Jump to content

Getting to Another Planet(How?)


Recommended Posts

So I've been trying recently to get to other planets and thought it would be relatively simple but for some reason i just cant reach them. I have plenty of fuel to get to any one of them that i wish and i figure Duna is the easiest so its where i mostly try to go. I utilize the hohmann transfer very similar to landing of the Mun(which i can do very easily) but my ship never crosses Duna at the same time and i am never grabbed by the planet's gravity. I just circle around and around for hours(like 20 years in-game time) and never come close enough. Im not capable of doing any of the complex math a lot of you guys use so i just want to know what it is im doing wrong.

Link to comment
Share on other sites

Accuracy is very difficult in solar orbit, because the areas that are within a planet's sphere of influence are very small compared to the scale that you're working on. Also, Duna has an eliptical orbit, so standard transfers probabaly won't work, because you have to know where it is, and where it WILL be. Try using mechjeb, even the mighty autopilot has had trouble!

Link to comment
Share on other sites

Before my mission, I calculated the phase angle and ejection angle and from there I just tried a few times(quicksafe and quickload are really useful). Duna needs to be about ~50 degrees in front of Kerbin. Now the tricky part:

You have to burn at a specific time so that you cross Duna's orbit at the correct time. To achieve this I do a "simulation". If I miss, I just hold F9 and load a quick save.

Link to comment
Share on other sites

Doing it manually is hard, very hard imo

So far I've managed Eve, Duna and now Moho and it took me a few hours in the last instance to nail it. One way I've found that works is matching orbital inclinations then raising and lowering your orbits until it partly overlaps, then warping to the overlap part and then burning pro or retro grade just until the conics system kicks in.. it can take a bit of time warping and F5ing and F9ing to get it just right..

Overall though patience is a key to pulling it off, no one ever said rocket science would be easy lolz, but its worth persisting at

Also mechjeb and ion engines make it easier, if you do decide to change your mind and go down the mod route

Link to comment
Share on other sites

try using this orbital calculator it works if you do go through the effort of measure the angles http://ksp.olex.biz/ a good tool to measure the angles is with this tool : MB-ruler it works in game too so its quite useful.

Thank you so much for the angle thing! All my transfers so far have been failures because my angles are off. Time to go to JOOL!

Link to comment
Share on other sites

One thing I've had to do when I've missed my target with interplanetary transfers (which is every time so far), is to go and look up the length of a year for the planet you're trying to get to. Then, mark the time that the planet reaches your apsis, add the length of the year to it, and that's the point of time that you'll have to be back there at.

For example, say you're heading to Duna, and you miss, Duna crosses your apoapsis at day 100, and you reach your apoapsis at day 120. Well, Duna has a year of 200.4 days, so it will be back at your apoapsis at day 300.4 Between day 300.4 and the current day (120), it's 180.4 days. So, you can thrust at your apoapsis, until the round trip time will take 180.4 days, and you and Duna should both arrive back at that point around day 300.4 Although you'll probably end up having to do some minor corrections anyway to intercept it when you get closer.

If it would take too much to alter your orbit to get there in time, you can wait a few orbits for more favorable conditions, or set it up to meet back there after 2 years or something like that.

I've found http://kspwiki.nexisonline.net/wiki/Celestials is handy for finding orbital characteristics of planets, if you don't want to watch them and time them yourself. :)

Edited by Soralin
Link to comment
Share on other sites

I landed safely on Eve today!! =)

It took at least 3 hours to find the right angle for the insertion burn.

Here is how i did it atlast.

First i did my burn in LKO at sunrise to reach escape velocity from kerbin.

When in kerbol orbit i found that -42ish degrees is pretty close. -51 degrees as it says in other guides did NOT work!?

Keep burning retrograde until the orbits touch.

Then major adjustments to orbit to find the damn SOI and finaly aerobraking in Eve atmosphere.

My design uses the Kosmos Angara tanks.

Second stage is 3 nuclear engines on three 4 meter long angara tanks.. With those i do all interplanetary manouvers.(including getting into circular orbit around kerbin)

Third is a single nuclear engine on one 4 meter tank

And last it's a small 1 crew lander with parachutes.

I was surprised how effective those nuclear engines are.. lasts forever and takes forever. =)

Some pictures






Bill will not come home any time soon though. =)

Link to comment
Share on other sites

(How to get to Duna)

First, wait until Kerbin and Duna are ~45 degrees apart. Once that happens, launch your rocket, wait until you get to the border between day/night on Kerbin on the OPPOSITE side of the direction that Kerbin is travelling, and keep firing prograde until you hit Duna.

Link to comment
Share on other sites

Hey guys, i finally managed to figure out my encounters without the use of mods. thanks for everybodys help and suggestion! I keep crashing at the moment(damn parachutes), but a few tweaks to my rocket design should be good. Duna is just the first step in many many planetary adventures Jeb and i will have

Link to comment
Share on other sites

This method will allow some wiggle room, at the expense of more fuel, and you don't need to do any math or use a protractor.

For duna, wait for it to be around 45° ahead of you, (this is the proper angle for the cheapest transfer) and then warp a little longer so it's about 35° to 40° ahead. (behind for even and moho)

Now burn to escape kerbin (leaving in the direction of kerbin prograde). burn until your sun apoapsis is right at duna's orbit. now warp until you leave kerbin SOI and immediately go back to 1x. Now, point prograde and very slowly raise your apoapsis so that the line where you cross duna's orbit on the way back down moves around the sun. after moving it about 20° you will see it momentarily show the duna encounter. have your finger over the x button.

Using this method, you can eyeball everything. but you will have to burn off a bunch of speed when you get there. If you can do aerobraking it should be no big deal.

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...