Celestia Forums

I decided to look at what text in another addition to on the spacecraft, and saw that every coordinate was registered in its flight to Mars. Is it really necessary to count?

If you are asking about how coordinates are used in an xyz or xyzv trajectory, then no. You don't have to provide many coordinates that are close together. Celestia interpolates between adjacent coordinates. When a trajectory is almost straight, like when traveling between planets, coordinates can be far apart. When the trajectory is curving rapidly, like when a spacecraft is orbiting a planet, then the coordinates need to be closer together.

The xyz or xyzv coordinates of many real spacecraft trajectories can be obtained from the NASA JPL Horizons ephemeris server. See https://ssd.jpl.nasa.gov/horizons/

A template for use with their email interface is available at https://www.classe.cornell.edu/~seb/celestia/horizons-template.txt

Modifying the output provided by Horizons so it can be used by Celestia is relatively straight forward.