How do you make a precision landing at non-equatorial locations?

[Grogs]

Hi all,

 

I did the Munar-1 mission in Making History last night. At the end of the mission, they ask you to splash the Apollo-style command module down at a point in the southern ocean. Lat -35; Long -85. I found this to be the hardest part of the mission. Coming from an equatorial orbit around the moon, I needed to do a plane change of at least 35 degrees to make it happen. Problem is that trying to get the plane change right and time it so that the target has rotated under the inclined orbit at the right time is really tough. What I ended up doing was setting up a plane change of ~ 40 degrees just after leaving the munar SOI (when it was cheaper), then capturing into an elliptical orbit around Kerbin. On the second or third orbit, the target rotated close enough to my orbit that I was able to get within the 150-km radius by applying several degrees of normal burn along with my de-orbit burn. This setup was far from ideal though. I had to burn over 1400 m/s of fuel, and I also had to burn a lot with RCS thrusters to tune things at the very end.

I'm wondering if there's an easier way to target a location off-equator like this. Ideally, I'd like to be able re-enter directly from the mun for scenarios when the fuel budget is tighter. I've heard the trajectories mod will put an 'X' on the map at the location where it estimates your craft will land. Is that the best way to do this? Are there other options to make this easier?

[bewing]

You need to establish an inclined orbit the way you did. It's good if the inclination is just a few degrees more than the required latitude.

To get the target right, you have to estimate the angles carefully. The first time you pass over the correct latitude, you check how many degrees of longitude away your actual target is. Kerbin rotates one degree per minute. So that tells you the correct period for your orbit to get back to the correct point at the correct time. To land fairly accurately, you either need a large retroburn, or you need to reenter steeply (very low Pe, high Ap).