CHARACTERIZING EXOPLANETS IN THE VISIBLE AND INFRARED: A SPECTROMETER CONCEPT FOR THE EChO SPACE MISSION

Transit-spectroscopy of exoplanets is one of the key observational techniques used to characterize extrasolar planets and their atmospheres. The observational challenges of these measurements require dedicated instrumentation and only the space environment allows undisturbed access to earth-like atmospheric features such as water or carbon dioxide. Therefore, several exoplanet-specific space missions are currently being studied. One of them is EChO, the Exoplanet Characterization Observatory, which is part of ESA's Cosmic Vision 2015–2025 program, and which is one of four candidates for the M3 launch slot in 2024. In this paper we present the results of our assessment study of the EChO spectrometer, the only science instrument onboard this spacecraft. The instrument is a multi-channel all-reflective dispersive spectrometer, covering the wavelength range from 400 nm to 16μm simultaneously with a moderately low spectral resolution. We illustrate how the key technical challenge of the EChO mission — the high photometric stability — influences the choice of spectrometer concept and fundamentally drives the instrument design. First performance evaluations underline the suitability of the elaborated design solution for the needs of the EChO mission.

Download Full-text

PAOS, the Physical Optics Propagation model of the Ariel optical system

10.5194/epsc2021-241 ◽

2021 ◽

Author(s):

Andrea Bocchieri ◽

Enzo Pascale

Keyword(s):

Extrasolar Planets ◽

Optical Design ◽

Maximum Amplitude ◽

Space Mission ◽

Propagation Model ◽

Optical Systems ◽

Physical Optics ◽

Cosmic Vision ◽

Atmospheric Remote Sensing ◽

Cassegrain Telescope

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, is a medium-class space mission part of ESA's Cosmic Vision programme, due for launch in 2029. Ariel will survey a diverse sample of about 1000 extrasolar planets in the visible and infrared spectrum to answer questions about their composition, formation and evolution. Ariel mounts an off-axis Cassegrain telescope with a 1100 mm x 730 mm elliptical mirror and has two separate instruments (FGS and AIRS) that cover the 0.5-7.8 micron spectral range. To study the Ariel optical performance and related systematics, we developed PAOS, the Proper Ariel Optical Simulator, an End-to-End physical optics propagation model of the Ariel Telescope and subsystems based on PROPER, an optical propagation library for IDL, Python and Matlab. PAOS is a Python code that consists of a series of calls to PROPER library functions and procedures that reproduces the Ariel optical design, interleaved with additional code that can be specified according to the simulation. Using PAOS, we can investigate how diffraction affects the electromagnetic wavefront as it travels through the Ariel optical systems and the resulting PSFs in the photometric and spectroscopic channels of the mission. This enables to perform a large number of detailed analyses, both on the instrument side and on the optimisation of the Ariel mission. In particular, PAOS can be used to support the requirement on the maximum amplitude of the aberrations for the manufacturing of the Ariel primary mirror, as well as to develop strategies for in-flight calibration, e.g. focussing procedures for the FGS and AIRS focal planes, and to tackle systematics such as pointing jitter and vignetting. With the Ariel mission now in the process of finalizing the instrument design and the data analysis techniques, PAOS will greatly contribute in evaluating the Ariel payload performance with models to be included in the existing Ariel simulators such as ArielRad, the Ariel Radiometric model, and ExoSim, the Exoplanet Observation simulator, for the purpose of studying and optimising the science return from Ariel.

Download Full-text

The PLATO space mission: studying planetary transits and stellar oscillations simultaneously

Proceedings of the International Astronomical Union ◽

10.1017/s174392130802721x ◽

2008 ◽

Vol 4 (S253) ◽

pp. 564-566

Author(s):

Malcolm Fridlund

Keyword(s):

Thermal Environment ◽

Space Mission ◽

High Time Resolution ◽

Stellar Oscillations ◽

Cosmic Vision ◽

Exoplanetary Systems ◽

Seismic Oscillations ◽

Host Stars ◽

Very High ◽

Planetary Transits

AbstractPLATO (PLAnetary Transits and Oscilliations of stars) is a proposed mission of the European Space Agency's Science programme Cosmic Vision 2015–2025, currently under industrial study, and with a planned launch by the end of 2017. Its task is to better understand the properties of exoplanetary systems. As such it will detect and characterise exoplanets using their transit signature in front of a large sample of bright stars and simultaneously measuring the seismic oscillations of the parent star of these exoplanets. The mission will be orbiting the Sun-Earth L2 point, which provides a stable thermal environment and maximum uninterrupted observing efficiency. The payload consists of a number (> 28) of individual catadioptric telescopes, covering > 550 sq. degrees. Since the goal is to search for terrestrial exoplanets within the habitable zone of their host stars, and carry out asteroseismological observations of the host stars, very high photometric precision, high time resolution, and high duty-cycle visible photometry is required. Ground-based observations are needed to complement the observations made by PLATO to allow for further exoplanetary characterization. This paper consists of a summary of the preliminary results achieved by the ESA internal pre-assessment study.

Download Full-text

Micro-Heat-Sinks for Space Applications

ASME 2nd International Conference on Microchannels and Minichannels ◽

10.1115/icmm2004-2323 ◽

2004 ◽

Cited By ~ 1

Author(s):

M. Marengo ◽

S. Zhdanov ◽

L. Chignoli ◽

G. E. Cossali

Keyword(s):

Biomedical Applications ◽

Heat Pipes ◽

Thermal Control ◽

Space Mission ◽

Small Dimension ◽

Heat Sinks ◽

Space Environment ◽

Space Applications ◽

Space Requirements ◽

Further Development

During the space missions, the problems related to the thermal conditioning of devices, to the personnel comfort and to the thermo-mechanical stresses are known and important. Furthermore for a space mission certain priorities are stressed, such as the small dimension and the lightness of thermal equipments. Due to the presence of high temperature gradients, which straightforwardly implies significant heating/cooling powers, these characteristics are sometimes difficult to obtain. The decreasing of the satellites payloads in terms of mass and volume has brought to the necessity of a further development of traditional space technologies, such as heat pipes and radiators. A promising technology is the fabrication of micro-heat-sinks for active and passive thermal control systems suitable for the space environment, which is always an important workshop for future progresses. In fact, miniaturized heat sinks will have a terrestrial large industrial diffusion for electronic component cooling, in propulsion and in the power production for satellites, spacecrafts and airplanes, in various biomedical applications and in cloth conditioning in harsh environmental conditions. The present paper intends to introduce the reader to the standard space requirements, to present some new prospective and experiments to present some new prospective and experimental results and to discuss the use of thermal MEMS for micro- and nano-satellites.

Download Full-text

Ultraviolet Astronomy

Highlights of Astronomy ◽

10.1017/s1539299600001039 ◽

1968 ◽

Vol 1 ◽

pp. 94-107

Author(s):

R. Wilson

Keyword(s):

Rapid Development ◽

Space Mission ◽

The Other ◽

Space Environment ◽

Ultraviolet Region ◽

Ultraviolet Astronomy ◽

New Techniques ◽

Total Cost ◽

Actual Space ◽

Preparatory Stage

Ultraviolet astronomy is in a phase of very rapid development and any review of the new techniques involved is necessarily conditioned by the fact that most of the work is in a preparatory stage. This paper, therefore, will not be restricted to a discussion of those techniques which have undergone the ultimate test of their effectiveness, i.e., an actual space mission, but will include a consideration of those techniques which are still under development. Some omissions are therefore inevitable.The presentation is divided into three categories: (a) the vehicle and its stabilisation (if any), (b) the optics, and (c) detectors. Category (a) presents the major new technological problems and contributes the greater part of the total cost. Experience in the other categories of optics and detectors had, of course, reached an advanced and sophisticated level at the time of the advent of the rocket, but new and difficult problems have been posed mainly by their operation in a space environment, but also by their use in the ultraviolet region of the spectrum.

Download Full-text

Agile methodologies applied to Integrated Concurrent Engineering for spacecraft design

Research in Engineering Design ◽

10.1007/s00163-021-00371-y ◽

2021 ◽

Author(s):

J. M. Álvarez ◽

E. Roibás-Millán

Keyword(s):

Concurrent Engineering ◽

Collaborative Design ◽

Continuous Process ◽

Space Mission ◽

Fundamental Aspect ◽

Design Solution ◽

Spacecraft Design ◽

Agile Methodologies ◽

Space Projects ◽

General Aspects

AbstractIn recent years, space projects have evolved to faster and more variable projects. To adjust the design processes in accordance, new work methodologies arise, as the Concurrent Engineering (CE). This working discipline is characterized by collaborative design and the flux of information being improved by working in a dedicated environment. CE has been recently adopted by space industry for the preliminary design phase of spacecrafts and other space systems. However, this methodology does not envisage tasks prioritization, which is a fundamental aspect to achieve an optimal design solution with an efficient allocation of resources. In this work a variation of CE discipline by applying Agile methodologies (in which the aspect of task prioritization is essential), is proposed. Agile methodologies allow the proper distribution of the design effort depending on the project priorities, the state of the design and the requirements, in a continuous process to improve the design solution. The general aspects of the proposed method are presented and applied to the design of a space mission, the results being analysed and compared with to the classical CE process in order to outline its differences and similarities with CE and Agile methodologies and show its potential for a new environment for space project design.

Download Full-text

The SEE-COAST concept

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310011154 ◽

2009 ◽

Vol 5 (H15) ◽

pp. 718-719

Author(s):

Anthony Boccaletti ◽

Alessandro Sozzetti ◽

Jean Schneider ◽

Pierre Baudoz ◽

Giovanna Tinetti ◽

...

Keyword(s):

Extrasolar Planets ◽

Visible Spectrum ◽

Space Mission ◽

Near Ir ◽

The Earth ◽

Reflected Light ◽

Polarimetric Imaging

AbstractThe SEE COAST concept is designed with the objective to characterize extrasolar planets and possibly Super Earths via spectro-polarimetric imaging in reflected light. A space mission complementary to ground-based near IR planet finders is a first secure step towards the characterization of planets with mass and atmosphere comparable to that of the Earth. The accessibility to the Visible spectrum is unique and with important scientific returns.

Download Full-text

SPICES: A Mission Concept to Characterize Long Period Planets from Giants to Super-Earths

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313013331 ◽

2012 ◽

Vol 8 (S293) ◽

pp. 429-434

Author(s):

Anthony Boccaletti ◽

Anne-Lise Maire ◽

Raphaël Galicher ◽

Pierre Baudoz ◽

Dimitri Mawet ◽

...

Keyword(s):

Extrasolar Planets ◽

Circumstellar Disks ◽

Science Program ◽

Zodiacal Light ◽

Long Period ◽

Cosmic Vision ◽

Exoplanetary Systems ◽

Nearby Stars ◽

Esa Cosmic Vision

AbstractSPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) was proposed in 2010 for a five-year M-class mission in the context of ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets located at several AUs (0.5-10 AU) from nearby stars (<25 pc) with masses ranging from a few Jupiter masses down to super-Earths (~2 Earth radii, ~10 M⊕), possibly habitable. In addition, circumstellar disks as faint as a few times the zodiacal light in the Solar System can be studied. SPICES is based on a 1.5-m off-axis telescope and can perform spectro-polarimetric measurements in the visible (450 - 900 nm) at a spectral resolution of about 40. This paper summarizes the top science program and the choices made to conceive the instrument. The performance is illustrated for a few emblematic cases.

Download Full-text

The Characterizing Exoplanet Satellite (CHEOPS): news and first results

10.5194/epsc2020-1121 ◽

2020 ◽

Author(s):

Monika Lendl

Keyword(s):

High Precision ◽

Extrasolar Planets ◽

Planetary Atmospheres ◽

Space Mission ◽

Current Status ◽

Scientific Program ◽

Transiting Planets ◽

Exoplanetary Systems ◽

First Results ◽

Global Understanding

The Characterizing Exoplanets Satellite (CHEOPS) is the first ESA space mission dedicated primarily to the study of exoplanetary systems. The satellite, carrying a 30cm photometric telescope, has been launched successfully in December 2019 and has seen first light in January 2020. Throughout it's nominal mission of 3.5 years, it will perform ultra-high precision photometry of bright stars know to host extrasolar planets. Next to searching for transits of planets known from radial velocities and measuring precise radii of known transiting planets, CHEOPS will dedicate approximately 25% of its observing time to characterizing exoplanet atmospheres.&#160; In this talk, I will describe the CHEOPS space mission, summarize its scientific program and detail how we will use CHEOPS to probe exoplanet atmospheres, such as optical-light occultations and planetary phase curves. After introducing the mission, I will give an update on it's current status, performances and show first results. I will conclude by discussing synergies with other facilities, both ground- and space-based, and illustrate how together they will advance our global understanding of planetary atmospheres.

Download Full-text

Ariel Phase B

10.5194/epsc2020-696 ◽

2020 ◽

Author(s):

Giovanna Tinetti ◽

Paul Eccleston ◽

Theresa Lueftinger ◽

Goran Pilbratt ◽

Ludovic Puig ◽

...

Keyword(s):

Extrasolar Planets ◽

Planetary Science ◽

Guidance System ◽

Mission Design ◽

Phase Curve ◽

Loop Control ◽

Baseline Design ◽

Cosmic Vision ◽

Cassegrain Telescope ◽

The Uk

Ariel was selected as the fourth medium-class mission in ESA&#8217;s Cosmic Vision programme in the spring 2018. This paper provides an overall summary of the science and baseline design derived during the phase A and consolidated during the phase B1. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. Transit, eclipse and phase-curve spectroscopy means that no angular resolution is required. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. Detailed performance studies have demonstrated that the current mission design will achieve the necessary precision to observe all the Ariel target candidates within the mission lifetime. &#160; The baseline integrated payload consists of 1-metre class, all-aluminium, off-axis Cassegrain telescope, feeding a collimated beam into two separate instrument modules. A combined Fine Guidance System / VIS-Photometer / NIR-Spectrometer contains 3 channels of photometry between 0.50 &#181;m and 1.1 &#181;m, of which two will also be used as a redundant system for provided guidance and closed-loop control to the AOCS. One further low resolution (R = ~15 spectrometer in the 1.1 &#181;m &#8211; 1.95 &#181;m waveband is also accommodated here. The other instrument module, the ARIEL IR Spectrometer (AIRS), provides spectral resolutions of between 30 &#8211; 100 for a waveband between 1.95 &#181;m and 7.8 &#181;m. The payload module is passively cooled to ~55 K by isolation from the spacecraft bus via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling to <42 K via an active Ne JT cooler.&#160; The Ariel mission payload is developed by a consortium of more than 50 institutes from 17 ESA countries, which include the UK, France, Italy, Poland, Spain, Belgium, the Netherlands, Austria, Denmark, Ireland, Czech Republic, Hungary, Portugal, Norway, Estonia, Germany and Sweden. A NASA contribution was approved in November 2019.

Download Full-text