Tips on getting to Minmus?

[Marth Vader]

I'm trying to get my first probe to Minmus, and I'd like some tips on the most efficient way to get there. Should I try a gravity slingshot with Kerbin to Minmus, to the Mun and then Minmus, or just straight up burn until I get there? Anything else I should know?

[Alientcp]

I usually do it in 1 go with a nuke engine, but its a long and tedious burn. With a slingshot, though possible, you might lose the encounter. I mean, you can do the slingshot interplanetary because if you orbit for a couple of days, the planet you are aiming for barely moved, but mimmus should have moved more because its closer to kerbin.

[Venusgate]

Slingshot will only save you maybe 50 m/s if done precisely and if the stars and moon align (hurr hurr)

Easier to just add an extra booster.
Just remember Minmus surface gravity is a LOT lower than Mun's. If you're not delicate on touchdown, you will bounce like a golf all on concrete.

[Marth Vader]

Don't yet have the nuclear engine, that's one of the reasons I'm going to Minmus.

Minmus is lined up pretty well with my orbit to do a decent slingshot. I may try abusing quicksaves and try that first.

[andylaugel]

The easy way I often use is to launch a rocket with decent dV, get into a 80 to 100 km orbit around Kerbin, target Minmus, make an inclination burn so the AN/DN both read 0.0, then do the intercept burn so it's Ap is just touching Minmus orbit (or a little less).

That said, a more efficient way involves doing the intercept burn first, then make the inclination burn higher up when you're going slower. It's a little tricker to deal with two maneuver nodes at once though.

A Munar slingshot is tricky to pull off right, and depends a lot on the Mun's position. I wouldn't bother with that in most cases.

Terrier or Poodle are both efficient Liq/Ox engines with reasonable thrust. Nervs can be better, but often aren't due to high mass and low thrust. Dawns are really only for small spacecraft, if you have a lot of patience.

[LittleBlueDuneBuggy]

Originally posted by Alientcp:

I usually do it in 1 go with a nuke engine, but its a long and tedious burn. With a slingshot, though possible, you might lose the encounter. I mean, you can do the slingshot interplanetary because if you orbit for a couple of days, the planet you are aiming for barely moved, but mimmus should have moved more because its closer to kerbin.

Originally posted by Venusgate:

Slingshot will only save you maybe 50 m/s if done precisely and if the stars and moon align (hurr hurr)

Easier to just add an extra booster.
Just remember Minmus surface gravity is a LOT lower than Mun's. If you're not delicate on touchdown, you will bounce like a golf all on concrete.

Originally posted by andylaugel:

The easy way I often use is to launch a rocket with decent dV, get into a 80 to 100 km orbit around Kerbin, target Minmus, make an inclination burn so the AN/DN both read 0.0, then do the intercept burn so it's Ap is just touching Minmus orbit (or a little less).

That said, a more efficient way involves doing the intercept burn first, then make the inclination burn higher up when you're going slower. It's a little tricker to deal with two maneuver nodes at once though.

A Munar slingshot is tricky to pull off right, and depends a lot on the Mun's position. I wouldn't bother with that in most cases.

Terrier or Poodle are both efficient Liq/Ox engines with reasonable thrust. Nervs can be better, but often aren't due to high mass and low thrust. Dawns are really only for small spacecraft, if you have a lot of patience.

WTF are you people talking about? He's not trying to get to Eeloo.

OP, get into LKO. Do inclination burn at AN, or DN. Go into map mode, and move screen so Minmus is right on the right edge of Kerbin. Set a maneuver node right at that edge. Burn prograde to encounter. At PE of Minmus, burn retrograde. Done. Takes about 4,500 dV.

[George Kerman]

Originally posted by andylaugel:

That said, a more efficient way involves doing the intercept burn first, then make the inclination burn higher up when you're going slower. It's a little tricker to deal with two maneuver nodes at once though.

Andy's approach is the most balanced method that involves some skill and less dV. It's also my favourite for Minmus because I can do it without thinking for a sec. It's also the right approach if you wanna launch right now and get to Minmus, not wait for stuff to happen. The Mun assist is if you wanna get bonus style points (imaginary points, that is) and don't mind waiting for the planets to align, meaning, Minmus has to be further in its orbit than the Mun. How far? It depends on your pinball abilities, I didn't bother with this because the difference is just 60 dV (ish). If you wanna practice your planetary pinball skills go to the Jool system where you got plenty of material to play with.

You could, however, launch during the right time of day to match Minmus's inclinitation from the get go. That involves some eyeballing of the Minmus's orbit and identifying either the AN/DN of Minmus and projecting it on Kerbin's surface (eyeballing it, that is). When your launch site is on that projected point, you target Minmus (meaning, set target in map view) and launch. You'd need to fly slightly south or north (depending whether it's AN or DN) until you see that the AN/DN compared to Minmus are, say, less than 1 degree, or as close to zero as possible without changing the direction too much. After reaching orbit, it's just one maneuver to intercept because you'd be coplanar already. This approach has more efficient uses for non-equatorial launches, for moons with significantly higher inclination of their orbits and for some interplanetary voyages.
I wouldn't bother with this approach until you have like 500 hours in the game, I was just describing it so you have the full picture.

[Venusgate]

Originally posted by LittleBlueDuneBuggy:

WTF are you people talking about? He's not trying to get to Eeloo

...

Done. Takes about 4,500 dV.

WTF are you talking about, just strap as many boosters in asparagus stages as you can and point straight at it!

[Alientcp]

The good part of going to mimmus is that you dont need too much fuel to scape and a suicide burn its best to land i guess.

Just make sure you land vertical, its very easy for your ship to fall.

[Marth Vader]

Originally posted by Alientcp:

The good part of going to mimmus is that you dont need too much fuel to scape and a suicide burn its best to land i guess.

Just make sure you land vertical, its very easy for your ship to fall.

Easy to fall indeed. After many mistakes a flawless approach, I managed to land. Thanks for all the tips, they helped quite a bit.

[RoofCat]

one more thing about landing - make sure your speed is in SURFACE mode.

Landing higher than on flats Minmus often uses Orbital velocity for some reason. The orbit is considered low there or whatever. So touching ground you may actually still have ~8m/s (irc) sideways - planetary rotation. It's actually important for all landings. Just click on the speed window to switch through them.

[Nova Solarius]

Get into orbit with a main stage, then use a Terrier with a decent fuel tank to make your way to Minmus and back. I'm currently trying to land on both Minmus and the Mun before landing back on Kerbin, and a Terrier with one FL-T800 tank (technically it's two T400s because I was too lazy to look for the T800) can get me to Minmus with plenty of fuel to spare.

[maculator]

Slingshoting the mun is ♥♥♥♥♥♥♥♥.
That tiny little bit of deltaV you could save there is nothing compared to what you are loosing because your not burning near to kerbin. And it's also utterly fiddely to get it right, by the time you're done dragging and groping the maneuver node you could've been to minmus 10 times.

The mun is never a good idea to slingshot even for interplanetary travel, it's just not worth it.

[LittleBlueDuneBuggy]

Originally posted by maculator:

Slingshoting the mun is ♥♥♥♥♥♥♥♥.
That tiny little bit of deltaV you could save there is nothing compared to what you are loosing because your not burning near to kerbin. And it's also utterly fiddely to get it right, by the time you're done dragging and groping the maneuver node you could've been to minmus 10 times.

The mun is never a good idea to slingshot even for interplanetary travel, it's just not worth it.

This man gets it.

[RoofCat]

Originally posted by maculator:

Slingshoting the mun is ♥♥♥♥♥♥♥♥.
That tiny little bit of deltaV you could save there is nothing compared to what you are loosing because your not burning near to kerbin. And it's also utterly fiddely to get it right, by the time you're done dragging and groping the maneuver node you could've been to minmus 10 times.

The mun is never a good idea to slingshot even for interplanetary travel, it's just not worth it.

that's not exactly correct. Mun has its issues and can provide ~60m/s for free at best. Going to close targets like Minmus, Eve, Duna. Passing it faster going further is worth less. The gravity is too small to bend your path enough at those velocities.

Also you can use Mun to amplify trajectory inclination going to Minmus. Just start with the opposite one. If you need to go up, target Mun slightly below equator. So you don't have to burn expensive fuel on LKO for full Minmus inclination. Though there are easier, quicker solutions for this indeed. Like launching at the right daytime and angle or targeting Minmus where it crosses Kerbin equator line.

Originally posted by maculator:

Slingshoting the mun is ♥♥♥♥♥♥♥♥.
That tiny little bit of deltaV you could save there is nothing compared to what you are loosing because your not burning near to kerbin.

this small part is rather completely wrong though. Or misunderstood how you do slingshots in KSP. You still do full burn on LKO. Passing Mun on the way to your target just adds those ~60m/s for free extra. So if normal transfer to Duna from ~72km LKO is around 1060m/s, using Mun you need just 1003m/s at LKO or so. But Mun must be in optimal position and you must pass over it as low as possible with your escape path being paralel to Kerbin orbit. So yeah, a bit trickier to plan and execute.

There are maneuvers in space travel where you do burn at Pe while passing gravity well. But in KSP and with Mun in particular you rather don't do that. At Mun it is not worth it since it has lower gravity and orbital velocity than Kerbin does and at other targets you need a lot of planning.


Jool is really great for slingshots and so is Eve. Kerbin is decent and so are Laythe and Tylo. The rest is rather neglectable except you are just having some node fun like with Mun. Bodies like Minmus with very low gravity are "completely" useless for those tricks. The impact would be really close to none.

[LittleBlueDuneBuggy]

Originally posted by RoofCat:

normal transfer to Duna from ~72km LKO is around 1060m/s

It is? I thought it was 900m/s. Here I was wondering why I was so inefficient at 980m/s. LOL, I guess I can put that one to bed.

Sorry to hijack, OP.