The ability to facilitate communication between space vehicles and terrestrial bodies has always been a primary function of satellites. And with the onset of a new space race, where governments, public organizations and private companies from all over the world are now deploying satellites, less expensive and faster means of getting into space have emerged.
Nanosatellites, which are far smaller versions of traditional satellites, mark a major technological advance addressing the cost and time issues that affect space deployment. To date, CubeSats are the most researched and utilized nanosatellites. As deployments of these standardized architecture satellites continue to increase, an understanding of how the devices are used and the best practices for designing CubeSat communication systems is necessary to stay competitive with other aerospace developers.
Uses and Applications of CubeSats
As the figure above illustrates, the number of CubeSat units launched into space now exceeds 3500. And the trend is likely to accelerate. Most of these spacecraft are intended for remote sensing and, of course, communications. However, CubeSats have also been used for applications that include the following: weather sentinels, folding and collapsable telescopes, autoinspection, refueling, thin solar cells and even interplanetary exploration. As the CubeSat technology advances, applications of these devices will undoubtedly continue to expand as well.
CubeSat Communications Operational Challenges
Similar to other satellites and spacecraft, effective communication system operation is critical for any successful CubeSat mission. As CubeSats are smaller, they can utilize more compact and lower powers for external communications. However, this comes at a price; transmission distance is reduced when compared with higher-powered transmitters. Likewise, tumbling presents another concern for the device as it orbits. Effects can include reduced transmission windows for sending or receiving data from a specific location. In addition to these technological issues, there are common challenges for the PCBAs and electronics developed to operate aboard these space systems.
CubeSat PCBA Development Challenges
- Thermal extremes
One pressing concern for any system launched into space is temperature, including the extremely high temperatures generated by rocket engines during launch, as well as the vast swings in temperature that occur at various altitudes above the earth. As electronics and circuit boards are vulnerable to excessive heat and cold, it is critical to maintain PCBAs within thermal operational tolerance levels.
Radiation is also a problem to address when designing and building CubeSats. Although spacecraft skin materials can mitigate the effects of some forms of radiation, certain particles, such as galactic cosmic rays (GCRs), high-energy radiation and radiation belt particles, can cause erratic behavior or damage CubeSat communication systems.
- Optimizing Size, Weight and Power (SWaP)
CubeSats are often chosen to minimize costs and reduce development and deployment times. By designing small, lightweight boards that use less power, manufacturers are meeting these objectives.
Companies can successfully meet these challenges by following a set of implementable guidelines based on design and manufacturing principles for aerospace communications, as discussed below.
The Engineer's Guide to PCBA Manufacturing Complexity
Guidelines for Developing Efficient CubeSat Communication Systems
Space—along with automotive systems and industrial facilities—is one of the most extreme environments in which electronics and PCBAs are deployed. However, aerospace PCBAs cannot typically be repaired or replaced, putting even greater responsibility on development and production.
Essentials for CubeSat Communication System PCBAs
- Utilize MMICs
Experienced aerospace entities, such as NASA, are pursuing optical monolithic microwave integrated circuits (MMICs) instead of discrete components. The reasons for this choice include their smaller size, precise component manufacturing, high-speed signal propagation and lower costs—all of which work toward optimizing the SWaP of your development.
- Use temperature and moisture resistant components
Aerospace systems, including CubeSats, utilize a thermal control system (TCS) to regulate internal temperatures. By selecting temperature and moisture resistant components, you can further mitigate the threat of heat and moisture to the operation of internal systems.
- Ensure a secure supply chain
As maintenance aboard CubeSats is not an option, your boards must contain high-quality components, not counterfeits or other inferior elements.
- Make boards and components rad-hard
Although it can be expensive to add radiation hardening to your development, the benefits cannot be overstated. Practicing redundancy and using previously tested and verified components can help mitigate the costs.
- Adhere to all pertinent regulations and standards
The aerospace industry is highly regulated, and several manufacturing standards may apply when building your boards. Working with an experienced aerospace CM will help ensure your CubeSat development complies.
- Employ adequate testing
Testing regimens are routinely performed on aerospace boards to ensure their reliability in space. At times, these tests include destructive methods such as Highly Accelerated Life Testing (HALT) and Destructive Physical Analysis (DPA). Although these tests create waste and unusable boards, they ensure that only the highest quality, reliable PCBAs are produced for space applications.
- Only work with a certified manufacturer
Perhaps the most important step you can take when building boards for CubeSat communication systems is to ensure your CM is certified for aerospace systems. By engaging with the right CM early on, you can avoid the pitfalls that may result in increased time and costs to bring up your board to the standards required for aerospace systems.
|Tempo's Custom Avionics for PCB Manufacturing Service
Tempo Automation is the industry leader for fast, accurate PCBA manufacturing for prototyping and low-volume production. We have experience building systems for the toughest space environments, including Mars. We will bring this experience and expertise to your aerospace project to ensure that your boards rise to the level demanded for deployment aboard spacecraft.
And to help you get started on the best path, we furnish information for your DFM checks and enable you to easily view and download DRC files. If you’re an Altium Designer or Cadence Allegro user, you can simply add these files to your PCB design software. For Mentor Pads or other design packages, we furnish DRC information in other CAD formats and Excel.