DVIDS – News – NPS Students Tackle Key Challenges of the Mobile CubeSat Network

Four students from the Naval Postgraduate School (NPS), representing the Navy and the Army, conducted a dissertation study to improve and review unique aspects of the Mobile CubeSat (MC3) management and control network, a network of ground stations run by the Ministry of Defense (DOD) providing a common infrastructure for small satellite research.

Nearly 10 years old, MC3 has become a multinational network and was conceived as a means of bringing together organizations that have developed their own CubeSat programs with a single community approach that focuses on a standard infrastructure that many governments could use over time. the weather. The NPS Space Systems Academic Group was eavesdropped on to build, maintain and operate the network, given its strengths in CubeSat-related activities and its focus on practical military education.

The network has eight active sites, with nine under construction, located in military, educational and commercial institutions. The network allows for a low-cost, rapid development environment in which satellite and terrestrial infrastructure technology can evolve without the weight of potential impact on high-value missions that are crucial to national security.

The growth of the network and its capabilities are commensurate with the challenges posed by its expansion. The four students strive to turn the challenges of growth in opportunities with their respective diploma projects, focused on autonomy within systems, to the integration of hardware and software.

“Students have contributed to a polished, reasonably range of capabilities that strengthen the network,” said Dr. Giovanni Minelli, a research fellow at the NPS Space Systems (SSAG) academic group. “Without our graduate students, who produce measurably useful results, small teams of lecturers and lecturers would not be able to pay the necessary attention to these new development efforts, given the work involved in keeping the network working for our users in orbit. . The dissertation often leads to interesting follow-up work that can be taken by a prospective student or can be directed to other groups around the Ministry of Science. “

US Army Major Timothy Marczewski is integrating a series of environmental sensors capable of monitoring the ground station’s thermal, power, humidity, vibration and even acoustic environment, so that open source machine learning algorithms can be almost real-time. applied to determine a normal operational baseline. Any off-border reporting would help predict an imminent failure, thus allowing the operator to react faster and minimize downtime.

“This is a way to autonomously monitor these geographically dispersed ground stations,” Marchevski said. “The purpose here is to predict errors or errors that could cause a pass, referring to a satellite passing through the place where data communication between the ground station and that satellite does not occur, due to something we have not identified before this pass. to make it happen. “

Using the sensors, Marczewski looked at clusters of data about the time of day and temperature in the satellite dome of the ground station to get an idea of ​​what “normal” looks like and allows users to see if normal conditions deviate and address possible errors.

Remaining in the field of autonomy, another student’s thesis seeks to develop software that autonomously characterizes the sensitivity of the antenna to receive signals from space. The sun produces a significant amount of radio signals in the range used by MC3 stations. The developed algorithms can record the intensity of these readings and when compared to the baseline without the sun, they can extract the instantaneous sensitivity of the antenna. By repeating this process daily, degradation or sudden abnormalities can be identified autonomously. At present, these measurements are performed manually, only once or twice a year when staff are on site and performing maintenance.

As important as ground stations are to the MC3 network, in-orbit equipment can also make or disrupt the efficiency of the entire network. U.S. Navy Lt. Col. Alison Claybo used her thesis to test end-to-end compatibility between the MC3 ground station and the NPS-defined software-defined CubeSat (SDR) radio, a payload designed and constructed through previous research on the dissertation. The study, conducted in her study, aims to find the necessary parameters and related software configurations to achieve interoperability between the payload SDR and commercial SDR receivers in the NPS MC3 ground station.

“XR-band SDRs offer attractive features such as higher bandwidth, higher data rates, advanced modulation schemes and increased resistance to environmental interference, such as attenuation,” said Claybo. “The proven form factor CubeSat leads to increasingly ambitious payloads and mission requirements, leading to more data products and the subsequent need for higher data rates from space to earth. Through the MC3 X-band initiative and the CubeSat project, SSAG is developing an infrastructure that meets this emerging need of the small satellite community. “

Instead of focusing on one aspect of the overall network, US Navy Lt. Anastasia Novoselovablat is working to integrate hardware and software to simulate the entire communication path of the upcoming CubeSat mission. This communication path consists of ground-based software that drives the vehicle, the spacecraft itself with its communication system and payload, which is currently being developed in New Zealand. The test site, called FlatSatNet, is able to connect to the payload in New Zealand by NPS to give mission software developers a chance to develop software interfaces before the flight load is sent to the NPS for satellite integration.

“This helps reduce the risk to the mission and sets a precedent that concurrent development can occur in the oceans to maximize cooperation between Allied government small-scale satellite programs,” Minnelli said. “The FlatSatNet concept allows us to test the entire communication architecture of the mission, including components developed internationally, before launching the satellite into orbit.”

Because space missions have some degree of uncertainty about them, Minnelli also noted SSAG scope projects so that students do not depend on the outcome of an experiment or mission that is beyond their control. In this way, they ensure that these types of results are the “icing on the cake” on an otherwise strong theoretical or experimental topic.

“I believe that the practical, comprehensive, project-oriented education we receive in the NPS space systems curriculum is one of the most first-class space education out there,” Claybo added. “The support I received from my dissertation advisors, as well as instruction and interaction with experienced professors – this is really special and will set me up for my next tour, as well as for my future career in space.”