of Mun Orbit One, the first extra-Kerbin space station around another body!! Champagne for everyone!!

Need a tldr version

[Voidryder]

Need a tldr version

Success!! Mun Orbit One!! Champagne Everyone!!

[wolfedg]

Success!! Mun Orbit One!! Champagne Everyone!!

Now now take it easy on the champagne. NOOOOOOOOOOOOOOOOOOOOOOOO (Spark Zap Pop Boom Sizzle) get that champagne away from the control console. Note to self, add "No food or drink" sign to mission control room door.

On a more serious note. I was really wondering if this random jettisoning of parts has happened to other players or if its a random bug.

Edited May 16, 2013 by wolfedg

[Voidryder]

Yeppers. Before the Great Forum Purge, there were a few bug reports of this happening to various players. I believe the most common response was 'it has to be some mod you have installed', which the reply usually was 'but I don't have any mods installed' which lead to much hilarity and guffawing by all for hours. Oh those were such heady days before the Great Purge. ::laughing hardily, wiping away tears::

[Spatzimaus]

Yeppers. Before the Great Forum Purge, there were a few bug reports of this happening to various players.:

It happens periodically, but it doesn't have to be because of any mods. There are two basic ways I've seen this happen:

1> Components are interpenetrating. When the vessel you're not controlling enters the detailed physics range (~2.3km), the game will recalculate all of its internal physics. Depending on your design, it might think two parts are now trying to occupy the same space, even if it knew better during the period you were controlling that module directly, and it will attempt to violently separate them. This is very common with "activated" parts: landing legs, those two docking ports with closing covers, and so on, but you can also get it in other ways, as many parts can accidentally be placed inside other parts if you're not paying attention.

2> The physics engine is overcorrecting. It's not uncommon for large designs with insufficient struts to shake themselves apart, especially if you've just recently transitioned from a high-stress state (say, launch) to a low-stress one (drifting in orbit). One of my stations tore itself to pieces, Tacoma Narrows style, by shaking itself after reaching orbit. It was effectively trying to twist around the "vertical" axis, and there weren't enough struts in place to dampen out that vibration. Note that ASAS can make this worse, but isn't the cause of the problem.

Regardless, the solution is to try again, and rescue your first kerbonauts. That's half the fun of this game, after all.

[Vanamonde]

I don't know about the other problem, but do not put your landing legs in the extended position until you're ready to land. That's because if you resume a flight in-progress with landing legs extended, sometimes they just detach themselves and float away. I've seen it happen twice.

[wolfedg]

It happens periodically, but it doesn't have to be because of any mods. There are two basic ways I've seen this happen:

1> Components are interpenetrating. When the vessel you're not controlling enters the detailed physics range (~2.3km), the game will recalculate all of its internal physics. Depending on your design, it might think two parts are now trying to occupy the same space, even if it knew better during the period you were controlling that module directly, and it will attempt to violently separate them. This is very common with "activated" parts: landing legs, those two docking ports with closing covers, and so on, but you can also get it in other ways, as many parts can accidentally be placed inside other parts if you're not paying attention.

2> The physics engine is overcorrecting. It's not uncommon for large designs with insufficient struts to shake themselves apart, especially if you've just recently transitioned from a high-stress state (say, launch) to a low-stress one (drifting in orbit). One of my stations tore itself to pieces, Tacoma Narrows style, by shaking itself after reaching orbit. It was effectively trying to twist around the "vertical" axis, and there weren't enough struts in place to dampen out that vibration. Note that ASAS can make this worse, but isn't the cause of the problem.

Regardless, the solution is to try again, and rescue your first kerbonauts. That's half the fun of this game, after all.

I don't know about the other problem, but do not put your landing legs in the extended position until you're ready to land. That's because if you resume a flight in-progress with landing legs extended, sometimes they just detach themselves and float away. I've seen it happen twice.

Good to know and it explains a lot. Thank you, as you can probably tell i'm fairly new to the game and don't know all its quirks

Also, I don't have any mods currently loaded, but did have some that have been unloaded by JSGME. Also the ships in question are of fairly basic design, so I don't believe its a strut issue unless that can carry over from its initial complex launch configuration which did have a lot of struts.

Example of the launch vehicle in question, the Pluto V M, an Apollo style lunar orbit rendezvous type mission. It has already lauched and sucesfully returned 3 crews to the Mun prior to this mission.

Edited May 17, 2013 by wolfedg

[SkyRender]

For future reference, never use the mid-sized landing legs if you can avoid it. They are the most prone to breaking off inexplicably when the physics engine blinks at them.

[Vanamonde]

never use the mid-sized landing legs if you can avoid it

They also LOVE to bounce your lander over on its head.