Argo sounding rockets measured radiation caused by the Project Argus high altitude nuclear explosions. The missiles reached 800 km altitude, launched from Wallops Island, AMR, and Ramey AFB, Puerto Rico.

• Argo rocket flights.

  In 3-week period, 19 five-stage Argo E5 sounding rockets were launched in USAF-NACA program to measure radiation caused by Project Argus, rockets reaching 500-mile altitude and were launched from Wallops Island, AMR, and Ramey AFB, Puerto Rico.

• First Argo D4.

  Four-stage Argo D4 rocket with an ARDC Javelin payload fired from Wallops Island to an altitude of 750 miles, first in a series of USAF-NASA launchings to measure natural radiation surrounding the earth.

• Argo D-4 launched.

  NASA Argo D-4 rocket was launched from Wallops, reaching an altitude of 585 miles and landing 817 miles out in the Atlantic, to gather data on the density of electrically charged helium atoms in the upper atmosphere.

• 17 - Emme, Eugene M, Aeronautics and Astronautics: An American Chronology of Science and Technology in the Exploration of Space 1915-1960, NASA, 1961. HTML when accessed: http://www.hq.nasa.gov/office/pao/History/timeline.html