Hey Frank! Welcome to ASKC! Glad you and your family have joined, it's a great club with a lot of great members.
To reserve Powell Observatory just email powell@askc.org or call 913.438.3825. That will connect you to our illustrious observatory director David Young. He will find a date that will work for you and your family and then one of the volunteer operators will meet you down there to open the observatory for you and show you around the night sky. Observatory reservations are free for members and we highly encourage our members to reserve the observatory as often as they like.
Hope to see you down there!
Mitch Cloud