The original GPS Time Capsule was laid in a ceremony held August 29, 1947. The box contained a doll dressed in a uniform, a letter to the GPS girl of the future, a New Testament, coins, a photograph of the three founders, a 1946-47 GPS handbook, a report card, a 1947 commencement program, a list of the Board of Trustees, a list of contributors, a list of alumnae, a brochure of the new GPS, the May 27, 1947 Static, The Look-In newspaper of May 3, 1947, and the Chattanooga Times of May 29, 1947.
A note included with the doll gave a description of the GPS uniform: "the dress can be of any color in linen or cotton material. The tucks, hemstitching, black tie, buttons, and belt are requisite. The tie is of black grosgrain ribbon, and the belts are of matching material." The note continued, "The GPS girl does not wear jewelry or cosmetics during school hours." Miss Jarnagin spoke to the audience during the 1947 placement ceremony, expressing her wish that Miss McCallie and Miss Duffy could be present to see the culmination of their dreams. She ended by stating that "Dreams come true when behind them is "work, sacrifice, and faith."
The 2007 Time Capsule was laid in a cornerstone of the new C. Ben Harnsberger Student Center during construction. With the support of the student body, the Student Council chose what to include in the capsule.
The box contains A Centennial History of Girls Preparatory School, a traditional uniform and plaid winter skirt, a DVD celebrating the centennial, the 2004-5 Blue Book, notes from students, information on the laptop program, an internet weather report, a demerit notepad, an invitation to the Junior-Senior Prom; Reflections, a May Day publication; the Centennial grosgrain uniform ribbon, textbooks, a current curriculum guide, and GPS: The Magazine. The original capsule from 1947 was placed with 2007's capsule.