Monday, April 13, 2009
In preparation for my April 14 IYA podcast, I wanted to add some graphics to my Flickr site to further illustrate the simulated Europa to Callisto journey that I "dramatize" in the podcast. The basic tools for this are Orbiter, IMFD v4.2 (not the latest version), and Andy McSorley's excellent Europa to Callisto IMFD tutorial. These are all free downloads.
IMFD is an amazing interplanetary navigation tool by Jarmo Nikkanen. Andy's tutorial was inspired in part by an earlier IMFD tutorial by Robert Denny, which also exists in video form. I prefer Andy's tutorial because it explains more about the various specialized terminology used in IMFD. I've been away from IMFD for a long time, so I had to read through Andy's tutorial completely before successfully flying from Europa to Callisto yesterday morning. This is also an excellent illustration of the "forgetting curve" since I was the proofreader and tester for that tutorial while Andy was developing it. Of course that was a couple of years ago and I can barely remember what happened last week (I think I was in Europe, not Europa).
It was not completely successful trip (I mean the Callisto one - the Europe trip went rather well). Rather than starting with Andy's tutorial starting point scenario, I took a different starting scenario and changed the date to March 14, 2084. This gave me some nice views of Io but it was not the best starting date for a time- and fuel-efficient transfer. Fortunately the Delta Glider carries a lot of fuel for its nuclear fusion (or whatever) rocket engines. The other thing was that I missed a step and ended up with a retrograde orbit (orbiting opposite the direction of rotation of Callisto, orbital inclination of 163.76 degrees in my case). This doesn't matter much when you're on a simulated joyride but IMFD allows you to precisely determine your arriving orbit if you use it properly, and I just sort of said "whatever." The picture above shows the final Callisto orbit.