CAPRICE (Cosmic AntiParticle Ring Imaging Cherenkov)

Balloon launched on: 8/8/1994 at 12:26 utc
Launch site: Lynn Lake Airport, Manitoba, Canada  
Balloon launched by: National Scientific Balloon Facility (NSBF)
Balloon manufacturer/size/composition: Zero Pressure Balloon SF3-459.37-080-NSXCHR-ST
Balloon serial number: W39.57-2-06
Flight identification number: 384N
End of flight (L for landing time, W for last contact, otherwise termination time): 8/9/1994 at 15:03 utc
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): 23 h
Landing site: 150 km N of Peace River, Alberta, Canada

The CAPRICE experiment was launched from Lynn Lake Airport in Manitoba, Canada at 7.28 local time on the morning of August 8, 1994. After a nominal ascent phase it reached a float altitude about 38.2 km at 11:07. Once at float altitude, the balloon started to move in a westerly direction with a velocity of 10-18 m/s. The position of the payload was monitored during the whole flight by the NSBF using the Global Positional System (GPS). The GPS instrument gave information on the altitude as well as of the latitudinal and longitudinal position. The GPS data was used both to track the payload and to predict possible landing places. In the figure above can be seen the altitude curve as a function of time. The flight altitude dropped during the flight from 38.2 km to 36.3 km.

As long as the payload was in range of the telemetry, commands could be sent directly to the payload and the payload could send data to the ground. When the payload after 18 hours flight got out of range, the control was taken over by a relay station at Ft. Mc Murray, Saskatchewan. At this point, communication from the payload was limited to engineering data but commands could still be sent up to it. Data taking was terminated and all detectors switched off on August 9, 1994 at 8.00 when the payload was running out of battery power. Approximately one hour later the magnet was discharged and at 9.10 the payload was switched off. At this stage the NSBF had full control of the payload and landing preparations started. One hour later, the balloon was detached and the gondola landed by parachute at 11.15, 150 km north of Peace River.

• CAPRICE website University of Siegen, Germany (via Archive.Org)
• A Measurement of the Antiproton and Proton Fluxes in Cosmic Rays using the CAPRICE Experiment Thesis by Niclas Weber PhD TU Stockholm (1997)
• A Measurement of the Proton Spectrum at 1 AU Near Solar Minimum with the Caprice Experiment Proceedings of the 25th International Cosmic Ray Conference 1997, Vol. 3, p.369
• A Measurement of the µ+/µ- Ratio at the Top of the Atmosphere with the CAPRICE Experiment Proceedings of the 25th International Cosmic Ray Conference 1997, Vol. 3, p.317
• CAPRICE website Royal Institute of Technology, Sweden (via Archive.Org)
• Measurements of primary cosmic-ray hydrogen and helium by the WiZard collaboration Advances in Space Research,Volume 27, Issue 4, 2001, Pag. 755
• NASA Balloon Flights (1989-1998) in NASA Historical Data Book, Vol. VII: NASA Launch Systems, Space Transportation, Human Spaceflight, and Space Science, 1989-1998
• Performance of the CAPRICE RICH detector during the 1994 balloon flight Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume 371, Issues 1-2, 1 March 1996, Pag. 169
• Positrons and electrons in the cosmic radiation measured by the CAPRICE94 experiment Mirko Boezio, PhD thesis, Royal Institute of Technology, Stockhom, Sweden (1998)
• The Antiproton flux near Solar Minimum Measured with the Caprice Experiment 25th International Cosmic Ray Conference, 1997, Vol. 4, p.217
• The CAPRICE RICH Detector 24th International Cosmic Ray Conference, Vol. 3, p.657 (1995)
• The cosmic ray positron to electron ratio in the energy range 0.85 to 14GeV Astronomy and Astrophysics, v.309, p.L15
• The Cosmic-Ray Antiproton Flux between 0.62 and 3.19 GeV Measured Near Solar Minimum Activity ApJ 487 415 (1997)
• The WiZard/CAPRICE Silicon-Tungsten Calorimeter 24th International Cosmic Ray Conference, Vol. 3, p. 661
• The WiZard/CAPRICE silicon-tungsten calorimeter Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 370, Issues 2-3, 1996, Pag. 403