Aldrich entered the Navy in 1859 in the Marlborough, Mediterranean Station, later serving in the Scout, 1865 to 1867, on the South American Station. He was promoted to lieutenant in 1866 and was First Lieutenant in the Challenger between 1872 and 1874. He then joined the Alert, 1875 to 1876, as senior lieutenant during the British Arctic expedition led by Sir G.S. Nares (q.v.). In the spring of 1876 he explored the northern coast of Ellesmere Island with the sledge Challenger. For service in this expedition he was promoted to commander. He was employed in the surveying vessels Sylvia and Fawn in the Far East and off Africa between 1879 and 1884, being promoted to captain in 1883. He continued to serve until 1908 when he retired with the rank of admiral.
The papers, which were presented in 1955 by Aldrich's niece, Miss B. Champion, cover only a short period of his career. There are extracts from journals, 1860 to 1867, returns from the sledge Challenger and notes and journals concerning surveying 1879 to 1884. There are no papers for the Challenger expedition in this collection: the main Arctic papers are with the Scott Polar Research Institute at Cambridge.