Advice for landing a Spaceplane on the Mun

[Rocket Farmer]

So I have a totally stock SSTO that I can now orbit the mun, drop a landing probe, fly back to kerbal an land back at space command with some rocket fuel to spare. So the next step would seem to land the whole plane on the surface. But I have a couple of questions first.

1. Given the new topography of .21 is there anywhere flat enough to land? Given I am stock I don't have VTol so i need at least 1/2 a runway of flat length. I am considering trying minmas first as I know it has flat valleys. Also it needs to be at least a runway wide.

2. So when landing a plane on a zero atmosphic body does everybody else just burn retrograde while backwards to slow down and then turn around and land at the last second? Should I instead mount rockets aimed forward or should I try the entire landing backwards? Do i try to land vertically almost on my rockets before turning to land normally? Basically what has worked?

3. Braking works at 50 m/s on a rover on the mun so is it safe to assume it will also slow my space plane at about 100 m/s without explodey consequences?

4. I assume takeoff is simply building up speed and then using reaction wheel / rcs to lift the nose as the flaps will be useless? Is this possible given I will weigh around 40 tonnes on takeoff?

[Johnno]

My advice would be to treat it like a regular lander, throw the whole 'airplane' idea out the window. Attach landing gear to the rear and land 'backwards'.

Unless you mount downward facing landing engine(s) there's no point to try and land horizontally, you'd have to slow down backwards (and upside down to help) only to tilt forward before touchdown, and if you're going at any vertical speed to try and use your brakes to save delta-v you're just setting yourself up for disaster.

[Mefi282]

On the Mün it's really impractical to land with a VTOL given that there are a lot of craters everywhere. You should consider to land on Minmus first because of the lower Gravity and the big flat terrain. Therefor the takeoff should be no problem but be sure to add enough reaction wheels. And yeah land backwards it's the only practical way.

[golegogo]

you could place a radial attachment point under the the center on mass and attach a small engine to it as a hover engine.

[sporkafife]

If your rocket engine is on the back of your spaceplane, just start landing as if it was a regular lander and you were going to land on the engine. At the last second, when you are hovering a few metres above the ground, push W and G to pitch forward and open the landing gear. That way you will land flat on your wheels.

[arq]

Agreed. When landing on a gear in a vacuum, you need to treat it like the rocket it is. Once you are hovering upright over the surface, pitch forward and come down on the gear. I had bad experiences trying to land conventionally on Minmus, even at 30m/s (I bounced then crashed 10 times before abandoning the idea).

But a conventional takeoff works fine. Just try to get off the surface ASAP so you don't hit any bumps.

[Sean Mirrsen]

My way of landing was sort of like... well, a reverse landing. The craft was VTOL, and used a single NERVA for slowing down the primary vector, which was purposely kept as close to parallel to the surface as possible. VTOL engines were used for quick bursts of upward motion, and eventually the whole thing just slowly touched down onto a downward slope of a hillock and stopped. That's probably inefficient as heck though, I just wanted to land horizontally.

If your primary engine is good enough to land vertically, tail first, you're probably better off doing that. Then at the very ground give it a little push upwards, and use RCS to flip over wheels down and land.

[satcharna]

My advice for you is to treat it like a conventional lander. Take it down vertically, land on your tail, and then flip over to your landing gear. Mun's gravity is low enough that any sane plane design can do so safely.

Trying to do a horizontal landing, such as a runway landing, would be foolish. As Mun lacks atmosphere, you'd be going down at a very high speed, while also moving over the surface at a similarly high velocity. Your plane would probably just explode on contact.

[Sean Mirrsen]

Well, I did land this thing.

It only took, like, two tries.

[Iansoreta]

Well, I did land this thing.

https://dl.dropboxusercontent.com/u/4152380/KSP_184_Screens/screenshot93.png

It only took, like, two tries.

https://dl.dropboxusercontent.com/u/4152380/KSP_184_Screens/screenshot91.png

That's dangerous thing to do. I mean Mun, and Minmus have no atmosphere, so the aerodynamic control surface and wings are virtually useless. Maybe you need to stick to VTOL technique, or use reverse thrust to help slow down horizontal movement since reducing horizontal velocity is impractical with rear facing nozzle of engine(you probably need to orient your space plane many times). Never tested yet but its worth a try.

- - - Updated - - -

Well, I did land this thing.

https://dl.dropboxusercontent.com/u/4152380/KSP_184_Screens/screenshot93.png

It only took, like, two tries.

https://dl.dropboxusercontent.com/u/4152380/KSP_184_Screens/screenshot91.png

That's dangerous thing to do. I mean Mun, and Minmus have no atmosphere, so the aerodynamic control surface and wings are virtually useless. Maybe you need to stick to VTOL technique, or use reverse thrust to help slow down horizontal movement since reducing horizontal velocity is impractical with rear facing nozzle of engine(you probably need to orient your space plane many times). Never tested yet but its worth a try.

[merendel]

I prefer not to land spaceplanes on vacume planets, they are just not well suited for that task unless designed with VTOL capability in mind. I have done the hover on the main engine and then pitch over on minmus but wouldnt want to do it on something with more gravity. Although if your designe is sturdy enough to survive a drop test you could litterly land very gently on the rear engiens (sub .5m/s touchdown) and then carefuly nose over to land on the gear with reaction wheels. The landing gear can handle the impact of tiping over, the question is will anything else get jared loose in the process.

[Hodo]

This is a pretty dead thread, August of 2013, so what 8 months dead?

[Specialist290]

Please don't bump old threads without a good reason. This issue's been long resolved, and I'd imagine the OP has moved on to new challenges.

Thread closed. Have a nice day