Straight up shot to the Mun.

[Epic DaVinci]

Hi, is there a known time to launch a mission to the Mun without getting into Orbit First?

I mean launching straight upwards untill a Mun encounter is achieved.

What position should the Mun be in, in relation to the Launch site?

[AnalogAddict]

If I'm not mistaken, the moon should be right near the horizon. For instance, Day 0 Hour 0 of a new game has the moon in perfect alignment to burn directly there. I say, start a new game, observe the positions, profit.

[annallia]

That would depend entirely on the speed of your craft. The mun is fairly small, while its orbit is slow if your craft is taking too long to reach it you could easily overshoot.

[Francesco]

If I'm not mistaken, the moon should be right near the horizon. For instance, Day 0 Hour 0 of a new game has the moon in perfect alignment to burn directly there. I say, start a new game, observe the positions, profit.

how can you launch directly vertical and intercept the Mun, when it is 90 degrees ahead of you?

[Epic DaVinci]

would it not have moved from the 90* position and be directly in my path by the time i reach it?

[Tiron]

It depends on your rocket, unfortunately. Because different rockets take different amounts of time to climb. (this is why Mechjeb's 'launch to rendezvous' function requires a 'practice' launch to the target altitude before you can use it: You need to determine how long the rocket takes to launch to that height, measured by the 'phase angle' the target object should be at when you launch.)

Regardless, going straight up is horribly inefficient, because you'll be losing speed to gravity the entire time. Much more efficient would be to launch normally directly to the Mun's altitude. This would entail getting both the timing and the apoapsis right so that you encounter the Mun without having done a Circularization burn yet. I've tried to use the aforementioned Launch to Rendezvous function to do this, without success because the rocket I was using had Turbofans for boosters and Mechjeb wouldn't let me have enough time to spool them up before launch. I haven't yet tried it with another design, though I swear I've heard it said it's less efficient than launching to orbit and then doing a transfer burn.

[AnalogAddict]

Ah I apologize, by straight to the moon I figured you meant a direct burn from the surface of kerbin to the mun surface, which could be accomplished during that period.

Yes I can see how it depends on the rocket, fortunately for me any mun bound craft I've ever built makes it out of the atmosphere in time. I frequently align the moon before launch and burn directly there, observing the oberth effect as well as kerbal-proper ascent guidelines.

[Scarecrow88]

The last time I did something like this, I still did my gravity turn as if I was going in to orbit around Kerbin, but just kept burning until my Apo intercepted Mun orbit and gave me an intercept. If I remember I just launched slightly earlier than if I was doing an ejection burn from orbit, so the Mun was just below the horizon.

[Pugspaceprogram]

Actually, there is a way, with a bug ship that is. You should launch when mün is 45° above the horizon on the left

Here you launch upwards until encounter is achieved. I would personally go into an orbit first as it is much more efficient and if you are recording, you don't look as 'nooby'

[BahamutoD]

Why does getting to the moon without doing proper Hohmann transfer or using the Oberth effect, or using proper g-turns for maximum efficiency flight paths have to be 'nooby'? I for one would be impressed by a craft that could launch straight up and land on the moon without orbiting. In fact, ill take that as a challenge.

[Pixel of Life]

I've done a few missions of that type. For direct flights, I usually launch when the Mun is about 45 degrees behind my current position. Some aggressive mid-course maneuvering is required to get an encounter but it seems to be quite a time saver (I haven't actually made a comparison, just assuming) as I can get from Kerbin to Mun in less than 6 hours.

[Stir_Fry_Beans]

This is how I used to land things on the Mun before I figured out g-turns and mech jeb XD I would say when its right on the horizon like the first guy suggested. If your point occurs before the Mun then you can simply execute a longer burn and intercept it on your way back down to Kerbin. Like CaptainKorhonen said this is a lot of faster and requires a lot less maneuvers! Hope it helps!

[Tw1]

This is how I used to land things on the Mun before I figured out g-turns

Same. My Kerbals still pull out that pile of boosters that first got them there from time to time, for nostalgia. And as previously mentioned, aim for 45 degrees.

[Selnes]

I did pretty much a straight burn to the moon the other day. The moon was almost directly over the space center so I decided to attempt a straight burn since I knew my ship could produce the Delta V and and had more fuel than needed for a standard Mun encounter.

I set the Mun as a target and burned toward the prograde target marker on the Nav ball, it was about 5 degrees off center toward 90 at the time. About half way to the Mun I had to do a coarse correction for an intercept. Since I was aiming for an orbit I did another correction once my ship got caught by the Mun's gravity.

So it is possible but I had to burn way more fuel than normal, almost double the amount, when accounting for the coarse corrections. With a bit more practice I probably could do it better, but I think I will stick with the standard Mun encounter burn from Kerbin Orbit. It gives more time to set up a maneuver with a better Mun Orbital trajectory.

[draeath]

Yep, start when the moon is just coming up the horizon. I did this, and burned until my apoapsis was near Mun's.

I was then able to do a 30dΆcourse-correction for a 250km periapsis during the mun encounter.

I really think this was more fuel-efficient.. the launch configuration was just about the same, and the first stage made it to an apoapsis of nearly 2000km, where before I had to leave it at around 400km if I wanted to deorbit it. As it is, since I never circularized, I was able to use -all- of the fuel from it pushing my payload out to the mun without leaving reserves for housekeeping.

I did have mechjeb up for all this, but I did not use -any- of it's control mechanisms - just the maneuver node editor for fine-tuning while planning the course correction and orbit data display. (heck the rocket was unsteered past 200m/s velocity - gotta love doing a proper gravity turn with FAR!)

Edited May 4, 2014 by draeath