Improvised Landing Gear and Lithobraking Discussion

[Burninate]

So the landing gear that's ingame now is horrible for major impacts, relative to a bunch of bendy 0.125T trusses. What's not clear, however, is the optimal arrangement for those trusses. As the game is right now, I would like to establish some sort of conventional wisdom about truss landing gears, and the weight and velocity that they can protect on heavy, fast vertical landings.

The restriction is: Lithobraking must cause zero damage to the truss structure. I want a reusable vertical lander, not something that will unpredictably break apart.

What have been your experiences with this technique? Pics requested.

This, when you remove the nonfunctional wheels (testing something else) will survive a 60m/s landing with zero damage.

Note: I am explicitly looking for discussion and feedback on what you guys have tried in this vein, I only included the example to clarify, not to show off.

Edited September 10, 2013 by Burninate
This wasn't a Spacecraft Exchange post.

[Whackjob]

When I get home I'll post the usual youtube video of mine.

[Vanamonde]

So the landing gear that's ingame now is horrible for major impacts

Major impacts are bad for anything. Adding parts to absorb damage ruins your fuel efficiency and gives the ship more momentum during an impact anyway. Why not just, you know, don't hit as hard?

[Burninate]

Major impacts are bad for anything. Adding parts to absorb damage ruins your fuel efficiency and gives the ship more momentum during an impact anyway. Why not just, you know, don't hit as hard?

Because on places with more gravity than than the Mun, that can be rather difficult unless you employ Mechjeb every time.

I will note that your statement can be adapted:

"Adding the ingame landing gear to absorb damage ruins fuel efficiency and gives the ship more momentum during an impact anyway. Why not, you know, don't hit as hard?"

The trusses can function as a much more effective and more positionally flexible landing gear than the 'landing gear' included, and I don't see much literature discussing how to use them while minimizing wasted mass, or how much impact they can assist with. So finding out what other people think about that is the goal of this thread.

[AmpsterMan]

I think one of the reasons one doesn't find much literature on the subject is because it is innwficient, unpredictable, and as far as I know, the upper limit on velocity at impact for structural integrity is rather low. Also, while the trusses may br intact after impact, the delicate components might be damaged. Couple this with the difficulty of pinpoint landings and the subject dies down quick.

The only case I see lithobreaking with struts maybe being a good idea is when delivering light, unmanned probes to bodies with an atmosphere to have the air be the main decelerator. As for trusses, I would use the smaller ones in a sort of ball formation.

[m1xte]

You can try structural pylons too they offer 999 impact tolerance an very flexible connection.

[magnemoe]

I think one of the reasons one doesn't find much literature on the subject is because it is innwficient, unpredictable, and as far as I know, the upper limit on velocity at impact for structural integrity is rather low. Also, while the trusses may br intact after impact, the delicate components might be damaged. Couple this with the difficulty of pinpoint landings and the subject dies down quick.

The only case I see lithobreaking with struts maybe being a good idea is when delivering light, unmanned probes to bodies with an atmosphere to have the air be the main decelerator. As for trusses, I would use the smaller ones in a sort of ball formation.

On bodies with atmosphere you can use parachutes. Its also some airbag soulution who works well both in real world and KSP.

Remember I used the lionheart Prometheus rover a lot back in 0.18 then I started, it managed rough landing as in 20 vertical and 50 horizontal however this sort of stuff don't scale well upward.

[Vanamonde]

So finding out what other people think about that is the goal of this thread.

I'm going to prognosticate that most people will agree that smashing your ship straight into the ground at 216km/h is inadvisable.

[Scotius]

Not to mention 90% of players lack patience to weave such intricate lacework. Also, how many parts it adds to the craft? And how much payload you had to cut to lift it all up? Yeah, Cool But Impractical.

[AmpsterMan]

On bodies with atmosphere you can use parachutes.

Which is the point I am trying to make. Almost any situation in which one might use trusses to lithobreak have another option that is better in every way I can think of. The only exception is if we use mods, but in that case, then what is the point. Just get airbags and be done with it.

[Blue]

Improvised Lithobraking sounds like a euphemism for "crash and burn" that isn't even trying xD

[Captain Sierra]

Hey now, The man wants to do an experiment and see what it takes to make a functional, reusable, lithobraking lander. I for one, am interested in seeing the results.

[Burninate]

What's that Alex? It has to be in the form of a challenge?

"Mayday, mayday, our shipment of colonists aimed for the beautiful hydrothermal resort colony on Laythe missed and accidentally landed on Tylo instead! An ion storm has disabled all our unmanned cores in the area, leading to the mishap - it seems that Jeb was the only one onboard that remembered the destination, and when he went offline, nobody could remember which one was the target. When they realized their parachutes weren't working, they burned all but the last 100 units of fuel in a crash landing into a hill. 64 kerbal passengers are stuck there strapped into their habitation pods, spacecraft lying on its side, with nothing but winter coats and their kerosene-powered furnace to keep them warm. This is on the *dark side* of Tylo, without line of sight to Kerbin - and with the ion storm disrupting communications, the only way this message got out is that the 3 pilots used the return stages to burn as far as they could on a tilted ballistic trajectory from the original landing, eventually reaching the *light side*, where they transmitted the message via laser. In light of this disaster, KASA has removed Laythe Venture's launch license with the exception of one rescue flight, but their rocket planners aren't sure how they can possibly move it all there without the whole ship falling apart on impact. Help us Obi-Wan Kenobi, you're our only hope!

Launch a craft from Kerbin and land it on Tylo with enough space and enough fuel to get 64 stranded passengers on the dark side and 3 stranded pilots on the other side of the planet to a comfortable landing on Laythe."

Does that sound like a reasonable test?

Edited September 10, 2013 by Burninate

[littlebattler]

the ideal lithobraking leg is just a long pole of trusses. "Planet Jousting", if you will. Provided you have control of your craft, you can have the pole be the part to first hit the ground. Can be reusable if you make the pole replaceable by the means of a docking port.

[Captain Sierra]

the ideal lithobraking leg is just a long pole of trusses. "Planet Jousting", if you will. Provided you have control of your craft, you can have the pole be the part to first hit the ground. Can be reusable if you make the pole replaceable by the means of a docking port.

That breaks planets, as discovered by Danny2642.

[littlebattler]

That breaks planets, as discovered by Danny2642.

isn't that fixed already?