How to tell the terrain you're landing on?

[Millie]

Another noob question!

I've noticed that landing on slopes is generally a bad idea. While I've finally managed to get to the Mun and back in one piece, I'd like in the future to have a bit of a moon base. While I am getting better at using manoeuvre nodes for targeting where I smash into... sorry... "land", I'm really bad at telling from the zoomed in view what the elevation or gradient of the surface is.

So, two main questions here:

1) how can I be a little more precise about where I land?

and

2) how can you tell what the terrain (kerbain?) is like at your target?

Is this something I need to find out with trial and error?

(Related to all that, it would be cool in the future if you had to send probes to these bodies to conduct mapping/scanning missions before you could tell anything about the surface. Would add something to career mode, certainly.)

Edited August 14, 2013 by Millie

[Psycix]

1) One way to do this is to kill ALL horizontal velocity and descent straight down.

Another way to do this is to use mechjeb's landing guidance. You can have it land for you, or, if you want to land manually, have the landing guidance simply show your predicted landing location on the map.

2) There may be better methods, but aside from trial and error I would recommend to send an exploration probe down.

EDIT:

I encountered this in another thread. It contains a slope map as well! http://www.kerbalmaps.com/

[Superfluous J]

I made an orbiter with 5 mini-landers that I can pop off at will and land. As there are 5 of them, I can be risky and try interesting areas. After landing, they have enough RCS to travel a dozen or two KM so I can find a nearby flat area. Then, I can target the probe when landing my actual craft.

As far as targeting, I used F5 to quicksave and F9 to restore. Try a landing, and if you come up way short or long, reload and burn later or earlier as needed. Just consider those other landings as simulations

Edited August 12, 2013 by 5thHorseman

[saik0]

Another noob question!

I've noticed that landing on slopes is generally a bad idea. While I've finally managed to get to the Mun and back in one piece, I'd like in the future to have a bit of a moon base. While I am getting better at using manoeuvre nodes for targeting where I smash into... sorry... "land", I'm really bad at telling from the zoomed in view what the elevation or gradient of the surface is.

So, two main questions here:

1) how can I be a little more precise about where I land?

When landing in vacuum you can approximate your landing location with the map view. At the opposite side of the orbit from your landing zone burn retrograde to place the Pe a few km over the LZ and coast. When you get to the Pe perform another retroburn, use the velocity indicator above the navball in surface mode (change between surface/orbit/target mode by clicking it) and kill the relative surface velocity. Next point radial (up, away from the surface), you can either slow down gradually or perform a suicide burn at low altitude. The latter is more efficient, but timing it right will require some math.

Atmospheric landings are a bit trickier, the atmosphere gets exponentially denser as you near sea level. There are some charts^[1][2] and a tutorials^[1] to help.

More instrumentation is always helpful, if you're not opposed to mods. There is Steam Guages and Kerbal Engineer Redux, that have a radar altimeter and can give you horizontal and vertical velocity independently. MechJeb is an autopilot and information plugin. It has a landing module that can model the atmosphere and show you precisely where your craft will land. You can use it to adjust your trajectory manually so you'll land right on target. It can also automate the landing, you can even input the coordinates, if that's what you want. Some users will tell you whether to use one or more of these plugins, that their way is the one true path to Kerbal fun. Ignore them and play the single player sandbox game in the manner you enjoy most.

and

2) how can you tell what the terrain (kerbain?) is like at your target?

Is this something I need to find out with trial and error?

(Related to all that, it would be cool in the future if you had to send probes to these bodies to conduct mapping/scanning missions before you could tell anything about the surface. Would add something to career mode, certainly.)

My site, kerbal maps has detailed maps of all the bodies. The slope mode is especially useful when choosing a landing/base location and is very easy to read. The bottom left corner will show the coordinates of the position of the mouse cursor. ISA MapSat is a plugin that generates elevation maps on-the-fly. You have to build an orbiter and place it in a polar(ish) orbit to create the maps. It's great, the tradeoff vs kerbal maps is that it must collect the terrain data in real time, and cant be as high resolution as pre-rendered maps without impacting performance.

[Amoun]

Definitely definitely use the kerbalmaps. I love that website, it's extremely useful.

All the tricks were already covered but I want to add that it is definitely just practice. Every craft is different, so there is no step 1, 2, 3, etc. Theory is always there but no precision. It's not too hard to get with practice. If anything, you can use MechJeb, it's a great tool.

[Bacterius]

You can also get your lander to hover for a bit in search of flat terrain before touchdown if you are unlucky with your initial landing spot. Takes a bit of fuel but usually it doesn't take very long to locate a flat landing spot. If you use Mechjeb (or are good with thrusting) you can just thrust approximately 1:1 against the Mun's gravity and use your RCS to quickly move you over where you want to land, or you can just freehand it. The best is, of course, to know exactly where you want to land in advance, but this approach is strangely satisfying.

Don't forget to put some lights on your lander for when you need to land on the dark side, it's really, really difficult to judge your altitude, horizontal velocity, or any other quantity of interest without a tool like Mechjeb in those situations. The stock flashlight starts lighting up the ground at around 400 metres altitude, iirc, giving you plenty of time to do any necessary corrections.

[Skorpychan]

I recommend smacking a few probes into the terrain first. Maybe even land a couple gently.

I've recently developed a tiny lander just for that, to augment the tiny ion probes I'm using to scan places visually. Even helps me practice the interplanetary transfers, thanks to them using the same transfer stage as my landers.

[MiniMatt]

Don't forget to put some lights on your lander for when you need to land on the dark side, it's really, really difficult to judge your altitude, horizontal velocity, or any other quantity of interest without a tool like Mechjeb in those situations. The stock flashlight starts lighting up the ground at around 400 metres altitude, iirc, giving you plenty of time to do any necessary corrections.

Very much this. I tend to stick them on all landing craft. Slightly angled such that two spots converge as you descend, they give excellent visual feedback of altitude and descent velocity in anything other than the brightest of conditions.

A technique I practiced over and over again, umm, 30 years ago on a certain computer game. A game modelled on events 40 years prior to that so I guess the technique has been well proven by now.

[Millie]

Thanks all! Plenty to chew on. I'll go away and digest.