Move Minmus to Duna's Orbit

[Tatonf]

When I began playing this game I didn't know anything about it and how physic works in space ; and I was like "Wow look at all the fuel I need to get to Mun, Minmus is even further away, no chance I'm going to it without a super large rocket".

I'm not sure I understand what you mean by "transfer windows". You can launch a directly into Minmus' inclination twice a day, no transfer windows needed. It's still harder than the Mun of course, and most people do inclination changes from orbit before learning to direct launch to Minmus' inclination, but waiting for Minmus to come around into a transfer window with Kerbin's equator is probably the worst option.

Can you explain why it is the worst option ? I think it's the simplest way to do it. Launch in an equatorial orbit, place a maneuvre node at ascending/descending node and just spam the button which add one orbit until you get your encounter. Super easy.

[mikegarrison]

Can you explain why it is the worst option ? I think it's the simplest way to do it. Launch in an equatorial orbit, place a maneuvre node at ascending/descending node and just spam the button which add one orbit until you get your encounter. Super easy.

Easy, but unnecessary. As Alshain said, you can launch directly in plane with Minmus twice a day. Once you learn how to do that, you will not want to waste the time waiting for Minmus to move to where it will be in the equatorial plane just as you happen to get there.

Mechjeb can launch your probe into Minmus's plane automagically, but you can get pretty close by eye from the map mode if you just understand that you want KSP to be in line with the equatorial nodes of Minmus's orbit at the time of launch and then you want to launch to either 6 degrees north or 6 degrees south, depending on which node is on the same side that KSP is on. Doing it by hand is a good exercise to understand what is really going on.

[Goddess Bhavani]

Can you explain why it is the worst option ? I think it's the simplest way to do it. Launch in an equatorial orbit, place a maneuvre node at ascending/descending node and just spam the button which add one orbit until you get your encounter. Super easy.

I think this is how new players will embrace the concept of setting up a transfer, and they will understand this procedure much easier than "transfer window".

[Red Iron Crown]

Last few posts are good examples of why the Mun is easier than Minmus for new players. It may require more dV for a Mun land and return, but getting there is just easier.

[Tatonf]

Easy, but unnecessary. As Alshain said, you can launch directly in plane with Minmus twice a day. Once you learn how to do that, you will not want to waste the time waiting for Minmus to move to where it will be in the equatorial plane just as you happen to get there.

Mechjeb can launch your probe into Minmus's plane automagically, but you can get pretty close by eye from the map mode if you just understand that you want KSP to be in line with the equatorial nodes of Minmus's orbit at the time of launch and then you want to launch to either 6 degrees north or 6 degrees south, depending on which node is on the same side that KSP is on. Doing it by hand is a good exercise to understand what is really going on.

So, you think that launching in an inclined orbit that match Minmu's one is simpler than hitting the time warp button ? What's the problem with taking time ? It's nothing compared to interplanetary travel.

I'm not talking about the educational "face" of this thing.

[Alshain]

When I began playing this game I didn't know anything about it and how physic works in space ; and I was like "Wow look at all the fuel I need to get to Mun, Minmus is even further away, no chance I'm going to it without a super large rocket".

Can you explain why it is the worst option ? I think it's the simplest way to do it. Launch in an equatorial orbit, place a maneuvre node at ascending/descending node and just spam the button which add one orbit until you get your encounter. Super easy.

Because there are only two points in Minmus orbit that will work. Since it's orbital period is about 50 days that means you could be waiting up to 25 days to get an encounter. Meanwhile, if you launched your vehicle directly into a 6 degree inclination (or -6 degree inclination) at the right time of day (one of the two times per day the KSC meets up with the point Minmus orbit crosses the equator), it will take at most a single orbit to find an encounter (the exact same as the Mun). Sure, your method works thanks to KSP time warp mechanics, but let's hope you don't play with life support mods.

Launching into Minmus orbit or even just really close to it is not that hard. In fact it isn't hard at all, you can simply eyeball it to within a degree and that is good enough for Minmus or really any moon. Even the old inclination change is a better option, it may take more fuel but you aren't time warping for a month.

The easy way is to utilize the Mun's orbit. If you adjust your camera in map mode so the orbit lines of both the Mun and Minmus look like a single straight line, the point where they intersect is where you want KSC to be when you launch. This is because KSC is on the equator and the Mun's orbit is too. Then you just offset your launch a little above or below 90 degrees and you should be pretty close to Minmus orbit, it does take a couple of practice runs but once you get a feel for it, it's so easy. (This also works for any inclined encounter, not just Minmus, I used it for a rescue contract just this morning). One thing to note is that the navball "feels" backward. If you are launching into an ascending orbit (so your craft is pointing north east on launch), you aim below 90 degrees, and vice versa). Whether you are ascending or descending will depend on which of the two launch windows you choose.

EDIT: here is a quick pictorial explanation of this launch

Step 1: Put your craft on the launch pad.

Step 2: Go to map mode, double click Kerbin to focus

Step 3: Aim your camera as shown in one of the two pictures below.

Step 4: Zoom in without moving the camera, when KSC is dead center planet, launch to a 6 degree (first picture) or 354 degree (second picture) inclination. (plant a flag at KSC before doing this, it helps unless you have the RT red dot like me)

It doesn't have to be perfect, thanks to gravitational forces of Minmus, close is usually good enough to get an encounter. If it isn't, it takes just a very minor inclination change to fix it.

So, you think that launching in an inclined orbit that match Minmu's one is simpler than hitting the time warp button ? What's the problem with taking time ? It's nothing compared to interplanetary travel.

I'm not talking about the educational "face" of this thing.

Yes I do, In the (real) time it takes to launch equatorial and find an encounter using your button mashing and then timewarp forward to that point, I'd already be on my way to Minmus if not there already.

Edited August 10, 2015 by Alshain

[goldenpsp]

So, you think that launching in an inclined orbit that match Minmu's one is simpler than hitting the time warp button ? What's the problem with taking time ? It's nothing compared to interplanetary travel.

I'm not talking about the educational "face" of this thing.

Timewarp isn't the end all solution to problems. Yes maybe if you are playing a stock game launching one mission at a time. But my career game has probably 12 flights going on all at once. Some are coordinated so that things land in a certain order etc. I can't simply "timewarp" without affecting everything else that is already in flight.

[mikegarrison]

So, you think that launching in an inclined orbit that match Minmu's one is simpler than hitting the time warp button ? What's the problem with taking time ? It's nothing compared to interplanetary travel.

I'm not talking about the educational "face" of this thing.

Yes, I do think it is simpler, once you know how to do it. Plus, the technique is generic. I use it all the time to launch satellites into their contract orbits.

(And simpler yet is to use MechJeb to do it for you, but that only works for things you can target, not contract sat orbits.)