French Space Research Articles

LithoSpace: An Idea for an Automated System for in situ Petrographic Thin Section Preparation on Mars and Other Extraterrestrial Rocky Bodies

Optical microscopy analyses using thin sections is one of the most standard techniques in geology. It permits identification of most rock-forming minerals and it is essential for micropaleontology since observation in transmitted light is the only way to observe individual, or colonies of, microfossils in their mineralogical and textural context. Thin sections are also used for other techniques such as Raman spectroscopy. In the framework of exploration of the Martian surface and of the search for potential relics of microbial life, the possibility to observe petrographic thin sections in situ would be revolutionary. Nevertheless, although optical microscopes can be readily designed for space exploration, thin section preparation is not easy to do in situ on extraterrestrial rocky bodies due to the generally harsh environmental conditions and to the difficulty to automate a protocol that normally requires several human interventions. The aim of the LithoSpace project, supported by the French Space Agency (CNES) since 2014, is to work on the development of an automated system permitting preparation of petrographic thin sections on extraterrestrial bodies, such as Mars, the Moon or asteroids. In this paper, we describe the approaches used to study rocks in situ during space missions and compare them to those used on Earth. Then, the relevance of making thin sections during space exploration is highlighted from the description of the data that could be collected from the analysis of these specific samples, using new instruments and instruments already sent to Mars. The standard preparation protocol is described as well as previously envisioned or existing in situ sample preparation systems. We then propose a protocol for automation of the preparation. Particular attention is paid to demonstrating the feasibility of making thin sections in the absence of liquid water and with energy consumption compatible with automated space probes. Tests are then carried out to control the quality of the prepared samples. On the basis of the demonstrated feasibility, an automated system is proposed as a conceptual all-in-one system. Finally, a “proof-of-concept” model developed with the help of students at different educational levels is presented.

Monitoring intertidal topography using the future SWOT (Surface Water and Ocean Topography) mission

Intertidal flats are very dynamic environments pressured by anthropogenic activities and climate change. There is an increasing need for updated intertidal topography maps for scientific and coastal management purposes. The future wide-swath altimetry mission SWOT (Surface Water and Ocean Topography) will provide valuable data for intertidal topography monitoring. SWOT will use interferometry to measure heights over water surfaces only, which will prevent the use of this method over intertidal areas. Since SWOT is expected to provide highly accurate 2D sea level measurements in coastal areas, it will be very beneficial for the waterline method. The waterline method is one of the most commonly used spaceborne methods for mapping intertidal topography. This method uses a combination between a series of satellite images acquired at different tidal stages (radar or optical) and sea level information (tide gauge records, models output, or satellite measurements). The aim of this study is to investigate the performance of SWOT in generating intertidal Digital Elevation Models (DEMs) using the waterline method (with a brief investigation regarding the interferometric capabilities of SWOT over intertidal areas). To this end, tests were made by generating intertidal DEMs from SWOT-type observables for two intertidal bays situated on the French coast: the Arcachon Bay and the Bay of Veys. SWOT-type observables were simulated using the SWOT large scale simulator developed by the French space agency (CNES - Centre National d’Etudes Spatiales). By comparing SWOT-derived DEMs to the validation DEMs (generated by the waterline method using Sentinel-1 and -2 images), SWOT showed a great potential for monitoring intertidal topographies. Mean Absolute Errors (MAE) and Root Mean Squared Errors (RMSE) reached respectively 5.2 cm and 8.4 cm for the Arcachon Bay and 10.2 cm and 17.3 cm for the Bay of Veys. However, the accuracy of SWOT is dependent on SWOT's orbit. An unfavorable sampling due to tidal aliasing decreases the accuracy of the DEMs. Thus, the period during which the series of satellite images are acquired (the acquisition period) shall be chosen carefully in order to generate accurate SWOT DEMs. SWOT will be able to generate relatively accurate DEMs with period of acquisitions of 3 months. With acquisition periods that provide adequate sampling of the tidal range, SWOT will be able to detect topographic changes between consecutive DEMs. The present work was supported by the CNES in the framework of the future mission SWOT.

ONBOARD/ON-GROUND IMAGE PROCESSING CHAIN FOR HIGH-RESOLUTION EARTH OBSERVATION SATELLITES

Abstract. Over the last decade, the French space agency (CNES) has designed and successfully operated high-resolution satellites such as Pléiades. High-resolution satellites typically acquire panchromatic images with fine spatial resolutions and multispectral images with coarser samplings for downlink constraints. The multispectral image is reconstructed on the ground, using pan-sharpening techniques. Onboard compression and ground processing affect however the quality of the final product. In this paper, we describe our next-generation onboard/on-ground image processing chain for high-resolution satellites. This paper focuses on onboard compression, compression artefacts correction, denoising, deconvolution and pan-sharpening. In the first part, we detail our fixed-quality compression approach, which limits compression effects to a fraction of the noise, thus preserving the useful information in an image. This approach optimises the bitrate at the cost of image size, which depends on the scene complexity. This technique requires however pre- and post-processing steps. The noisy HR images obtained after decompression are suited for non-local denoising algorithms. We show in the second part of this paper that non-local denoising outperforms previous techniques by 15% in terms of root mean-squared error when tested on simulated noiseless references. Deconvolution is also detailed. In the final part of this paper, we put forward an adaptation of this chain to low-cost CMOS Bayer colour matrices. We demonstrate that the concept of our image chain remains valid, provided slight modifications (in particular dedicated transformations of the colour planes and demosaicing). A similar chain is under investigation for future missions.

Thermal analysis and constraints for the MASCOT landing site selection on the Asteroid Ryugu

In June 2018, after 4 years of cruise, the Japanese space probe Hayabusa2 [1-Watanabe S. et al.: Hayabusa2 Mission Overview. (2017)] reached the Near-Earth Asteroid (162173) Ryugu. Hayabusa2 carried a small Lander named MASCOT (Mobile Asteroid Surface Scout) [2-Ho T. M. et al.: MASCOT-The Mobile Asteroid Surface Scout on-board the Hayabusa2 mission. (2017)], jointly developed by the German Aerospace Center (DLR) and the French Space Agency (CNES), to investigate Ryugu's surface structure, composition and physical properties including its thermal behaviour and magnetization in-situ. The Microgravity User Support Centre (DLR-MUSC) in Cologne was in charge of providing all thermal conditions and constraints necessary for the selection of the final landing site and for the final operations of the Lander MASCOT on the surface of the asteroid Ryugu.This article provides a comprehensive assessment of these thermal conditions and constraints, based on predictions performed with the Thermal Mathematical Model (TMM) of MASCOT using different asteroid surface thermal models, ephemeris data for approach as well as descent and hopping trajectories, the related operation sequences and scenarios and the possible environmental conditions driven by the Hayabusa2 spacecraft.A comparison with the real telemetry data confirms the analysis and provides further information about the asteroid characteristics.

The main stakes of the CNES's safety policy for space operations

CNES, the French space agency, is involved in the development and exploitation of orbital systems, launch systems, balloons and launch range in French Guyana (CSG). Safety is a CNES strong value which is shared among its staff and which is embedded in all its initiatives and its own space operations. Moreover, CNES is entitled by the French government to control the correct application of the French Space Operations Act which the main objective is to ensure the protection of people, assets and environment against risks resulting from space operations. In order to fulfill the safety objectives, rules have been issued which are the core of the technical regulation order and the order regulating the operations at CSG facilities. This paper shortly describes the main principles which govern applied safety rules for authorizing the current launch, satellite and balloon operations. The development of space business in France and in Europe leads to consider new innovative projects or missions which rise new safety challenges that are listed in this paper. The stakes are to issue adapted safety regulations for managing the operations of the devised concept, but keeping the same level of safety for the protection of people on ground or in airplane, of assets and of environment as the one reached for the current space operations. In the meantime, the safety measure will be refined in order to foster the development of Space business, especially at the CSG. These questions will feed a work for updating. the French Space Operations acts and the subsequent documentation in the near future.

Estimation of Bathymetry and Benthic Habitat Composition from Hyperspectral Remote Sensing Data (BIODIVERSITY) Using a Semi-Analytical Approach

The relevant benefits of hyperspectral sensors for water column determination and seabed features mapping compared to multispectral data, especially in coastal areas, have been demonstrated in recent studies. In this study, we used hyperspectral satellite data in the accurate mapping of the bathymetry and the composition of water habitats for inland water. Particularly, the identification of the bottom diversity for a shallow lagoon (less than 2 m in depth) was examined. Hyperspectral satellite data were simulated based on aerial hyperspectral imagery acquired above a lagoon, namely the Vaccarès lagoon (France), considering the spatial and spectral resolutions, and the signal-to-noise ratio of a satellite sensor, BIODIVERSITY, that is under study by the French space agency (CNES). Various sources of uncertainties such as inter-band calibration errors and atmospheric correction were considered to make the dataset realistic. The results were compared with a recently launched hyperspectral sensor, namely the DESIS sensor (DLR, Germany). The analysis of BIODIVERSITY-like sensor simulated data demonstrated the feasibility to satisfactorily estimate the bathymetry with a root-mean-square error of 0.28 m and a relative error of 14% between 0 and 2 m. In comparison to open coastal waters, the retrieval of bathymetry is a more challenging task for inland waters because the latter usually shows a high abundance of hydrosols (phytoplankton, SPM, and CDOM). The retrieval performance of seabed abundance was estimated through a comparison of the bottom composition with in situ data that were acquired by a recently developed imaging camera (SILIOS Technologies SA., France). Regression coefficients for the retrieval of the fractional species abundances from the theoretical inversion and measurements were obtained to be 0.77 (underwater imaging camera) and 0.80 (in situ macrophytes data), revealing the potential of the sensor characteristics. By contrast, the comparison of the in situ bathymetry and macrophyte data with the DESIS inverted data showed that depth was estimated with an RSME of 0.38 m and a relative error of 17%, and the fractional species abundance was estimated to have a regression coefficient of 0.68.

Swimming pools, Islamic dress and colonial differentiation: the cleansing role of law in ‘the republic [that] lives through an uncovered face’

ABSTRACT On 23 June 2019, seven Muslim women staged a protest at a swimming pool in Grenoble, France in defiance of rules prohibiting burkinis in swimming pools. French law 2010–1192 criminalizes the bodies of visibly Muslim women by prohibiting full-face coverings in French public space. This creates precarious bodies through law and facilitates an institutional Islamophobia, which I argue circulates in French society through a logic of hygiene. This logic of hygiene refers not merely to cleanliness but to the racial purity of the French republic. Law performs a dual cleansing role: it cleanses public space(s) of the presence of colonial markers and acts to displace colonial memory in France. This article traces the emergence of pro-ban feminist arguments supporting the criminalization of Islamic dress in France to a historical foundation of humiliation and cleanliness in post-WWII shavings of the hair of dissident French women. The article draws parallels with the forced uncovering of the hair of Muslim women in historical colonialism and in contemporary France to conceptualize hair as the patriarchal symbol of the French republic. Muslim women are made precarious through law's complicity with the hygiene and sterilization agendas of French coloniality and post-war capitalist modernization. The conclusion is that Muslim women are the site of the racial and gender differentiation necessary for the maintenance of the French republic.

Beaches and Muslim belonging in France: liberty, equality, but not the burkini!

Drawing on Marco Antonsich’s framework for analyzing belonging while also engaging critical legal geographies, this article applies a legal lens to Muslim belonging. It does so through discourse analysis of court, legislative, and political pronouncements regarding burkini bans that surfaced in France shortly after a terror attack by a self-identified Muslim, and with ‘burkini’ serving as a proxy for Islam in their rhetoric. The article focuses on the language used by France’s highest administrative court in overturning one city’s ban, as well as language used by French political leaders in supporting the bans, to examine the message of belonging conveyed to Muslims in France. Legal language is the focus because of its ability to frame conversations regarding societal norms, with the language explored here framing the broader debate on Muslim belonging in French public space and arguably what the French population believes is necessary to belong in French society. This exploration provides a foundation for further research by scholars exploring issues of identity, migration, belonging, race, and religion, using methodologies such as feminism and critical race theory that can readily connect with the critical legal approach applied here.

Aurnague Michel and Stosic Dejan (eds), The Semantics of Dynamic Space in French: Descriptive, experimental and formal studies on motion expression. (Human Cognitive Processing, 66.) Amsterdam/Philadelphia: John Benjamins, 2019, ix + 396 pp. 978 90 272 0320 5 (hardcover), 978 90 272 6250 9 (e-Book)

Aurnague Michel and Stosic Dejan (eds), The Semantics of Dynamic Space in French: Descriptive, experimental and formal studies on motion expression. (Human Cognitive Processing, 66.) Amsterdam/Philadelphia: John Benjamins, 2019, ix + 396 pp. 978 90 272 0320 5 (hardcover), 978 90 272 6250 9 (e-Book) - Volume 31 Issue 3

Maneuvers to reduce Ariane 5 upper stage lifetime duration in orbit

The Cryogenic Upper Stage on Ariane 5 (ESCA) uses the HM7B engine which is a heritage of the Ariane 1 Upper Stage engine. This induces that ESC stage is not re-ignitable in orbit, as such a feature can be avoided for GTO (Geostationary Transfer Orbit) launches from French Guiana. As a result, it is not possible to perform a controlled reentry of the Upper Composite once the launcher's main mission is completed. As Ariane 5 was designed well before 2008, it has to justify of its best effort in the aim at respecting the so called “25-years rule” relative to the maximum life duration on orbit (Article 55 of the Technical Rules of the French Space Operations Act).The upcoming Ariane 6 launcher is fully compliant since Upper Stage will be re-ignitable and deorbited with a controlled atmospheric reentry.In order to do our best effort and minimize the A5 Upper Composite life duration on orbit, ARIANEGROUP, ARIANESPACE, ESA (European Space Agency) and CNES (French Space Agency), have joined efforts to implement, recurrently, maneuvers to reduce lifetime by using remaining onboard energy to decrease altitude of the Upper Composite GTO orbit after payloads' injection. The technical approach is to use residuals propellants, after commercial phase, to create, by cold liquid/gas ejection, a delta velocity in an optimized direction, without introducing any hardware change to the current launcher system definition. LH2/GH2 (liquid and gaseous hydrogen) are ejected through the HM7B nozzle, without re-ignition, which allows to reach a certain level of thrust enabling to reduce both perigee and apogee altitudes and therefore the Upper Composite's life duration.After some experimental flights, maneuvers for Upper Stage perigee/apogee decrease are now implemented as the reference for the ESC end of flight before final passivation.This article will expose maneuvers applied at the end of Upper Stage flight and gains expected in term of life duration minimization. Durations will be compared with Upper Composite previous situation without maneuver.

Absolute calibration of timing receiver chains at the nanosecond uncertainty level for GNSS time scales monitoring

The use of global navigation satellite systems (GNSS) for time transfer is widespread, in particular for the computation of the coordinated universal time (UTC). It is an inexpensive, easy-to-implement method to compare distant clocks. This time transfer method can also be applied to the monitoring of the GNSS time scales and of the broadcast UTC conversion parameters. One mission of the French space agency (CNES) is to perform this task for Galileo. For that purpose it is mandatory to carry out an absolute calibration of the propagation delay of a GNSS receiver chain. This propagation delay is the one between the GNSS antenna phase centre and the time reference that feeds the receiver chain. In order to allow a link to UTC, the time reference must be a UTC(k).CNES has developed a method of absolute calibration of GNSS receiver chains, in which the delays of the GNSS antenna, the antenna cable and the GNSS receiver are determined separately, with a total uncertainty in the range of 1 ns (1 – σ). The purpose of this paper is to present the method developed by CNES along with its uncertainty budget for GPS, Galileo and BeiDou signals. A validation in common-clock with actual GPS and Galileo signals is also provided. The absolute calibration is finally applied to an accurate monitoring of the GNSS time scales, the Galileo broadcast UTC conversion parameters and the broadcast Galileo to GPS time offset (GGTO), with associated uncertainties.

«Проблемне поле» французької гуманістики: досвід другої половини ХІХ століття

The material of the article is focused on the second half of the 19th century - an important and very specific stage in the development of French humanities. Specific historical and cultural traditions that positively influenced the research of the 1850s and 1870s and contributed to active cultural processes in the period of the end of the Romantic era are singled out.Emphasis is placed on the formation of theoretical and practical - a structural element of European humanities - in the logic of which organically combined research and artistic creativity. It is emphasized that its scientific potential was very strongly manifested in the French space thanks to F. d'Aubignac, F.-M. Voltaire, D. Diderot - prominent figures of national culture.During the 19th century theoretical and practical parity was established in the French humanities and found a logical continuation both in outlining and justifying the expediency of the next aesthetic and artistic movement: - realism - naturalism - symbolism - The blurring of the creative principles of romanticism by both realism (O. de Balzac) and naturalism (E. Zola) is stated, and the position of S. Baudelaire is emphasized, who on one hand criticized romanticism since the late 1840s, and on the other hand, gradually rooted the principles of the aesthetics of decadence and symbolism - the origins of which literary critics associate with his poetry - in the European cultural space. It is argued that these processes formed a problem field of French humanities, which outlined the contradictory movement of further artistic development.The article highlights the figure of T. Gautier, who continued to profess the principle of parity, positioning himself as a poet, novelist, theorist and journalist. It is emphasized that he tried to harmonize the then tendencies of French humanities around the of for art's sake, which is still perceived and evaluated by the scientific community very ambiguously. Conducted comparative analysis of interpretations of theory for and defined its aesthetic principles, as both Gauthier and his immediate entourage - S. Baudelaire, G. de Nerval, S. Leconte de Lisle - strongly denied the importance of the functionality of art, emphasizing its self-sufficiency and self-worth. It is emphasized that as a result of such a orientation, they, on the one hand, refuted a number of statements of both the first and second generation of French educators, and on the other hand, significantly strengthened the aesthetic factor in assessing the phenomenon of art in the late 19th century.The aesthetic factors used by T. Gautier and his supporters are considered. Trying to prove the value of a work of art, not the functions it can perform. In this context, the object of attention are beauty, ideal, beautiful - ugly, dream-delirium and a set of issues related to the logic of the creative process and psycho-physiological states of the artist who carries it out (inspiration, imagination, fantasy, sensuality - rationality).The special significance of the last two decades of the 19th century is noted, when, on the one hand, the scientific space includes intuitionism - the concept of H. Bergson - thus defining the emergence of a new problem field, and on the other, exhibits fauvist paintings of H. Matisse (1905) that witnessed the emergence of avant-garde.

CH4 and CO2 IPDA Lidar Measurements During the Comet 2018 Airborne Field Campaign

Installed onboard the German research aircraft HALO, the integrated-path differential-absorption (IPDA) lidar CHARM-F measures weighted vertical columns of both greenhouse gases (GHG) below the aircraft and along its flight track, aiming at high accuracy and precision. Results will be shown from the deployment during the CoMet field campaign that was carried out in spring 2018, with its main focus on one of the major European hot spots in methane emissions: the Upper Silesian Coal Basin (USCB) in Poland. First analyses reveal a measurement precision of below 0.5% for 20-km averages and also low bias, which was assessed by comparison with in-situ instruments. The measurements flights were designed to capture individual CH4 and CO2 plumes from e.g. coal mine venting and coal-fired power plants, respectively, but also to measure large and regional scale GHG gradients and to provide comparisons with the Total Carbon Column Observing Network (TCCON). Many other different instruments, both airborne and ground-based, complemented the lidar measurements to provide a comprehensive dataset for model analyses. CHARM-F also acts as the airborne demonstrator for MERLIN, the “Methane Remote Lidar Mission”, conducted by the German and French space agencies, DLR and CNES, with launch foreseen in ~ 2024. In this context, the airborne lidar data are likewise important for mission support such as for e.g. algorithm development and improvement and, moreover, the CoMet mission was also an important step for MERLIN validation preparation.

A New Metric for Estimating the Disparity of Antenna Patterns in Synthetic Aperture Imaging Radiometry

The soil moisture and ocean salinity (SMOS) satellite has provided for about ten years systematic passive L -band measurements from space. For several months, phase 0 studies are conducted by the French space agency for a second-generation high resolution (HR) follow-on mission. This contribution is making the connection between this SMOS hr project and the SMOS mission by revisiting the following problematic: the impact of the disparity of the antenna patterns on the reconstruction floor error observed in the retrieved brightness temperatures. This impact is revisited in light of the progress made since that time and a new metric is introduced for estimating the disparity between antenna patterns. It would be helpful for the design of future missions based on imaging by aperture synthesis with interferometric arrays comprising a large number of antennas.

Performance of the EUSO-Balloon optics

EUSO-Balloon is the first balloon pathfinder of the JEM-EUSO (Joint Experiment Missions - Extreme Universe Space Observatory) framework. It is an ultraviolet (UV) telescope designed to test the key technologies and methods necessary for the indirect detection of Ultra High Energy Cosmic Rays (UHECR) by observing from above the fluorescence emission produced by Extensive Air Showers (EAS) in the 290-430 nm band. The instrument was launched on the 24$^{t}^{h}$ of August, 2014 by the French space agency (CNES) from the stratospheric balloon base in Timmins, Canada and performed an 8 hour night time flight. One of the key technologies of EUSO-Balloon is the refractive optical system which consists of two large aspherical Fresnel lenses (≈ 1 m$^{2}$) and aims at focusing the UV light into a detector plane formed by an array of Multi-Anode Photomultiplying tubes. This work presents a description of the optical system, the test bench and methods used to characterize its performance and the global efficiency. The measured performance can be understood through the addition of a semi-empirical diffusion model to the classic ray-tracing model of the optics.

Theoretical Problems Underlying Sprite Observations of the Planned Taranis Satellite Mission

Abstract Tool for the Analysis of Radiations from lightnings and Sprites (TARANIS) is a French Space Agency’s (CNES) satellite mission planned for launch in 2020. It is designed for investigating phenomena related to thunderstorm activity, transient luminous events (TLEs) and amongst them – red sprites. The satellite is equipped with cameras, photometers, energetic particles detectors, ion probe and electromagnetic sensors of wide frequency spectrum. It will be the most versatile satellite for measuring TLEs ever sent to space. In this article, theories that are fundamental for understanding sprites and sprites-related measurements of TARANIS mission are presented. The current state of sprites phenomenology and their possible generation mechanisms are presented. The article briefly covers streamer discharges, cloud charge structure at the TLE occurrence, electric breakdown of the air and Runaway Relativistic Electron Avalanche (RREA). At the end, TARANIS mission equipment and goals that are related to presented theories are presented.

Family as communicative and personal space in French and Belarusian cultural linguistic communities

Family as communicative and personal space in French and Belarusian cultural linguistic communities

State credit and foreign debt in the early nineteenth century: contradictory representations of a renovated scenario

ABSTRACTThis article aims at presenting the main elements of a cultural transformation concerning debt and credit that took place in Europe and the Americas in the early nineteenth century. It describes the main changes in the international financial institutions and mechanisms, and connects them to the development of a new literature that discussed old and new concepts concerning finances. It introduces positive and negative discourses in relation to credit and debt, and their political meaning, that were born and popularised mainly in the British, French and Spanish public spaces, between the 1820s and the 1850s.

MERLIN: design of an IPDA LIDAR instrument

The Methane Remote Sensing LIDAR Mission (MERLIN) is a joint French–German cooperation on the development, launch and operation of a climate monitoring satellite, executed by the French Space Agency CNES and the German DLR Space Administration. It is focused on global measurements of the spatial and temporal gradients of atmospheric methane (CH4) with a precision and accuracy sufficient to constrain methane fluxes significantly better than with the current observation network. Airbus Defence and Space GmbH was selected by the German DLR Space Administration as the industrial prime contractor for the mission phase C/D, to build the MERLIN Payload, which is the first realization of such an instrument for space. This presentation will concentrate on the architecture and the optical design of the MERLIN Payload, which ensures reliable, high-performance operation of the bi-static DIAL, consisting of separate transmitter (Tx) and receiver paths (Rx). The MERLIN satellite is a secondary passenger payload on the launcher. As such, the satellite places many constraints on the instrument, pertaining to the power, mass and volume allowable. The available resources force the MERLIN instrument to have passive thermal control while necessitating a very compact design due to the demanding envelope constraints. This creates a large operational temperature range with thermal gradients on the structure, requiring an extremely robust optical design in a compact envelope. The robust optical design, for the Rx and Tx paths, employs several passive measures and an active pointing control for Rx and Tx co-alignment. Further details of the instrument development status during the ongoing phase C will be shown by an overview of the current hardware and design status of the major subsystems.

Design of Very High-Resolution Satellite Telescopes Part I: Optical System Design

The telescope design of a very high-resolution earth observation satellite is a challenging task, due to several constraints, including the size, mass, performance, tolerance, assembly, integrating, and environmental aspects. However, the demand for very high-resolution satellite imageries has increased day by day due to the numerous commercial and military applications. In this paper, two different optical configurations with ground sampling distance of 25 cm are investigated according to a definite mission statement. The first configuration represents an on-axis Korsch scheme, whereas the second design is based on the arrangement of the off-axis three-mirror anastigmatic configuration. Both designs have the advantage of small conic mirror constants without higher order parameters. Tolerance analysis of both designs utilizing a Monte Carlo algorithm is performed. The suggested baffling arrangements are simulated and tested according to a series of point sources with different off-axis angles. Finally, a comparison between the performance of the proposed designs and a recent study given by the French space agency is presented. The results show that the proposed designs can be implemented by the existing technologies and launched into space by the available launch vehicles.