Purpose of the flight and payload description

MIFRASO was a hard X-Ray telescope. The name's acronym came from the three institutions involved in the development (MIlan, FRAscati and SOuthampton).

The main detection system is composed of eight independent scintillation counters, each consisting of a primary NaI(T1) crystal (200 x 200 x 6 mm 3) actively shielded by a 5 cm thick NaI(T1) crystal of the same area. The eight detectors were arranged in two sets of four. A thin plastic scintillator, used for the rejection of the direct effects of charge particle interactions shielded each set of the four counters.

The aperture of the X-ray telescope was collimated by copper slats to 2º fwhm. A passive graded shield consisting of 2 mm Pb, 2 mm Sn and 1 mm Cu surrounded the collimators and the sides of the crystals.

A completely unshielded crystal, identical to the primary X-ray detection scintillator, was incorporated on the payload in order to provide experimental data on the quality of the various shielding systems. This detector was fitted to the end of a 2 m long boom so as to minimise the effects due to the mass of the main telescope.

Details of the balloon flight

Balloon launched on: 6/5/1982 at 00:44 utc
Launch site: Columbia Scientific Balloon Facility, Palestine, Texas, US  
Balloon launched by: National Scientific Balloon Facility (NSBF)
Balloon manufacturer/size/composition: Zero Pressure Balloon Winzen 969.857 cuft (17.78 microns. Stratofilm) / SF-447.84-070-NSCR-01
Balloon serial number: W34.25-3-01
Flight identification number: 1289P
End of flight (L for landing time, W for last contact, otherwise termination time): 6/5/1982 at 13:23 utc
Balloon flight duration (F: time at float only, otherwise total flight time in d:days / h:hours or m:minutes - ): F 14 h 50 m
Landing site: 19 miles NE of Midland, Texas, US
Payload weight: 2279 kgs

External references

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