Getting To Minmus

[NewportBox]

I've been following Scott Manley's tutorials all the way up through where he walks you through getting to Minmus for a landing, and am now stuck.

I've built my rocket / lander exactly as his was built, and on the first attempt managed to get a landing - but didn't have enough fuel to make it back... so it's stuck there lol. (I'll launch a rescue mission once I land on Minmus multiple times)

The problem is that now I can't get an encounter with Minmus to save my life. What steps do you guys take in order to get to a place that has a different angled orbit? I can get to the mun without problems, but this is harder. Do you match the inclination before attempting the transfer?

Thanks in advance for all replies!

Newport

Edited June 13, 2014 by NewportBox

[diomedea]

It is simpler to make your mission as a sequence of burns aimed at achieving a specific goal. If you already are in a circular low orbit around Kerbin (LKO), the next step would be to make the inclination match with Minmus: set Minmus as target, so the line of nodes appear; then open a maneuver node on either the Ascending or Descending node and add some Delta-V to the normal component: when doing right, the inclination shown for the orbit after the burn will get down, you should aim to make it close to 0.0. Form the orbit already on the same orbital plane of Minmus, the next step would then be to plan the Hohmann transfer (that I bet you know about).

It is not mandatory to make separate steps, and some steps may not be needed at all: you will make an encounter with Minmus also with an inclined orbit, if the encounter point is with one of the nodes.

[cantab]

For Minmus, I would recommend sticking your apoapsis out near Minmus's orbit to get a close intersect, then making a mid-course correction for the inclination to hit its SOI.

[asb3pe]

I got Jebediah stuck too while following along with Scotts videos. hehe But I actually did what Scott suggested, and I used the little thrusters to get myself off Minimus and back into a Kerbin orbit... and then when I had used up all my thruster fuel and was REALLY "dead in the water", I did about 20 EVA's with good guy Jeb pushing on the back of the capsule to slow down my orbit until it fell onto Kerbin... and somehow Jebediah returned home safe and sound! Here's the thread I made last week about it - I guess it's a common problem?

Anyhoo... yeah, getting an encounter is hit or miss with me too, I struggle with doing the orbits but it's almost more a function of the oftentimes problematic adjustment sliders. I zoom out, they go away and its so small I can't click to re-open them... so I have to zoom back in, click to get the sliders out, then zoom out again... I'm sure this is a routine everyone goes thru, but that's why I post here and read the forums to try and learn how others do it and hopefully pick up some easy tips to make playing KSP easier.

I def do two maneuvers to Minimus, like Scott showed, one to get out to the general vicinity (hopefully with an encounter showing but if not I can usually get there anyways) and then a second "burn" at the ascending node or somewhere near there. The second burn is more "up/down" (the magenta sliders) than anything else.

Edited June 12, 2014 by asb3pe

[asb3pe]

For Minmus, I would recommend sticking your apoapsis out near Minmus's orbit to get a close intersect, then making a mid-course correction for the inclination to hit its SOI.

Yeah I click on the target object to see its distance, then I set my apoapsis to that distance, and then I swing it around my orbit to see if I can find an encounter. If the vertical is quite a ways off, I might not get one and I might try to use the magenta sliders (up/down) to see if I can get on real quick (but not spend too much time on those).

[Pecan]

I'm with diomedia - from orbit around Kerbin, first match planes, then perform the transfer burn. It isn't as efficient but it is easier.

(Chapters 4 & 5 of the tutorial in my signature if you want to try with different vehicles).

[diegzumillo]

The cheapest way to get there would be to launch at the correct inclination, but this can be tricky if you don't yet master the concepts involved. I think the easiest path there (conceptually speaking) is like diomedea said: get to orbit, match planes of inclination and then do a Hohmann transfer. Don't worry about efficiency for now, just make larger rockets, if fuel is a problem

Since the SOI of Minmus is so small, it's important to get step 2 as precise as possible. Also, if you're having trouble finding an intersection, remember to move the node all the way along the craft's orbit while keeping the planned trajectory always touching minmus trajectory... I'm not sure if this is clear enough.

[LethalDose]

I'm with diomedia - from orbit around Kerbin, first match planes, then perform the transfer burn. It isn't as efficient but it is easier.

(Chapters 4 & 5 of the tutorial in my signature if you want to try with different vehicles).

Yikes. If insufficient dV is already a problem, this advice isn't going to make it better.

Instead of doing an inclination change near Kerbin, I would create a manuever node for a prograde burn at the AN/DN node that I would put the apoapsis on Minmus' orbit. Then use the new "+orbit" button on the maneuver node (r-click on the node and it's the blue icon in the lower right) to advance the time on the node until that manuever gives you a Minmus encounter.

That should get you a pretty low dV approach.

[Kerba Fett]

It takes about 225m/s of dV to match inclination with Minmus, so before you do try just making a maneuver node and see if you can get close. If your intercept is near where Minmus' orbit crosses the plane of kerbins orbit you may be able to just use the normal +- (purple) controls to adjust the node.

As long as you can get an encounter it doesn't matter what your PE is. You can adjust it on the way.

If Minmus is at the high or low point of its orbit then it's easier to match inclination first.

When you get back, try to land on one of the planes near the edge. They're easy to land on and you can use your EVA pack to travel about 10km to visit nearby biomes without moving the lander.

When you return to Kerbin, remove the data from any experiment bays and store it in the pod and try to get your Kerbin PE down to about 35km to areobrake for landing without needing fuel to deorbit.

[Kryxal]

Adjusting the inclination at periapsis isn't going to do much at apoapsis ... you'd be better off making a second node maybe a third of the way there if things are looking at all close, or drop that maneuver node right on the post-transfer burn AN or DN.

[Alistone]

I would suggest that you not copy Scott Manleys craft for use in the same mission that he uses them. He has practiced enough that he will likely be more fuel efficient during liftoff and with his orbital and landing maneuvers. If you are still learning I would suggest using a ship designed to land and return from the mun in order to practice landing and returning from minmus. That way you'll have plenty of deltaV to use hovering as you try to land.

I do the same thing as LethalDose (quoted below) does. Basically set up a direct prograde burn (yellow circle only) that has your orbit intersect Minmus. Once you set that maneuver up you add orbits (or just wait) until you get small closest approach or encounter with minmus. Once you see the timing will get you close you can fine tune the maneuver with the blue/pink/yellow to lower your Minmus periapsis to 13km. Then just execut the maneuver and you should be on your way.

Protip; for large/long burns don't bother with the last 10-20 dV of the maneuver. Just save your fuel for a small correction burn at another maneuver node you set up in a minute or two.

You could try to match inclination and match orbit, but it feels so much simpler to just get a simple maneuver that puts in onto it's orbit and just wait for the timing to match so that it is present when you get there. Inclination changes are always easier at slower (higher) parts of an orbit and this method is actually letting minmus gravity help pull you in its direction thus doing some of your inclination change for you.

Yikes. If insufficient dV is already a problem, this advice isn't going to make it better.

Instead of doing an inclination change near Kerbin, I would create a manuever node for a prograde burn at the AN/DN node that I would put the apoapsis on Minmus' orbit. Then use the new "+orbit" button on the maneuver node (r-click on the node and it's the blue icon in the lower right) to advance the time on the node until that manuever gives you a Minmus encounter.

That should get you a pretty low dV approach.

[Castille7]

Not sure if anyone mention it but keeping your craft on a ninety degree course will help

[Shiv]

I got Jebediah stuck too while following along with Scotts videos.

My first moon/planet landing is always a fail, and then my second landing is always a rescue mission lol. Sometimes (often) the third one is a rescue mission as well...

[NewportBox]

Ty for all of the replies!

I'm going to try this again

Newport