As the weekly channeling sessions at Giant Rock continued through the early 1950s, the concept of an "Ashtar Command" was appropriated for use by a number of prominent early contactees and channelers, based on the figure of Ashtar, originally promoted by Van Tassel. Robert Short (AKA Bill Rose), editor of the 1950s UFO magazine "Interplanetary News Digest", was a member of Van Tassel's group. He began to popularise the messages, but as Van Tassel did not agree that other Ashtar messages were authentic, Short broke away and began his own group called "Ashtar Command".