The development of the Iris sounding rocket had begun at NRL prior to the transfer of its Rocket-Sonde group to NASA. Iris was built by the Atlantic Research Corp. for the Naval Bureau of Ordnance, with NRL monitoring the design, the production, and the payload. The development of the rocket was completed by NASA, with the first NASA firing taking place at Wallops Island on July 22, 1960. In contrast to the monsters in the Argo series, Iris is a small, two-stage, solid-propellant rocket capable of lifting 100 lbs. to about 200 miles. NASA has not used the Iris rocket since 1962.