MICROSCOPE Mission scenario, ground segment and data processing

Testing the Weak Equivalence Principle (WEP) to a precision of 10-15 requires a quantity of data that give enough confidence on the final result: ideally, the longer the measurement the better the rejection of the statistical noise. The science sessions had a duration of 120 orbits maximum and were regularly repeated and spaced out to accommodate operational constraints but also in order to repeat the experiment in different conditions and to allow time to calibrate the instrument. Several science sessions were performed over the 2.5 year duration of the experiment. This paper aims to describe how the data have been produced on the basis of a mission scenario and a data flow process, driven by a tradeoff between the science objectives and the operational constraints. The mission was led by the Centre National d’Etudes Spatiales (CNES) which provided the satellite, the launch and the ground operations. The ground segment was distributed between CNES and Office National d’Etudes et de Recherches Aerospatiales (ONERA). CNES provided the raw data through the Centre d’Expertise de Compensation de Trainee (CECT: Drag-free expertise centre). The science was led by the Observatoire de la Coote d’Azur (OCA) and ONERA was in charge of the data process. The latter also provided the instrument and the Science Mission Centre of MICROSCOPE (CMSM).

The SVOM mission

The Sino-French space mission SVOM is mainly designed to detect, localize and follow-up Gamma-Ray Bursts and other high-energy transients. The satellite, to be launched mid 2023, embarks two wide-field gamma-ray instruments and two narrow-field telescopes operating at X-ray and optical wavelengths. It is complemented by a dedicated ground segment encompassing a set of wide-field optical cameras and two 1-m class follow-up telescopes. In this contribution, we describe the main characteristics of the mission and discuss its scientific rationale and some original GRB studies that it will enable.

Ice Sheet Topography from a New CryoSat-2 SARIn Processing Chain, and Assessment by Comparison to ICESat-2 over Antarctica

In this study, we present a new level-2 processing chain dedicated to the CryoSat-2 Synthetic Aperture Radar Interferometric (SARIn) measurements acquired over ice sheets. Compared to the ESA ground segment processor, it includes revised methods to detect waveform leading edges and perform retracking at the Point Of Closest Approach (POCA). CryoSat-2 SARIn mode surface height measurements retrieved from the newly developed processing chain are compared to ICESat-2 surface height measurements extracted from the ATL06 product. About 250,000 space–time nearly coincident observations are identified and examined over the Antarctic ice sheet, and over a one-year period. On average, the median elevation bias between both missions is about −18 cm, with CryoSat-2 underestimating the surface topography compared to ICESat-2. The Median Absolute Deviation (MAD) between CryoSat-2 and ICESat-2 elevation estimates is 46.5 cm. These performances were compared to those obtained with CryoSat-2 SARIn mode elevations from the ESA PDGS level-2 products (ICE Baseline-D processor). The MAD between CryoSat-2 and ICESat-2 elevation estimates is significantly reduced with the new processing developed, by about 42 %. The improvement is more substantial over areas closer to the coast, where the topography is more complex and surface slope increases. In terms of perspectives, the impacts of surface roughness and volume scattering on the SARIn mode waveforms have to be further investigated. This is crucial to understand geographical variations of the elevation bias between CryoSat-2 and ICESat-2 and continue enhancing the SARIn mode level-2 processing.

The key role of GNSS for monitoring geodetic parameters of the Earth

Глобальные навигационные спутниковые системы (ГНСС) являются основным инструментом для контроля геодезических параметров Земли, построения и постоянного контроля земной системы отсчета и связи измерений различных спутниковых геодезических технологий. ГНСС состоят из наземного сегмента (приемники ГНСС) и орбитальной группировки (навигационные спутники системы). Микроволновый диапазон сигналов ГНСС позволяет использовать данные системы при любых погодных условиях, а двухчастотные несущие позволяют, в значительной степени, исключить ионосферную задержку распространения сигналов. Помимо выполнения основных геодезических определений навигационные системы также могут быть использованы для решения социальных и других позиционных измерений, требующих высокой точности. В данной статье автором рассмотрены основные задачи, решаемые ГНСС, определены требования к точности продуктов навигационных систем и приведены направления развития наземной и орбитальных частей ГНСС, учитывая потребности мирового геодезического сообщества. Global navigation satellite systems (GNSS) are a fundamental tool for monitoring geodesic parameters of the Earth, building and constantly monitoring the Earth’s reference system and connecting measurements of various satellite geodetic technologies. GNSS consist of a ground segment (GNSS receivers) and an orbital grouping (navigation satellites of the system). The microwave range of GNSS signals allows using these systems in all weather conditions, and the two-frequency carriers allow, to a large extent, eliminating the ionospheric delay of signal propagation. In addition to performing basic geodetic definitions, GNSS can also be used to solve social and other positional measurements that require high accuracy. In this article the author discusses the main tasks solved by GNSS, defines the requirements for the accuracy of navigation systems products, and provides directions for the development of the ground and orbital parts of GNSS taking into account the needs of the international geodetic community.

FOCSE: CNES Exploration contributions for Operations and Innovation

<p>In 2017, CNES has enforced its visibility and ambitions in Scientific exploration programs by creating the FOCSE (French Operations Centre for Science and Exploration) center. FOCSE groups all the Science Operations activities, including ground segment development, operations and data valorization for the domains involved in the Scientific exploration including Astrophysics & Fundamental Physics, Planets, Small bodies & Solar Physics and Human Spaceflight (Nutrition, Healthcare, Life Science, …). This gives an advantage increasing synergy and commonalities between the different missions and allowing operational people to focus only on what makes each mission original and specific.</p> <p> </p> <p>FOCSE integrates the CADMOS Centre created in 1993, the COMS (Planets Mission centers), Astronomy & Solar systems mission in order to implement a synergetic merge of science in astronomy, solar systems, microgravity and space exploration (robotic and manned). As an example of synergy, we will present the FOCSE Moons & small bodies facility that will be set up for Cubesats activities within the frame of ESA’s planetary defense HERA mission and also in support to JAXA’s MMX mission. This effort will capitalize on our expertise based on our contributions to Rosetta/Philae and Hayabusa2/Mascot on Mission Analysis and visualizing tools to support Scientific activities. We will also present the Spaceship project that has started in coordination with ESA to contribute to the development of technologies for exploration.</p> <p> </p> <p>More recently, CNES proposes to set up a new innovation Lab facility, based on an immersive and open facility for innovation on exploration technologies. Technologies of interests have been identified and will be developed with our partners and also with new actors, in order to allow dynamic spin in and spin off approaches for Exploration technologies. Thanks to this new facility, CNES will provide technical means to create new, innovative, disruptive systems, gather assets from Research, Universities and Industries (from startup to large industrial group) into the same melting-pot, foster collaboration between partners and CNES experts in all space sciences/technologies and operations and join international network of spaceships.</p> <p> </p> <p>The CNES roadmap on Science is defined, the Technological part of this roadmap will be expanded with new Technological opportunities. The proposed paper will present an overview of the CNES strategy and how we implement it on a kind of “DevOps” approach to accelerate and innovate as much as possible, including also a digital factory platform, with the main idea to federate to the network of French Exploration actors (means and expertise) to enforce synergies with ESA and international partners in order to contribute to future Exploration missions.</p> <p> </p>

Small Satellites Constellations and Their Impact on CBRNe Management in Africa

A wave of small satellites massive constellations, in the range of hundreds of units each, is progressively populating the Low Earth Orbit (LEO) with a low-price, and varied, offer of Telecom (speed band) and Earth Imaging services (Starlink, Planet, One Web, etc.). It is a market - driven trend based on new satellite interlocking technologies, which cut down the supplier costs of launch and in orbit operations compared to the traditional technology based on big (and much heavier) geostationary satellites operating at high altitudes. This is a disruptive phenomenon especially for the developing world, where such vital services have always been hard to access, and their use therefore remained scarce, not consolidated, or even completely missing. Among these, Emergency management is definitely crucial. The geographical focus of this study is Africa and it deals not only with Institutional PRS users but with a wider potential context (corporations, private subjects, etc.). It clearly appears that a general degree of “Country readiness” toward Space technology and organization is necessary for these initiatives to take place. This can be achieved through certified international cooperation. The authors then, based on an estimated demand Model for services with their relative pricing corresponding to a cost-designed constellation of small microsatellites, presented already, among other, at several International Astronautical Federation(IAF)Symposia on Space Economy, simulate the resulting type of services available: TLC by band types and relative upload and download rates, Earth imaging by refresh rates and optical quality and resolution, Ground segment configuration for signal backhauling and user terminal receiving.. This info isapplied to a specific African Country case (Nigeria) whose significance emerged over other Countries after the application of comparative grids. Finally, an insight on the specifically configuration of services for Chemical, Biological, Radiological, Nuclear, and Explosive (CBRNe) like management by local users, both maritime and land, with the relative costs, is offered. This is consequently left open for follow ups and discussion, due to the customer – design, project financing approaches of this Model programme.

ArgoMoon: the Italian cubesat for Artemis1 mission

<p>In order to increase the scientific and technological return of the Artemis I mission, NASA has directed the SLS Program to accommodate Secondary Payloads on board of the Space Launch System (SLS), to be deployed with the Orion capsule; among them, ArgoMoon cubesat has been selected as European contribution. It is a 6U platform designed by Argotec on behalf of the Italian Space Agency (ASI) and will be released from the launch vehicle Interim Cryogenic Propulsion Stage (ICPS). The main objectives of the satellite are: i) taking photographs to document the ICPS after the deployment of the Orion capsule and the deployment of the other secondary payloads mounted on-board; ii) taking photographs of the Earth and the Moon; iii) validate guidance and autonomous targeting technology and iv) verifying a new technology for power distribution, satellite data acquisition and processing suitable for nanosatellite volume. In fact, the cubesat will be the first national spacecraft working in near Deep Space and operated through a Ground Segment mainly based in Italy.</p> <p>ArgoMoon design is based on the HAWK platform, designed by Argotec following an “all in-house” concept. Some of the main features of this platform are the focus on rad-hard subsystem components, a high level of autonomy capability supported by artificial intelligence, and the scalability towards larger bus sizes.</p> <p>Early after deployment, ArgoMoon will be able to operate autonomously and perform SLS tracking and proximity flight navigation, making use of a complex image recognition algorithm based on artificial intelligence. These operations are carried out by two optical payloads and the obtained photography will be used to support the NASA and payload communities in providing information regarding the status of their deployment and the condition of the second stage as it completes the final phase of its mission. After that, ArgoMoon will be operative for another six months for technological validation and Moon observation purposes.</p> <p>During the communication windows throughout the entire satellite lifetime, ArgoMoon will be operated and monitored entirely by the Argotec Mission Control Centre, connected to the Deep Space Network (DSN). The Flight Control Team (FCT) will follow the flight operations with in-house developed software able to plan and validate in orbit activities, verifying the on-board.</p> <p>After a successfully integration and test campaign, the cubesat has been shipped to USA for the filling activities on the propulsion tanks and the final delivery to NASA for the integration in the SLS, expected in July 2021.</p> <p>The results of this mission will strongly contribute to future of Space Exploration based on small satellite platforms in Deep Space.</p>

The PLATO mission: Overview and status

<p>PLATO is an ESA mission dedicated to the study of exoplanets and stars, with a planned launch date in 2026. By performing photometric monitoring of about 250 000 bright stars (m<sub>V</sub> < 13), PLATO will be able to discover and characterise hundreds of exoplanets, including small planets orbiting up to the habitable zone of solar-like stars. PLATO’s precision will also allow for a precise characterisation of the host stars through asteroseismology. These objectives require both a wide field of view and high sensitivity, which are achieved with a payload comprising 24 cameras with partially overlapping fields of view. They are complemented by 2 more cameras optimised for brighter stars that will also be used as fine guidance sensor. The PLATO development phase started after the mission adoption in July 2017. The Mission Preliminary Design Review (PDR) was declared successful in October 2020. The implementation and delivery to ESA of the flight model CCDs for all cameras (4 CCDs per camera) has been completed. Currently the Structural Thermal Model (STM) of the payload optical bench is being manufactured, while the STM of a single camera has already been successfully tested. In parallel, a first engineering model of a complete, fully functional camera is being integrated, to verify its performance under operational conditions, and the qualification models of the different payload units are being built.</p> <p>We will present the status of the PLATO payload implementation in the context of the satellite development. In particular, we will describe the payload manufacturing, integration, and tests that will be reviewed at the Critical Milestone in the second half of 2021. We will also summarise the progress made in the science preparation activities, as well as on the ground segment.</p>