Lander Design and Landing Tutorial

[RocketBlam]

I recorded this to show everyone how to design a lander that could land on Mun and Minmus, and return to Kerbal safely. If you need to know how to design a lander that can land on Mun and Minmus, this will teach you how.

https://www.youtube.com/watch?v=O_xu8pF2OTU

[Osprey]

Not bad, though that lander is carrying an uneccesary amount of weight in fuel.

I also tend to avoid descending from >9km, as this means you spend more time in the Mun's gravity well and need to spend more effort slowing down the vertical acceleration towards the ground. Weirdly, I find coming in low and fast is much easier than descending slowly from a great height.

[Kasuha]

Good tutorials are always welcome but there is a separate section for them.

[PlonioFludrasco]

Not bad, though that lander is carrying an uneccesary amount of weight in fuel.

I also tend to avoid descending from >9km, as this means you spend more time in the Mun's gravity well and need to spend more effort slowing down the vertical acceleration towards the ground. Weirdly, I find coming in low and fast is much easier than descending slowly from a great height.

Yep, you're right.

But get a look to your TWR while in the VAB, or you won't have enough time to slow down.

[RocketBlam]

It's a good amount of fuel to land, ascend and return to Kerbal, from Mun or Minmus.

If you can do it with less, reliably, without being unduly complicated, that's great! I'd love to see it. For the beginner, this gives him/her enough to get back to Kerbal.

As for coming in low and fast, I find that pretty challenging. This tutorial is more for a beginner, and having some extra time to make adjustments is useful.

Edited April 23, 2014 by RocketBlam

[RocketBlam]

Good tutorials are always welcome but there is a separate section for them.

I didn't see that. Thanks.

If you want to move it there, I am down with that.

Edited April 23, 2014 by RocketBlam

[Tokay Gris]

Not bad, though that lander is carrying an uneccesary amount of weight in fuel.

Can't watch the video for some reason.

Never mind...

What to keep in mind when designing a lander is also, where on the celestial body you want to land.

If you want to land at the equator, you need a lot less fuel than if you want to land in the polar regions.

If you do a "there and back" mission from Kerbin to Mun and back then this is not so important.

But if you do (like I do as soon as it is possible) a repeat mission profile (put station with science lab in equatorial orbit around Mun, repeatedly dock lander, transfer data, clean out experiments, refuel, land again somewhere else, rince and repeat until all there is doable is done, then return to Kerbin), you need either different landers for different landing sites or one lander that can do them all.

I don't know hoe much delta-V the lander in the video has, but the one I am using right now for Mun has just short of 4000 m/s. And if a polar or polar lowlands landing is done, there is not that much reserve. IIRC (can't check right now, this is purely from memory) around 800 m/s.

[RocketBlam]

Can't watch the video for some reason.

Never mind...

What to keep in mind when designing a lander is also, where on the celestial body you want to land.

If you want to land at the equator, you need a lot less fuel than if you want to land in the polar regions.

If you do a "there and back" mission from Kerbin to Mun and back then this is not so important.

That's a good point. This is for mostly near-equatorial landings on the Mun.

On Minmus, you have a lot more leeway, since the gravity is lower and you have more Delta-V to work with.

[Tokay Gris]

For some reason I could only see the first 20 seconds or so of the video.

What I saw looked not bad. But I do have a few questions:

- Why does it have RCS-capabilty and no docking port I could see? (Maybe I just didn't see it)

- Why additional batteries?

- Didn't notice any solar panels, but somehow youtube does not work as expected on this computer.... So it is very possible I just did not see them.

... Could you probably post a picture of that vessel? It gave me a few ideas.

[Tokay Gris]

Ok, was able to see a little more of the video.

I take back the comment about no solar panels. There are some.

Still: Why RCS-capability? It doesn't need to dock. It can't even dock, since there are no docking ports.

(It would be easy to add one, thouh. The small 'chute on top seems to be superfluous.)

That way, you could reduce the weight and with that increase the delta-V.

I like the design, though. Smaller than my "there and back"-lander.

[RocketBlam]

It doesn't have docking ports. The point is that it can land on either Kerbal moon and return to Kerbal without docking.

It has RCS to deal with drift while landing, as shown in the video.

Maybe you should wait to comment until you have seen the full video.

Edited April 23, 2014 by RocketBlam

[Tokay Gris]

It has RCS to deal with drift while landing, as shown in the video.

That is what i don't understand. But I can't watch the video right now. No idea why...

So you use the RCS to stabilise for the drift?

The way I see it (and please keep in mind that I still like your design), you could land without it. And you could do it without the RCS. And this way reduce the weight. Not quite sure how much the RCS-tanks weight, but since the whole vessel is rather light, it could be significant.

[Dkmdlb]

Dude, the planet is called Kerbin. Not Kerbal.

[RocketBlam]

That is what i don't understand. But I can't watch the video right now. No idea why...

So you use the RCS to stabilise for the drift?

The way I see it (and please keep in mind that I still like your design), you could land without it. And you could do it without the RCS. And this way reduce the weight. Not quite sure how much the RCS-tanks weight, but since the whole vessel is rather light, it could be significant.

It is entirely possible to land without RCS, it's just a lot harder to correct for drift. This video is a tutorial for beginners.

[Tokay Gris]

It is entirely possible to land without RCS, it's just a lot harder to correct for drift. This video is a tutorial for beginners.

I found it quite as easy to just point the vessel a little bit to do this.

Your way of doing it is new to me. That is all. Haven't done that myself. But will try your way next time.

[Pecan]

Tutorials are always good. A request for those of us that don't have unlimited broadband or can't watch 45-minute videos for other reasons; any chance of writing about the salient points?

[Osprey]

What to keep in mind when designing a lander is also, where on the celestial body you want to land.

If you want to land at the equator, you need a lot less fuel than if you want to land in the polar regions.

But if you do (like I do as soon as it is possible) a repeat mission profile (put station with science lab in equatorial orbit around Mun, repeatedly dock lander, transfer data, clean out experiments, refuel, land again somewhere else, rince and repeat until all there is doable is done, then return to Kerbin), you need either different landers for different landing sites or one lander that can do them all.

Or put the station in a polar orbit so it can reach any point on the body's surface as long as you wait for the body to rotate below the orbital path of the station, then you only need the land and return fuel for an equivalent equatorial landing and re-dock. This does mean when you land, you have to wait about 1/2 day before taking off directly into the orbital path again, but that's only a pain on slow-rotating bodies like the Mun, and time-warp is a universal fix for any problem.

Edited April 23, 2014 by Osprey

[Tokay Gris]

Maybe you should wait to comment until you have seen the full video.

Please don't misunderstand me.

I am not critisizing your design. Well, I am, but in a - I hope - constructive way.

I like it! Especially the small tank in the middle. As soon as I finish downloading KSP on this mashine (not mine... like I said, mine is "drunk". On white wine actually. Which is propably ok if you are human, but not so good for a laptop, it seems), I will use something very similar.

I am just thinking of how to improve on it.

And - which shows how much I like your design - the only thing I CAN argue is RCS. I seems to me the way to use it just for drift is not necessary, doesn't make it that much easier (actually, I think it makes it more complicated) and adds weight.

I will, however, try your method of landing. And see if it makes it easier. A gut feeling says that it doesn't. But I will test it.

[RW-1]

Nicely done!

For a beginner who might not have any knowledge of what they are doing, that will do the job. which was the objective.

[SRV Ron]

It is entirely possible to land without RCS, it's just a lot harder to correct for drift. This video is a tutorial for beginners.

If using a joystick, RCS is the way to go. Otherwise, watch your retrograde marker on the navball and make minor corrections on the WSAD keys to bring it back to center as your drop your descent speed to under 10m/sec.

Get some practice in at the launch center using just a lander with enough power to fly in Kerbal's gravity. When you can master touch and go landing there, it will be much easier on Minmus and elsewhere. This is a good design to play with with no worry about killing Kerbals and the ability to deploy parachutes if needed.

A small probe lander;

I even managed to land my LADEE on Mun in my first try with plenty of fuel left for takeoff, a craft not designed to do that. Note, the LADEE has no thrusters and is steered by using SAS to center to the retrograde marker on the Navball. At a touchdown speed under 4m/sec it just settled in place tipping upslope on touchdown.

Edited April 23, 2014 by SRV Ron

[RocketBlam]

I'm surprised to hear more people don't use RCS for landing. I find landing much harder without it.

[Specialist290]

I didn't see that. Thanks.

If you want to move it there, I am down with that.

It should be in the proper place now

[luizopiloto]

The ultimate quest... land and return from Eve...

[RocketBlam]

The ultimate quest... land and return from Eve...

http://i.imgur.com/z6wJTVb.png

I have a thread about that too. See "Challenges".