Miles Space is proud to be included in NASA’s State of the Art Report for 2021.

When the first edition of NASA’s State-of-the-Art Small Spacecraft Technology report was published in 2013, 247 CubeSats and 105 other non-CubeSat small spacecraft under 50 kilograms (kg) had been launched worldwide, representing less than 2% of launched mass into orbit over multiple years. In 2013 alone, around 60% of the total spacecraft launched had a mass under 600 kg, and of those under 600 kg, 83% were under 200 kg and 37% were nanosatellites (1). Of the total 1,282 spacecraft launched in 2020, 94% were small spacecraft with an overall mass under 600 kg, and of those under 600 kg, 28% were under 200 kg, and 9% were nanosatellites (1). Since 2013, the fight heritage for small spacecraft has increased by over 30% and has become the primary source to space access for commercial, government, private, and academic institutions.

As with all previous editions of this report, the 2021 edition captures and distills a wealth of new information available on small spacecraft systems from NASA and other publicly available sources. This report is limited to publicly available information and cannot reflect major advances in development that are not publicly disclosed. We encourage any opportunity to publish mission outcomes and technology development milestones (e.g. via conference papers, press releases, company website) so they can be reflected in this report. Overall, this report is a survey of small spacecraft technologies sourced from open literature; it does not endeavor to be an original source, and only considers literature in the public domain to identify and classify devices. Commonly used sources for data include manufacturer datasheets, press releases, conference papers, journal papers, public filings with government agencies, news articles, presentations, and the compendium of databases accessed via NASA’s Small Spacecraft Systems Virtual Institute Federated Search. Data not appropriate for public dissemination, such as proprietary, export controlled, or otherwise restricted data, are not considered. As a result, this report includes many dedicated hours of desk research performed by subject matter experts reviewing resources noted above. Content in this 2021 edition is based on data available by July 2021.

Each chapter is a mini-stand-alone report on spacecraft subsystems. The organizational approach for each chapter is relatively consistent with previous editions and includes an introduction of the technology, current development status of the technology’s procurable systems, and a summary of technologies surveyed. New for this year’s report is a table of contents for each chapter to better assist the reader in locating specific information. As in previous years, chapters are updated with new and maturating technologies and reference missions and include information from previous editions. Tables in each section provide a convenient summary of the technologies discussed, with explanations and references in the body text. The authors have attempted to isolate trends in the small spacecraft industry to point out which technologies have been adopted as a result of successful demonstration missions.

The report’s subject chapters have changed, and information has been added and removed to reflect changes and growth in the small spacecraft market. A new chapter titled “Small Spacecraft Avionics” encompasses information from the previous “Command and Data Handling” and “Flight Software” chapters and provides more insight on a new generation of SmallSat avionics systems. The “Communications” chapter underwent a complete update to better display useful information for mission design engineers and has been separated appropriately into radio frequency and optical telecommunications descriptions and associated technologies. The “Complete Spacecraft Platforms” chapter has been reorganized to include more information on the development of small spacecraft platforms, provide systems engineering considerations, and to expose recent and upcoming trends in small spacecraft buses. The “Power” chapter was also completely reworked to focus more on engineering requirements and processes for choosing a device. Lastly, the authors tried to use the terms “SmallSat,” “microsatellite,” “nanosatellite,” and “CubeSat” in a consistent manner, even as these terms are often used interchangeably in the space industry.

A central element of this report is to list state-of-the-art technologies by NASA standard Technology Readiness Level (TRL) as defined by the 2020 NASA Engineering Handbook, found in NASA NPR 7123.1C NASA Systems Engineering Processes and Requirements. The authors have endeavored to independently verify the TRL value of each technology by reviewing and citing published test results or publicly available data to the best of their ability. Where test results and data disagree with vendors’ own advertised TRL, the authors have attempted to engage the vendors to discuss the discrepancy. Readers are strongly encouraged to follow the references cited to the literature describing the full performance range and capabilities of each technology. Readers of the report should reach out to individual companies to further clarify information. It is important to note that this report takes a broad system-level view. To attain a high TRL, the subsystem must be in a flight-ready configuration with all supporting infrastructure—such as mounting points, power conversion, and control algorithms—in an integrated unit.

An accurate TRL assessment requires a high degree of technical knowledge on a subject device, and an in-depth understanding of the mission (including interfaces and environment) on which the device was flown. There is variability in TRL values that depends on the design factors for a specific technology. For example, differences in TRL assessment based on the operating environment may result from the thermal environment, mechanical loads, mission duration, or radiation exposure. If a technology has flown on a mission without success, or without providing valid confirmation to the operator, such claimed “flight heritage” was discounted. The authors believe TRLs are most accurately determined when assessed within the context of a program’s unique requirements.

While the overall capability of small spacecraft has matured since the 2020 edition of this report, technologies are still being developed to make deep space SmallSat missions more routine. This has led to intense scrutiny over the radiation tolerance of small spacecraft, especially given their tendency to use low-cost, commercial off-the-shelf (COTS) components. Consequently, this report also includes radiation mitigation strategies for small spacecraft missions. Future editions of this report may include content dedicated to the rapidly growing fields of assembly, integration, and testing services, and mission modeling and simulation–all of which are now extensively represented at small spacecraft conferences. Many of these subsystems and services are still in their infancy, but as they evolve and reliable conventions and standards emerge, the next iteration of this report may also evolve to include additional chapters.


Download the full 2021 Report here.


Bryce and Space Technology. “SmallSat by the Numbers, 2021.” Updated August 13, 2021. [Online] [Accessed: August 24, 2021].

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