Magnetic field, solar flare data.

Typical orbit: 523 km x 857 km at 50 degrees inclination. Mass: 41 kg (90 lb). Associated Launch Vehicle: Juno II.

• 1959 July 16 - Explorer S-1 - Program: Explorer. Launch Site: Cape Canaveral. Launch Vehicle: Jupiter. FAILURE: Control lost after 5.5 sec. Destroyed by range safety. Mass: 41 kg (90 lb).

• 1959 October 13 - Explorer 7 - Program: Explorer. Launch Site: Cape Canaveral. Launch Vehicle: Jupiter. Mass: 42 kg (92 lb). Perigee: 523 km (324 mi). Apogee: 857 km (532 mi). Inclination: 50.30 deg. Period: 98.60 min.

  Spacecraft engaged in research and exploration of the upper atmosphere or outer space. Returned magnetic field and solar flare data.

• USAF Satellite Database, USAF Institute of Technology, 1995. Accessed at: ftp://archive.afit.af.mil/pub/space/.

• McDowell, Jonathan, Jonathan's Space Home Page, Harvard University, 1997-present. Jonathan McDowell's complete on-line listing of all objects orbited and over 20,000 rocket launches Accessed at: http://www.planet4589.org/jsr.html.

• Krebs, Gunter, Gunter's Space Page, University of Frankfurt, 1996. Accessed at: http://www.skyrocket.de/space.

• JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Accessed at: http://msl.jpl.nasa.gov/home.html.

• Bramscher, Robert G, Spaceflight, "A Survey of Launch Vehicle Failures", 1980, Volume 22, page 351.

• NASA Report, Micrometeorite penetration experiment on explorer vii satellite - 1959 iota , . Accessed at: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19630004552_1963004552.pdf. -right click to download pdfs!