PPB (Polar Patrol Balloon) - Test flight

This was the third Polar Patrol Balloon (PPB) test flight carried out at Syowa Station, Antarctica to obtain the data of stratospheric radiation environments and to test the PPB systems. The payload consisted of an auto-ballast controlling system, an ARGOS/NOAA positioning/data transfer system, a thermometer, a barometer, telemetry and command receiver. The balloon was launched on January 5 1990. The initial ceiling height was about 32 km and the threshold altitude of the auto-ballast release was set to be 27 km. On the 3rd day of flight, the PPB started to drop the ballast. During 4th day to 8th day the ballast consumption a day was about 1% of the total weight of PPB. However, after 9th day the consumption increased to 5 to 7% due to the local sunsets at the balloon altitude. The ballast was completely consumed on 20 Jan and then the PPB gradually decreased its altitude; finally down to 25 km in the daytime and 15 km in the night time. On 27 Jan when the PPB reached about seven eighth of the circumpolar circle, the zonal wind almost stopped and then turned its direction from easterly to westerly. This succesful flight convinced the scientific team that the PPB could make a complete circumpolar flight, provided that it could be launched before getting a local sunset.

Balloon launched on: 1/5/1990 at 8:00 utc
Launch site: Syowa Station, Antarctica  
Balloon launched by: National Institute of Polar Research (NIPR) / Institute of Space and Astronautical Science (ISAS)
Balloon manufacturer/size/composition: Zero Pressure Balloon 1.500 m3
End of flight (L for landing time, W for last contact, otherwise termination time): 2/??/1990
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): 28 d

• Polar patrol balloon project in Japan Advances in Space Research Volume 14, Issue 2, Pag.201