Overview of Small Satellite Technology and Systems Design

Abstract

The key and ongoing challenge of small satellites has been to create new systems or capabilities that could accomplish key technical tasks or deliver services with reasonable reliability and proficiency, but within smaller parameters of mass, volume, and, in many cases, cost as well. In other cases there have been focused efforts to find alternative technologies, systems, or components that could approximate the function of larger systems or technologies, but which would allow a significant mass, volume, and/or cost reduction. However, communication, surveillance, and other missions will require relatively large constellations of small satellites, whereas one or a few larger satellites would suffice. Large constellations increase collision risk and are more likely to experience failures even though individual members might be very reliable.

For many years the design of experimental or applications satellites has started with designing a spacecraft with the objective of accomplishing a specific task, mission, or targeted objective. This led to the second step where system design engineers proceeded to design the spacecraft that had the capability in terms of lifetime, reliability, pointing ability, power system, antennas, onboard processing equipment and software, sensors, antennas, or payload equipment to carry out the mission and then arrange for a launch vehicle.

Engineers exercised an abundance of caution with large safety factors and space qualified components with exceptionally high reliability. This led to satellites regularly exceeding design lifetime by factors of two or three. Engineers learned that they need not have been so highly conservative. Missions with durations of only a few years could use off-the-shelf components and less demanding reliability. This experience facilitated smaller satellites.

Developers of small satellites have often approach the design activity as if it were a strategic planning process, taking a specified constraint of mass and volume and seeing how much operational or research capability could be fitted into these limitations and then redesigning the new system to enhance its service or experimental output. This type of thinking has in many ways has helped to create the so-called world of “NewSpace” or “Space 2.0” and being able to do more and more with less and less. This has produced remarkable improvements in productivity and has enhanced technical design.

There are many innovations that now making small satellite industries thrive. These include new manufacturing techniques such as additive manufacturing, new cost-effective launch systems, and new user devices on the ground such as flat panel antennas, whose costs are now reducing. This chapter, however, seeks to provide an overview the new technology and systems associated with the design of small satellites themselves.

This overview chapter thus seeks to give some insight into the progress that is being made into the better design and more effective use of small satellite structures, power systems, antenna, sensors, stabilization, and pointing systems as well as the other key components, systems, and subsystems critical to small satellites’ successful operation. These innovative designs are important to the success of all types of small satellites that range from CubeSats and smaller on one hand plus the microsats and minisats that are key to deployment of the new large-scale commercial constellations. Innovations that apply to one type of small satellite can and often do apply to other types as well.

Finally this section addresses not only technical advances that relate to small satellites as free flyers in space but two other innovations that may become increasingly important in the future. Thus innovations related to hosted payloads that can fly on other satellites – large or small – represent another type of “small satellite.” These are also addressed as well as high-altitude platforms (HAPs) that can serve the same function as a small satellite for an island country or in a constellation can provide services akin to that of a satellite.