Picking a landing spot

[hhatch]

I just went to Minmus and ending up landing on the dark side. So I went back and was trying to figure out how to land on a flat area on the sun side. I tried creating all kinds of maneuvers and finally I just had to bring down apoapsis and go into a low orbit. Is there another way to do this  without expending too much fuel ?

[OhioBob]

If you want to land at a spot under the apoapsis, you have no choice but to lower the apoapsis.  The only other thing to do is wait until the area under the peraipsis is in daylight (which it will be eventually).

(edit)  Based on what I see in the screenshot, performing a retro-burn at periapsis should take only 62 m/s delta-v to circularize the orbit at an altitude of 6,475 km.  That's pretty minor and shouldn't cost much fuel at all.  Thankfully Minmus has really low gravity, so orbital maneuvers are pretty cheap to perform.

 

Edited December 29, 2017 by OhioBob

[Aegolius13]

Usually, there is no reason NOT to circularize into a low orbit before you land.  Think of it this way: suppose you started as shown in the pic above, and then did a big retrograde burn at Peri to lower your Apo all the way to ground level.  At some point during that burn, your Apo is going to equal your Peri (i.e., you'll be in a circular orbit).  You don't lose any efficiency by stopping the burn at this point, and then doing a deorbit burn once you're lined up with a desired landing spot.    

What if your Peri is way higher than needed?  You can do a small retrograde burn at the far-out Apo, to lower your Peri to a level that's close to the surface but still safe, then circularize as described above.  But the 6.5km Peri shown in your pic is a fine altitude for picking out a Minmus landing site.  Sometimes you may even want to start higher so you can do faster time warp, even if you lose a tiny bit of d-v efficiency.  

[hhatch]

Thanks for the info and comments. I just launched another ship to Minmus and want to do a precision landing next to the ship I landed before. After I screw that up I'm sure I'll  be back here.

[bewing]

You can always cancel your orbital speed and just fall straight down. If you do a little clicking, you can see how long it will take to get to the surface. Then you can guess how much your destination CB will rotate in that time.

Edited December 30, 2017 by bewing