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Runtime Verification Triggers Real-Time, Autonomous Fault Recovery on the CySat-I

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NASA Formal Methods (NFM 2022)


CubeSats are low-cost platforms that are popular for conducting spaceborne experiments, however they are known to have high failure rates (\(\sim \)25% failure rate). In order to improve the likelihood of success of Iowa State University’s first CubeSat (CySat-I), we integrate Runtime Verification (RV) on the CySat-I to allow for fault detection at runtime. Although CubeSats have been previously identified as a possible target for RV, this is the first time that a RV engine has been deployed on a CubeSat. We utilize the R2U2 runtime verification engine due to its low overhead; we embed R2U2 directly on the On-Board Computer (OBC) to monitor the current state of the CySat-I. R2U2 continuously monitors the different subsystems on the CySat-I, and R2U2’s fault detection triggers predefined fault recovery strategies. Since the Electrical Power System (EPS) is a common source of failure, we specifically focus on this subsystem. We design a list of twenty-two specifications from English requirements corresponding to the EPS and translate them into Mission-time Linear Temporal Logic (MLTL). We perform mock launches on Earth with external fault injection to illustrate that R2U2 successfully reasons about faults and the CySat-I effectively performs fault recovery. We demonstrate that the CySat-I can successfully recover from eight unique EPS faults at runtime in a timely manner with no errors. During our mock launches, R2U2 discovered a potential error in the manufacturer’s firmware related to the EPS’s under-voltage event monitoring, and this led to a more in-depth investigation of the error by the manufacturers.

Supported by NSF:CPS Award 2038903. Reproducibility artifacts available at

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  1. 1.

    All twenty-two specifications with categorization appear here:

  2. 2.

    All eight specification faults appear here:


  1. Amazon Web Services: The FreeRTOS\(^{\rm TM}\) Reference Manual (2017)

    Google Scholar 

  2. Bouwmeester, J., Langer, M., Gill, E.: Survey on the implementation and reliability of CubeSat electrical bus interfaces. CEAS Space J. 9(2), 163–173 (2016).

    Article  Google Scholar 

  3. Cauwels, M., Hammer, A., Hertz, B., Jones, P., Rozier, K.Y.: Integrating runtime verification into an automated UAS traffic management system, pp. 340–357 (09 2020).

  4. Dabney, J.B., Badger, J.M., Rajagopal, P.: Adding a verification view for an autonomous real-time system architecture. In: Proceedings of SciTech Forum, 2021–0566, AIAA, January 2021.

  5. EnduroSat: Electrical Power System (EPS I & EPS I Plus) - I2C Protocol User Manual (2019)

    Google Scholar 

  6. EnduroSat: Onboard Computer (OBC) Type II - User Manual (2019)

    Google Scholar 

  7. EnduroSat: Electrical Power System (EPS I & EPS I Plus) User Manual (2020)

    Google Scholar 

  8. Gross, K.H., et al.: Formally verified run time assurance architecture of a 6u CubeSat attitude control system. In: AIAA Infotech Aerospace, p. 0222 (2016)

    Google Scholar 

  9. Hertz, B., Luppen, Z., Rozier, K.Y.: Integrating runtime verification into a sounding rocket control system. In: Dutle, A., Moscato, M.M., Titolo, L., Muñoz, C.A., Perez, I. (eds.) NFM 2021. LNCS, vol. 12673, pp. 151–159. Springer, Cham (2021).

    Chapter  Google Scholar 

  10. Kempa, B., Zhang, P., Jones, P.H., Zambreno, J., Rozier, K.Y.: Embedding online runtime verification for fault disambiguation on Robonaut2. In: Bertrand, N., Jansen, N. (eds.) FORMATS 2020. LNCS, vol. 12288, pp. 196–214. Springer, Cham (2020).

    Chapter  Google Scholar 

  11. Kilcoin, M., Kempa, B., Goldenberg, J., Nelson, M., Gonzalez-Torres, T.: Cysat-1 concept of operations (2020).

  12. Kulu, E.: Nanosatellite & CubeSat database.

  13. Langer, M., Bouwmeester, J.: Reliability of CubeSats - statistical data, developers’ belief, and the way forward. In: Proceedings of the 30th Annual AIAA/USU Conference on Small Satellites (2016)

    Google Scholar 

  14. Langer, M., Weisgerber, M., Bouwmeester, J., Hoehn, A.: A reliability estimation tool for reducing infant mortality in CubeSat missions. In: 2017 IEEE Aerospace Conference (2017).

  15. Luppen, Z.A., Lee, D.Y., Rozier, K.Y.: A case study in formal specifications and runtime verification of a CubeSat communications system. In: AIAA SciTech Forum (2021).

  16. Nelson, M.E.: Implementation and evaluation of a software defined radio based radiometer. Master’s thesis (2016)

    Google Scholar 

  17. Nelson, M.E., Lee, D.Y., Kilcoin, M., Gordon, L., Brown, W.: Preparing CySat-1: a look at Iowa state university’s first CubeSat. In: Proceedings of the 34th Annual Small Satellite Conference (2020)

    Google Scholar 

  18. Reinbacher, T., Rozier, K.Y., Schumann, J.: Temporal-logic based runtime observer pairs for system health management of real-time systems. In: Ábrahám, E., Havelund, K. (eds.) TACAS 2014. LNCS, vol. 8413, pp. 357–372. Springer, Heidelberg (2014).

    Chapter  Google Scholar 

  19. Rozier, K.Y.: R2U2 in space: system and software health management for small satellites. In: Spacecraft Flight Software Workshop (FSW), December 2016.

  20. Rozier, K.Y.: Specification: the biggest bottleneck in formal methods and autonomy. In: Blazy, S., Chechik, M. (eds.) VSTTE 2016. LNCS, vol. 9971, pp. 8–26. Springer, Cham (2016).

    Chapter  Google Scholar 

  21. Rozier, K.Y., Schumann, J.: R2U2: tool overview. In: RV-CuBES 2017. An International Workshop on Competitions, Usability, Benchmarks, Evaluation, and Standardisation for Runtime Verification Tools. Kalpa Publications in Computing, vol. 3, pp. 138–156. EasyChair (2017).

  22. STMicroelectronics: STM32CubeIDE User Manual (2020)

    Google Scholar 

  23. Stump, A., Sutcliffe, G., Tinelli, C.: StarExec: a cross-community infrastructure for logic solving. In: Demri, S., Kapur, D., Weidenbach, C. (eds.) IJCAR 2014. LNCS (LNAI), vol. 8562, pp. 367–373. Springer, Cham (2014).

    Chapter  Google Scholar 

  24. Swartwout, M.A.: The first one hundred CubeSats: a statistical look (2013)

    Google Scholar 

  25. Venturini, C., Braun, B., Hinkley, D., Berg, G.: Improving mission success of CubeSats. In: Proceedings of the 32nd Annual AIAA/USU Conference on Small Satellites (2018)

    Google Scholar 

  26. Venturini, C.C.: 8 steps improving small set mission success.

  27. Villela, T., Costa, C.A., Brandão, Alessandra, M., Bueno, F.T., Leonardi, R.: Towards the thousandth CubeSat: a statistical overview. Int. J. Aerosp. Eng. 2019 (2019).

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Correspondence to Alexis Aurandt , Phillip H. Jones or Kristin Yvonne Rozier .

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Aurandt, A., Jones, P.H., Rozier, K.Y. (2022). Runtime Verification Triggers Real-Time, Autonomous Fault Recovery on the CySat-I. In: Deshmukh, J.V., Havelund, K., Perez, I. (eds) NASA Formal Methods. NFM 2022. Lecture Notes in Computer Science, vol 13260. Springer, Cham.

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