ARIEL (Atmospheric Remote-sensing InfraRed Large-survey) is the fourth medium-class mission (M4) of the European Space Agency, part of the Cosmic Vision program, whose launch is planned by late 2029. ARIEL aims to study the composition of exoplanet atmospheres, their formation and evolution. The ARIEL’s target will be a sample of about 1000 planets observed with one or more of the following methods: transit, eclipse and phase-curve spectroscopy, in both visible and infrared light. The scientific payload is composed by a reflective telescope having a 1m-class elliptical primary mirror, built in solid Aluminum, and two focal-plane instruments: FGS and AIRS. FGS (Fine Guidance System)3 has the double purpose of performing photometry (0.50-0.55 µm) and low resolution spectrometry over three bands (from 0.8 to 1.95 µm) and, simultaneously, to provide data to the spacecraft AOCS (Attitude and Orbit Control System). AIRS (ARIEL InfraRed Spectrometer) instrument will perform IR spectrometry in two wavelength ranges: between 1.95 and 3.9 µm (with a spectral resolution R > 100) and between 3.9 and 7.8 µm with a spectral resolution R > 30. This paper provides the status of the ICU (Instrument Control Unit), an electronic box whose purpose is to command and supply power to the AIRS warm front-end (as well as acquire science data from its two channels) and to command and control the TCU (Telescope Control Unit).
The ARIEL mission has the task of conducting a large, unbiased spectroscopic survey of exoplanets, in order to explore the nature of exoplanet atmospheres and interiors and, through this, the key factors affecting the formation and evolution of planetary systems in our galaxy. Ariel is composed of two scientific instrument: one is the FGS which provides the Fine Guidance System capabilities and in addition combines a VIS photometer and a NIR low resolution spectrometer. The other instrument is the Ariel IR Spectrometer (AIRS) which provides spectra with resolution between 30 and 100 on a spectral band between 1.95 and 7.8 micrometers. This paper will focus on the application SW of the Instrument Control Unit of the Ariel mission, which is in charge of controlling the AIRS instrument as well as the Telescope Control Unit (TCU), which controls the M2 Mirror Mechanism (M2M) and provides the temperatures of the Payload. In particular, we will discuss the design of the ASW and the development status of the SW. The Ariel ICU is based on a dual core Leon3-FT processor; the ASW is based on the space profile of the Multiprocessor version of RTEMS 6; we plan to use the multicore nature of the processor to separate the control functions from the data processing part (mainly compression). The ASW implements several standard PUS services, plus a set of instrument specific services for controlling the AIRS Detector Control Units (DCU) and the TCU. We will discuss the results of the coupling tests that have been performed to verify the communications between the ICU and the subsystems (DCUs and TCU), as well as between the ICU and the platform (using a dedicated Spacecraft Interface Simulator)
Euclid is a European Space Agency (ESA) wide-field space mission dedicated to the high-precision study of dark energy and dark matter. In July 2023 a Space X Falcon 9 launch vehicle put the spacecraft in its target orbit, located 1.5 million kilometers away from Earth, for a nominal lifetime of 6.5 years. The survey will be realized through a wide field telescope and two instruments: a visible imager (VIS) and a Near Infrared Spectrometer and Photometer (NISP). NISP is a state-of-the-art instrument composed of many subsystems, including an optomechanical assembly, cryogenic mechanisms, and active thermal control. The Instrument Control Unit (ICU) is interfaced with the SpaceCraft and manages the commanding and housekeeping production while the high-performance Data Processing Unit manages more than 200 Gbit of compressed data acquired daily during the nominal survey. To achieve the demanding performance necessary to meet the mission’s scientific goals, NISP requires periodic in-flight calibrations, instrument parameters monitoring, and careful control of systematic effects. The high stability required implies that operations are coordinated and synchronized with high precision between the two instruments and the platform. Careful planning of commanding sequences, lookahead, and forecasting instrument monitoring is needed, with greater complexity than previous survey missions. Furthermore, NISP is operated in different environments and configurations during development, verification, commissioning, and nominal operations. This paper presents an overview of the NISP instrument operations at the beginning of routine observations. The necessary tools, workflows, and organizational structures are described. Finally, we show examples of how instrument monitoring was implemented in flight during the crucial commissioning phase, the effect of intense Solar activity on the transmission of onboard data, and how IOT successfully addressed this issue.
Euclid, the M2 mission of the ESA’s Cosmic Vision 2015-2025 program, aims to explore the Dark Universe by conducting a survey of approximately 14 000 deg2 and creating a 3D map of the observable Universe of around 1.5 billion galaxies up to redshift z ∼ 2. This mission uses two main cosmological probes: weak gravitational lensing and galaxy clustering, leveraging the high-resolution imaging capabilities of the Visual Imaging (VIS) instrument and the photometric and spectroscopic measurements of the Near Infrared Spectrometer and Photometer (NISP) instrument. This paper details some of the activities performed during the commissioning phase of the NISP instrument, following the launch of Euclid on July 1, 2023. In particular, we focus on the calibration of the NISP detectors’ baseline and on the performance of a parameter provided by the onboard data processing (called NISP Quality Factor, QF) in detecting the variability of the flux of cosmic rays hitting the NISP detectors. The NISP focal plane hosts sixteen Teledyne HAWAII-2RG (H2RG) detectors. The calibration of these detectors includes the baseline optimization, which optimizes the dynamic range and stability of the signal acquisition. Additionally, this paper investigates the impact of Solar proton flux on the NISP QF, particularly during periods of high Solar activity. Applying a selection criterion on the QF (called NISP QF Proxy), the excess counts are used to monitor the amount of charged particles hitting the NISP detectors. A good correlation was found between the Solar proton flux component above 30 MeV and the NISP QF Proxy, revealing that NISP detectors are not subject to the lower energy components, which are absorbed by the shielding provided by the spacecraft.
Ariel is the M4 mission of the ESA’s Cosmic Vision Program 2015-2025, whose aim is to characterize by lowresolution transit spectroscopy the atmospheres of over one thousand warm and hot exoplanets orbiting nearby stars. It has been selected by ESA in March 2018 and adopted in November 2020 to be flown, then, in 2029. It is the first survey mission dedicated to measuring the chemical composition and thermal structures of the atmospheres of hundreds of transiting exoplanets, in order to enable planetary science far beyond the boundaries of the Solar System. The Payload (P/L) is based on a cold section (PLM – Payload Module) working at cryogenic temperatures and a warm section, located within the Spacecraft (S/C) Service Vehicle Module (SVM) and hosting five warm units operated at ambient temperature (253-313 K). The P/L and its electrical, electronic and data handling architecture has been designed and optimized to perform transit spectroscopy from space during primary and secondary planetary eclipses in order to achieve a large set of unbiased observations to shed light and fully understand the nature of exoplanets atmospheres, retrieving information about planets interior and determining the key factors affecting the formation and evolution of planetary systems.
KEYWORDS: Sensors, X-rays, Electronics, Signal detection, Field programmable gate arrays, Amplifiers, System on a chip, Software development, Prototyping, Data compression
In this paper we describe the current development state of the Athena X-IFU instrument control unit and its application software. Athena is a ESA large mission scheduled for launch in the early 2030s, that has reached the instrument requirement review phase. Not all of the needed functionalities are frozen yet, but the baseline concept and implementation will be described. While the hardware part will be based on well developed solution, some of the software functionalities, in particular the OBCP engine, will need to be developed and qualified. We will describe our approach for development and testing. The X-IFU instrument will use a Spacewire network for communications with the platform and internally between the ICU and the other subsystems, with the ICU providing the routing capabilities for housekeeping telemetry and telecommand as well as the scientific data. We will describe some aspects of the implementation of such a network.
The Coronal Magnetograph - CorMag - experiment aims at studying the magnetic field topology of the solar corona. The direction of the coronal magnetic field vector would be derived from narrow-wavelength bandpass observations of the linearly polarized FeXIV line-emission (530.3 nm), interpreted through the "saturated" Hanle effect. CorMag will be a medium-duration, high-altitude balloon payload of the European Union-funded HEMERA Program. CorMag is an internally-occulted coronagraph whose design was derived from the externally-occulted, formation-flying ASPIICS coronagraph of the PROBA-3 ESA solar mission. The configuration for this mission will be illustrated, together with the expected polarization sensitivity. This mission is a demonstrator for future space-based coronagraphs with the capability of visible-light and infrared polarization measurements for coronal magnetic field diagnostics.
ESA’s mission Euclid while undertaking its final integration stage is fully qualified. Euclid will perform an extra galactic survey (0<z<2) using visible and near-infrared light. To detect the infrared radiation is equipped with the Near Infrared Spectro-Photometer (NISP) instrument with a sensitivity in the 0.9-2 μm range. We present an illustration of the NISP Data Processing Unit’s Application Software, highlighting the experimental process to obtain the final parametrization of the on-board processing of data produced by an array of 16 Teledyne’s HAWAII-2RG (HgCdTe) - each of 2048×2048 px2, 0.3 arcsec/px, 18 μm pixel pitch; using data from the latest test campaigns done with the flight configuration hardware - complete optical system (Korsh anastigmat telescope), detectors array (0.56 deg2 firld of view) and readout systems (16 Digital Control Units and Sidecar ASICs). Also, we show the outstanding Spectrometric (using a Blue and two Red Grisms) and Photometric (using YE 0.92-1.15μm, JE 1.15-1.37μm, and HE 1.37-2.0 μm filters) performances of the NISP detector derived from the end-to-end payload module test campaign at FOCAL 5 - CSL; among them the Photometric Point Spread Function (PSF) determination, and the Spectroscopic dispersion verification. Also the performances of the onboard processing are presented. Then, we describe the solution of a major issue found during this final test phase that put NISP in the critical path. We will describe how the problem was eventually understood and solved thanks to an intensive coordinated effort of an independent review team (tiger team lead by ESA) and a team of NISP experts from the Euclid Consortium. An extended PLM level campaign in ambient in Liege and a dedicated test campaign conducted in Marseille on the NISP EQM model, with both industrial and managerial support, finally confirmed the correctness of the diagnosis of the problem. Finally, the Euclid’s survey is presented (14000 deg2 wide survey, and ∼40 deg2 deep-survey) as well as the global statistics for a mission lifetime of 6 years (∼1.5 billion Galaxy’s shapes, and ∼50 million Galaxy’s spectra).
KEYWORDS: Process control, Data processing, Computer architecture, Control systems, Network architectures, Amplifiers, Operating systems, Space operations
In this paper we describe the activities towards the design of a common framework for the Instrument Control and Data Processing Units for the three scientific payload instruments on board the joint ESA-JAXA SPICA mission, currently at the end of its phase A study. In this context, we started a program to assess modular architectures based on the use of a quad-core fault-tolerant LEON4 SPARC V8 processor on a SpaceWire network. We will describe the results of our initial tests using both Asymmetric Multi processing (AMP) and Symmetric Multi Processing (SMP) configurations. In addition, the possibility to adopt the RTEMS real time operating system, already space qualified on single core processors, will be evaluated both in terms of latency performances and of dynamical allocation of the resources. Finally, we will present the outline of the way forward for the next phases of the SPICA project.
In this paper we describe the final status of the application software (ASW) of the instrument control unit (ICU) of NISP, the Near-Infrared Spectro-Photometer of the Euclid mission, as the version for Flight has been tested and delivered to the industry for the next integration phases. This software is based on a real-time operating system (RTEMS) and will interface with all the subunits of NISP, as well as the command and data management unit (CDMU) of the spacecraft for telecommand and housekeeping management. We will describe in particular the final tests and the main obstacles which had to be faced in order to implement an efficient and reliable interface with all the NISP subsystems.
KEYWORDS: Sensors, Data processing, Space operations, Data acquisition, Signal detection, Electronics, Control systems, Interfaces, Software development
In this paper we describe the application software (ASW) of the instrument control unit (ICU) of NISP, the Near-Infrared Spectro-Photometer of the Euclid mission. This software is based on a real-time operating system (RTEMS) and will interface with all the subunits of NISP, as well as the command and data management unit (CDMU) of the spacecraft for telecommand and housekeeping management.
KEYWORDS: Control systems, Software development, Space operations, Data processing, Sensors, Control systems, Data acquisition, Field programmable gate arrays, Technetium, Electronics, Calibration
In this paper we describe the detailed design of the application software (ASW) of the instrument control unit (ICU) of
NISP, the Near-Infrared Spectro-Photometer of the Euclid mission. This software is based on a real-time operating
system (RTEMS) and will interface with all the subunits of NISP, as well as the command and data management unit
(CDMU) of the spacecraft for telecommand and housekeeping management. We briefly review the main requirements
driving the design and the architecture of the software that is approaching the Critical Design Review level. The
interaction with the data processing unit (DPU), which is the intelligent subunit controlling the detector system, is
described in detail, as well as the concept for the implementation of the failure detection, isolation and recovery (FDIR)
algorithms. The first version of the software is under development on a Breadboard model produced by
AIRBUS/CRISA. We describe the results of the tests and the main performances and budgets.
KEYWORDS: Space telescopes, Space operations, Telescopes, Space operations, Local area networks, Databases, Control systems, Fermium, Frequency modulation, Device simulation, Data modeling
The Near Infrared Spectro-Photometer (NISP) on board the Euclid ESA mission will be developed and tested at various
levels of integration by using various test equipment. The Electrical Ground Support Equipment (EGSE) shall be
required to support the assembly, integration, verification and testing (AIV/AIT) and calibration activities at instrument
level before delivery to ESA, and at satellite level, when the NISP instrument is mounted on the spacecraft. In the case of
the Euclid mission this EGSE will be provided by ESA to NISP team, in the HW/SW framework called "CCS Lite", with
a possible first usage already during the Warm Electronics (WE) AIV/AIT activities. In this paper we discuss how we
will customize that "CCS Lite" as required to support both the WE and Instrument test activities. This customization will
primarily involve building the NISP Mission Information Base (the CCS MIB tables) by gathering the relevant data from
the instrument sub-units and validating these inputs through specific tools. Secondarily, it will imply developing a
suitable set of test sequences, by using uTOPE (an extension to the TCL scripting language, included in the CCS
framework), in order to implement the foreseen test procedures. In addition and in parallel, custom interfaces shall be set
up between the CCS and the NI-IWS (the NISP Instrument Workstation, which will be in use at any level starting from
the WE activities), and also between the CCS and the TCC (the Telescope Control and command Computer, to be only
and specifically used during the instrument level tests).
KEYWORDS: Data storage, Near infrared, Computing systems, Data processing, Sensors, Data archive systems, Data modeling, Control systems, Databases, Data conversion
The NISP instrument on board the Euclid ESA mission will be developed and tested at different levels of integration
using various test equipment which shall be designed and procured through a collaborative and coordinated effort. The
NISP Instrument Workstation (NI-IWS) will be part of the EGSE configuration that will support the NISP AIV/AIT
activities from the NISP Warm Electronics level up to the launch of Euclid. One workstation is required for the NISP
EQM/AVM, and a second one for the NISP FM. Each workstation will follow the respective NISP model after delivery
to ESA for Payload and Satellite AIV/AIT and launch. At these levels the NI-IWS shall be configured as part of the
Payload EGSE, the System EGSE, and the Launch EGSE, respectively. After launch, the NI-IWS will be also re-used in
the Euclid Ground Segment in order to support the Commissioning and Performance Verification (CPV) phase, and for
troubleshooting purposes during the operational phase.
The NI-IWS is mainly aimed at the local storage in a suitable format of the NISP instrument data and metadata, at local
retrieval, processing and display of the stored data for on-line instrument assessment, and at the remote retrieval of the
stored data for off-line analysis on other computers.
We describe the design of the IWS software that will create a suitable interface to the external systems in each of the
various configurations envisaged at the different levels, and provide the capabilities required to monitor and verify the
instrument functionalities and performance throughout all phases of the NISP lifetime.
KEYWORDS: Control systems, Electronics, X-ray imaging, X-rays, Sensors, Interfaces, Space operations, X-rays, Control systems, Data compression, Signal detection, Field programmable gate arrays
Athena is one of L-class missions selected in the ESA Cosmic Vision 2015-2025 program for the science theme of the Hot and Energetic Universe. The Athena model payload includes the X-ray Integral Field Unit (X-IFU), an advanced actively shielded X-ray microcalorimeter spectrometer for high spectral resolution imaging, utilizing cooled Transition Edge Sensors. This paper describes the preliminary architecture of Instrument Control Unit (ICU), which is aimed at operating all XIFU’s subsystems, as well as at implementing the main functional interfaces of the instrument with the S/C control unit. The ICU functions include the TC/TM management with S/C, science data formatting and transmission to S/C Mass Memory, housekeeping data handling, time distribution for synchronous operations and the management of the X-IFU components (i.e. CryoCoolers, Filter Wheel, Detector Readout Electronics Event Processor, Power Distribution Unit). ICU functions baseline implementation for the phase-A study foresees the usage of standard and Space-qualified components from the heritage of past and current space missions (e.g. Gaia, Euclid), which currently encompasses Leon2/Leon3 based CPU board and standard Space-qualified interfaces for the exchange commands and data between ICU and X-IFU subsystems. Alternative architecture, arranged around a powerful PowerPC-based CPU, is also briefly presented, with the aim of endowing the system with enhanced hardware resources and processing power capability, for the handling of control and science data processing tasks not defined yet at this stage of the mission study.
The Astrometric Instrument Model system comprises several monitoring and diagnostic tasks for the astrometric
instrument aboard Gaia. It is a hierarchy of dedicated software modules aimed at decreasing the parameter degeneration
of the relation linking the observations to the instrumental behavior, and optimize the estimation process at the CCD and
field-of-view crossing level. Critical for the system is the definition and maintenance of a physical instrument model
fitting the science data, and able to accommodate non nominal configurations. Precise modeling of the astrometric
response is required for optimal definition of the data reduction and calibration algorithms, and to ensure high sensitivity
to both instrumental and astrophysical source parameters.
The implementation of the simultaneous combination of several telescopes (from four to eight) available at
Very Large Telescope Interferometer (VLTI) will allow the new generation interferometric instrumentation
to achieve interferometric image synthesis with unprecedented resolution and efficiency. The VLTI Spectro
Imager (VSI) is the proposed second-generation near-infrared
multi-beam instrument for the Very Large
Telescope Interferometer, featuring three band operations (J, H and K), high angular resolutions (down to
1.1 milliarcsecond) and high spectral resolutions. VSI will be equipped with its own internal Fringe Tracker
(FT), which will measure and compensate the atmospheric perturbations to the relative beam phase, and in
turn will provide stable and prolonged observing conditions down to the magnitude K=13 for the scientific
combiner. In its baseline configuration, VSI FT is designed to implement, from the very start, the minimum
redundancy combination in a nearest neighbor scheme of six telescopes over six baselines, thus offering better options for rejection of large intensity or phase fluctuations over each beam, due to the symmetric set-up.
The planar geometry solution of the FT beam combiner is devised to be easily scalable either to four or eight
telescopes, in accordance to the three phase development considered for VSI. The proposed design, based
on minimum redundancy combination and bulk optics solution, is described in terms of opto-mechanical
concept, performance and key operational aspects.
In ground based interferometric observations, fringe stabilization over long integration times is a mandatory task in order
to achieve useful performances even on faint sources. This is done by dedicated instruments which search the maximum
of the fringe envelope and consequently correct the optical path of the interfering beams. Localization of the fringe
maximum position is corrupted by noise coming both from turbulent atmosphere and instruments. Atmospheric
fluctuations are corrected at telescope level, but high frequency disturbance, as well as inter-telescope one, still remain.
These residuals must be recognized and separated from the source signal, in order to properly model the instrument
behaviour. Moreover, algorithms for fringe tracking must be strong enough to tolerate residual noise and instrument
model inaccuracy.
We provide some examples of noise performance of both calibration and fringe maximum localization based on
laboratory experiments.
The VLTI system foresees two generations of fringe sensor: FINITO and PRIMA FSUs. The former is dedicated to H band; it controls the internal OPD with a temporal modulation with an external reference OPD. The latter, working with the ABCD model and in K band, is based on the introduction of known phase offsets for the interferometric signal (spatial phase modulation) and on the measurement of the corresponding combined power. Simulation models for both FSUs are developed with Matlab. Instrumental parameters, i.e. phase, transmission, visibility, are tabulated for ease of maintenance and to speed execution time. For the use of siderostats, due to fast turbulence, the need for intensity calibration arises. Assuming slow intensity variations with respect to phase variations, different algorithms can apply, yielding to numerical control of perturbations as a function of model parameters.
FINITO is the first generation VLTI fringe sensor, optimised for three beam observations, recently installed at Paranal and currently used for VLTI optimisation. The PRIMA FSU is the second generation, optimised for astrometry in dual-feed mode, currently in construction. We discuss the constraints of fringe tracking at VLTI, the basic functions required for stabilised interferometric observations, and their different implementation in the two instruments, with remarks on the most critical technical aspects. We provide an estimate of the expected performance and describe some of their possible observing and calibration modes, with reference to the current scientific combiners.
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