Testing and qualification

Also known as AIT, AIV, Environmental testing, Qualification, Verification

How a small satellite proves it will survive launch and work in orbit: model philosophy, vibration, thermal vacuum, bake-out, functional and deployment tests. Small teams test less than agencies, and the early failure statistics of CubeSats show what that costs.

Document
SQ-EN-003
Updated
20 Oct 2026
Reading time
5 min
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Why test#

The first hundred CubeSats taught the community that cheap, fast development has its own failure statistics: a large share of early missions died within days, many from problems a system-level test would have caught[1]. Later surveys connected failures to the power and communication subsystems and to insufficient testing, and argued for more functional and environmental verification at system level[2]. Testing is the cheapest insurance a small team can buy.

Model philosophy#

Agencies separate the roles of the hardware a project builds[3]:

  • Engineering model (EM). Representative in form and function; used to debug interfaces and software.
  • Qualification model (QM). Identical to flight; tested at qualification levels and durations, with margin above the expected environment, and never flown.
  • Protoflight model (PFM). Flight hardware tested at qualification levels for acceptance durations; the usual choice of small missions that cannot afford a separate QM.
  • Flight model (FM). Tested at acceptance levels to find workmanship defects.

Most PocketQube and CubeSat teams fly a protoflight model after an engineering model, which is a sound compromise when the levels and durations are respected.

Test as you fly#

The most useful principle is to test the spacecraft in the configuration and sequence it will fly: deployables stowed, separation switches pressed, timers running, the flight software in its launch mode. Grizu-263A followed a test-as-you-fly sequence of bench tests, engineering-model tests, thermal-vacuum tests and vibration tests before delivery[4].

flowchart LR
  BENCH["Bench and board tests"] --> EM["Engineering model: integration and software"]
  EM --> FUNC["Functional and end-to-end radio tests"]
  FUNC --> VIB["Vibration: resonance survey, random"]
  VIB --> TVAC["Thermal vacuum and cycling"]
  TVAC --> BAKE["Bake-out"]
  BAKE --> FINAL["Final functional test, deployer integration"]

References

  1. [1]Swartwout, M. (2013). The first one hundred CubeSats: a statistical look. Journal of Small Satellites, 2, 213–233.
  2. [2]Langer, M., & Bouwmeester, J. (2016). Reliability of CubeSats — statistical data, developers’ beliefs and the way forward. In: 30th Annual AIAA/USU Conference on Small Satellites (SSC16-X-2).
  3. [3]European Cooperation for Space Standardization. (2022). ECSS-E-ST-10-03C Rev.1: Space engineering — Testing. ESA Requirements and Standards Section.ecss.nl(accessed 20 October 2026)
  4. [4]nadir lab. (2026). PocketQube picosatellites: A review of standards, mission trends and miniaturization constraints, with lessons learned from Grizu-263A, Türkiye’s first PocketQube [Preprint]. nadir lab.Read on nadir lab.
  5. [5]NASA Goddard Space Flight Center. (2021). GSFC-STD-7000B: General Environmental Verification Standard (GEVS) for GSFC Flight Programs and Projects. NASA.standards.nasa.gov(accessed 20 October 2026)
  6. [6]NASA Small Spacecraft Systems Virtual Institute. (2026). Structures, Materials, and Mechanisms. State-of-the-Art of Small Spacecraft Technology (2026 edition), Chapter 6. NASA Ames Research Center.nasa.gov(accessed 20 October 2026)
  7. [7]The CubeSat Program, Cal Poly SLO. (2022). CubeSat Design Specification, Rev. 14.1 (CP-CDS-R14.1). California Polytechnic State University.nasa.gov
  8. [8]Uludag, M. S., Yakut, E., Speretta, S., Radu, S., Chronas-Foteinakis, N., Bouwmeester, J., Menicucci, A., & Gill, E. (2019). Getting the Delfi-PQ ready for multiple launch options. In: International Symposium on Space Technology and Science (ISTS), Fukui (2019-f-08).pure.tudelft.nl
  9. [9]nadir lab. (2026). Materials engineering for PocketQube picosatellites: A scaling-based review and design guide [Preprint]. nadir lab.Read on nadir lab.
  10. [10]European Cooperation for Space Standardization. (2008). ECSS-Q-ST-70-02C: Space product assurance — Thermal vacuum outgassing test for the screening of space materials. ESA-ESTEC.
  11. [11]Uludağ, M. S., & Speretta, S. (2025). Delfi-PQ: in-orbit performance and lessons learned in developing a 3P PocketQube. In: 76th International Astronautical Congress, Sydney (IAC-25-B4.6B.6) (609–623).doi:10.52202/083084-0062
  12. [12]NASA CubeSat Launch Initiative. (2017). CubeSat 101: Basic Concepts and Processes for First-Time CubeSat Developers. NASA.nasa.gov(accessed 20 October 2026)

Cite this SatWiki entry

@misc{nadirlab2026testing,
  author       = {{nadir lab.}},
  title        = {{Testing and qualification}},
  year         = {2026},
  month        = oct,
  howpublished = {nadir lab. SatWiki SQ-EN-003 (Rev. 1)},
  url          = {https://nadirlab.space/en/wiki/testing-qualification/}
}