The ESA Science Programme Committee (SPC) selected CHEOPS (Characterizing Exoplanets Satellite) in October 2012 as the first Small-class mission (S1) within the Agency’s Scientific Programme, with the following requirements: science driven mission selected through an open Call; an implementation cycle, from the Call to launch, drastically shorter than for Medium-class (M) and Large-class (L) missions; a strict cost-cap to ESA, with possibly higher Member States involvement than for M or L missions. The CHEOPS mission is devoted to the characterization of known exoplanets orbiting bright stars, achieved through the precise measurement of exoplanet radii using the technique of transit photometry. It was adopted for implementation in February 2014 as a partnership between the ESA Science Programme and Switzerland, with a number of other Member States delivering significant contributions to the instrument development and to operations. The CHEOPS instrument is an optical Ritchey-Chrétien telescope with 300 mm effective aperture diameter and a large external baffle to minimize straylight. The compact CHEOPS spacecraft (approx. 300 kg, 1.5 m size), based on a flight-proven platform, will orbit the Earth in a dawn-dusk Sun Synchronous Orbit at 700 km altitude. CHEOPS completed the Preliminary Design Review at the end of September 2014, and passed the Critical Design Review in May 2016. In the course of 2017, flight platform and payload have been integrated and tested, while satellite level activities are planned to start in early 2018, targeting flight readiness by the end of the year. The paper describes the latest CHEOPS development status, focusing on the acceptance test performed on instrument and platform, as well as on the satellite level environmental test campaign.
The fairing of the launcher selected for the Space Infrared telescope for Cosmology and Astrophysics (SPICA) mission is not compatible with a primary mirror of 3.5m in diameter. Thus three alternative optical designs of the SPICA Telescope Assembly (STA) with a primary mirror of reduced size were defined and their theoretical optical performances assessed. The impact of the size reduction on the STA optical performances was then quantified. Based on the results of the study, we defined a STA optical design optimum in terms of optical performances and of accommodation of instruments in the STA focal surface.
The James Webb Space Telescope (JWST), with its unprecedented sensitivity, will provide a unique set of tools for the study of transiting exoplanets and their atmospheres. The Near Infrared Spectrograph (NIRSpec) is one of four scientific instruments on JWST and offers a high-contrast aperture-spectroscopy mode developed specifically for exoplanet observations.
Here we present the NIRSpec Exoplanet Exposure Time Calculator (NEETC) software, an exposure time calculator optimized to evaluate the signal-to-noise ratio and simulate spectra for observations of transiting exoplanets. The NEETC is being developed to help the NIRSpec instrument team, and ultimately future JWST users, to fully investigate NIRSpec’s observation modes and the feasibility of exoplanet observations. We give examples of how the NEETC can be used to prepare observations, and present results highlighting the capabilities and limitations of NIRSpec.
CHEOPS (CHaracterizing ExOPlanets Satellite) is the first ESA Small Mission as part of the ESA Cosmic Vision program 2015-2025. The mission was formally adopted in early February 2014 with a planned launch readiness end of 2017. The mission lead is performed in a partnership between Switzerland, led by the University of Bern, and the European Space Agency with important contributions from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden, and the United Kingdom. The mission is dedicated to searching for exoplanetary transits by performing ultrahigh precision photometry on bright starts already known to host planets whose mass has been already estimated through ground based observations. The instrument is an optical Ritchey-Chretien telescope of 30 cm clear aperture using a single CCD detector. The optical system is designed to image a de-focused PSF onto the focal plane with very stringent stability and straylight rejection requirements providing a FoV of 0.32 degrees full cone. The system design is adapted to meet the top-level science requirements, which ask for a photometric precision of 20ppm, in 6 hours integration time, on transit measurements of G5 dwarf stars with V-band magnitudes in the range 6≤V≤9 mag. Additionally they ask for a photometric precision of 85 ppm in 3 hours integration time of Neptune-size planets transiting K-type dwarf stars with V-band magnitudes as faint as V=12 mag. Given the demanding schedule and cost constrains, the mission relies mostly on components with flight heritage for the platform as well as for the payload components. Nevertheless, several new developments are integrated into the design as for example the telescope structure and the very low noise, high stability CCD front end electronics. The instrument and mission have gone through critical design review in fall 2015 / spring 2016. This paper describes the current instrument and mission design with a focus on the instrument. It outlines the technical challenges and selected design implementation. Based on the current status, the instrument noise budget is presented including the current best estimate for instrument performance. The current instrument design meets the science requirements and mass and power margins are adequate for the current development status.
The European Space Agency (ESA) Science Programme Committee (SPC) selected CHEOPS (Characterizing Exoplanets
Satellite) in October 2012 as the first S-class mission (S1) within the Agency’s Scientific Programme, targeting
launch readiness by the end of 2017. The CHEOPS mission is devoted to the first-step characterization of known
exoplanets orbiting bright stars, to be achieved through the precise measurement of exo-planet radii using the technique
of transit photometry. It is implemented as a partnership between ESA and a consortium of Member States led by
CHEOPS is considered as a pilot case for implementing ”small science missions” in ESA with the following
requirements: science driven missions selected through an open Call for missions (bottom-up process); spacecraft
development schedule much shorter than for M and L missions, in the range of 4 years; and cost-capped missions to ESA
with possibly higher Member States involvement than for M or L missions.
The paper describes the CHEOPS development status, focusing on the performed hardware manufacturing and test
The Exoplanet Characterisation Observatory (EChO) mission was one of the proposed candidates for the European Space Agency’s third medium mission within the Cosmic Vision Framework. EChO was designed to observe the spectra from transiting exoplanets in the 0.55-11 micron band with a goal of covering from 0.4 to 16 microns. The mission and its associated scientific instrument has now undergone a rigorous technical evaluation phase and we report here on the outcome of that study phase, update the design status and review the expected performance of the integrated payload and satellite.
EChO is an M-class mission candidate within the science program Cosmic Vision 2015-2025 of the European Space Agency. It aims at characterising the atmosphere of known transiting exoplanets, potentially from giant Hot Jupiters down to Super-Earths orbiting in the habitable zone of M-dwarf stars.
It was selected in February 2011 to enter an assessment phase (phase 0/A). Following the completion of the Concurrent Design Facility study conducted by ESA in June/July 2011, two parallel industrial studies were carried out throughout 2012, and were then extended till August 2013. Similarly, two parallel instrument studies were conducted till mid-2012, following which an Announcement of Opportunity was released and concluded in February 2013 by the selection of a single instrument consortium.
This paper describes the status of EChO upon completion of the system level and instrument studies. It includes a discussion on the evolution of the science and mission requirements, the description of the final preliminary design and performance parameters, as well as programmatic estimates in terms of technology readiness and schedule.
The next step for EChO will consist of passing the Preliminary Requirements Review, planned by the end of 2013, followed by the down-selection of a single M3 mission.
The Japanese SPace Infrared telescope for Cosmology and Astrophysics, SPICA, will provide astronomers with a long
awaited new window on the universe. Having a large cold telescope cooled to only 6K above absolute zero, SPICA will
provide a unique environment where instruments are limited only by the cosmic background itself. A consortium of
European and Canadian institutes has been established to design and implement the SpicA FAR infrared Instrument
SAFARI, an imaging spectrometer designed to fully exploit this extremely low far infrared background environment
provided by the SPICA observatory.
SAFARI’s large instantaneous field of view combined with the extremely sensitive Transition Edge Sensing detectors
will allow astronomers to very efficiently map large areas of the sky in the far infrared – in a square degree survey of a
1000 hours many thousands of faint sources will be detected, and a very large fraction of these sources will be fully
spectroscopically characterised by the instrument. Efficiently obtaining such a large number of complete spectra is
essential to address several fundamental questions in current astrophysics: how do galaxies form and evolve over cosmic
time?, what is the true nature of our own Milky Way?, and why and where do planets like those in our own solar system
come into being?
The Space Infrared Telescope for Cosmology and Astrophysics (SPICA) is a 3.2m cooled (below 6K) telescope
mission which covers mid- and far-IR waveband with unprecedented sensitivity. An overview of recent design
updates of the Scientific Instrument Assembly (SIA), composed of the telescope assembly and the instrument
optical bench equipped with Focal Plane Instruments (FPIs) are presented. The FPI international science and
engineering review is on-going to determine the FPI suite onboard SPICA: at present the mandatory instruments
and functions to perform the unique science objectives of the SPICA mission are now consolidated. The final
decision on the composition of the FPI suite is expected in early 2013. Through the activities in the current pre-project
phase, several key technical issues which impact directly on the instruments’ performances and the science
requirements and the observing efficiency have been identified, and extensive works are underway both at
instrument and spacecraft level to resolve these issues and to enable the confirmation of the SPICA FPI suite.
EChO is an M-class mission candidate within the science program Cosmic Vision 2015-2025 of the European Space
Agency. It was selected in February 2011 to enter an assessment phase (phase 0/A). Following the internal Concurrent
Design Facility study conducted by ESA in June/July 2011, a call for instrument studies was released in September,
resulting in two consortia being selected to study the complete science instrument on board EChO throughout 2012.
Similarly, two parallel competitive industrial studies of the complete mission will end early 2013.
The instrument study focuses on the design and accommodation in the spacecraft of the scientific instrument, a
spectrometer divided into several channels covering the 0.55 to 11 micron (0.4 to 16 micron goal) wave band. It also
includes the design of the active cryogenic chain required to operate the instrument focal plane detectors.
The industrial study focuses on the complete system-level design, including the mission analysis and operations, the
spacecraft design (both service and payload modules) and also programmatic aspects such as risk mitigation, schedule
and cost analyses.
This paper describes the status of the EChO assessment study at the mid-term review (June/July 2012). It includes a short
introduction to the EChO mission, a brief update on recent work by the Science Study Team (SST) to refine the science
requirements, the description of the telescope trade-off and baseline selection, as well as the status of both instrument
consortia and industrial system-level studies.
The Exoplanet Characterisation Observatory (EChO) is a medium class mission candidate within the science program
Cosmic Vision 2015-2025 of the European Space Agency. It was selected in February 2011 as one of 4 M3 mission
candidates to enter an assessment phase. The assessment activities start with the definition of science and mission
requirements as well as of a preliminary model payload, followed by an internal Concurrent Design Facility (CDF)
study. Parallel industrial studies will follow in 2012, after which the 4 missions will be reviewed to identify candidates
entering definition phase studies in 2013.
EChO aims at characterising the atmosphere of known transiting exoplanets, potentially from giant Hot Jupiters down to
Super-Earths orbiting in the habitable zone of M-dwarf stars. It will use a 1 m class telescope, feeding a spectrometer
covering the wave lengths from 0.4 to 11 microns with a potential extension to 16 microns. While spatial differentiation
of the exoplanet and its host star is not necessary, spectral differentiation will be achieved by making differential
measurements of in- and out- of transit frames to cancel the star signal.
This paper describes critical requirements, and gives an overview of the model payload design. It also reports on the
results of the CDF.
The Japanese led Space Infrared telescope for Cosmology and Astrophysics (SPICA) will observe the universe over the
5 to 210 micron band with unprecedented sensitivity owing to its cold (~5 K) 3.5m telescope. The scientific case for a
European involvement in the SPICA mission has been accepted by the ESA advisory structure and a European
contribution to SPICA is undergoing an assessment study as a Mission of Opportunity within the ESA Cosmic Vision
1015-2015 science mission programme. In this paper we describe the elements that are being studied for provision by
Europe for the SPICA mission. These entail ESA directly providing the cryogenic telescope and ground segment
support and a consortium of European insitutes providing a Far Infrared focal plane instrument. In this paper we
describe the status of the ESA study and the design status of the FIR focal plane instrument.
We have developed a novel wideband spectrometer for astronomical heterodyne spectroscopy. The spectrometer, WASP, has 3250 MHz bandwidth and 33 MHz resolution, a combination well matched to submillimeter spectroscopy of high-redshift objects, interacting galaxies, active galactic nuclei, and planetary atmospheres. The spectrometer is an autocorrelation spectrometer with analog microwave integrated circuit multipliers separated by microstripline transmission line delays. Our prototype spectrometer is compact, requires little power (75 W), and integrates stably for many hours.