Explorer 1 Credit - NASA

Discovered Van Allen radiation belts. Spacecraft engaged in research and exploration of the upper atmosphere or outer space.

Typical orbit: 266 x 2329 km, 33.3 deg inclinaton. Mass: 5.00 kg (11.00 lb). Associated Launch Vehicle: Jupiter C.

• 1954 June 25 - Project Orbiter begun. - Launch Vehicle: Redstone.

  In a meeting, Dr. Wernher von Braun, Frederick C. Durant III, Alexander Satin, David Young, Dr. Fred L. Whipple, Dr. S. Fred Singer, and Commander George W. Hoover agreed that a Redstone rocket with a Loki cluster as the second stage could launch a satellite into a 200-mile orbit without major new developments. This became a joint Army-Navy study project after meeting at Redstone Arsenal on August 3. Project Orbiter was a later outgrowth of this proposal and resulted in the launching of Explorer I on January 31, 1958.

• 1954 August 15 - Von Braun proposes launch of US satellite. - Program: Explorer. Launch Vehicle: Redstone.

  Von Braun report 'A Minimum Satellite Vehicle Based on Components Available from Developments of the Army Ordnance Corps' in response to June Pentagon meeting proposes $ 100,000 to launch satellite by Redstone.

• 1955 August 24 - Redstone recommended as satellite launcher. - Program: Explorer. Launch Vehicle: Redstone.

  Research and development Policy Council (DOD) unanimously recommended that the time-risk factor in the scientific satellite program be brought to the attention of the Secretary of the Defense for determination as to whether a Redstone backup program was indicated.

• 1957 October 5 - Von Braun promises first US satellite in 60 days. - Program: Explorer. Launch Vehicle: Redstone.

  Explorer 1 Pickering, Van Allen, and Von Braun hold a model of Explorer 1 in triumph at a post-flight press conference.... Credit- NASA

  Von Braun briefs Secretary of Defence McElroy on Jupiter-C/Redstone for immediate US satellite launch. Promises launch in 60 days. Medaris says 90.

• 1958 February 1 - Explorer 1 - Program: Explorer. Launch Site: Cape Canaveral. Launch Vehicle: Redstone. Mass: 5.00 kg (11.00 lb). Perigee: 347 km (215 mi). Apogee: 1,859 km (1,155 mi). Inclination: 33.20 deg. Period: 107.20 min.

  Explorer I, the first U.S. earth satellite, was launched by a modified Army Ballistic Missile Agency Jupiter-C. Explorer I, developed by the Jet Propulsion Laboratory, carried the U.S.-IGY (International Geophysical Year) experiment of James A. Van Allen and resulted in the discovery of the radiation belt around the earth.

• 1958 March 5 - Explorer 2 - Program: Explorer. Launch Site: Cape Canaveral. Launch Vehicle: Redstone. FAILURE: Fourth Stage failed to ignite. Mass: 5.00 kg (11.00 lb).

• 1958 March 26 - Explorer 3 - Program: Explorer. Launch Site: Cape Canaveral. Launch Vehicle: Redstone. Mass: 5.00 kg (11.00 lb). Perigee: 186 km (115 mi). Apogee: 2,799 km (1,739 mi). Inclination: 33.40 deg. Period: 115.70 min.

  Radiation, micrometeoroid data.

Bibliography:

Explorer 1 Lift-off of Explorer 1... Credit- NASA

• McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: http://www.planet4589.org/jsr.html.
• JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: http://msl.jpl.nasa.gov/home.html.
• Emme, Eugene M, Aeronautics and Astronautics: An American Chronology of Science and Technology in the Exploration of Space 1915-1960, NASA, 1961. Web Address when accessed: http://www.hq.nasa.gov/office/pao/History/timeline.html.
• Ordway, Frank, and Sharpe, Mitchell, The Rocket Team, Collector's Guide Publishing, Ontario, Canada, 2000.
• Bramscher, Robert G, Spaceflight, "A Survey of Launch Vehicle Failures", 1980, Volume 22, page 351.
• Grimwood, James M., Project Mercury: A Chronology, NASA Special Publication-4001.

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