Explorer 2

Infobox_Spacecraft
Name = Explorer 2


Organization = Army Ballistic Missile Agency
Major_Contractors = Jet Propulsion Laboratory
Mission_Type = Earth science
Satellite_Of = Earth
Launch = March 5, 1958 at 18:28 UTC
Launch_Vehicle = Jupiter-C
Mission_Duration = 0 days
NSSDC_ID = EXPLR2
Webpage = [http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=EXPLR2 NASA NSSDC Master Catalog]
Mass = 14.52 kg (31.36 lb) [ cite web
url = http://history.nasa.gov/sputnik/expinfo.html
title = Data Sheet - Explorer Information
accessdate = 2008-02-02
publisher = Department of Astronautics, National Air and Space Museum, Smithsonian Institution ]

Explorer 2 (EXPLR2) was to be a repeat of the Explorer 1 mission. However, due to a failure in the rocket during launch, the spacecraft did not reach orbit.

Explorer 2 was launched from Cape Canaveral Air Force Station (now Kennedy Space Center) LC-26a in Florida on March 5, 1958 at 18:28 UTC, by a Jupiter-C launch vehicle.cite web
url = http://www.planet4589.org/space/lvdb/launch/Redstone
title = Launch Vehicle Database - Redstone
accessdate = 2008-02-03
publisher = JSR] The Jupiter-C has its origins in the United States Army's Project Orbiter in 1954. The project was canceled in 1955, when the decision was made to proceed with Project Vanguard.

Following the launch of the Soviet Sputnik 1 on October 4, 1957, the Army Ballistic Missile Agency (ABMA) was directed to proceed with the launching of a satellite using the Jupiter-C, which had already been flight-tested in nose-cone re-entry tests for the Jupiter IRBM (intermediate-range ballistic missile). Working closely together, ABMA and Jet Propulsion Laboratory (JPL) completed the job of modifying the Jupiter-C and building the Explorer 1 in 84 days.

Spacecraft design

Explorer 2 was equipped with a Geiger counter for the purposes of detecting cosmic rays. After Explorer 3, it was decided that the original Geiger counter had been overwhelmed by strong radiation coming from a belt of charged particles trapped in space by the Earth's magnetic field (see: Van Allen radiation belt). Explorer 2 was also equipped with a wire grid array and an acoustic detector for the purpose of micrometeorite detection.

Mission results

Due to a malfunction in the Jupiter-C launch vehicle, the fourth stage did not ignite. [cite web
url = http://msl.jpl.nasa.gov/Programs/explorer.html
title = Mission and Spacecraft Library - Explorer Program
accessdate = 2008-02-02
publisher = Jet Propulsion Laboratory] Subsequently Explorer 2 did not reach orbit.

References