The year 1953 saw the rockoon join the stable of sounding rockets capable of reaching beyond the 100 kilometres (62 mi) boundary of space (as defined by the World Air Sports Federation). Employed by both the University of Iowa and the Naval Research Laboratory, 22 total were launched from the decks of the USS Staten Island and the USCGC Eastwind this year. All branches of the United States military continued their program of Aerobee sounding rocket launches, a total of 23 were launched throughout 1953. The Soviet Union launched no sounding rockets in 1953; however, the Soviet Union did conduct several series of missile test launches.