Product Assurance is a key step in New Space projects where SMALL SATS is one of the protagonists, due to the relatively low maturity of the sector and COTS parts for this type of mission. The Product Assurance Plan is the first step to a successful and well-managed project, and many of the activities that will be developed during the mission will be based on this Product Assurance Plan.
To begin with, product assurance is the discipline that deals with the study, planning, and implementation of activities needed to assure that the result is a product with a satisfactory degree of quality. Product assurance covers the following disciplines:
- Product Assurance Management;
- Quality Assurance;
- Dependability Assurance;
- Electrical, Electronic, and Electromechanical (EEE) Components;
- Materials, Mechanical Parts, and Processes;
- Software Product Assurance;
- Cleanliness and Contamination Control;
- Configuration Management.
In developing all these tasks, the Product Assurance Plan defines the requirements to be applied for the project’s design, production, testing, storage, transport, delivery, and operations. This product assurance plan applies to all phases of the project up to the launch of the spacecraft. It also applies to all the subcontractors of the projects, and therefore, all of them shall demonstrate compliance with its requirements.
Product assurance plan sections and requirements
As an example of the topics covered by a Product Assurance Plan, we are going to briefly dissect some of the sections and requirements included in it, specifically regarding EEE parts (also focus on New Space projects)
Component Selection
The requirements and steps to choose the most suitable EEE parts are explained. This section shall include a list of components whose use is forbidden either by known instability or known reliability issues. These requirements can vary greatly from project to project. Still, they are usually relaxed in New Space projects concerning traditional space projects because the useful lifetime of the mission is normally shorter.
It also includes the primary sources for procurement (usually, the manufacturer directly or a franchised distributor). It is important that this section also clarifies the quality grades suitable for the project and any other physical, mechanical, or environmental requirements for the components to be used in the mission. This section is significant for New Space projects. A good selection will reduce the number of tests needed for validation at the component level, impacting greatly on cost and lead time (which are strong constraints in these projects).
Radiation Hardness Assurance
All the general radiation constraints: applicable effects and sensitive parts, Radiation Verification Testing need, indication on how to simulate the effects, and the criteria for valid data shall be the minimum information. The specific radiation environment can be included in this PA plan, or, by contrast, it could be a separate document that must be referenced in the PA plan (which is the usual way).
TID values are usually low for LEO New Space missions (typically in the range of a few Krads to some tens Kraus). Still, it is important to remark that COTS parts do not usually have radiation data from manufacturers. Components are key for radiation tolerance to select parts with heritage or previous data. If no acceptable data is available, the parts need to be tested. There are also alternatives to avoid testing of all radiation-sensitive parts, such as board testing.
Component approval
In this section, instructions are provided on how to proceed with component validation. It is indicated when a Parts Control Board is needed and what documentation shall be presented. Common documents are PADs, Justification documents, and/or Declared Component List.
Process to validate lots for flight
Especially in New Space projects, where the constraints are different than in “classical” space and the approach is not so focused on total risk avoidance but risk management, there has to be a clear process that clarifies the process that a lot has to undergo to be used, depending on the initial quality level and the previous data available. This baseline approach can be modified under special circumstances, but it must be duly justified and approved during the component approval process.
ALTER provides a one-stop service covering all quality assurance activities applicable to small satellites. The appropriate selection of components, the performance of small sats testing, customized solutions for miniaturization, and the full capabilities of our laboratories are our added value for the validation of small satellites.
