How to navigate moving one lander to meet another lander when both are already on the ground on Mun

[Paulyuk6]

Hi all

I have successfully placed 2 (basic) landers on the mun.     They are about 40km apart.  One of them has zero fuel so cannot take off.  I want to fly my other lander over to rescue the pilot and then fly both of them home.

BUT I cannot figure out how to plot a course to get to him.  If I was already in orbit I think I could plot a course to intercept his location. But how do I plot a course when both craft are already on the ground?    

Paul

[Snark]

23 hours ago, Paulyuk6 said:

I have successfully placed 2 (basic) landers on the mun.     They are about 40km apart.  One of them has zero fuel so cannot take off.  I want to fly my other lander over to rescue the pilot and then fly both of them home.

BUT I cannot figure out how to plot a course to get to him.  If I was already in orbit I think I could plot a course to intercept his location. But how do I plot a course when both craft are already on the ground?

Well, first of all... it's actually probably easier to fly the stranded pilot across the 40 km on EVA.

Kerbal EVA packs are ridiculously overpowered-- they have like 600 m/s of dV in them.  If you just take the stranded pilot EVA, designate the fueled craft as his "target" (so you can see it on the navball), and then just take off by thrusting forward and upward until you've got a forward speed of, say, 100 m/s and a good strong vertical boost, then you can just cruise to the target pretty easily (thrusting upwards as needed to keep you "airborne", and then braking when you get to the destination.)

Takes zero fuel, is pretty easy to get there.     So, that's what I would do, in such a situation.

If you prefer flying the ship, though, it's not too bad.  Here's what you'd do:

1. Go into map view and zoom in as close as you can so you get an idea of what bearing from your fueled craft is the stranded craft.  i.e. is it to your east?  northeast?  south?  etc. 
   • Figure it out as a degree bearing (approximate), since that's what the navball is calibrated in.  0 = north, 90 = east, 180 = south, 270 = west.  What's the bearing to the target?
2. Now switch back to flight view.  Your craft is sitting on the ground pointed close to straight up, so you should be able to see all the different navball bearings on the navball.
3. Looking at the navball, and bearing in mind the approximate bearing that you figured out in step 1, note which direction that is.  If you draw a line from the zenith (straight up) direction to that bearing, which way is it pointing on your screen on the navball?  Up, down, left, right?  This is the direction you'll need to rotate after liftoff.
4. Take off on full throttle, and instantly after you're off the ground, rotate the ship until you're pointed 45 degrees above horizontal (i.e. your marker is on the 45-degree line of elevation), with your azimuth (i.e. compass bearing) pointing in the general direction of the target.
5. While you're still thrusting, now quickly switch back to map view.  You can see your projected trajectory, making a parabolic arc up into the sky and back down again into the ground.
6. As you keep thrusting, that arc will grow, and your projected impact point with the ground will move away from you.  It should be moving towards the target, assuming you got your azimuth correct when you took off.
7. Watch until your projected landing spot reaches the target, then cut throttle.  You're now en route! 
8. Coast until you're approaching your impact landing, then just thrust as needed so that you land instead of going splat.
9. At this point you should be pretty close to your target.  Actually doing a precision landing right next to it can take some fine tuning that I haven't gone into, here... but you'll be pretty close, and even if you're a few hundred meters away (or even a kilometer), you're still way closer than you were, and it should be really easy to EVA-fly the stranded pilot to your nearby landed ship.

Does this help?

[Vanamonde]

If you set the other craft as target, an icon in its direction will appear on the navball. Then you could fly toward it using that as a compass. 

[Paulyuk6]

Fantastic!  Thank you so much for this advice, and taking the time to explain it in detail.   I will give these a try right away.

 

Paul