PLATO (PLAnetary Transits and Oscillation of stars) is the ESA Medium size dedicated to exo-planets discovery and cataloguing, adopted in the framework of the Cosmic Vision 2015-2025. The PLATO launch is planned in 2026 and the mission will last at least 4 years in the Lagrangian point L2. The primary scientific goal of PLATO is to discover and characterize a large amount of exo-planets hosted by bright nearby stars. The PLATO strategy is to split the collecting area into 24(+2) identical 120 mm aperture diameter fully refractive cameras with partially overlapped Field of View delivering an overall instantaneous sky covered area of about >2100 square degrees. The opto-mechanical sub-system of each camera, namely Telescope Optical Unit (TOU), is basically composed by a 6 lenses fully refractive optical system, presenting one aspheric surface on the front lens, and by a mechanical structure made in AlBeMet. In this paper we will update on the current working status of the TOUs.
.We describe the main tasks of the Product Assurance process for the Telescope Optical Unit (TOU) of the ESA PLATO mission, that starts from the design phase and proceeds through all phases, up to the final product, with the aim of improving the likelihood of success of the mission. When dealing with the opto-mechanical components of the TOU, several aspects regarding safety and performance have to be analyzed and tracked. From the PA point of view, we focus in this paper on materials and processes selection that shall be suitable and robust enough for the space environment. Cleanliness and contamination control is needed to overcome loss of optical performance. Validations and qualifications on prototypes is fundamental to assess the reliability of the instrument for its purpose and for the lifetime of the mission.
In 1999 the European solar scientific community proposed to ESA the Solar Orbiter (SO), a mission to explore the circumsolar region, to perform quasi helio-synchronous observations, and to obtain the first out-of-ecliptic imaging and spectroscopy of the solar poles and of the equatorial corona. Presently, SO is one of the three missions under study within the ESA Cosmic Vision 2015-2025 program, and a key ESA-NASA missions within the International Living with a Star Program. SO, to be launched on January 2017, is expected to provide major advances steps forward in understanding the Sun-heliosphere connection.
CHEOPS (CHaracterizing ExOPlanets Satellite) is an ESA Small Mission, planned to be launched in early 2019 and whose main goal is the photometric precise characterization of the radii of exoplanets orbiting bright stars (V<12) already known to host planets. The telescope is composed by two optical systems: a compact on-axis F/5 Ritchey-Chrétien, with an aperture of 320 mm and a Back-End Optics, reshaping a defocused PSF on the detector. In this paper we describe how alignment and integration, as well as ground support equipment, realized on a demonstrator model at INAF Padova, evolved and were successfully applied during the AIV phase of the flight model telescope subsystem at LEONARDO, the Italian industrial prime contractor premises.
CHEOPS is the first small class mission adopted by ESA in the framework of the Cosmic Vision 2015-2025. Its launch is foreseen in early 2019. CHEOPS aims to get transits follow-up measurements of already known exo-planets, hosted by near bright stars (V<12). Thanks to its ultra-high precision photometry, CHEOPS science goal is accurately measure the radii of planets in the super-Earth to Neptune mass range (1<Mplanet/MEarth<20). The knowledge of the radius by transit measurements, combined with the determination of planet mass through radial velocity techniques, will allow the determination/refinement of the bulk density for a large number of small planets during the scheduled 3.5 years life mission. The instrument is mainly composed of a 320 mm aperture diameter Ritchey-Chretien telescope and a Back End Optics, delivering a de-focused star image onto the focal plane. In this paper we describe the opto-thermo-mechanical model of the instrument and the measurements obtained during the opto-mechanical integration and alignment phase at Leonardo company premises, highlighting the level of congruence between the predictions and measurements.
PLATO (PLAnetary Transits and Oscillation of stars) is the ESA Medium size dedicated to exo-planets discovery, adopted in the framework of the Cosmic Vision program. The PLATO launch is planned in 2026 and the mission will last at least 4 years in the Lagrangian point L2. The primary scientific goal of PLATO is to discover and characterize a large amount of exo-planets hosted by bright nearby stars, constraining with unprecedented precision their radii by mean of transits technique and the age of the stars through by asteroseismology. By coupling the radius information with the mass knowledge, provided by a dedicated ground-based spectroscopy radial velocity measurements campaign, it would be possible to determine the planet density. Ultimately, PLATO will deliver the largest samples ever of well characterized exo-planets, discriminating among their ‘zoology’. The large amount of required bright stars can be achieved by a relatively small aperture telescope (about 1 meter class) with a wide Field of View (about 1000 square degrees). The PLATO strategy is to split the collecting area into 24 identical 120 mm aperture diameter fully refractive cameras with partially overlapped Field of View delivering an overall instantaneous sky covered area of about 2232 square degrees. The opto-mechanical sub-system of each camera, namely Telescope Optical Unit, is basically composed by a 6 lenses fully refractive optical system, presenting one aspheric surface on the front lens, and by a mechanical structure made in AlBeMet.
The optical design of the FLuORescence Imaging Spectrometer (FLORIS) studied for the Fluorescence Explorer (FLEX) mission is discussed. FLEX is a candidate for the ESA’s 8th Earth Explorer opportunity mission. FLORIS is a pushbroom hyperspectral imager foreseen to be embarked on board of a medium size satellite, flying in tandem with Sentinel-3 in a Sun synchronous orbit at a height of about 815 km. FLORIS will observe the vegetation fluorescence and reflectance within a spectral range between 500 and 780 nm. Multi-frames acquisitions on matrix detectors during the satellite movement will allow the production of 2D Earth scene images in two different spectral channels, called HR and LR with spectral resolution of 0.3 and 2 nm respectively. A common fore optics is foreseen to enhance by design the spatial co-registration between the two spectral channels, which have the same ground spatial sampling (300 m) and swath (150 km). An overlapped spectral range between the two channels is also introduced to simplify the spectral coregistration. A compact opto-mechanical solution with all spherical and plane optical elements is proposed, and the most significant design rationales are described. The instrument optical architecture foresees a dual Babinet scrambler, a dioptric telescope and two grating spectrometers (HR and LR), each consisting of a modified Offnёr configuration. The developed design is robust, stable vs temperature, easy to align, showing very high optical quality along the whole field of view. The system gives also excellent correction for transverse chromatic aberration and distortions (keystone and smile).
The Multi Element Telescope for Imaging and Spectroscopy (METIS) is the coronagraph selected for the Solar Orbiter
payload, adopted in October 2011 by ESA for the following Implementation Phase. The instrument design has been
conceived by a team composed by several research institutes with the aim to perform both VIS and EUV narrow-band
imaging and spectroscopy of the solar corona. METIS, owing to its multi-wavelength capability, will address some of
the major open issues in understanding the physical processes in the corona and the solar wind origin and properties,
exploiting the unique opportunities offered by the SO mission profile. The METIS Processing and Power Unit (MPPU) is the Instrument's power supply and on-board data handling modular electronics, designed to address all the scientific requirements of the METIS Coronagraph. MPPU manages data and command flows, the timing and power distribution networks and its architecture reflects several trade-off solutions with respect to the allocated resources in order to reduce any possible electronics single-point failure. This paper reports on the selected HW and SW architectures adopted after the Preliminary Design Review (PDR), performed by ESA in early 2012.
This paper describes Ma_Miss (Mars Multispectral Imager for Subsurface Studies), the miniaturized instrument for
spectrometric and stratigraphic analysis of sub-soil developed by SELEX Galileo in the context of ESA ExoMars
mission. The Ma_Miss experiment is coordinated by the Principal Investigator Angioletta Coradini (IFSI-INAF, Rome)
and is funded by the Italian Space Agency (ASI).
The exploration of Mars requires a detailed in-situ investigation of the Martian surface and sub-surface. Determining the
composition of the Martian subsoil will provide a direct indication of the steps through which the sample material
evolved along geological timescales.
Ma_Miss is an instrument fully integrated in the Drill system (developed by SELEX Galileo) hosted by a Rover
operating on Mars surface; Ma_Miss illuminates the wall of the drill borehole and acquires its reflectance signal in the
Visible and Infrared (0.4-2.2 micron) range, analyzes it through a miniaturized spectrometer (20nm spectral resolution),
and transmits the digital data to the Rover.
The innovative instrument concept was driven by several key needs, related to challenging scientific requirements and
extreme environmental constraints. Implementation of the concept has required a deep interdisciplinary concurrent
development in order to solve critical aspects of engineering and manufacturing, covering miniaturized monolithic optics
and novel concept for fiberoptic connectors capable to automatically mate/de-mate during the robotic assembly of the
Drill elements on Mars.
The research project FABIOLA (Fluorescence Applied to BIOLogical Agents detection), coordinated by EDA
(European Defense Agency), has two main goals: to demonstrate the feasibility of detection of BW agents using LIF
(Laser Induced Fluorescence) technique, and develop BW early warning point detection lab-demonstrator based on LIF.
The Optical Detection System collects the fluorescence radiation emitted by the aerosol particle under test (hit by a
sequence of two UV laser pulses with 50ns delay), splits it into four wavebands covering the 350-600nm range, and
acquires the time decay shape by means of 4 ultra-fast MCP-PMTs that are read by a fast electronics. A fifth PMT is
devoted to the acquisition of the elastically scattered signal at the same laser excitation wavelength (293 and 337nm) for
data normalization. The Optical Detection System is based on waveband separation by a train of dichroic beamsplitters;
high-pass filtering is used for rejection of the scattered excitation beam. A lens system provides parallel beam on
dichroics and uniform illumination of MCP-PMTs. Main design drivers of ODS are the four selected fluorescence bands,
the required fast response for acquiring decay time of ns-order, and the capability to operate with two excitation pulses
(at 293 and 337nm) which shall be effectively rejected by fluorescence channels.
Laser Induced Fluorescence (LIF) could permit fast early warning systems either for point or stand-off detection if a reliable classification of warfare biological agents versus biological or non-biological fluorescing background can be achieved. In order to improve LIF discrimination capability, a new system is described in which the fluorescence pattern is enriched by the use of multiple wavelength delayed excitation while usual spectral fluorescence analysis is extended to time domain to use both aspects as criteria for classification. General considerations and guidelines for the system design are given as well as results showing good discrimination between background and simulants.
The definition and preliminary design of a thermal imager for earth observation applications has been performed, justified by a thorough analysis of user requirements. A survey of international programmes and other sources have been used to derive the radiometric requirements at ground level. Then instrument requirements at top of atmosphere have been obtained by means of the usual split-window techniques for land and sea. Preliminary instrument radiometric performances have been estimated on the basis of a review of possible instrument concepts (detectors and scan modes). A trade-off analysis between instrument requirements and performances led to the identification of two classes of instruments - the first based on high performance, cooled infrared detectors, and the second relying on microbolometer technology, with lower performance but not constrained by the need for a cryocooler. The applications feasible by means of each of them have been identified. The chosen instrument baseline was that using uncooled microbolometers, for which the best spatial and radiometric resolution achievable has been assessed, in order to cover as many applications as possible in view of the analysis of requirements. The selected baseline has been further detailed, up to a complete outline of the instrument, in order to confirm the achievable performance and assure its feasibility.
Radiometric Calibration is an essential activity, both on- ground and in-flight, for the correct operations of any Radiometer System. In the frame of M.I.M.R. (Multi-Frequency Imaging Microwave Radiometer) project, Officine Galileo participated from the early phases with system activities relevant to calibration and with development of Calibration devices. In particular the breadboard of the in-flight calibrator during phase B, and the Targets for on-ground radiometric characterization of M.I.M.R. during present Demonstrator phase, were designed, manufactured and tested. This paper describes the two Targets, working at fixed cryogenic temperature (Fixed temperature Target, FT) and at temperature settable from cryogenic to ambient (Variable temperature Target, VT) that have been used for the M.I.M.R. Demonstrator test campaign. Moreover the in-flight calibrator, that was also used in this campaign, is described.