SPARK CHAMBER

The scientific purpose of this flight was to measure the energy spectrum and angular distribution of protons above 60 Mev and alpha particles above 240 Mev in the primary cosmic rays and cosmic ray albedo using a digital spark chamber and associated scintillation counters. The instrumentation was composed of four gaps containing two plates each, a plate being made up of 5-mil wires strung 16 to the inch on an insulating frame; adjacent plates were strung in mutually orthogonal directions. Each wire passed through a magnetic core which was flipped by the spark current, making it possible to examine the state of the core system of each plate electronically to determine the particle path. Planar plastic scintillators on each outside face of the spark gaps triggered the spark-chamber high voltage, and were also used to obtain particle energy information from pulse height analysis.

Balloon launched on: 7/9/1966
Launch site: Columbia Scientific Balloon Facility, Palestine, Texas, US  
Balloon launched by: National Center for Atmospheric Research (NCAR)
Balloon manufacturer/size/composition: Zero Pressure Balloon Raven 5.000.000 cuft (0.75 MIL. X-124)
Flight identification number: 227P
End of flight (L for landing time, W for last contact, otherwise termination time): 7/9/1966
Landing site: Aborted flight at launch
Payload weight: 613 kgs

The launch attempt was unsuccessful in that the payload failed to release properly. The problem was traced to a faulty switch in the release device that prevented the opening of arms on the launch vehicle. Balloon was destroyed to avoid damage to the gondola. The same experiment was launched succesfully on July 10.

• Balloon Flight Record Facilities for Atmospheric Research Nº 2, Winter 1966/67
• Jet Propulsion Laboratory Annual Report 1966 p. 24-25  
• NCAR Scientific Balloon Facility Annual Report, 1966 National Center for Atmospheric Research, January 1967