The Thirty Meter Telescope (TMT) Primary Mirror (M1) is composed of 492 hexagonal aspheric segments. In order to compensate for residual polishing errors, installation errors, gravity effects and parasitic forces in the whiffletree support, each segment is equipped with 21 Warping Harness (WH) mechanisms, which allow low order corrections to the optical surface. The primary mirror segment aberrations after shape corrections with warping harness have been identified as the single largest error term in the Thirty Meter Telescope (TMT) image quality error budget [1]. The WH mechanism consists of a Linear Actuator, Ball Link and a Leaf Spring with strain gauge sensor. The Warping Harness key requirements are: high positioning accuracy, 50 years operational life time with minimum maintenance, low cost, high reliability, high resolution, low hysteresis, high stability in unpowered state, large operational temperature range, low power dissipation, vacuum compatibility and survival of accidental condensing conditions. Smooth motor has developed a robust, low cost linear actuator for the TMT M1 Warping Harness. A WH Accelerated Life Cycle Test with increased temperature extremes was successfully completed. Acceleration factors were calculated with the Coffin-Manson model for temperature. Compliance with the technical requirements for the WH system has been demonstrated.
Large Size Telescope (LST) is the largest telescope of the Cherenkov Telescopes Array (CTA), the next-generation ground-based γ-ray observatory. Its low weight and powerful motors aim to make it repointing any position in the sky in less than 20 s with a position accuracy lower than 30 arcsec. However, such a fast rotation of a big telescope implies constraints on motors and telescope structure. For this purpose, a Matlab/Simulink model taking into account all the components of LST was developed. This static model of LST is perturbed by several kinds of disturbances such as wind loading or motors effects which apply torques on the structure of LST. Numerous outputs such as pointing accuracy, power consumption and reached velocity can be monitored. These monitored parameters allow us to check the fulfilling of technical requirements by using the chosen components and to have references for the first tests on the real telescope.
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: 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: 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: 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.
The Euclid mission objective is to understand why the expansion of the Universe is accelerating through by mapping the geometry of the dark Universe
by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision
program with its launch planned for 2020 (ref [1]).
The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (900-
2000nm) as a photometer and spectrometer. The instrument is composed of:
- a cold (135K) optomechanical subsystem consisting of a Silicon carbide structure, an optical assembly (corrector and camera lens), a filter wheel
mechanism, a grism wheel mechanism, a calibration unit and a thermal control system
- a detection subsystem based on a mosaic of 16 HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a
mechanical focal plane structure made with molybdenum and aluminum. The detection subsystem is mounted on the optomechanical subsystem
structure
- a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the
spacecraft via a 1553 bus for command and control and via Spacewire links for science data
This presentation describes the architecture of the instrument at the end of the phase C (Detailed Design Review), the expected performance, the
technological key challenges and preliminary test results obtained for different NISP subsystem breadboards and for the NISP Structural and Thermal
model (STM).
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.
A new concept of electromechanical shutter has been designed and qualified for the OSIRIS imaging system to fly onboard the Rosetta Mission, whose main scientific goal are the randez-vous and the study of the Comet Wirtanen. The shutter, is composed by two blades, driven by dedicated four-bar linkages, that are moved independently by two torque motors each mounted on the same shaft of an high resolution optical encoder. A dedicate fail safe mechanism is also integrated in order to make the shutter single point failure proof. The mechanism has been designed in order to fulfil high reliability with high performance. Reliability has been verified by life testing over 100000 cycles (factor 2 on expected operative cycles). Performance verified by calibration show that the minimum exposure time with a uniformity of 1/500 is 10 ms over a large sensitive area (about 30x30 mm). The exposure time can vary from 10ms to 5s. Scope of this paper is to present the mechanism and to demonstrate that it accomplishes the sciences and interfaces requirements.
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