Mun Refuel Station Problems

[Shikashi]

Hey there, fellow Kerbal folks.

Got some problems with my mun colony.

Allow me to introduce you to the "Muna" Mun colony project

Not too long ago i planned on making a mun colony to generate endless science.

I already have got five kerbals up there.

Now i was in the dire need of a refuel and ore refinement drill tower.

I added some low hanging structural fuselages(the one that have a crash resistency of 70 M/S).

When it came to landing, i exploded at a touchdown of 60 M/S or less...

Can anybody explain me why?

Here is the refuel station itself:

EDIT: Got the tower to work, pictures will follow

Edited October 22, 2015 by Shikashi
Got the tower to work

[*Asterix*]

A lot of parts in game never really follow their max tolerance speed. It's happened to me before with capsules and reuseable boosters. I'd suggest using some different parts or adding some landing legs somewhere if possible. Maybe try a softer touchdown, like 30m/s or lower.

[Shikashi]

Gonna try it out straight after my ocarina practise, thank you

[Clipperride]

You could also trim some mass. Unless you plan on mining in a very low ore density level, you could easily halve the number of drills. You can also work out the amount of power you'll need to run through the night with this calculator (on the surface of a moon, set the Ap and Per to 0). Another way to cut mass is to only run the unit during the day and save on batteries.

Happy landings!

[ForScience6686]

Why are you trying to land at that speed? You should be touching down under 5 m/s.

[magnemoe]

60 m/s is not an landing its an crash, same with 30 m/s= 108 km/h. now even if the legs them self manage it the rest of the ship will not.

The legs are connected to the ISRU containers with 7 m/s crash tolerance, had they been on top of the legs they might have survived but not as an structural element with such an impact.

As other say 5 m/s is an fitting speed.

[ForScience6686]

Unless is a one time landing and you plan to bury the ship in the surface. My duna drop capsule which is a one way trip can survive up to 20 m/s, but it's design is only for a survivable landing. It uses only air brakes to slow and then sepratrons to slow enough to not explode on touch down.

[FlyingPete]

You're "landing" way too fast. At 60m/s, that means you're slamming into the ground at over 200km/h- a.k.a crashing. Consider 10m/s an absolute maximum, ideally under 5.

[Snark]

Bear in mind that impact survival doesn't depend only on the crash tolerance of the parts hitting the ground. You still have all that mass sitting on top of the structural fuselage, and that mass had a lot of inertia when it's heading downwards at 60 m/s. Parts in KSP have a finite strength about being "squashed", quite aside from their impact tolerance. Likely what's happening here is that your ship is crushing those fuselages.

Even if the parts themselves don't get obliterated under the strain, the joints between them can fail, too. (Quick show of hands from folks who have had a massive Eve lander come apart like a pile of jackstraws upon touchdown?)

Suggest landing more gently, and also consider using landing struts, since they have built-in shock absorbers.

On an unrelated note, you probably have more drills than you need, as previous posters have pointed out. And drills are quite power-hungry, you may want to consider using the sun-tracking solar panels rather than OX-STAT. They're a lot more effective, and it'll lower the part count, too.

[Shikashi]

I guess it's a low ore density area, haven't set up any survey satellites yet.

As for the OX-STAT, they are the only panels i've got...

Ok, i added a lot of struts, I really thought that it would make the "landing".

Gonna try out a new landing...

[mudkest]

as allready pointed out, 60 m/s is way to fast. it is 216 km/h wich might still be emaningless, so I'll add 135 miles/hour. So try to slow down a bit more, you're landing at speeds higher then you are allowed to go on motorways, with the exception of the german autobahn. And even then you need a pretty decend car to reach those speeds

10 m/s landing is still fast, like cycling into a concrete wall.

[Snark]

I guess it's a low ore density area, haven't set up any survey satellites yet.

As for the OX-STAT, they are the only panels i've got...

Ok, i added a lot of struts, I really thought that it would make the "landing".

Gonna try out a new landing...

Struts will help if the problem is joint failure between parts. But if the problem is that the fuselages are just getting crushed by the rest of the ship's inertia, then struts probably won't help much with that.

One thing you might try would be to rotate the fuselages outward by 45 degrees or more, like a person standing with legs spread wide. This would allow them to flex a bit at the joint, I.e. take joint-bending strain rather than squashing strain, which could help absorb some of the shock. Like landing with your knees bent instead of having them locked and straight underneath you.

[Shikashi]

as allready pointed out, 60 m/s is way to fast. it is 216 km/h wich might still be emaningless, so I'll add 135 miles/hour. So try to slow down a bit more, you're landing at speeds higher then you are allowed to go on motorways, with the exception of the german autobahn. And even then you need a pretty decend car to reach those speeds

10 m/s landing is still fast, like cycling into a concrete wall.

I am familiar with the german autobahn, living in middleeurope

Miles/hour are meaningless, but 216 KM/H is quite a lot ...

[Generalstarwars333]

Can you show us the rest of the MUNA colony? without using imgur?

[Fraus]

Well it may or may not be useful but have you considered a few sepratrons to use for a suicide burn landing? Enough at least to make your landing survivable and to minimize damage if at all possible I mean.

[Shikashi]

Why sepratrons?

I didn't use imgur at all, it is just a small persons transporter with a hitchhiker container and the starting pod with jeb inside...

[ForScience6686]

Sepratrons would be a one time use. I will be using them in a similar fashion for a duna landing and the Sepratrons are used to drop the speed to survivable. It is designed for one way only ap I'm not worried about destroying the landing legs.

[interface]

landing legs FTW. buggy 32bit KSP sometimes allows objects not on legs or wheels to fall through terrain and endlessly fall towards the center of a planets gravity well. You don't want that to happen to your crucial base infrastructure!

[Generalstarwars333]

Why sepratrons?

I didn't use imgur at all, it is just a small persons transporter with a hitchhiker container and the starting pod with jeb inside...

Imgur is some image posting site most people on the forum use. It's blocked on my school computer, so I can't see imgur images. So I'm always happy when I can actually see the pictures. I only use my school computer to view the forums, since on my other computer I'm basically just doing ksp and don't have time for the forums...

[KerikBalm]

They can skip across the ground at oblique angles with 60 m/s surface velocity... they may even survive a fall at 60 m/s.... but they don't survive being squashed, and the joints certainly will not.

Ox stats as you have them will not provide enough power to run even half your drills, and at midday they will produce almost no power....

Sorry to say it, but you've pretty much go to start over.

Do a controlled landing at <10 m/s, use extendable solar panels (if you've unlocked ISRU, you should have those), don't have so many ore tanks (more fuel tanks, less ore tanks)

Landing struts are nice because they can survive impacts quite well actually... they may "break" in a way that a lvl3 engineer can repair them...

I've had some duna lander designs pre 1.0 (the atmo does seem thicker on Duna now :/ ) that used struts to cushion the fall -no propulsive landing- just parachutes and shock absorbing struts.. I think the touchdown speed was higher than their rated impact tolerance.. but I simply had to have my kerbal get out and repair the struts after every landing... he had to get out to repack the chutes anyway... so it was pretty much equivalanet... repack chutes, reset shock absorbing struts

[Shikashi]

So, without much redoing I can finally "land" my tower, only problem is that it tips over,gonna lower the CoM...

[ForScience6686]

Try and extend your base as well, that will make it more stable.

[Shikashi]

Yeah, that was a plan too, gonna do both :3

Poor Jebediah and Bill are trapped on the mun, Bill being far away from any civilisation in the middle of a debris field, while Jeb leads the colony