Hildegard Gertrud Helen Korf Kallmann-Bijl (September 18, 1908 – November 7, 1968) was a German-born physicist with Jewish roots who emigrated to the United States where she founded and was the first chair of Committee on Space Research (COSPAR) in Brussels, Belgium. She has been described as "one of the most active pioneers in her examination of the physics of high atmosphere for the flight calculations of satellites."[1][2]