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Aerospace engineering

A Brazilian satellite

The Amazonia 1, developed in Brazil, will monitor natural resources and help fight deforestation

Amazonia 1 prototype served to demonstrate that its components can withstand the extreme temperatures in space

Léo RamosAmazonia 1 prototype served to demonstrate that its components can withstand the extreme temperatures in spaceLéo Ramos

If all goes as planned, in 2018 Brazil will launch the first mid-size satellite fully designed and built within its borders.   Called Amazonia 1, it was developed in the laboratories of the National Institute for Space Research (INPE) and its mission will be to monitor Brazil’s natural resources. It is an Earth-monitoring satellite, the first based on a multi-mission platform—a generic structure developed by INPE to manufacture 500 kg-class satellites. The Amazonia 1 will be launched into a 750 km orbit and will pass over Brazil every five days. Equipped with a camera capable of capturing images with a width of 850 km, the satellite will help monitor deforestation of the Amazon Forest, predict agricultural harvests, monitor coastal regions and manage water resources. “The Amazonia 1 is the first highly complex satellite designed, assembled and tested in Brazil,” says Adenilson Roberto da Silva, the INPE researcher responsible for satellites based on the multi-mission platform. “With it, we, like several other countries, will have complete control over the development of three-axis-stabilized satellites.” Devices with this feature can change their position and orientation with respect to Earth while in orbit, which allows them to better focus on their targets. R$183 million have already been spent to develop the satellite, and another approximately R$50 million will be needed to complete the project, for a total of R$233 million. This sum refers not only to the cost of the satellite, but also to development of systems and equipment. “A second satellite will cost only about half this amount,” says Silva. “I am optimistic that, after this satellite, we will not only be able to satisfy domestic demand, but also export, like the Brazilian aeronautical industry does,” says Leonel Perondi, director of INPE. The Amazonia 1 is part of the National Space Activities Program (PNAE), managed by the Brazilian Space Agency (AEB).

In December 2015, INPE successfully concluded the satellite’s heat tests, an important stage in development when the equipment is subjected to the conditions it will face in orbit. “In space, the satellite will be subject to space radiation and extreme temperatures. The most exposed parts will face temperatures of about -80ºC during the night and +80ºC during the day,” states Silva.

Before this battery of tests, carried out in the INPE Integration and Test Laboratory in São José dos Campos, São Paulo State, the Amazonia 1 had already passed other tests. In late 2013, the structural mock-up—a sort of replica of the satellite itself—underwent mechanical tests that simulated the vibration and acoustic conditions that it will be subject to during launch. Shortly afterwards, in early 2014, the thrusters to be used in the device were tested. Developed by the Brazilian company Fibraforte, also located in São José dos Campos, the six thrusters to be used on the satellite are essential to conducting the maneuvers needed to reach and maintain orbit in space.

The Amazonia 1 is the first satellite produced as part of the multi-mission platform designed by INPE

Léo RamosThe Amazonia 1 is the first satellite produced as part of the multi-mission platform designed by INPELéo Ramos

“Now that the heat mock-up has been validated, we are working on a new stage: integration and testing of the electrical mock-up, where we will check electrical compatibility and test the interfaces between all subsystems and equipment. These tests are scheduled for 2016,” explains Silva. Also planned for this year are the electromagnetic compatibility tests to demonstrate that all satellite subsystems are functioning perfectly, without generating undue interference. “If all goes well, we will begin integration and tests of the flight mock-up, scheduled for 2017. This is the last stage before completing the satellite,” explains Silva. INPE has not yet decided when the satellite will be launched, nor with which rocket, but the choice will be among the rockets available on the current international market, as Brazil does not yet have a rocket for this purpose. The satellite was designed to be compatible with a family of launchers, such as the Ukrainian Dnepr, the American Minotaur-C, and the European Vega, among others.

Classified as a remote-sensing satellite with a low-altitude polar orbit, the Amazon 1 will orbit the planet by passing over the two poles, coming from the North towards the South, and flying over Brazil during the day. It will always cross the Equator at 10:30 a.m. Orbiting at a speed of 7.5 kilometers per second, it will take 100 minutes to circle the earth. One important feature of the satellite is that it will fly over the same point on Earth every five days, in what is called the revisit period. For comparison purposes, the revisit period of the China-Brazil Earth Resources Satellites (CBERS), a series of satellites developed together with China, is 26 days. “The short revisit period of Amazonia 1 increases the likelihood of its camera capturing useful images,” explains Silva. The Amazonia 1 will have a camera with image resolution of 60 meters (m) by 60 m, while the CBERS-4 has several cameras, with the highest resolution being 5 m by 5 m.

Launch of the Amazonia 1 will be 25 years after that of the first entirely Brazilian satellite, named Data Collection Satellite 1 (SCD-1), in 1993. Five years later, in 1998, another satellite from the same family, SCD-2, was sent into orbit. These devices, still working, receive environmental information transmitted by data collection platforms installed in remote locations in Brazil and send it to INPE ground stations in Cuiabá, Mato Grosso State, and in Alcântara, Maranhão state. The data calculated (temperature, pressure, humidity, rainfall, etc.) are used for various purposes, such as weather prediction, studies related to ocean currents and tides, and agricultural planning.

There are large differences between the two satellites. The second weighed just 115 kg, about one fifth of that of the Amazonia 1, which is just over 500 kg. The satellite stabilization system is also different. The SCD family of satellites are stabilized in space by rotation and, when in orbit, act like a top, spinning around its axis. “The only control we have is over its speed of rotation. It is always pointing towards the same point in space and it would be impossible to reposition it to better monitor an environmental disaster,” explains Silva. The Amazonia 1, though, is stabilized along three axes, and its camera can be pointed in any direction in order to capture an image. The two satellites are also different in terms of orbit control. Since it does not have a propulsion subsystem, the SCD falls a few dozen meters closer to earth every year, whereas the Amazonia 1 will use thrusters developed by Fibraforte to maintain its orbit during its entire useful life of four years.

Antenna of the satellite that will be launched in 2018

Léo RamosAntenna of the satellite that will be launched in 2018Léo Ramos

National partners
The nationalization of the various components making up the Amazonia 1 is an important feature of the project. The Wide Field Imager (WFI) camera, responsible for capturing images of Brazil, was made by a consortium consisting of the companies Equatorial Sistemas, in São José dos Campos, and Opto Eletrônica, São Carlos, in upstate São Paulo. The imager’s objective lenses were developed by the two companies, while the signal-processing electronics, assembly, integration and subsystem tests were carried out by Equatorial. This same camera, with a few differences, is installed on CBERS-4.

Equatorial is also responsible for developing the satellite’s digital data recorder (DDR) and Omnisys, in São Bernardo do Campo, São Paulo State, will manufacture the remote terminal unit (RTU), which serves as the interface between the WFI camera and the on-board computer of the X-band data transmitter, which will send the images captured back to Earth, in addition to the transmitter antenna.  The voltage converter was ordered from AEL Sistemas, in Porto Alegre, Rio Grande do Sul State. The solar panels, which generate energy to power the satellite, were produced by Orbital.

The institute agreed to develop and finalize several subsystems, including heat control, power supply—incorporating the solar panels—and service telemetry and remote control. The latter two were developed in conjunction with Mectron, a company in São José dos Campos. The satellite’s structure is being built by Cenic Engenharia, also in São José dos Campos, while the altitude control and data processing subsystem was developed through a technology transfer agreement with the Argentinean company Invap. “When the Amazonia 1 development cycle is complete, we will have full control of the entire manufacturing chain of a satellite of this size, which will allow us to take on larger projects, for other applications,” says Silva. “We built up company competence so that they will be capable of designing and manufacturing space systems in Brazil,” concludes Perondi.

According to Pierre Kaufmann, professor at the Mackenzie Presbyterian University Engineering School in São Paulo and coordinator of the Mackenzie Radio-Astronomy and Astrophysics Center, construction of the Amazonia 1 is a justifiable undertaking, although it does not represent a technological leap in global terms, because other countries know how to manufacture satellites of this size and complexity.  “The Amazonia 1 does not represent an internationally competitive innovation, but it is important to us. Since the space industry is strategic, it is important for Brazil to have technological autonomy,” he says. Until now, stresses Kaufmann, Brazil has used remote sensing satellites purchased abroad or developed with partners, as was the case with CBERS. According to Professor José Leonardo Ferreira, of the University of Brasília Physics Institute, formerly of INPE and a former consultant to the Brazilian Space Agency (AEB), the Amazonia 1 represents another step towards technological independence in the space industry. “It is important to know how to develop space systems and have total autonomy with respect to their use and applications.”

Project
Development and qualification of a 5N mono-propellant satellite thruster (nº 2003/07755-5); Grant Mechanism Innovative Research in Small Businesses Program (PIPE); Principal Investigator Humberto Pontes Cardoso (Fibraforte); Investment R$399,026.25.