The Rise of Mexican Nanosatellite Innovation

The researcher at the Institute of Geography of the National Autonomous University of Mexico, Jorge Prado Molina, together with his team of students, develops innovative low-cost technology in the space area for nanosatellites.

The coordinator of the National Earth Observation Laboratory in that academic entity, who in the last year obtained three patent titles in that area granted by the Mexican Institute of Industrial Property, stated in an interview that nanosatellites represent a niche opportunity. So that emerging countries, like ours, reach space; However, “we are not taking advantage of it.”

The cost of these devices, currently used for remote sensing, telecommunications or to carry out component testing or scientific experiments, for example, is low. Practical cases where constellations of small satellites can obtain images of the Earth with high resolution (three meters) and daily coverage or provide internet services are a reality today.

We must begin to generate our own technology, since we currently buy satellite images, when we could manufacture our instruments with the collaboration of groups at UNAM and other higher education institutions dedicated to satellite development. “We must avoid the dependency that we have been carrying and that must be broken at some point. We propose that it be now,” he suggested.

Innovations

The scientist, together with the students of the Faculty of Engineering Humberto Hernández Arias, Juan Alejandro Reyes González, Jorge Prado Morales and Julio César Balanzá Ramagnoli, as well as the retired professor of the Popular Autonomous University of the State of Puebla, Domingo Vera Mendoza, They have made inventions related to the techniques and principles used in the aerospace industry for the design and manufacture of satellites used for research and commercial uses.

They created a satellite simulator for nanosatellites with unrestricted movement in three axes; another system whose objective is to determine the center of mass of these devices and one more of mobile elements to readjust, in orbit, the center of mass of these devices.

Doctoral student Jorge Prado Morales explained that a nanosatellite has a mass of less than 10 kilograms; Currently there is a standard called Cubesat that allows them to be built more quickly, since some components, including subsystems, can be exchanged between different manufacturers.

And he recalled that at the beginning, these small satellites were used for training students (who cannot participate in large satellite missions worth billions of dollars), and today, thanks to the miniaturization of the components and the reduction in their costs of production, have acquired greater complexity and can carry out various missions, at a lower cost.

Likewise, he mentioned that there is an increase in the proportion of scientific articles linked to the space area that relate nanosatellites, regarding large missions. “By allowing the experimentation of concepts, nanosatellites represent, for companies and educational institutions, a platform for scientific and technological developments.”

Origin UNAM

Satellites, regardless of their size, must pass rigorous qualification tests to be accepted aboard the rocket launcher that will place them in orbit, and be reasonably certain that they will function once they are in the extreme conditions of the space environment.

The satellite simulator with unrestricted movement in three axes is directly linked to the ground operation tests, to ensure that the components of the orientation control system, such as sensors, actuators and on-board computer, are correctly connected and that the algorithms they work properly.

From the perspective of dynamical systems, the lack of friction is the most important characteristic that must be reproduced in the laboratory. The control and orientation tests require a simulator to verify the proper functioning, as well as the performance of all the components of this significant subsystem.

The sphere-shaped device, patented by the university team, allows the complete nanosatellite to be introduced, achieving unrestricted movement in three axes, that is, it allows it to float and rotate in a frictionless medium in 360 degrees, unlike other simulators where the turning is limited to a certain angle. “With the device we can simulate that the satellite is in space and check the correct functioning of the orientation determination and control system.”

The team also patented a system that determines the center of mass of nanosatellites, which is essential to know at the time of launch to balance the rocket and to improve the performance of the orientation control system in orbit. The academic pointed out the complication of determining this parameter: “Inside the satellite there are cables, connectors and different elements with irregular geometry and mass distribution, which make it difficult to obtain the center of mass analytically, through computer-assisted systems or by other methods.”

The tool presented substantially facilitates this task that is conventionally carried out, for example, by hanging the satellite from several edges, projecting a laser that intercepts the faces of the satellite, its position is compiled and after solving a system of equations, the center of mass of the object.

The university students proposed placing the nanosatellite on a platform that floats by injecting air, using a principle: if the center of mass of the device corresponds to the geometric center of the platform, the horizontal is obtained. When there is a deviation from the center of mass, the platform tends to tilt to one side.

In that case, it is compensated by placing small counterweights of known mass at a certain distance; “By knowing the location of the counterweights once the horizontal is achieved, we can determine the deviation of the center of mass regarding the geometric center.” It is similar to a scale or balance that reaches equilibrium.

This technological advance has numerous advantages for the development of small satellites, in addition to drones, since it enables rapid rearrangement of the components of said aircraft, added Prado Morales.

Finally, a system of moving elements was obtained to readjust the center of mass of the nanosatellites in orbit, whose main advantage is energy savings once in space, up to 30 percent. “If the center of mass is not located at its geometric center, the satellite loses its pointing due to interaction with the space environment; then we must activate its actuators through the control system, and return it to the desired position. The proposed procedure places the center of mass in the geometric center, thus reducing control maneuvers and, therefore, increasing the life of the satellite batteries,” he specified.

Patents are original ideas, innovations that no one has made, which is why it is a great merit that these proposals are developed, even with reduced budgets. It is necessary to further promote a national policy that gives technology the importance it has, in addition to increasing communication and rapprochement between industry and universities, said Prado Molina.

Those obtained by university students are related to some aspects linked to the development of spatial projects; They are property of the UNAM and a technology transfer can be carried out to companies or institutions, as has happened with satellite simulators developed by university students at the Vietnam National Satellite Center, for example.