The Integrated Payload Controller (IPC) is a modular interface electronics, which aims at isolating payloads from the platform systems, in particular from both C&DH and EPS subsystem, so that they do not have to be adapted to the particular payloads hosted on-board. To this aim, the payload controller provides diverse communication interfaces for the different kinds of payloads and is capable to distribute power according to the different payloads needs. It further provides computing power to perform payload data on-board processing and offers high storage capacity. It achieves high reliability primarily with COTS components and redundancy.
A first step to guide the requirement definition process is the identification and study of existing platform in the targeted range (10-150 kg, LEO orbit), which can benefit from the adoption of the IPC. Based on the mission survey, a selection of platform requirements is determined, which is expected to support the technology evaluation and trade-off among candidate architectures for the IPC.
The aim is to identify a set of common requirements, which can be applicable to the vast majority of platform within the identified target. The focus is placed onto the following topics: electrical interface, harness, power and communication, on-board computing and radiation tolerance requirements. Some requirements, which are typically assigned to the OBDH, PSU, or PDU platform subsystems, will be here assigned to the IPC under study. Other aspects such as specific functionality/performance, mechanical/thermal interface and environment and EC compatibility, will not be treated here since they are regarded to be mission and/or platform dependent, while the IPC should be designed with the highest possible degree of flexibility in mind. Furthermore, at a feasibility study stage the primary importance is the nature of a requirement, e.g. that a certain requirement item exists. Of secondary importance is the recommended range (where quantification is possible).
The missions surveyed for requirements have also been surveyed for missions utilizing payload controller technology. The different design philosophies of the STPSat and TET payload controllers shine through in the comparison results: STPSat defines a standard interface to which payloads have to comply leading to an inflexible system regarding payload needs; TET on the other hand utilizes a modular architecture giving it the flexibility needed to support as wide a range of payloads as possible. The result is obvious. The payload control system developed for the TET platform already satisfies many of the requirements in its current form. The modular nature of the system facilitates further development and ensures flexibility, so the system can be adapted to each platform and payload(s) according to mission requirements. Due to these factors the TET “Payload Support System” is considered a very good basis for further development.