Ore Containers and Ore Retrieval Contracts

[Enorats]

So - after multiple failed attempts at returning ore from my extraplanetary launch facility on Minmus.. I have to ask - has anyone managed to get an ore container to survive landing on Kerbin? They seem to have horrifyingly weak joints (even with the joint reinforcement mod) and anything I attach them to (or to them) just breaks the second it hits land, destroying the tank. If it lands on water, the tank is instantly destroyed (even if the tank is inside a bay and never contacts the water). I even built a ship I could launch from Minmus that was basically two adapter fuel tanks with a Mk 3 cargo bay in between, radial engines on the rear with some air breaks, and a heat shield in front. With several KAS winches it's perfect for returning wrecks to the surface.. but trying to attach an ore container inside the Mk 3 bay (directly to the wall, or even with other pieces and struts in between) leads to a total failure. The drop pod has enough parachutes to slow even a fully filled bay to ~8 m/s, so I doubt the speed of the impact is the problem. I've tried landing it on it's end (which destroys the heat shield.. they're also horrifyingly weak) and I've tried landing it flat by pumping fuel from the front tank to the rear and balancing the center of mass. Neither way makes a difference.

[adinfinitum]

Huh, I've only done one ore retrieval contract so far, but I don't recall having that problem. I would say 8 m/s is still landing a little hard, thats about 18 mph. If I've got anything coming down at more than 6m/s I expect something to break. Getting the landing speed down to 4m/s is worth a shot.

[Eric S]

The drop pod has enough parachutes to slow even a fully filled bay to ~8 m/s, so I doubt the speed of the impact is the problem.

The crash tolerance of the ore containers is 7 m/s, so the speed of the impact can't be ruled out. If the ore containers are the first part to hit, it's almost definitely the problem, in fact.

I haven't tried this yet, but I just got a contract to do so, so I'll know more later.

[Raptor9]

I would say 8 m/s is still landing a little hard, thats about 18 mph. If I've got anything coming down at more than 6m/s I expect something to break. Getting the landing speed down to 4m/s is worth a shot.

+1 I had a similar issue when I was trying to make a 7 Kerbal pod for LKO ferry flights. It was a Mk1-2 pod with a Hitchhiker at the bottom, and a small tank and 'Poodle' below that. During testing if I didn't get the parachute-assisted impact to around 4m/s in water, the only part to survive was the Mk1-2 and anything surface attached to it. The rest of the ship broke apart and disappeared. If I used a set of thrusters or the main engine to ease into the water, everything was fine.

[Enorats]

The ore container isn't hitting at all, it's contained inside of a Mk 3 bay to protect it from reentry heat and held in place by struts. Tbh, I've almost never had any problems with a speed under 10 m/s. The science jr's are about the only thing I've encountered that can't take that much.

[ThreePounds]

Maybe you should actually try less struts. Speed doesn't break stuff, actually. It's acceleration. Try a more flexible connection between your ore containers and the cargo bay - docking ports for instance. It doesn't really matter what hits the ground first if your craft is rigid thanks to struts: chains always break at their weakest link.

[T.A.P.O.R.]

I've done one from Mun, but had to revert and try to find a dry place to land as my containers are apparently hydrophobic.

[X-SR71]

Does it perhaps help if you add a girder at the bottom? They have high impact tolerance.

[Reactordrone]

Despite the look on Tamgie's face this is a perfectly safe landing attitude for an ore extraction/retrieval ship.

See, a perfect one point landing.