Space

Earth observation technologies are critical for understanding environmental change, supporting sustainable development, and addressing socio-ecological challenges. Today’s satellite imaging systems, however, still face limitations such as low spatial resolution (~1 km), long acquisition times (often several days), and restricted spectral coverage (mostly visible light).

The EU-funded project SURPRISE has addressed these challenges by introducing advanced space-based camera systems using spatial light modulators (SLMs), an area in which Fraunhofer IPMS has long-standing expertise.

A New Imaging Paradigm for Space: VIS–NIR–MIR Spectral Coverage & Real-Time Data

The project's goal was to develop a space-ready imaging demonstrator that leverages:

• Broadband spectral capability across the visible (VIS), near-infrared (NIR), and mid-infrared (MIR) ranges
• Higher ground resolution for sharper environmental insights
• Integrated on-board data processing and real-time encryption
• Compressive Sensing (CS) to reduce data load and enhance security

CS technology enables the creation of high-resolution images using a single-pixel detector, making it especially valuable for the MIR range, where conventional 2D detectors are lacking. This results in more compact, energy-efficient systems and allows native data encryption during acquisition, which is an advantage for secure Earth observation applications.

Fraunhofer IPMS: Enabling Space-Qualified Optoelectronic Components

Fraunhofer IPMS has contributed its deep know-how in spatial light modulators to design and develop an SLM optimized for the harsh conditions of space. This includes:

• Radiation-resistant MEMS design
• Robust operation across thermal extremes
• Compatibility with satellite systems and data pipelines

In the three-and-a-half-year project, which was completed in June 2023, an SLM of the current technology generation from Fraunhofer IPMS successfully underwent a test under space conditions. The 256 x 256 pixel device was evaluated for temperature (from -40 °C to 80 °C), vacuum (< 10-5 mbar), and vibrations in the X, Y, and Z axes. Not a single pixel failed. These experimental findings, together with the simulation results, confirm the robustness of the spatial light modulators from Fraunhofer IPMS and encourage further activities for the development of SLM technology for space.

Human activity generates increasing amounts of waste, not only on Earth, but also in space. Space debris is becoming a growing concern for satellite operations and long-term space sustainability. One promising solution is the modularization of satellite systems, allowing individual components to be replaced instead of decommissioning entire satellites. This significantly extends their service life and reduces space waste.

To enable seamless communication between modular components, Fraunhofer IPMS has developed a compact optical transceiver based on the Li-Fi GigaDock® technology that ensures high-speed, reliable data transfer. Integrated into the iSSI® interface developed by iBOSS GmbH, this innovation has been undergoing tests aboard the International Space Station (ISS) since February 2022.

Standardized Interfaces for Modular Satellites

For satellite modules to be flexibly docked, undocked, or reconfigured directly in orbit, standardized and easy-to-couple interfaces are essential. These interfaces must support not only mechanical connection but also data and power transfer between modules to ensure full system functionality.

To address this need, RWTH Aachen University filed a patent for such a modular connection system, which is now commercialized by its spin-off iBOSS GmbH under the name iSSI® (intelligent Space System Interface). This system defines a standard interface for next-generation modular satellites.

Li-Fi GigaDock®: Optical Transceiver Technology from Fraunhofer IPMS

A central component of the iSSI® interface is the Li-Fi GigaDock®, developed by Fraunhofer IPMS. At its core is a highly integrated optical wireless transceiver that enables contactless, full-duplex, bidirectional data transmission at speeds of up to 5 Gbps across a range of up to five centimeters.

Key benefits of the Li-Fi GigaDock® technology include:

• High-speed data transfer up to 5 Gbps for efficient communication between satellite modules
• Contactless operation, ideal for space environments where physical wear must be minimized
• Full-duplex and bidirectional communication ensures seamless and simultaneous data exchange
• Short-range transmission (up to 5 cm) supports compact and modular satellite designs
• Resilience under motion, suitable for rotor-to-stator transmission, maintaining performance even at high rotational speeds
• No electromagnetic interference, making it well-suited for sensitive aerospace and industrial environments

This cutting-edge transceiver design enables flexible, modular satellite architectures and opens the door to future applications in space, robotics, and high-speed industrial systems.

Fraunhofer IPMS develops payload electronics for mobile quantum key distribution via high-altitude platforms. The project "QuNET+MOBIXHAP" is pushing the boundaries of secure communication by developing a mobile, high-altitude platform (HAP) for quantum key distribution (QKD) via free-space optical links.

Quantum keys, transmitted using light particles, offer a major advantage over classical cryptographic methods: due to the laws of quantum physics, these keys cannot be intercepted or copied unnoticed, making QKD an ideal foundation for secure communication infrastructures of the future.

While QKD is already used in fiber-optic networks, longer distances and mobile use cases require free-beam-based transmission, for example via satellites or HAPs. The goal of the project is to develop a fully autonomous and robust stratospheric communication system that can reliably operate under extreme environmental conditions.

Next-Generation Quantum Platforms

Fraunhofer IPMS supports the project by contributing to the system design and defining the requirements for the HAP-based communication architecture. A key focus is the development and integration of the Payload Management Unit (PMU), the central hub coordinating data communication and system control onboard the mobile node.

Key development areas of the PMU include:

• Payload & system networking: Reliable and synchronized data exchange between subsystems
• Control core integration: Managing quantum communication payloads and onboard resources
• Optical extension interface: Connection to free-space optical transceivers
• Real-time software: Embedded control and monitoring of the entire payload system

Quantum Key Distribution in Mobile Networks: A Technology Demonstrator

In the next project phase, microcontrollers and network components will be integrated into the system to ensure precise time synchronization between all mobile node elements, which is a critical requirement for QKD. Here, existing IP cores from Fraunhofer IPMS will be leveraged.

Fraunhofer IPMS is also involved in:

• Developing control and monitoring mechanisms within the PMU
• Calculating optical link budgets for various mission scenarios
• Estimating quantum key generation rates based on different QKD protocols

The project will culminate in a 3-node demonstrator that evaluates the performance of key communication links, both HAPS-to-HAPS and HAPS-to-ground.

Toward a Quantum-Ready Stratospheric Network

As a final step, the complete system design for the HAPS testbed will be developed, including all validation and pre-test procedures for the quantum link demonstration. Fraunhofer IPMS will play a central role in integrating the PMU into the overall system, ensuring seamless interaction with all relevant HAP subsystems.

The result: a milestone on the way to scalable, mobile quantum communication systems developed with stratospheric applications in mind, and ready to support the secure digital infrastructure of tomorrow.

Fraunhofer IPMS develops high-precision MEMS scanners for space-ready LiDAR systems. The project "miniLiDAR" aims to develop a miniaturized LiDAR system for rendezvous and docking applications in space. This application demands the highest precision combined with a compact system design, making it an ideal field for MEMS-based optical technologies.

MEMS Vector Scanner: Precise Laser Beam Steering in a Compact Format

As a core part of the system, the Fraunhofer Institute for Photonic Microsystems IPMS is developing a novel two-dimensional quasi-static microscanner mirror (MEMS vector scanner). The technology offers:

• Large mirror aperture of 3–5 mm
• Mechanical deflection angle of 11 × 13 degrees
• Arbitrary 2D vectorial scan trajectories
• Adaptive, highly precise positioning of the transmit laser beam

Unlike commonly used galvanometer scanners, the MEMS scanner is based on monocrystalline silicon. This provides key advantages:

• Wear-free operation through purely mechanical flexure design
• High mechanical reliability with minimal mass
• Miniaturization of the LiDAR system by eliminating rotating parts

In addition, Fraunhofer IPMS is developing the necessary control algorithms for precise beam positioning and a compact MEMS scan module for LiDAR system integration. Finally, initial experimental tests are being carried out on the reliability of the MEMS scan module.

The project results form the basis for compact, robust, and highly precise solid-state LiDAR systems for space applications, which is a crucial step toward safe and automated satellite or spacecraft rendezvous and docking in orbit.