Notes and Bugs

Notes:
• The option to download the plot as a postscript file now sends it in a zip file. (2/28/01)
• The form driven plot became broken when we retired Perl 4, but is now working again under Perl 5. (5/27/01)
• A table with the Wild 2 orbital elements for observers has been added along with an observer ephemeris spanning the dates of the mission. (2/28/99)
• An updated ephemeris for the STARDUST Spacecraft that takes into account the one-day slip in the launch time is now used by this program. The ephemerides files for Wild 2 and the planets shown here have also been updated and time synchronized with the launch time. A final flight operational Spacecraft ephemeris will be issued later and will be incorporated when available.
• Note, the Flight Days are counted beginning from zero at launch (injection time 4:25:50 pm EST) and chage at this time, not midnight.
• The distances of Wild 2 and the Spacecraft from Earth and the Sun are computed at the time the flight statistics page is envoked. Values are based on linear interpolation between successive days.
• The Stardust trajectory consists of three loops two of which are very close together giving the appearance of one thicker loop. These can be distinguished by making plots with tighter ranges.
• Gnuplot is easily crashed by putting in goofy settings. It may be helpful to look at the gnuplot plotfile (see bottom of page) and compare plots that work with ones that don't if you have problems. Failures result in a broken picture.
• The x,y scale factors are set to give the correct aspect ratio for the display when the x and y ranges are set to equal spans. Setting them otherwise gives distorted pictures. Also obviously they can not be set equal or backwards.
• The default plot samples setting is 100. Setting it higher increases the compute time and may be useless if your monitor can not display it. I have hopes of adding an anti-alias option when I find a filter or get time to write one.
• By using a smaller z-range you can exaggerate the orbital inclination and thereby spread out the differences. An honest view has the x,y and z range spans all equal. The default picture has a 4:1 exaggeration in the z axis (perpendicular to the x and y axes which lie in the ecliptic) to aid in visualizing the differences in inclination of the various orbits.
• The t-range default is 0:pi in order to compute once around the orbits (see equations). Setting this smaller causes only partial orbits to be plotted. Note however that the STARDUST orbit is not computed but rather plotted from a file of cartesian points so the t-range setting has no effect on it.

  Bugs:

• Once the OPS spacecraft ephemeris is available it will be substituted and the ephemerides for the other bodies will be recomputed to the same start time.
• The Postscript output option is broken. It gives a raw EPS file which is huge and the plan is to make this a zipped EPS file.
• The Planets Legend is not well behaved when you use View and Scale settings different from the defaults, so you may want to turn Planet Legend Off and Planet Labels On, or use neither.
• Likewise, the Axis labels and Title may need to be turned off when using different views and scale factors.
• There is a problem with Netscape browsers keeping the previous image in cache and displaying that rather than a newly generated image (I don't know about IE). A way to clear the cache in Netscape is to hold down the Shift key down while pressing the Reload button on the Netscape browser.