Any advice for launch to insertion into a specific orbit w/ FAR?

[Drew Kerman]

Since Ascent Komputron is not working with FAR, I'm a bit stuck here. Even Arrowstar of KSPTOT fame couldn't really offer up any good solution. It's a bit annoying to plan a mission from the start using an orbit I'm not entirely sure I can attain properly. Take for example, this upcoming Mun mission:

Here I am after departing Kerbin arriving at Mun Pe just prior to a RAAN of 250, which is when I need to incline my orbit to match that of a satellite to rendezvous with. Very efficient! But it relies on my craft being at a certain point at a certain time in space around Kerbin to work as shown here. Otherwise when I finally achieve orbit I have to do a lot of work re-optimizing the mission with my actual starting orbital data. I'm not looking for perfect, but I am looking for close, which I know real space agencies can achieve. I just don't really know where to begin in getting there.

Edited December 13, 2014 by Gaiiden

[Starman4308]

Since Ascent Komputron is not working with FAR, I'm a bit stuck here. Even Arrowstar of KSPTOT fame couldn't really offer up any good solution. It's a bit annoying to plan a mission from the start using an orbit I'm not entirely sure I can attain properly.

Every real-world mission planner ever says "hi".

Either give broader tolerances in your mission planning, or launch early into a parking orbit, allotting time and OMS fuel to tweak your orbit to be in the right place for your planned maneuver. The Space Shuttles never launched directly to an ISS rendezvous: they would always evaluate the orbit the Shuttle got to, and then plan ISS rendezvous from there.

EDIT: For reference, the Falcon 9 manual says +/- 10 km accuracy for LEO perigee/apogee.

Edited December 11, 2014 by Starman4308

[Drew Kerman]

Every real-world mission planner ever says "hi".

well it was my understanding they at least had a good idea where their rocket would be once it entered into orbit. Right now I don't, I'm just putting it in the orbit I'd like to be in. Now I'm trying to figure out if it's possible to plan a way to get close to there during launch.

I do appreciate the parking orbit advice though. My initial plan begins at 100km so while I already did plan to launch ahead of the start time for my mission, I could also launch into a 75km orbit to use for plotting a maneuver that would get me into the proper 100km orbit for my mission. Again, I'd love to be able to skip that though.

Edited December 11, 2014 by Gaiiden

[Taki117]

I do appreciate the parking orbit advice though. My initial plan begins at 100km so while I already did plan to launch ahead of the start time for my mission, I could also launch into a 75km orbit to use for plotting a maneuver that would get me into the proper 100km orbit for my mission. Again, I'd love to be able to skip that though.

Why not just launch into a 100km orb it and then adjust as needed for the mission? In fact, what is the mission? We kinda need more to go on to be helpful. If you are just going to the Mun (and not using RSS) then you simply turn east and put yourself in a parking orbit, if you are using RSS and lunching for a high latitude (Say Baikonur) then you want to wait until tye Mun is roughly overhead (Your launch site crosses the orbital path of the Moon) and launch from there.

[Drew Kerman]

Why not just launch into a 100km orb it and then adjust as needed for the mission? In fact, what is the mission? We kinda need more to go on to be helpful. If you are just going to the Mun (and not using RSS) then you simply turn east and put yourself in a parking orbit, if you are using RSS and lunching for a high latitude (Say Baikonur) then you want to wait until tye Mun is roughly overhead (Your launch site crosses the orbital path of the Moon) and launch from there.

Actually it doesn't matter what the mission is - I could be doing anything not just going to Mun. The problem is that all my mission planning (in KSPTOT) must start from an initial orbit and now I'm wondering what the best way is to get there from the surface. But because it's really cool, here's the mission:

I've already done one pre-planned mission that is on its way to Duna with no issues, but my starting orbit did not have to be as precise as in this case, which has me transferring to Mun just at the right time to incline my orbit and get a quick rendezvous with an orbiting spacecraft.

[Starman4308]

Actually it doesn't matter what the mission is - I could be doing anything not just going to Mun. The problem is that all my mission planning (in KSPTOT) must start from an initial orbit and now I'm wondering what the best way is to get there from the surface. But because it's really cool, here's the mission:

You might try launching into a parking orbit, and then use KSP TOT to design a mission to go from your parking orbit to your destination orbit.

[Drew Kerman]

You might try launching into a parking orbit, and then use KSP TOT to design a mission to go from your parking orbit to your destination orbit.

Done that for probes, but not an ideal solution for kerbed missions. I could end up with a transfer burn days away and just waste life support resources in orbit around Kerbin.

[Kryxal]

Try plotting the mission from a parking orbit ... once you have a departure point, launch maybe 2 hours early and fiddle with your orbital period so you hit the right place at the right time, then re-run your solution with your actual orbit and you should be good. The initial burn can act as an initial "kick" so make your actual transfer more efficient.

[Hodo]

Done that for probes, but not an ideal solution for kerbed missions. I could end up with a transfer burn days away and just waste life support resources in orbit around Kerbin.

I have always done parking orbits then performed a burn to my target planet. But I use SSTO spaceplanes for all of my space work even interplanetary work now. So for real distant hops outside of the Kerbin SOI, I have to do a refuel at a station at 100km orbit then perform the mission. This is honestly the most cost affective way to perform most missions.