Kurt and Hal Gottschalk exercising with a medicine ball in a reproduction of an illustration for the book "Kinder-Turnen in Haus" by Fritz Strube. Sports

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Fritz Gottschalk and his children boating on a mountain lake; Titisee, Germany.

From left to right: Ursula, Walter, Hal, Kurt, Fritz, and Elizabeth Gottschalk; the lake is probably the Titisee near the Swiss border in the Black Forest, Germany

Fritz Gottschalk, Therese Gottschalk nee Molling and Lotte Stern nee Wallerstein on a hiking tour in the mountains.

Therese Gottschalk nee Molling, wife of Fritz Gottschalk; Lotte Stern nee Wallerstein, 1st cousin of Lotte Stern nee Wallerstein

Studio portrait of Fritz Gottschalk as a young man; Hannover, Germany.

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Fritz Gottschalk on the beach with his three oldest children, Hans Ludwig, Elizabeth and Kurt; Norderney, Germany. Portraits; Family

Kids from left to right: Hans Ludwig, Elizabeth, Kurt Gottschalk

Fritz Gottschalk with his wife Therese nee Molling sitting on the beach next to a strandkorb; Norderney, Germany. Portraits Couples

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Passport photo of Fritz Gottschalk Portraits Men

Photograph from Fritz Gottschalk's Nazi identification papers

Tombstone for Fritz Gottschalk who died in an avalanche in 1935; Bothfeld Cemetery; Hannover.

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Fritz Gottschalk outdoors dressed in his hiking clothes Portraits Men

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Walter Gottschalk and Fritz Gottschalk (Papa) saying goodbye to Elizabeth and Hans Krakauer who are on board the ship Koenigstein leaving to emigrate to America; Antwerp, Belgium.

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Tombstone for Fritz Gottschalk who died in an avalanche in 1935; Bothfeld Cemetery; Hannover.

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Fritz Gottschalk and his children boating on a mountain lake; Titisee, Germany.

From left to right: Ursula, Walter, Hal, Kurt, Fritz, and Elizabeth Gottschalk; the lake is probably the Titisee near the Swiss border in the Black Forest, Germany

Friedrich Bergammer (Fritz Glueckselig) standing in the doorway of the gallery store M. Glueckselig & Son; 108 East 57th Street, New York Portraits Men

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An Optimal g-Guidance Scheme for Satellite Launch Vehicles

A closed-loop steering logic based on an optimal (2-guidance is developed here. The guidance system drives the satellite launch vehicle along a two- or three- dimensional trajectory for placing the payload into a specified circular orbit. The modified g-guidance algorithm makes use of the optimal required velocity vector, which minimizes the total impulse needed for an equivalent two-impluse transfer from the present state to the final orbit. The required velocity vector is defined as velocity of the vehicle on the hypothetical transfer orbit immediately after the application of the first impulse. For this optimal transfer orbit, a simple and elegant expression for the Q-matrix is derived. A working principle for the guidance algorithm in terms of the major and minor cycles, and also for the generation of the steering command, is outlined.

Portrait of Friedrich Bergammer (Fritz Glueckselig) Portraits Men

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