Cubesat Testing

Important Considerations for Cubesat Testing

CubeSats are a class of research spacecraft called nanosatellites. The advantage of developing a CubeSat is that development time and cost are considerably less than conventional satellites. CubeSats are great because they let schools, universities and other research teams launch their own missions. This helps them understand, discover, and advance new technologies. But first, CubeSat Testing must be performed to ensure launch safety. Companies developing satellites often need services that supplement their development. CubeSat Testing is an important part of the process. CubeSat testing questions that are important to consider can include:

• Does my product require external testing to meet consumer, production, launch provider or lifecycle standards?
• Have those standards been identified?
• What are the quality and reliability testing protocols for my product to verify the investment?
• How can I reduce development/construction costs?
• How can I reduce risk, particularly during transportation and launch?
• Has internal development testing been performed on representative sub-systems to characterize engineering parameters, gather data, and validate the design approach?

As a satellite development company identifies their testing requirements, they may determine the need for additional support in creating custom tests and adjusting designs to better meet their goals. At Sigma Designs, we offer a variety of testing support services and hold A2LA accreditation and ISO/IEC 17025:2017 for Testing/Calibration Laboratories. In addition, we have experience testing a wide range of products including satellites and other aerospace-related products.

Rideshare Service

If you are looking to launch your CubeSat into space, you’re most likely using one of the growing number of rideshare services offered by various launch vehicles. The top Rideshare Services include SpaceX, Rocket Lab‘s “Electron Rideshare Program,” and Arianespace‘s “Vega Small Spacecraft Mission Service (SSMS).” Rideshare services require rigorous product testing before launching a CubeSat. Clients must ‘launch/space qualify’ their CubeSat to ensure quality standards. Let’s look at the general test requirements.

Identifying Testing Requirements Early

When identifying testing requirements and standards that are appropriate for the product, there are usually 2 types of tests to conduct: mechanical and verification. During mechanical development, it is useful to conduct thermal and vibration tests on individual subsystems. When conducting verification testing, on the other hand, the purpose is to qualify that integration and mounting of all components are safe and sturdy. Generally, the goal is to screen and catch design issues early and reduce over-test on the overall system due to design deficiency and workmanship defects.

A CubeSat needs to test like it will fly. It’s important to determine if it is structurally intact after testing. Can the CubeSat still power-on and transmit? Each rideshare service has specific testing requirements, but in most cases, the following testing will be required:

• Acoustic
• Vibration
• Shock
• Thermal Balance
• …And EMC (not a service provided at Sigma Designs)

Testing

Sigma Designs runs a comprehensive test laboratory that offers customizable equipment for each specific test. A team of specialized experts in the test lab conducts various tests including acoustic, shock, vibration, pressure, temperatures, and vacuum testing. It is worth noting that our vacuum testing can reach altitudes of up to 100,000 feet. However, we currently do not possess the capacity to perform Thermal Vacuum testing, which is the recommended method for vacuum testing in the space industry. As for acoustic testing, we utilize our state-of-the-art 24-inch progressive wave acoustic chamber.

Sigma Designs CubeSat testing falls within these maximum parameters:

• Volume/Size:  12U
• Mass:  50Kg

Test Plans

A written test plan is necessary to ensure all parties are in alignment with goals and objectives of the specific tests before testing begins. A test plan may include:

• What is being tested.
• What test procedure and test levels will be followed.
• Defined test parameters/conditions and steps to be performed.
• Acceptance criteria – Requirements that will be verified and the specific evidence that verifies each requirement.
• Allowable measurement uncertainty requirement for each measured parameter.
• Pre-test functional check.
• Post-test functional check.

Testing Details

After completing the following tests, the CubeSat should be structurally intact, and be able to transmit or power-on when appropriate. Sigma Designs tests components and satellites for launch according to NASA GEVS, Falcon 9, and other launch system requirements

• Acoustic
  Evaluates the CubeSat for exposure to high-intensity acoustic noise environments inside the launch vehicle during segments of the flight profile. Critically, it must survive the initial liftoff, transonic transition, and Max-Q phases of flight. Sigma’s acoustic test capabilities utilize a progressive wave tube, enabling near-compliance with reverberant chamber or DFAN methods at an order of magnitude lower cost. This system is ideal for component and small satellite testing.
  
  
• Vibration
  Evaluates the CubeSat for exposure to a vibrating environment during the flight profile. This is to ensure component and structural integrity. Testing consists of random, sine, and/or low-level diagnostic pre/post-test sine sweeps. The strength of the test levels depends on various parameters. This test is useful when conducted on individual subsystems to aid in mechanical development.
  
  
  
• Shock
  An extension of Vibration testing, it evaluates the CubeSat for exposure to sudden or severe impacts during the launch and flight environments.

• Thermal Balance
  Evaluates the CubeSat thermal design and thermal control system capability to maintain thermal conditions by exposure to simulated on-orbit worst-case hot and worst-case cold environments.  Additionally, it’s also a good idea to consider testing for safe-hold or survival mode conditions. This test is useful when conducted individual subsystems to aid in mechanical development.
  
  
• Thermal Vacuum
  An extension of Thermal Balance, it evaluates the CubeSat for exposure in vacuum and cycling between temperatures extremes based on those in a simulated space environment.  Where applicable, hot, and cold turn-on can be demonstrated. (Note: not a capability of Sigma Designs)

TEST REPORT

After testing, a detailed test report(s) shows the requirement verification. It will also include the following items to help clients make informed decisions and identify potential weaknesses:

• Photos of test setup, including accelerometer, and thermal measurement locations.
• Test report with time stamps, problems encountered, and problem resolutions.
• Vibration Control/input data verses CubeSat response.
• Graphs of test data showing durations and levels meet requirements.
• Results, conclusions, and evidence that CubeSat survived (we hope) testing.
• The degree of success in meeting test objectives.
• Any analyses, anomalies, discrepancies, deficiencies, or periods of interruption.
• List of test equipment, with applicable calibration dates.

Conclusion

Many standalone environmental and other testing support services throughout the product development cycle are beneficial for CubeSat development. By seeking out the testing requirements including ingress, material, battery, mechanical life cycling, storage, ISTA, UAS, and MIL-STD testing, developers can save costs and verify that a product will perform as required.

The SIGMADESIGN Test Lab is A2LA Accredited to ISO/IEC 17025:2017