Description of the payload

A balloon-borne gamma-ray experiment, which is an instrument designed to obtain images of cosmic sources.

The MASCO experiment employs a Modified Uniformly Redundant Array coded mask (hence her name) and a NaI(Tl) position sensitive detector.

More than simply an instrument MASCO, has been one of the most important astronomy and astrophysics projects developed in Brazil of the last decade.

In addition to the development of the system of obtaining of images, it was necessary also to develop an automatic system that during the flight, pointed the telescope towards the target objective. This attitude control system was designed to provide a few arcminutes pointing and stabilization for a ~ 2,000 kg, 7-m high, 2-m wide, 2-m deep gondola that encompasses the telescope and its associated electronics.

Details of the balloon flight and scientific outcome

Launch site: Nova Ponte Airfield, Minas Gerais, Brazil  
Balloon launched by: Instituto Nacional de Pesquisas Espaciais (INPE)
Balloon manufacturer/size/composition: Zero Pressure Balloon Raven 1.200.000 m3
Payload weight: ~ 2000 kgs

The balloon was launched at 2:04 am on April 1st, 2004, from the air strip of the Nova Ponte airfield, a tiny city of the Minas Gerais state.

The craft was launched by dynamic method with the help of a crane acting as launch vehicle.

After a nominal ascent phase, the balloon achieved float altitude near 40 km of height and started a very slowly drift to the west.

At daybreak, started de telecomanded operation of the telescope and after near 11 hours of stable flight (half of the time flight expected) was sent the separation command. The payload parachuted to the ground and landed in a farm located near Capinópolis close to the border of the Goias state.

The balloon flown on this flight was the biggest one flown on all history of the brazilian scientific balloon program.

This flight had two main targets. In the technological side, essentially it was related to proving the pointing system and the mechanical system of the gondola, wich worked satisfactorily. In the scientific side it was tried to observe the sources of the Crab, of the region of the Center of the Galaxy and, depending on the development of the flight, the Great Cloud of Magallanes. This objective could not be completely fulfilled by troubles in the electronics of the system of data acquisition.

External references and bibliographical sources

Images of the mission

The MASCO telescope is hung up by a crane during a hang test in Nova Ponte Airport Start of the inflation of the very big balloon View of the balloon at float as seen using a telescope The gondola near landing MASCO's landing site