 The Viking made its final flight in 1955 | |
| Rockets | |
|---|---|
| Maiden flights |  Aerobee RTV-N-10c Aerobee RTV-N-10a Aerobee Hi Aerobee AJ10-27 Loki rockoon Deacon-Loki rockoon Nike-Deacon Nike-Nike-Tri-Deacon-T40 X-17 HJ-Nike R-1E R-5M |
| Retirements | Aerobee RTV-N-10a Aerobee AJ10-27 Deacon-Loki rockoon Nike-Nike-Tri-Deacon-T40 |
In 1955, both the United States and the Soviet Union (USSR) announced plans for launching the world's first satellites during the International Geophysical Year (IGY) of 1957–58. Project Vanguard, proposed by the US Navy, won out over the US Army's Project Orbiter as the satellite and rocket design to be flown in the IGY. Development of Intercontinental Ballistic Missiles, the Atlas by the US and the R-7 by the USSR, accelerated, entering the design and construction phase.
Both the US and USSR continued to launch a myriad of sounding rockets to probe the outer reaches of Earth's atmosphere and to take quick glimpses of the sun beyond the obscuring layers of air. The Aerobee Hi, first launched in April, promised a comparatively low cost alternative to other high altitude sounding rockets. The State University of Iowa meanwhile experimented with balloon-launched rockoons on its fourth expedition into the Atlantic Ocean.