Hopefully the following information will help out.
On my quest to uncover everything related to Fox Kids, I have discovered probably more information than you need. The three part mini-series Red Planet aired three times on the Fox Kids Network. It premiered on Saturday, May 14, 1994 in the last timeslot of the day, with the second and third parts aired on Saturday, May 21, 1994 and Saturday, May 28, 1994 (respectively). In the fall of 1994, Fox decided to pre-empt Where on Earth is Carmen Sandiego?, which aired in the 11:30 AM timeslot, from the end of October 1994 to February 1995 in order to air a series of specials such as the Spider-Man sneak preview, Grunt and Punt, AJ's Time Traveler's, etc. Nevertheless, Red Planet repeated on Saturdays in this time slot on January 7, 1995, January 14, 1995 and January 21, 1995. Finally, almost a year and a half later, Red Planet aired again during the Fox Kids Spring Fling. This time, it pre-empted Life With Louie for three weeks. The airdates were Saturdays May 4, 1996, May 11, 1996, and May 18, 1996. Red Planet has not aired in the United States since and did not air in primetime on Fox.
The series was produced by Gunther-Wahl Productions. Lee Gunther, whom the Gunther part of the production company comes from, was the VP of Foreign Productions at Fox Kids, which is why it aired on Fox Kids. Gunther has since passed away (1998).
As for the other series, like cquinniey said, is Invasion America, which aired on the WB Network in primetime and also on Saturday mornings on KidsWB. It aired on Tuesday nights from June 8, 1998 to July 7, 1998, airing all 13 episodes. Then, 10 of the 13 episodes repeated on KidsWB from September 19, 1998 until October 31, 1998.