I should have mentioned, I used the HST TLE from heavens-above for both calculations: HST 1 20580U 90037B 07119.84385043 .00000347 00000-0 14117-4 0 8628 2 20580 028.4663 145.3557 0003364 307.4907 052.5376 15.00228841732698 regards, Jason -- KStars: KDE Desktop Planetarium kstars at 30doradus.org