The Future Missions and Instruments division is involved in the definition and preparation of future Earth Observation Missions as part of the Earth Observation directorate of the European Space Agency. This covers activities in phase 0/A system studies, instrument feasibility studies, technology developments, airborne instruments developments in support of Earth Explorer, SCOUT, Copernicus, Meteorological missions, but as well in the New space context with dedicated instrument or technology development supporting the Incubed programme.
In particular, in the context of the science driven missions SCOUT missions, ESA is pursuing activities on the CUBEMAP mission which development has been initiated and the TANGO mission for which risk retirement activities are on-going. System and Instrument studies at the level of Phase A are also conducted for the Earth Explorer 10 mission, Harmony, embarking as secondary payload a Thermal Infrared Imager. For the Earth Explorer 11, phase 0 studies will be initiated with optical payloads based on Infrared Fourier Transform spectrometers for the CAIRT and NITROSAT missions. In addition, studies are conducted for an opportunity mission to be developed in cooperation with NASA, the Next Generation Gravity Mission, for which pre-development activities of the Laser Tracking Instrument are carried out. In addition, studies and technology developments for future Gravimeters based on Quantum Sensors are also being performed in coordination with ESA Technical Directorate.
ESA is also preparing the next generation of the Sentinel 2 and sentinel 3 optical missions. In this context, while requirements are being consolidated, with in general an increased spatial resolution, higher revisit time and increased number of spectral bands, the Agency is also identifying the need for technology pre-developments that will be required to support such missions and instruments concepts.
Concerning Meteorological missions, following the successful use and assimilation of the Aeolus data by weather forecast centers, Eumetsat has expressed interest for a potential operational wind lidar mission. ESA is conducting instrument and technology pre-developments of the wind lidar with the objective to increase the instrument robustness and correct the issues which have been noted in flight as well as addressing the increase lifetime as required for an operational mission.
In the frame of New space and miniaturized instruments, the future missions and instruments division is conducting studies for new and compact instrument concepts, such as instruments based on static Fourier Transform Spectrometers aiming at measuring CO2, CH4 or water vapour trace gases, which could be embarked on a cubesat or smallsat and be complementing larger missions developed in the context of Copernicus. In addition, in support of the commercially driven Incubed programme, the division is supporting the development of medium to high resolution imagers in the context of MANTIS and SAT4EO projects.
The presentation will give an overview of the missions, requirements, instrument concepts as well as technologies involved.

The MicroCarb mission, an innovative pathfinder to CO2 monitoring

Ph. Landiech1, D. Pradines1, D. Jouglet1, E. Cansot1, C. Deniel2, FM Bréon3
1 - Centre National d’Etudes Spatiales, 18 Av Edouard Belin, 31055 Toulouse Cedex, France
2- Centre National d’Etudes Spatiales, 2 Place Maurice Quentin, 75001 Paris, France
3 - Laboratoire des Sciences du Climat et de l’Environnement ; CEA/DRF/LSCE, 91191 Gif sur Yvette Cedex, France

MicroCarb is a space mission designed to monitor the atmospheric load of Carbon Dioxide with the aim of improving our understanding of the Carbon cycle. It therefore has similar mission and monitoring objectives as the currently flying GOSAT, OCO-2 or TANSAT satellites.
The project is conducted by the CNES under French ANR funding, in partnership with the UK Space Agency, and involves the scientific community from both France and UK. A cooperation with Eumetsat for the ground segment implementation and a support from the European Commission through a H2020 programme delegated to ESA are also in place.
Compared to similar ongoing space mission, MicroCarb is fitted into a 180 kg microsatellite. Its instrument, based on a passively cooled grating spectrometer, includes an additional spectral band at 1.27 µm on top on the 3 dedicated to CO2 and O2. It is expected that this additional band will allow a better estimate of the surface pressure and atmospheric scattering, despite its contamination by airglow.
Microsatellite agility combined with an across track steerable mirror will allow to cover both nadir and over ocean glint data sampling, but also pointing to targets of opportunities. All these MicroCarb operating modes aim at an optimal science return, with glint, nadir, target, scan and “city” modes. The later makes it possible to acquire dense sampling over a target of opportunity, such as a power plant or a large city.
The project is currently completing its assembly phase (phase D) and the launch is scheduled for 2023.
The presentation will give an overview of the instrument design, the operating modes, associated performances, the data processing and the expected scientific impact, but also foreseen first year Cal/Val plan.

We present an overview of the development of enabling optical technologies at SRON Netherlands Institute for Space Research with an application in atmospheric remote sensing and climate research. This work is carried out together with partners in the Netherlands and was made possible by the Netherlands Space Office and ESA. In this contribution we present the following examples; first, we show the design and manufacturing of the silicon-based immersed gratings that were developed to compress the volume of the short-wave infrared (SWIR) channels of the imaging spectrometers onboard the Copernicus Sentinel 5 mission and its precursor Sentinel 5p carrying the TROPOMI instrument. These channels operate in the 1 – 2 micrometer wavelength range and combine a spectral resolution of 0.3 nm with a 7 km spatial resolution and daily global coverage. The SWIR channels are used to observe carbon monoxide and methane and continue to yield valuable data for climate research since the launch of Sentinel 5p in 2017. Second, we explain the operational principle of a compact spectropolarimeter SPEXone that has no moving parts but instead uses a spectral modulation technique to achieve very accurate measurement of the polarization state. SPEXone also uses an innovative multi-angle imager to project its five along-track viewing angles on a single focal plane. This instrument will fly on the NASA PACE mission to measure detailed properties of aerosols in order to reduce a major uncertainty in current climate models. In another application it can be used to correct for aerosol scattering in trace-gas retrievals that require high accuracy like for CO2. Lastly we will touch upon ongoing work in our lab in the development of instruments for deployment in future constellations of small satellites complementing the Sentinels. Those instruments provide an enhanced spatial resolution enabling trace-gas monitoring at the facility scale, while the constellation concept increases the temporal resolution by an order of magnitude, enabling mapping of the diurnal cycle. This revolutionary increase in capabilities provides vital insight in human influence on our climate and air quality. This concept has been worked out for the Twin ANthropogenic Greenhouse Gas Observers (TANGO) mission, developed in the ESA SCOUT programme. In this context we have started the development of a next generation of miniaturized sensitive imaging spectrometers of decimeter size using novel photonic components.

Climate change is one of the main global challenges of our time as recognised by the 195 countries that signed the 2015 Paris Agreement. Air pollution, according to the WHO, is the cause of millions of deaths due to air pollution each year. In a number of European countries, the release of nitrogen into the atmosphere, and the subsequent deposition in protected nature areas leads to a loss in biodiversity.

Earth observation satellites provide an unique opportunity to measure the greenhouse gases and air pollutants responsible for this. This presentation will provide an overview of innovations in instrument technology ongoing at TNO that will allow us measure the responsible trace gases at higher spatial detail, with increased precision, and using affordable instrument concept. In particular it will discuss the Spectrolite family of instruments, which has been derived from the successful TROPOMI instrument, and different types of interferometer technologies under development for use in the UV-VIS, SWIR and TIR to facilitate space-based emission quantification of a wide range of trace gases like CO2, methane and ammonia.

The presentation will discuss how an end-to-end development approach of missions (science-instrument-spacecraft-users) allows speeding up the development and deployment of such instruments. Furthermore, it will discuss how small satellite mission can complement the global datasets of Copernicus mission with specific data products of the atmosphere. It will use the example of the TANGO greenhouse mission concept as an example of this, and provide the development of its spectrometer systems as an example

The feasibility has been conducted of a multi-modal instrument called Oracle that was funded by ESA as part of its ‘Future EO passive optical missions for small satellites’ initiative in 2018. Oracle facilitates the simultaneous retrieval of ocean colour, sea skin temperature and aerosol optical depth using a colour imager, a thermal imager and a spectro-polarimeter respectively. Oracle has been designed for accommodation in a microsatellite and contains an internal calibration device, which can be used by all three modes separately and simultaneously.

Research into the use of multi-model observations show that these data streams can be used synergistically to understand the oceans and changes in marine health. It has been recently demonstrated that the use of sea skin temperature and ocean colour can improve the understanding of phytoplankton production by monitoring phytoplankton physiology and resources. Additionally, sea skin temperature modulates the transfer of gases (e.g. CO2) between the ocean and the atmosphere. This relationship has been used together with ocean colour to help quantify the flux of gases between ocean and atmosphere. It is generally accepted that a better ocean colour product is obtained by correcting for aerosols in the atmosphere. This is usually undertaken by using heritage two-step methods involving an atmospheric model with aerosol data from the NIR bands of the ocean colour imagers. There is significant benefit to be had from using multi-angular spectro-polarimeters that provide more precise information, particularly regarding absorbing aerosols, which are prevalent over large oceanic areas.

, the Oracle instrument has been sized to provide a good ground coverage with a swath of 1150km from an orbit altitude of 560km with a spatial resolution of 100m for ocean colour, 300m for sea skin temperature and 900m for aerosol optical depth. The ocean colour product contains eight bands, which area subset of OLCI, the thermal imager contains three long-wave bands and the spectro-polarimeter contains eleven bands with seven viewing angles and three polarisation orientations.

The multi-modal on-broad calibration device ensures that the uncertainties in products of interest are acceptable. These products include: the total chlorophyll concentrate (Chl), which is an essential climate variable defined by GCOS, the particulate organic carbon content (POC), which is a key variable used in quantifying ocean carbon cycling, and the chlorophyll concentration of microphytoplankton (Microplankton Chl), which is a useful predictor of carbon export and energy transfer to the marine food web.

Absolute gravity measurements at the level of 10 nm.s-2 have been demonstrated with gravimeters based on atom interferometry (Kasevich, 1992) which rely on the wave nature of matter postulated by quantum mechanics. Similar to classical absolute gravimeters, they measure the acceleration of free-fall test masses (in this case a cloud of laser-cooled atoms) compared to the local ground reference frame.
This pioneering work gave rise to an important research activity that led to the development of high performance experiments. Mobile versions of these experiments were developed so that these instruments could participate to international comparisons of absolute gravimeters, where quantum gravimeters have demonstrated top-level performance in terms of sensitivity, long-term stability and accuracy (Francis, 2013). Following this experimental validation of the performances offered by quantum technologies for high performance absolute gravity measurements, an intense research and development activity was initiated at the beginning of the 2010s in order to fill the gap between the complex academic experimental setups available at that time, and compact transportable instruments that can be operated reliably for outdoor measurements. We have participated to this effort through the development of our Absolute Quantum Gravimeter (AQG), dedicated to ground operation.

This instrument has reached an unprecedented level of technological maturity and has demonstrated a very interesting competitive advantage for high performance absolute gravity measurements (Ménoret, 2018). An overview of this quantum sensor including a description of its operating principle, the technological challenges associated to this technology as well as the main fields of application will be presented.

In parallel to our activities in the field of quantum gravimeters for ground operation, a significant effort is being conducted in order to bring quantum technologies to the appropriate TRL for the development of a space quantum gravity sensor. This technology would offer an interesting added value for space geodesy and the objective of the GRICE project consists in providing an improved gravity map compared to the available data. Fundamental science would also benefit from these quantum technologies and the STE-QUEST project aims at performing a test of the Weak Equivalence Principle with an unprecedented level of performance. In order to reach these long-term objectives, a pathfinder mission (CARIOQA) is being prepared. It consists in developing a payload that will integrate a quantum accelerometer in order to demonstrate the operation of the instrument in a satellite and confirm the on-board performances are in line with our theoretical predictions. The design of this sensor imposes a large number of stringent technical requirements and we will describe the work we are conducting in order to develop a laser system optimized for the preparation of a cloud of laser cooled atoms close to the absolute zero and the interrogation of this atomic sample for highly accurate and stable acceleration measurements, and compatible with the integration in a satellite.

Kasevich, M., and Chu, S., Measurement of the gravitational acceleration of an atom with a light pulse atom interferometer. Applied Physics B, 54, 321–332 (1992)
Francis et al. The european comparison of absolute gravimeters 2011 (ECAG-2011) in Walferdange, Luxembourg: results and recommendations. Metrol. 50, 257 (2013).
Ménoret et al., "Gravity measurements below 10−9 g with a transportable absolute quantum gravimeter", Nature Scientific Reports, vol. 8, 12300 (2018)