PAGE CONTENTS
Objectives
The Data Relay Constellation (DRC) project goal is the development of optical communication terminals and electrical propulsion.
Concerning electrical propulsion, the goal is to implement long duration tests in order to improve the maturity of Aerospacelab’s 600W propulsion system. Targeted tests include a system validation test (consisting of a coupling tests between the thruster, the flow control unit and the PPU), a Xenon endurance test, a Krypton endurance test and a cathode thermal fatigue test. The endurance test will demonstrate the compatibility of the thruster erosion to high total impulse missions.
Concerning the optical communication terminals, the goal is to develop optical intersatellite link terminals for telecom satellite platforms that are ESTOL compliant, low cost of platform integration, enabling high data transfer rates at low cost.
Benefits
The technologies developed under the Data Relay Constellation (DRC) project offers significant advantages over existing technologies by the high data transfer rate, adaptation to telecom satellite platforms, and low cost for a complete platform solution.
Features
The Data Relay Constellation (DRC) project developed optical communication terminal shall be ESTOL compliant, with volumetric aspect ratio that is suitable for telecom satellite platforms. It shall offer a complete platform system solution, enabling a reduced cost for both terminal and platform. It shall allow flexible AIT with customisable features, following fast paced platform development, building and testing.
Challenges
Key challenges of the Data Relay Constellation project for the OCT development are the fast-changing market on a technology with limited maturity in routine operation but fast advancements.
Additionally, the low-cost and high-volume manufacturing targets in combination with the OCT technology complexity are a big challenge.
Lastly, the testing of OCT on ground to confirm the pointing, acquisition and tracking performance under similar conditions as in space are complex and require dedicated test equipment development.
For electric propulsion, the main challenges are to ensure the thruster and cathode can operate during very long durations after a mechanical environment qualification sequence. Endurance test require a specific setup to ensure an automatic monitoring. Long duration tests effects like beam target graphite back sputtering that will have to be mitigated.
System Architecture
The Data Relay Constellation (DRC) project developed optical communication terminal shall have the following major building blocks:
- Optical Interface module: having the interface to the platform router and holder the transceiver modules for multiple optical heads.
- Optical amplification unit: each optical head has an optical amplifier, to amplify both the transmitter and receiver signal.
- Optical head unit: with a coarse pointer and an optical bench, executing the Pointing Acquisition and Tracking of the optical link and ensuring its stability.
An optical intersatellite link solution shall have between one and four optical heads.
Plan
The project plan follows structured phases:
- Phase A (Conceptual Design): Mission definition, system architecture, preliminary risk assessment (Milestone: System Requirements Review – SRR).
- Phase B (Preliminary Design): Subsystem specifications, technical trade-offs, and preliminary testing plans (Milestone: Preliminary Design Review – PDR).
- Phase C (Detailed Design): Final subsystem engineering, prototyping, and validation testing (Milestone: Critical Design Review – CDR).
- Phase D (Assembly, Integration, and Testing): Manufacturing, subsystem integration, system-level testing, and launch preparation (Milestone: Launch Readiness Review – LRR)
Current Status
The Data Relay Constellation project is currently in Phase B (Preliminary Design). Phase A was successfully completed, defining clear mission objectives, requirements, and initial architecture. Preliminary design is actively progressing and set for completion by October 2026. Presently, subsystem technical trade-offs, risk mitigation, and validation simulations are underway. Preparations for detailed subsystem engineering and prototyping (Phase C) are about to commence, positioning the project for smooth transition toward detailed design and eventual operational deployment.
