Small and Large Satellites: Joint Operations in Earth Observation

While projects for the exploration of space remain ambitious and financially as well as technologically demanding projects, their benefit in understanding our planet is unrivaled [1]. On top of enabling technologies that keep drastically altering the way we communicate, navigate, or build our cities, they currently present the only means of assessing key environmental variables on a global scale [2]–[5]. Today, we witness the New Space era with promises of ever easier, faster, and cheaper space access as a major driving force for the future development to four space capabilities, specifically in Earth Observation (EO), but also in communication (COM) and navigation (NAV) applications. Since from an economic point of view, only now it became possible to achieve resolution and coverage matching the needs of many applications outside the scientific community by means of small satellite constellations[6]–[9]

Additive Manufactured Structures for the 12U Nanosatellite ERNST

One of the emerging technologies in recent years is additive manufacturing. It promises unprecedented design freedom in both modeling and rapid manufacturing. We are reaping the benefits of additive manufacturing for our 12U nanosatellite ERNST by printing the optical bench that supports the spacecraft payloads. We design the structures by using a finite-element numerical approach for optimizing the topology with respect to 1) available design space, 2) payload interfaces, 3) mechanical launch loads, and 4) thermal loads generated by the cryocooler of the MWIR main payload. We cope with the latter by integrating a pyramidal structured radiator surface in the optical bench as a functional element. Making use of the selective laser melting technique, we manufactured the first version of the optical bench for the engineering model of the ERNST spacecraft from AlSi10Mg alloy. Vibrational testing proved the suitability of our multidisciplinary design approach and the production quality. We are currently implementing the next version of the ERNST optical bench including spacecraft design changes and using Scalmalloy®, a material developed for additive manufacturing that provides high tensile strength and low thermal expansion. This marks a next step on the way to the application of additive manufactured components in space

ERNST: Demonstrating Advanced Infrared Detection from a 12U CubeSat

The ERNST mission will demonstrate complex infrared detection capabilities using a 12U CubeSat platform. ERNST’s main payload is an advanced cryogenically-cooled infrared imager that implicates demanding requirements in terms of power demand, heat dissipation, and vibration response for a nanosatellite. The optical bench that integrates optics, a filter-wheel for switching between spectral bands, and the detector-cooler system has been additively designed and manufactured, giving it a bionic appearance and combined with a highly efficient radiator. An onboard radiation monitor and a COTS camera complete the mission payloads. The ERNST 12U platform is based on high-performance CubeSat subsystems for avionics, UHF, and X-band communication, attitude control, and power management. The commercial components are made compatible through a backplane solution. In-house developments include a fast DPU and an autonomous de-orbit dragsail. The platform provides 30 Watt (OAP) and \u3e6U payload volume. After comprehensive environmental and functional testing of the Engineering Model, the Flight Model is currently being integrated. Starting operations in February 2023, ERNST will verify early warning concepts and technology

Demonstration of a Heterogeneous Satellite Architecture During RIMPAC 2018

The Micro-Satellite Military Utility (MSMU) Project Arrangement (PA) is an agreement under the Responsive Space Capabilities (RSC) Memorandum of Understanding (MOU) involving the Departments and Ministries of Defence of Australia, Canada, Germany, Italy, Netherlands, New Zealand, Norway, United Kingdom and United States. MSMU’s charter is to inform a space enterprise that provides military users with reliable access to a broad spectrum of information in an opportunistic environment. The MSMU community participated on a non-interference basis in the biennial Rim of the Pacific (RIMPAC) exercise from 26 June to 2 August 2018. This provided an opportunity to explore the military utility of a heterogeneous space architecture of satellites including traditional government and commercial satellites, as well as micro-satellites and nanosatellites associated with the “new space” paradigm. The objective was to test the hypothesis that a heterogeneous space architecture, mostly composed of small satellites, can bring significant value to the operational theatre. This paper describes the results from the MSMU experiment, outlines the lessons learned in terms of the infrastructure required to support such an experiment, and offers insights into the military utility of the heterogeneous space architecture. It concludes that a cooperative heterogeneous space architecture does have advantages and value, and that micro-satellites and nanosatellites contribute significant capability

Integrating a large nanosatellite from CubeSat components - challenges and solutions

Since the first release of the CubeSat standard a diverse market for CubeSat components has developed. Recent years have also seen a trend towards larger CubeSats. Consequently, all components necessary for systems in the range of small microsatellites are now available on the CubeSat market. This also includes more advanced subsystems like ADCS with three-axis stabilization and high data rate transmitters. When combining systems from different manufacturers, several compatibility issues arise. While all subsystems share the PC/104 format, missing standardization of pin assignment as well as low flexibility of the components make integration harder than necessary. Fraunhofer EMI currently designs and builds the 12U nanosatellite ERNST (Experimental Spacecraft based on Nanosatellite Technology). The satellite contains an advanced mid-wavelength-infrared imaging payload. Most requirements of this payload exceed the capabilities of 1-3U CubeSats. Instead of realizing the mission with a commercially available microsatellite bus, we pursue the concept of building a 12U nanosatellite from components designed for smaller CubeSats. For ERNST, the subsystem compatibility issues are solved using a PC/104 backplane. The components are grouped into multiple stacks that are connected through this backplane, which then translates between the different pin assignments

A concept for an ultra-low power sensor network - detecting and monitoring disaster events in underground metro systems

In this paper, the concept for an ultra-low power wireless sensor network (WSN) for underground tunnel systems is presented highlighting the chosen sensors. Its objectives are the detection of emergency events either from natural disasters, such as flooding, or from terrorist attacks. Earlier works have demonstrated that the power consumption for the communication can be reduced such that the data acquisition (i.e. sensor subsystem) becomes the most significant energy consumer. By using ultra-low power components for the smoke detector, a hydrostatic pressure sensor for water ingress detection and a passive acoustic emission sensor for explosion detection, all considered threats are covered while the energy consumption can be kept very low in relation to the data acquisition. The total average consumption for operating the sensor sub-system is calculated to be less than 35.9 mu W

Ultra-low power sensor system for disaster event detection in metro tunnel systems

In this extended paper, the concept for an ultra-low power wireless sensor network (WSN) for underground tunnel systems is presented highlighting the chosen sensors. Its objectives are the detection of emergency events either from natural disasters, such as flooding or fire, or from terrorist attacks using explosives. Earlier works have demonstrated that the power consumption for the communication can be reduced such that the data acquisition (i.e. sensor sub-system) becomes the most significant energy consumer. By using ultra-low power components for the smoke detector, a hydrostatic pressure sensor for water ingress detection and a passive acoustic emission sensor for explosion detection, all considered threats are covered while the energy consumption can be kept very low in relation to the data acquisition. In addition to 1 the sensor system is integrated into a sensor board. The total average power consumption for operating the sensor sub-system is measured to be 35.9 µW for lower and 7.8 µW for upper nodes

An MWIR payload with FPGA-based data processing for a 12U nanosatellite

In this paper, we describe an infrared imaging payload for a 12U nanosatellite. It contains a cryocooled MWIR detector and FPGA-based data processing unit. The system performs background monitoring in spectral bands with low atmospheric transmission. At the core of the system, a modern FPGA System-on-chip provides the computational performance, interfaces and mass storage for capturing, processing and storing high-resolution images. While the payloads mass of 2.5 kg and power requirements of 17 W exceed the capabilities of the common 2-3U CubeSats, it brings a level of performance to the increasingly popular 12U form factor that was previously reserved for much larger systems