High Latitude

[rockbloodystar]

Hi,

to get all the science you need to land in some non-equatorial regions of Mun.

To get to Low Munar Orbit, whit is the most effieicnt launch?

is it just point east? or should i point towards the angle of inclination my orbit will end up? is that just my latitude?

To get back to Kerbin, what is the most efficient launch?

cheers,

RBS.

[KvickFlygarn87]

Just go with east, yeah. Your launch will end up with an inclination but this is fine.

[Xiphos]

Launch to the east (because you get a free speed boost from the rotation of kerbin). Do your rendezvous with the mun as normal. When you first enter the SOI of the mun, set a maneuver node down and change your inclination there. At this point it should be very cheap (Low DeltaV maneuver.) Hope this helps.

[LethalDose]

When heading to/landing in other biomes on Kerbin, I just use suborbital trajectories. Launch, and set your heading towards the biome you want to land at.

I usually detach a second small lander stage around apex and perform a correction burn.

[rockbloodystar]

Hmm,

not sure you've answered my question.

Assume I am on Mun at a latitude of 60 degrees north.

If do my gravity turn towards a heading of 90 (east) surely that is ineffecient as the craft will "fall south". I would have thought that another heading (120 ?) would be more effecient.

RBS.

[Traches]

There's no way to get an equatorial orbit when you're not launching from the equator, so no matter what you'll do you'll get an inclined orbit. Also, the mun rotates so slowly that unlike kerbin, it doesn't really matter which direction you choose to launch as far as dV to orbit matters.

For your transfer back to kerbin, you'll need to wait for the mun to move around in its orbit until your orbit lines up to where your orbit lines up with the mun's prograde and retrograde directions in your orbit to get the best efficiency. (When you're on the equator, that's all the time. With a polar orbit, that's twice a munar orbit.) If you can line up your inclination at launch to do that, you'll save some time!

[Frederf]

For direct ascent from a latitude to the least energy orbit you want to have an inclination to match your latitude. If you launch from 53*N then you would launch on a heading of 90+53 southeast assuming the body isn't rotating.

For arriving at the Mun inclined I've found a free return trajectory (a whopping 20m/s extra) from a slightly (how much?) inclined LKO will result in a capture up to polar on the Mun. The vertical (out of plane) speed when you hit the Mun's SOI minus the fact that the gravity brake slows your lateral angular momentum bends your orbit up quite steeply.

[numerobis]

The ground track of a satellite is pretty much a sine wave. You want to burn along the tangent to the ground track; if you want inclination 60 and you start from 60N, that means you should start burning due East. Prograde will soon deviate from eastward; keep burning prograde for your heading (and, on Mun, probably for your pitch also, given how low orbital velocity is). When you cross the equator is when you'll be heading 60S -- that's the descending node.

[Grover]

A few people here seem to have the wrong idea, when you launch from ANY latitude, to get the lowest inclination you ALWAYS launch due east or west, otherwise you add the difference in your heading to your latitude to get a higher inclination (and launching towards the equator doesnt work either), feel free to quicksave and test it

And as for the easiest way to return, raise your apoapsis high, towards the edge of the muns SOI (without escaping) with your equatorial ascending or descending node as close to the AP as possible, then adjust your inclination and return home as normal, sure youll spend more fuel, but it beats waiting half a month in orbit, and the extra fuel isnt mucb, considering your trans-kerbin ejection will cost much less Dv from a higher orbit (since youve already climbed up through muns SOI)

The only hard part is finding a good landing spot near the north pole, because those mountains are trecharous

[Frederf]

Lowest inclination yes. Least energy requirement, no. And that assumes impulse maneuvering. Cushioning your fall toward the equator over a long burn can ultimately reduce your inclination to zero if you reach orbital speed just as your cushioning stops, but that takes much more dV.

[PhanThom]

Not sure what you meant with the first question but concerning getting back to kerbin from the mun I suggest to lift off in the opposite direction in which the mun is orbiting kerbin

[catastrophy]

I never change inclination when returning to Kerbin from the Mun. You end up in Kerbin orbit anyway. I always launch East. Lifting off in the opposite direction the Mun is orbiting Kerbin is not really adviseable, I think. Exiting the Mun Influence in the opposite direction is what is probably better a proposition.

Just get a Munar orbit and check with a node which Munar Escape gives the best orbit around Kerbin. If you've got low fuel, keep in mind you only need to get the periapsis into Kerbin atmosphere (<75km). The craft will go down eventually then.

[Kasuha]

If you have delta v to spare, launch any direction and burn to exit Mun's SOI in Mun retrograde direction.

If you want to perform most efficient maneuver, launch towards the Mun's prograde/retrograde point. That is the point on Mun surface facing exactly prograde or retrograde direction of Mun's orbit. You may not have lowest inclination but that's irrelevant because this orbit is parallel to Mun's orbit and you can eject from that in direction parallel to Mun's orbit which is the most effective ejection direction.

Edited November 26, 2013 by Kasuha

[radonek]

If you have delta v to spare, launch any direction and burn to exit Mun's SOI in Mun retrograde direction.

If you want to perform most efficient maneuver, launch towards the Mun's prograde/retrograde point. That is the point on Mun surface facing exactly prograde or retrograde direction of Mun's orbit. You may not have lowest inclination but that's irrelevant because this orbit is parallel to Mun's orbit and you can eject from that in direction parallel to Mun's orbit which is the most effective ejection direction.

Enlightening. Thank you.

[Frederf]

It's best illustrated by starting in a circular orbit around the Mun (it's important that it's circular) and making a maneuver node to exit Mun's SOI with some prograde amount. Keeping the prograde value constant, as you drag the node around the orbit you'll see what effect your exit direction has on the resulting orbit around Kerbin. The most efficient will produce the most eccentric (or most westward if you really overpowered it) skinny resultant orbit around Kerbin.

[rockbloodystar]

The ground track of a satellite is pretty much a sine wave. You want to burn along the tangent to the ground track; if you want inclination 60 and you start from 60N, that means you should start burning due East. Prograde will soon deviate from eastward; keep burning prograde for your heading (and, on Mun, probably for your pitch also, given how low orbital velocity is). When you cross the equator is when you'll be heading 60S -- that's the descending node.

Thanks, that is clear.

RBS.