"Women at War 1939-1945" The Auxiliary Territorial Service: At a Ministry of Supply experimental station, trials of rocket fuels were made to determine accuracy. Members of the ATS manned observation posts along the coast from which they observed and recorded the position of shell bursts. About 40 members of the ATS were engaged in this work. The picture shows the plotting room at headquarters where members of the ATS compile statistics on rocket behaviour from observer reports.