The team of University of Brasilia (UnB) was pioneer in the study of hybrid rockets in Brazil. The research has started as early as 2000 with the development of a 800N Hybrid propulsion motor based in gaseous oxygen and polyethylene combustion pair. This motor was build with a 9 combustion ports, holes in the fuel block or grain, and was used in several studies of propellant’s specific impulse and specific mass.

Due to high explosion hazard associated with oxygen and the fact that gaseous oxygen occupies much volume, making it impossible to be used in flight rockets, and liquid oxigen should be maintained at extremely low temperatures, the UnB’s Hybrid Team turned to another oxidizer, nitrous oxide (N2O). The nitrous oxide can be liquified in ambient temperature, is not harmful to humans and is available in the market as a medical gas. Also the nitrous oxide possesses self-pressurization capabilities making unnecessary heavy and complex pumps or pressurization subsystems.

In order to increase the low regression rate, the speed in witch the solid fuel burns and increases the diameter of the combustion port, of the polyethylene found in the previously tests, the Hybrid team focused in different new propellants with significantly better rates. The chosen propellant was paraffin. The use of paraffin as a hybrid rocket fuel was proposed by a researcher in the University of Stanford (Dorhein, 2003) and the high regression rates of the paraffin solved one of the main disadvantages of hybrid rockets. Paraffin based rockets promise to revolutionize the rocket industry for they made possible for the first time to combine the simplicity of hybrid rocket with the high thrust demanded by space missions.

With the large experience acquired in the test bench the launch of small sounding rockets began in 2005 with the launches of the LILE 1 and LILE 2 the firsts hybrid rockets ever launched in Brazil. These rockets were launched from a farm near Brasilia but they had no telemetry system and it is impossible to estimate the apogee of the trajectory. But those rockets were yet too small, the next step would be a giant leap for Brazilian hybrid rocket engineering.

LILE Rocket after Launch

The year is 2005 and The Santos Dumont sounding rocket program begins, a program to develop large aluminum hybrid rockets capable of reaching altitudes as high as 8 km an possessing computer controlled telemetry and parachute recovery systems. The program was divided in to two stages the development of the SD-1 and the SD-2, the first one being a 500N rocket and the second one a 1500N rocket. Not only the rockets were developed, a test bench apparatus was constructed to test the rocket’s motors before launch. The SD-1 motor was constructed and tested several times with everything set the 2 launches were successively done and the development of the SD-2 could begin.

In 2006 the tests in the SD-2 class motor had began and the motor was fired more than 30 times in horizontal and vertical positions. In 2008 group of students from The Hybrid team went to São José dos compos with the mission to validate aerodynamic profile of the SD-2 rocket in the Brazilian Aeronautics and Space Institute. Several improvements were made in the rocket with the knowledge gained in this short period. The improved SD-2b motor is currently under qualification tests and the first launch will occur soon after.

Some Hybrid Team’s members Prior to SD-1 Launch

SD-2 and SD-2b

Parallel to the Santos Dumont rocket program a advanced test benches program was developed, this program was aimed in developing versatility rocket test benches capable of generating good experimental material for propulsion studies. The first bench employed in the program was a refurbished INPE (National Institute of Space Studies) bench that a group a UnB students operated in one of the greatest rocket test campaigns ever made in Brazil with more than 50 test fires made in a month. With the knowledge gained in the INPE campaign a new versatile test bench was design by the Hybrid Team. The new bench was designed for a modular operation in a way that new experiments could easily be adapted and realized. The modular test bench has being used in experiments as diverse as; thrust modulation, bio-parafin research, nozzle refrigeration and combustion instability characterization. The test bench operated in UnB is currently the most active experimental rocket facility in Brazil making an average of 30 test fires a year.

Rocket test fire in INPE

The Modular test Bench

Currently the Hybrid Team and it’s members are working in several research lines like; bio rocket fuel, ceramic coated nozzles, autonomous aircraft, electric propulsion, trajectory prediction and optimization, aerodynamic simulation and multidisciplinary rocket design optimization. The UnB’s Hybrid Team in the contest of the Aerospace Initiative is working in the development of skilled manpower for several Brazilian space related initiatives such the Brazilian-Ucranian joint venture Alcantara Cyclone Space and the Formosa Rocket Launch Field. Currently 10 engineer are being trained to by the Hybrid Team and The LARA laboratory to work for ACS in a aerospace an masters program. Those professionals will be among the first technical staff of the new company and will directly work in the 2012 Cyclone-4 launch in Alcantara-MA. Professionals trained in the Hybrid Team of the are occupying positions in the Brazilian Space Agency (AEB), Ministry of Education (MEC), University of Brasilia and ENSMA.

Computationally optimized rocket motors

The Hybrid Team’s N-prize division aims to continue this tradition of excellence in aerospace engineering developing a rocket capable of wining the N-prize. This rocket could be the first Brazilian designed rocket ever to insert a satellite in orbit and also the first full hybrid launch vehicle to do so. The N-prize vehicle will combine the best technology available in hybrid rockets motors and rocket design in a multidisciplinary optimization approach to develop the best rocket possible with in budget constraints.

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