Design of a small size, low profile L-band antenna, optimized for space-based ADS-B signal reception

Air traffic services, like the Automatic Dependent Surveillance Broadcast (ADS-B), already became a fundamental part in the civil and military aviation by the provision of aircraft tracking on ground and from space, in controlled and noncontrolled airspaces. In particular, the surveillance of aircraft from space has been identified as a trend-setting service and demand. In this paper, we present the design of a small size, low profile patch antenna, optimized for aircraft signal detection in spacecraft applications. The proposed antenna design is circularly polarized, using a single-feed configuration and it is tailored to small dimensions and the operation in a space environmen

Space Mission and Hardware Design: From the Idea to a Successful Demonstration in Space

The half-day workshop aims to introduce the general workflow for space missions as seen from agencies like ESA or DLR and the requirements for a successful development and final operation in space. In this workshop, the topics space mission and hardware design are addressed: talking about critical mission phases, constraints in space hardware design and development and on how common pitfalls can be avoided. Two invited talks are presenting the lessons learned and best practice experience for scientific payloads that have been designed, developed and successful demonstrated space

Probes to the Inferior Planets - a New Dawn for NEO and IEO Detection Technology Demonstration from Heliocentric Orbits Interior to the Earth’s?

With the launch of MESSENGER and Venus Express, a new wave of exploration of the inner solar system has begun. Noting the growing number of probes to the inner solar system, it is proposed to connect the expertise of the respective spacecraft teams and the NEO and IEO survey community to best utilize the extended cruise phases and to provide additional data return in support of pure science as well as planetary defence. Several missions to Venus and Mercury are planned to follow in this decade. Increased interest in the inferior planets is accompanied by several missions designed to study the Sun and the interplanetary medium (IPM) from a position near or in Earth orbit, such as the STEREO probes and SDO. These augment established solar observation capabilities at the Sun-Earth L1 Lagrangian point such as the SOHO spacecraft. Thus, three distinct classes of spacecraft operate or observe interior to Earth's orbit. All these spacecraft carry powerful multispectral cameras optimized for their respective primary targets. MESSENGER is scheduled to end its six-year interplanetary cruise in March 2011 to enter Mercury orbit, but a similarly extended cruise with several gravity-assists awaits the European Mercury mission BepiColombo. Unfortunately, the automatic abort of the orbit insertion manoeuvre has also left Akatsuki (a.k.a. Venus Climate Orbiter (VCO), Planet-C) stranded in heliocentric orbit. After an unintended fly-by, the probe will catch up with Venus in approximately six years. Meanwhile, it stays mostly interior to Venus in a planet-leading orbit. In addition to the study of comets and their interaction with the IPM, observations of small bodies akin to those carried out by outer solar system probes are occasionally attempted with the equipment available. The study of structures in the interplanetary dust (IPD) cloud has been a science objective during the cruise phase of the Japanese Venus probe Akatsuki from Earth to Venus. IPD observations in the astronomical H-band (1.65 µm) are supported by its IR2 camera down to 1.5 µW/m2sr in single 2 minute exposures. In the same setting, point sources of 13 mag can be detected. Obviously, a number of large asteroids exceed this threshold. The Earthguard-1 study, completed in 2003 by the DLR Institute of Planetary Research and Kayser-Threde under ESA contract, proposed a dedicated steerable Ø20...35 cm telescope and CCD camera payload on a probe to the inner solar system, to detect Near-Earth and Inner-Earth Objects (NEOs, IEOs) in favourable opposition geometry. A ride-share on a Mercury orbiter and a dedicated low-thrust propulsion spacecraft to a heliocentric 0.5 AU orbit were studied. A similar-sized telescope is presently being developed for the AsteroidFinder satellite of DLR. Therefore, the technical feasibility of a number of asteroid observation scenarios involving spacecraft and targets interior to Earth’s orbit is assessed based on the latest available spacecraft information and asteroid population models. A rough estimate of the required effort in terms of ground-based spacecraft operations and on-board resources is given for selected representative scenarios

A wireless communication and positioning experiment for the ISS based on IR-UWB

This paper introduces a wireless experiment for sensing and positioning to be deployed in the Columbus module of the International Space Station (ISS). The experiment allows the monitoring of environmental parameters and it demonstrates the motion tracking of astronauts or free-flying objects by utilizing impulse radio – ultra wideband (IR-UWB) in combination with Micro Electromechanical Systems (MEMS) sensors. Recent work revealed a great potential in utilizing WSN in space habitats; however, the focus was only based on sensing in the narrowband Industrial Scientific and Medical (ISM) 2.45 GHz band, whereas this work extends these capabilities by utilizing IR-UWB for positioning and it optionally uses internal light sources for energy harvesting to drive the sensor nodes. The paper describes the operational scenario and the hardware and software concept are presented in detail. Finally the expected results are presented, which focus on the analysis of different use cases for the implementation of wireless sensor networks and to help and to identify new applications for future space missions

Dynamic link analysis and its in-orbit verification on a spin-stabilized satellite mission Eu:CROPIS

In this paper, we present the in-orbit verification of a dynamic link budget approach for the communication link of the Eu:CROPIS (Euglena and Combined Regenerative Organic-Food Production in Space) satellite. Due to the high satellite spin rates of up to 30 rpm the satellite antennas radio frequency (RF) beam becomes strongly dynamic, consisting of fast amplitude variations and phase rotations. Both effects degrade the link quality and might lead to an abort of the communication. The paper presents an accurate method of how to simulate these dynamic effects and examines the simulation outputs with real in-orbit measurements. Both results are compared with each other and deviations are discussed

Design of a small size, low profile L-band antenna, optimized for space-based ADS-B signal reception

traffic services, like the Automatic Dependent Surveillance Broadcast (ADS-B), already became a fundamental part in the civil and military aviation by the provision of aircraft tracking on ground and from space, in controlled and noncontrolled airspaces. In particular, the surveillance of aircraft from space has been identified as a trend-setting service and demand. In this paper, we present the design of a small size, low profile patch antenna, optimized for aircraft signal detection in spacecraft applications. The proposed antenna design is circularly polarized, using a single-feed configuration and it is tailored to small dimensions and the operation in a space environment

Maximizing Throughput in Deterministic and Low Latency Intra-Spacecraft UWB Sensor Networks

Sensor networks based on Impulse-Radio Ultra Wideband (IR-UWB) technology have gained traction in fields where precise localization and robust communication links are required. In spacecraft and launchers these networks can be used to connect sensors to a central on board computer or to provide a communication link between the different subsystems. This contributes to a reduced cable harness, a key driver in overall spacecraft mass and design complexity. A problem in low power wireless sensor networks is the low data throughput. This paper presents a high data throughput extension to an 802.15.4 standard compliant MAC layer for Ultra Wideband to accommodate for e.g. payload data acquisition or software update distribution to the different subsystems. Where the previous protocol allowed for a mere 3 kB/s of throughput in a typical configuration, the augmented MAC layer now is able to achieve up to 341 kB/s

Antenna subsystem far-field characterization of the spin-stabilized satellite Eu:CROPIS

In this paper, we present the far-field characterization of the antenna subsystem of the Eu:CROPIS (Euglena and Combined Regenerative Organic-Food Production in Space) satellite. Its specialty, in contrast to other satellite missions, is the spin-stabilization used in order to simulate the Moon and Mars gravitational fields for the biological on-board experimentation. Thereby, spin rates of up to 30 rpm are obtained, which have influence on the communication link. From the perspective of the ground station, the far-field becomes dynamical, including phase rotations and amplitude variations. Both can degrade the communication link and might lead to a loss of signal. Hence, a detailed analysis of these destructive phenomena is essential to be able to test possible effects on the receiver electronics beforehand and to avoid such issues in orbit. The far-field characterization is therefore an essential part of the overall design and verification process. It is initially performed by an Electromagnetic (EM)-field simulation, utilizing a (Multi-Level Fast Multipole Method) MLFMM-solver. After the identification of critical regions a mock-up based measurement in an anechoic chamber is performed to verify the simulated results. This paper introduces both characterization methods and compares the results

Wireless intra-spacecraft communication with inspaWSN protocol stack based on IR-UWB

In recent years, many attempts were made to replace wired connections with wireless communication networks in spacecraft and launchers. The benefits include a simplification of the harness design and routing as well as a reduction of harness cables and thus mass in space systems. However, commonly used wireless communication techniques are less reliable compared to their wired counterparts. Moreover, they are sensitive to RF interferences and multipath fading, which is an important design driver in a spacecraft environment with highly reflective enclosures. This paper presents a novel wireless protocol architecture for intra-spacecraft wireless sensor networks (inspaWSN), which makes use of the impulse-radio ultra wideband (IR-UWB) PHY according to IEEE 802.15.4-2011 and an optimized low latency and deterministic network protocol (LLDN) in order to achieve the strict requirements on existing spacecraft networks, e.g. low and deterministic latency behavior for the attitude and orbit control system (AOCS). The implementation and evaluation of the proposed protocol stack is performed on an STM32 microcontroller network consisting of 3 nodes. The results in this paper show that it is able to fulfill the strict timing requirements in order to accomplish deterministic communication with a latency of 10 ms and less in a typical AOCS configuration

A study on low-latency wireless sensing in timecritical satellite applications

The utilization of wireless sensor networks in satellite applications is promising, but at the same time a challenging task due to the stringent requirements. Especially time-critical subsystems, like the attitude and orbit control system (AOCS), require a low-latency and robust communication within its sensors and actuators network. In this paper, we propose a novel approach for wireless intra-satellite communication, which is based on the recently introduced IEEE 802.15.4e with its low-latency deterministic network (LLDN) mode utilizing IEEE 802.15.4a impulse radio – ultra wideband (IR-UWB). The analysis shows that it is able to fulfil the strict timing requirements in order to accomplish a deterministic communication with a latency of 10 ms and less in a typical AOCS configuration