Questions on orbit parameters
Posted: 05.12.2004, 00:19
I'm a second year Aerospace Engineering undergraduate at the University of Michigan, and a current project in one of my classes is to design a series of transfer orbits to get a satellite from burnout over Cape Canaveral to geosynchronous orbit with the longitude of Ann Arbor.
So I have calculated the standard 6 parameters (eccentricity, ascending node, etc.) and now I want to insert one of my orbits into Celestia, in an SSC file, just to see exactly if my predictions are correct (the first orbit at burnout actually crashes into the Earth east of Madagascar, according to my predictions). Also because it would look cool (I've been using Celestia on and off for a few years now).
My first question is: just how accurate and reliable are the orbital calculations done in Celestia? The programs our professors want us to use are all costly and resource-consuming. I just want to know if a freeware, open source program such as this has the same capabilities.
Second question: for specific parameters such as ascending node, what is the reference used to measure those angles by? i.e. at what longitude would the ascending node be 0? Is it referenced to the stars or the Earth itself?
With those questions asked, I'll describe my scenario: At a certain arbitrary time t=0 (let's say January 1st, 2005, at 12:00 PM), the satellite is ten degrees of longitude east of Cape Canaveral, at an altitude of 200 miles. I have the orbit parameters already calculated, I just want to know how to time and design the orbit in the SSC file so that when I go to that date, I will see the ship exactly at the starting point.
So I have calculated the standard 6 parameters (eccentricity, ascending node, etc.) and now I want to insert one of my orbits into Celestia, in an SSC file, just to see exactly if my predictions are correct (the first orbit at burnout actually crashes into the Earth east of Madagascar, according to my predictions). Also because it would look cool (I've been using Celestia on and off for a few years now).
My first question is: just how accurate and reliable are the orbital calculations done in Celestia? The programs our professors want us to use are all costly and resource-consuming. I just want to know if a freeware, open source program such as this has the same capabilities.
Second question: for specific parameters such as ascending node, what is the reference used to measure those angles by? i.e. at what longitude would the ascending node be 0? Is it referenced to the stars or the Earth itself?
With those questions asked, I'll describe my scenario: At a certain arbitrary time t=0 (let's say January 1st, 2005, at 12:00 PM), the satellite is ten degrees of longitude east of Cape Canaveral, at an altitude of 200 miles. I have the orbit parameters already calculated, I just want to know how to time and design the orbit in the SSC file so that when I go to that date, I will see the ship exactly at the starting point.