Dr. James Van Allen, who helped usher in the space age as the scientist in charge of the instrument on JPL's Explorer 1 satellite in 1958, died Wednesday, August 9, at the age of 91. On the left, Dr. Van Allen (image courtesy Univ. of Iowa); on the right, a model of Explorer 1, held by JPL's Director William Pickering, scientist James Van Allen and rocket pioneer Wernher von Braun.