Space

Earth observation data is becoming increasingly important for our understanding of the planet and for addressing socio-ecological challenges – for example, in environmental monitoring. Methods for data acquisition and processing from space are currently limited by long acquisition times (up to several days per measurement), low spatial resolution (about 1 km), and the usable spectral range (primarily in the visible). Novel camera systems based on spatial light modulators can provide a remedy here. These are being realized and tested for the first time within the EU project SURPRISE. Fraunhofer IPMS contributes with its long-standing expertise with spatial light modulators and plans to develop a spatial light modulator suitable for space applications.

The main goal of the project is to develop a demonstrator. Core parameters include spectrally broadband operating range – in the visible (VIS), near-infrared (NIR), and mid-infrared (MIR) – improved performance in terms of ground resolution, and innovative on-board data processing and encryption functionality. Innovative Compressive Sensing (CS) technology is used for this purpose. It allows a two-dimensional image to be captured using a single-pixel detector. This is particularly interesting for the mid-infrared because no suitable 2D detectors are available in this spectral range. Compressive Sensing also offers advantages in processing large amounts of data as well as native data encryption. 

Humans cause too much waste not only on Earth. Space debris is also becoming an ever greater problem. To make satellite systems more sustainable, they should be created in a modular system in the future so that individual components can be replaced, thus extending the service life of the satellites. To ensure a problem-free interface between the components, the Fraunhofer Institute for Photonic Microsystems IPMS has developed a transceiver that guarantees data transfer between the components. This was integrated into the iBOSS GmbH interface and has been on board the ISS (International Space Station) for testing purposes since February 2022.

In order to be able to flexibly attach and detach modules directly in space, easy-to-couple and standardized components are particularly important. In addition to the mechanical coupling of the individual modules, it is essentially a matter of ensuring the transfer of data and energy between the individual modules so that satellites can be combined as required. For this reason, RWTH Aachen University applied for a patent years ago, which has now been brought to market by the spin-off iBOSS GmbH as iSSI^® (intelligent Space System Interface) and forms a standard interface for such systems.

Part of the interface is a development of Fraunhofer IPMS and also known as Li-Fi GigaDock^®. The core of the technology is an optical wireless transceiver, a highly integrated device that enables contactless full-duplex and bidirectional data transmission with a data rate of up to 5 Gbps. The possible transmission distance of the optical data interface is five centimeters. The component can also be used for rotor-to-stator transmission, as the transceiver functions perfectly even at high speeds. 

In quantum communication, fundamental physical processes are used for transmission security in communication systems. With the development of quantum communication networks, this novel security technology can be made available to a large number of users in the future. Already today, quantum keys can be transmitted over point-to-point links for cryptographic security. Until now, quantum communication networks have primarily been aimed at connecting buildings at different locations over long distances. However, analogous to today's classical networks, in a quantum-secured network of the future, the individual devices in a building must also be able to send and receive quantum keys. Here, new technologies for quantum local area communication networks (Q-LAN) must be developed.

The first use of optical Li-Fi technology for quantum key distribution is an innovative approach. Various application scenarios are already identified and partially tested in the project. The practical work lays an important foundation for a multi-layered quantum internet and enables a versatile use of the developed technology for wireless quantum communication in local area networks.

The goal of the project is the development of a miniaturized LiDAR system for rendezvous and docking applications in space.

As a core part of the system, Fraunhofer IPMS is developing a new type of 2D quasi-static microscanner mirror (MEMS vector scanner) with a large mirror aperture of 3...5 mm and 11x13° mechanical deflection angle, which for the first time enables adaptive and precise two-dimensional beam positioning of the transmit laser on any (vectorial) scan trajectory.

In contrast to currently used galvanoscanners, the microscanner mirror made of monocrystalline silicon is characterized by complete freedom from wear and high mechanical reliability (due to low mass combined with high mechanical load capacity) and thus enables a highly miniaturized fast scanning solid-state LiDAR system without rotating parts.

Faunhofer IPMS is also 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