IMFD Using BaseApproach to hit specific orbital plane?

Ark

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Is there a way to use Baseapproach or another IMFD function to plan your approach to a planet so that you end up on the same (or close to it) orbital plane as, say, a space station? My specific case is that I'm trying to fly an Antares LR to a rendezvous with a station in lunar orbit. Delta-v is limited, so I want to drop right into the station's plane without stopping in lunar parking orbit and making a plane change.

I fooled around with BaseApproach's GEO mode and used the custom longitude/latitude function to set the inclination, and I got close a couple of times, but is there a reliable and accurate way to do it? Surely it's possible to plan an approach like that, but how?
 

fireballs619

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Well, I am certainly no expert in either of the MFDs that you mentioned, but I don't know of any method that wouldn't require a maneuver that would require similar dV earlier on in the flight. How tight is your delta-V budget, may I ask?
 

orbekler

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I think IMFD does that, and this option should be Re-entry, but not always you can. After specifying the target base, try to change Hint, if the purple line appears (HTO), then you can. If not you'll have to change the option in Orbit Insert, and specify the number of orbits before you're sync-ed with the base (max=3).
Don't know about dV required, though.
Edit: Sorry, I misunderstood you query. You have to use Orbit Insertion, but I didn't try yet to approach straightly an orbiting station, it could be a good challenge.
 
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Ark

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Well, I am certainly no expert in either of the MFDs that you mentioned, but I don't know of any method that wouldn't require a maneuver that would require similar dV earlier on in the flight. How tight is your delta-V budget, may I ask?

Tight enough that a 30 degree plane change burn spoils the return to Earth.

---------- Post added at 05:47 PM ---------- Previous post was at 05:40 PM ----------

Edit: Sorry, I misunderstood you query. You have to use Orbit Insertion, but I didn't try yet to approach straightly an orbiting station, it could be a good challenge.

Orbit Insertion?
 

Adelanthal

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Oddly enough, I use just the OrbitMFD and do plane change burns as part of MCCs. Not as fuel efficient as it could be, but a LOT cheaper than trying to plane change later.
 

orbekler

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Orbit Insertion?
I'm testing, however this could be the path: during mid-course, reset Course->Target Intercept with the station you want (I'm trying with OB-1, but could be any), perform AB. The Course->Orbit Insert maybe could be skipped, as the station is an off-plane target, so we should perform just a straight docking, but it's just an idea, we'll see after some test.
 

jarmonik

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Is there a way to use Baseapproach or another IMFD function to plan your approach to a planet so that you end up on the same (or close to it) orbital plane as, say, a space station? My specific case is that I'm trying to fly an Antares LR to a rendezvous with a station in lunar orbit. Delta-v is limited, so I want to drop right into the station's plane without stopping in lunar parking orbit and making a plane change.

There are two methods those should work pretty well. If you want a precise flight then your best bet is the second method with the LTMFD.

A "rough" genereic method with IMFD to reach a lunar orbital station from the Earth:
1. Setup an intercept trajectory with the moon
2. When you go inside the lunar SOI open the Planet Approach program.
3. Setup PeA to match the station altitude.
4. Adjust EqI to get zero AgP and execute the burn. (This will move the plane alignment point into the apoapis)
5. Open Orbit-Insert and set the Ecc into 0.8 and execute the orbit insertion into a highly elliptical orbit.
6. Open Align-Planes MFD and execute the plane alignment burn when you are near the apoapis.
7. Execute 2nd orbit insertion burn into a circular orbit.


More precise procedure for the LTMFD:

You need to wait the launch window. You can find the launch window by looking the TrL of the Moon using OrbitMFD. The TrL that is your launch window is the LAN of the lunar orbital station plus an offset. The offset is depended about the inclination of the lunar orbital station and the transfer time as well as the Earth parking orbit inclination and a few other things.

Let's consider a flight to the Luna-OB1 that has an inclination of 90deg and the LAN of 0deg. We use a transfer time of 70h and earth parking orbit that has zero RInc with the Moon. This condition will give us an offset of roughly 8 deg.

So, the TrL of the Launch window is 0 + 8 = 8 deg.
An other launch window is 180deg later 0 + 8 + 180 = 188 deg

When you are in the Earth parking orbit you can fine tune the LAN by altering the PeT (time of arrival). You can set and fine tune the inclination by setting/altering the Hed. The Hed is your flight heading in the periapis. To get into a polar orbit the Hed must be either zero or 180deg.

This method should take you directly in the orbital plane of the Luna-OB1 with an accuracy of 0.1deg if everythin is properly set.

PS. It's also a good idea to enable the "Auto EXE" from the configuration page of the LTMFD.
PPS. In the LTMFD you need to press EXE to update the flight data after loading a scenario.
 
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