Celestia Forums

In a message posted somewhere else in the forums, it was mentioned
"One utility which can produce trajectory files that only have to be modified slightly for use with Celestia is SwingBy by JAQAR."
It outputs .jsb files.
Is there a tutorial anywhere covering how to convert these .jsbs file types to xyz files?

thanks

SwingBy's SB.tf trajectory file is what you want, not its .jsb file.

run the Astrodynamics package
select the menu item Tools/SBC
select SwingBy's menu item Options/Write Trajectory Files of best solutions
use the various tabs to specify appropriate start, flyby and destination parameters
select File/Run-stop optimization

copy (or rename) and edit SB.tf to have filetype xyz or xyzv.
Delete the header and the last three (velocity) columns if you're creating an xyz file.
Delete just the header if you want an xyzv file (requires Celestia to have been built from current svn code).

In your SSC file specify something like

since SwingBy's trajectories are referenced to the Earth's equator, not to Celestia's default ecliptic coordinate system.

Selden,

Do you know what the units for velocity are in JAQAR's tf files? Celestia uses km/s; I'm hoping that's enough of a standard that I don't have to add a Units property to SampledTrajectory.

--Chris

Chris,

Yes, they're km/sec. Here's an example.

I'd forgotten that they use MJD, so that'll require some modification.