Orbiter-Forum  

Go Back   Orbiter-Forum > Orbiter Addons > Addon Development
Register Blogs Orbinauts List Social Groups FAQ Projects Mark Forums Read

Addon Development Developers post news, updates, & discussions here about your projects in development.

Reply
 
Thread Tools
Old 04-03-2018, 02:10 PM   #1
llarian
Orbinaut
 
llarian's Avatar
Default Determing position and orbit for ships in solar orbit ...

I am planning a new addon that includes placing six ships/stations in a single solar orbit. The preliiminary orbit design calls for a single orbital plan tilted 1 degree to the ecliptic, 1.6 AU from the sun. The ships will be placed 45 degrees from each other along the orbit. I had originally thought of starting at the First Point of Ares and working my way around.

Zo ... how do I determine the orbital elements for such an orbit and for each craft?

Thanks in advance.
llarian is offline   Reply With Quote
Old 04-03-2018, 02:39 PM   #2
Face
Beta Tester
 
Face's Avatar

Default

Quote:
Originally Posted by llarian View Post
 I am planning a new addon that includes placing six ships/stations in a single solar orbit. The preliiminary orbit design calls for a single orbital plan tilted 1 degree to the ecliptic, 1.6 AU from the sun. The ships will be placed 45 degrees from each other along the orbit.
I am no trajectory expert, but isn't that done by simply keeping the orbital elements equal except for mean anomaly, which is the angle you increase gradually by 45 degrees (which will make it 8 points around the orbit, not 6)? Mean anomaly vs. true anomaly shouldn't vary too much if the orbit is not too eccentric.

According to OrbiterWiki, this is the ELEMENTS format:
Quote:
Originally Posted by http://www.orbiterwiki.org/wiki/Orbital_elements
 ELEMENTS 6731158 0.0004046 51.6412 163.8597 185.4817 215.0447 54745.343391

where

6731158 - Semi-major axis in meters.
0.0004046 - Eccentricity.
51.6412 - Inclination.
163.8597 - Longitude of Ascending Node.
185.4817 - Argument of Periapsis.
215.0447 - Mean Anomaly.
54745.343391 - Epoch in Modified Julian Date.
So you could do "ELEMENTS 239400000000 0 1 0 0 <0+n*45> 54745.343391" with 0<=n<=7 . If you want 6 elements, change it to <0+n*60> and go with 0<=n<=5.
Face is offline   Reply With Quote
Old 04-03-2018, 04:53 PM   #3
Marijn
Orbinaut
 
Marijn's Avatar
Default

You don't mention a periapsis and apoapsis, only a 1.6AU distance. So I assume you are after a perfect circular orbit.

Orbiter's scenario editor needs six values to be set to define an orbit. The first one, the semi-major axis (SMa), can be calucated by summing apogee and perigree and divide these by two. Eccentricity is zero because it's a perfect circle. And inclination is set by you to be 1 degree.

This gives you the first three numbers.

SMA = (1.6AU + 1.6AU) / 2 = 1.6AU.
Ecc = 0
Inc = 1

The other three are for some reason much harder for me to understand. If you think of inclination as tilt, then the fourth value, the longitude of the ascending node (LAN), can be thought of as swivel.

The last two values, LPe and eps, define the position of a satellite on the orbital trajectory if I am right. I can't offer a good explanation at this time on how to set or calculate these. Perhaps somebody else can. Usually I go with trial and error from here.
Marijn is online now   Reply With Quote
Reply

  Orbiter-Forum > Orbiter Addons > Addon Development


Thread Tools

Posting Rules
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
Forum Jump


All times are GMT. The time now is 12:23 PM.

Quick Links Need Help?


About Us | Rules & Guidelines | TOS Policy | Privacy Policy

Orbiter-Forum is hosted at Orbithangar.com
Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2007 - 2017, Orbiter-Forum.com. All rights reserved.