Introduction:  Comet Interceptor is the first Fast (F-class) mission in ESA’s Cosmic Vision program [1], and is the first rapid response mission, waiting in space for its target comet to appear. Its goal is the first in situ investigation of a long-period comet. Comet Interceptor (Spacecraft A or S/C A) will carry two deployable probes, allowing multipoint investigations of the target. Probe B1 is contributed by JAXA and probe B2 by ESA. The mission will be launched in 2029 on an Ariane 6 towards the Sun-earth Lagrange point L2, together with the Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) mission.

Science Objectives: All space missions to comets have so far visited short-period comets (SPCs). Comet Interceptor will, for the first time, target a long-period comet (LPC), ideally a dynamically new one. The mission will investigate the processes of planetesimal formation by evaluating which of the phenomena observed by previous missions, particularly during the rendezvous of Rosetta with Comet 67P, are primordial and which have developed during the many perihelion passages of those SPCs. Specifically, the objectives of Comet Interceptor are:

• Comet Nucleus Science - What is the surface composition, shape, morphology, and structure of the target object?
• Comet Environment Science - What is the composition of the coma, its connection to the nucleus (activity) and the nature of its interaction with the solar wind?

Mission Profile: After launch and transfer to L2, Comet Interceptor will wait for its target comet. In the unlikely case that no suitable LPC is found, the target will be selected from a list of SPCs.

The comet encounter will take place near earth’ orbit (between 0.9 and 1.2 AU from the sun), at the ecliptic node of the target comet. The duration of the waiting time (typically a few years) and of the transfer to encounter (typically between several months and a few years) depend on the target.

In the last two days before the fast flyby (velocity between 10 km/s and 70 km/s) the probes will be released from S/C A and pass by the target. Comet Interceptor is designed to withstand the environment of Comet 1P Halley at the time of the flyby by the Giotto mission at a speed of 70 km/s and a closest approach distances of 1000 km for S/C A, 850 km for probe B1 and 400 km for probe B2. The closest approach distances may be adjusted according to flyby velocity and target comet activity. The data from the probes are transferred to S/C A by an intersatellite link, and up to 6 months after the flyby are reserved for data downlink from S/C A to earth.

Payload: The instrumentation of Comet Interceptor is:

Spacecraft A:

• Comet Camera (CoCA): Visible high-resolution imager, 4 colour filters;
• Modular InfraRed Molecular & Ices Sensor (MIRMIS): IR Imaging spectrometer, 0.9 – 25 μm;
• Mass Analyzer for Neutrals in a Coma (MANiaC): Mass Spectrometer, mass/charge range up to ~1000;
• Dust, Fields, and Plasma (DFP-A) instrument suite: dust detector, magnetometer, plasma instrument measuring electric fields and plasma density and temperature, ion and energetic neutral atoms spectrometer, and electron spectrometer.

Probe B1:

• Hydrogen Imager (HI): Ly α imager;
• Plasma Suite (PS): Magnetometer and Ion Mass Spectrometer;
• Narrow Angle Camera (NAC) and Wide Angle Camera (WAC): NAC for high-resolution nucleus imaging, WAC for Coma imaging.

Probe B2:

• Entire Visible Sky (EnVisS): All-sky imager with polarimetric capability;
• Optical Periscope for Comets (OPIC): Visible Imager for science and navigation;
• Dust, Fields, and Plasma (DFP-B2): Dust detector and magnetometer.

Conclusions: The Comet Interceptor mission provides various firsts:

• First mission to an LPC,
• First multipoint investigation of a comet with three spacecraft,
• First rapid response mission.

References: [1] Jones, G. H. et al. (2024), Space Sci. Rev 220, issue1, article 9.

How to cite: Küppers, M. and the Comet Interceptor Team: Comet Interceptor: Visiting a Pristine World, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-109, https://doi.org/10.5194/epsc-dps2025-109, 2025.

By the end of 2029, the European Space Agency (ESA) will launch its first Fast-class mission, Comet Interceptor (Jones et al., 2024). The mission is designed to study and explore a dynamically new comet, with the aim of deepening our understanding of formation and evolution of comets and, more in general, of the Solar System.

To achieve this goal, the mission is composed of several instruments dedicated to both in situ measurements and remote sensing. One of the instruments that operates in the latter mode is the Entire Visible Sky camera, EnVisS, which is designed to measure the radiance and polarization characteristics of the light scattered by the dust particles in the cometary coma (Fulle et al., 2000).

The fish-eye camera of EnVisS works in push-frame mode, taking images of the entire coma within the visible wavelength range. The main components are an optical head (composed of ten lenses), a Filter Strip Assembly, and a CMOS detector.

The best performance of the instrument is achieved when the images show the highest Signal to Noise Ratio (SNR), which, as per requirements, has to be larger than 10 for the broadband images (Da Deppo et al., 2022). For this reason, one of the analysis that must be performed consists of defining the most suitable observational strategy in terms of the detector binning and exposure time while getting closer to the target. With this goal in mind, a simulator of a comet and its coma has been developed and the SNR of simulated EnVisS images has been estimated. In Figure 1 the building blocks of the general simulation environment are shown.

Figure 1: Building blocks of the general simulation environment used for the EnVisS camera to estimate the Signal to Noise Ratio.

The simulator considers a pure equidistant fish-eye model for the camera, an attenuation by optics and filter transmission, as well as the appropriate quantum efficiency curve of the detector working with 12 bits configuration. Furthermore, only broadband observations are taken into account and the geometric information of the flyby is given considering the spice kernel provided by ESA [4], which consists of a flyby around comet 8P/Tuttle, with a close approach (CA) distance of 250 km, and a spin period of the probe of 4 s.

The main problem that had to be faced to estimate SNR is the uncertainty derived from the fact that the target, its activity level, and its coma characteristics are unknown, thus, several assumptions have then been made. In particular, a spherical and symmetric coma with dust particles following a power law size distribution (r ^−a, where r is the particle size and a the exponent) has been taken into account. The activity of the target has been defined by a water production rate of 1e30 molec/sec and a dust production defined in terms of dust-to-gas ratio. The dust size distribution ranges from 0.1 μm to 1 mm divided in 50 bins. Furthermore, Mie scattering with refractive index n = 1.8+0.1i and effective wavelength of 656 nm have been used. Only after testing the validity of these assumptions, the estimate of the SNR of EnVisS observations has been computed.

For the analysis, several different cases have been studied. In particular, the impact of the slope of the dust size distribution, a, and the total dust production rate, Q_d, of the comet have been analyzed for different binnings and exposure times.

The simulation results show that, maintaining the same detector parameters, the signal detected by the camera sensor is extremely different for the studied cases. Consequently, different observational strategies must be adopted from case to case.

To define the best strategy for each instance, all the data collected from the previous tests have also been quantitatively described in terms of the saturated and useful fractions of the phase curve, and of how those fractions evolve with time.

This analysis has shown that to have the maximum useful fraction, a combination of different binning and exposure times is necessary during the whole flyby period. Furthermore, a combination of two different images taken with different binnings or same binning but different exposure times might be a possible solution to achieve the maximum SNR possible and recreate almost the entire phase function.

For this study, the suitable binnings and exposure times to obtain the best coverage of the phase function with the highest possible SNR as a function of time have been considered for the combinations Q_dust/Q_gas = 3 and three different slopes (a = 3.1, 3.5, 4.1), and two dust to gas ratios (Q_dust/Q_gas = 1, 6) and a = 3.5.

The final best observational strategy is summarized in the table in Figure 2.

Figure 2: Summary of the binning and exposure time to obtain the best coverage of the phase function as a function of the time to close approach (or distance) for the test performed considering the uncertainty in the slope of the dust size distribution.

ACKNOWLEDGMENTS

This activity has been funded by the Italian Space Agency (ASI) via contract 2023-14-HH.0 to the Istituto Nazionale di Astrofisica (INAF).

REFERENCES

[1] Jones, G., Snodgrass, C., and Tubiana, C., e. a., “The comet interceptor mission.,” Space Sci Rev 220, 9 (2024).

[2] Fulle, M., Levasseur-Regourd, A. C., McBride, N., and Hadamcik, E., “In situ dust measurements from within the coma of 1p/halley: First-order approximation with a dust dynamical model,” The Astronomical Journal 119, 1968 (apr 2000).

[3] Da Deppo, V., Della Corte, V., Zuppella, P., Nordera, S., Pernechele, C., Lara, L. M., Castro, J. M., Jiménez, J., Martinez, I., Praks, J., and the EnVisS Team, “The entire visible sky (enviss) imager for the comet interceptor esa mission,” Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-273 (2022).

[4] https://s2e2.cosmos.esa.int/bitbucket/projects/SPICE_KERNELS/repos/comet-interceptor/browse

How to cite: Naletto, C., Gutierrez, P. J., Lara, L. M., Moualla, L., Zuppella, P., Della Corte, V., and Da Deppo, V.: EnVisS Signal to Noise Ratio estimates, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1015, https://doi.org/10.5194/epsc-dps2025-1015, 2025.

The instrumentation of ESA's Comet Interceptor mission contains the Optical Periscopic Imager for Comets (OPIC), provided by the University of Tartu, Estonia. OPIC is the first Estonian instrument onboard an ESA Solar System exploration mission.

Comet Interceptor in an ESA F-class mission aiming to fly by a long-period comet visiting the inner Solar System, or an interstellar object like ‘Oumuamua that flew past the Sun in 2017. Scheduled for launch in 2029, Comet Interceptor will be parked in the Sun-Earth Lagrange point L2, waiting for up till 5 years until a suitable target object has been detected and chosen.

In addition to the primary spacecraft, provided by ESA, Comet Interceptor comprises two smaller probes: B1 provided by the Japanese Space Agency JAXA and B2 provided by ESA. The probes will be separated circa one day before the encounter with the target object, performing closer fly-bys than the primary spacecraft. The probes will hence face a higher risk of impacts by micrometeorites and dust particles in case the target object is an active comet. To mitigate the risk of data loss, the probes will continuously transmit measurement data to the primary spacecraft during the fly-by.

OPIC is a part of the payload of probe B2. It is a monochrome visual range camera taking images in the direction of travel. To avoid micrometeorites to directly impact the optics of OPIC, the instrument is pointed perpendicular to the flight direction and a periscope is used to align its field of view with the translation direction of probe B2.

The Field of View of OPIC, spanning 18.3 x 18.3°, scans the area around the target object with the rotation of the probe. Images taken far from the target are used to characterize gas and dust surrounding the object. Close to the target the firmware of OPIC prioritizes and crops the images to be transmitted to the primary spacecraft, to ascertain that the target is visible in the acquired data. Combined with images taken by the two other spacecraft of the mission, these data are used to construct a 3D model of the object and its potential dust jets.

OPIC is developed and tested by Tartu Observatory, institute of the University of Tartu. The instrument’s Principal Investigator is Dr. Mihkel Pajusalu. The flight and qualification models of the instrument are implemented by the industrial partner CrystalSpace OÜ (Estonia). The image prioritizing and cropping code is developed by Bitlake Technologies Ltd. (Latvia). Aalto University (Finland) participates in science planning and data processing.

The presentation summarizes the technical implementation of the OPIC instrument and the status of the project.

How to cite: Kahanpää, H., Pajusalu, M., and Salumets, S. and the OPIC team: OPIC instrument for Comet Interceptor, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1350, https://doi.org/10.5194/epsc-dps2025-1350, 2025.

 Introduction

The purpose of the ESA space mission Comet Interceptor, to be launched in 2029, is to study a Dynamically New Comet (DNC), building upon the significant scientific results of Rosetta, and extend the knowledge of cometary exploration. Exploring DNCs is a challenging task, because the target of the mission must be discovered in advance, according to the standard mission planning timeline. To reach this goal, the spacecraft, after the launch, will reach the L2 Lagrange point, waiting for the target selection. Comet Interceptor includes a main spacecraft (A) and two sub-spacecraft (B1 and B2). DISC, in particular, is part of the Dust, Field and Plasma suite, which will be boarded on the spacecraft A and B2. During the DNC fly-by, DISC will count the dust particles and measure their momentum. The fly-by speed will be in the range between 10-70 km/s.

DISC consists of an aluminium box case, size 121x115,5x46 mm³, equipped with two electronic boards, a sensing plate, a dust shield and three piezoelectric transducers (PZTs). DISC continuously acquires signal from the PZTs, but it starts registering data only when the digital signal reaches a set value. When the event is triggered, the signal is acquired from the PZTS for for 200 microseconds at 1 MHz sampling rate. From the analysis of the three signals acquired it is possible to retrieve the impact position and the particle momentum.

Expected performance

To evaluate the performance of DISC, it is necessary to operate different strategies, in order to take into account the range of dust particles momentum that DISC will hit. Comet Interceptor flyby speed is estimated to be in the range of 10 – 70 km/s. As it is not feasible to perform hyper velocity impact test on a laboratory facility, it was decided to evaluate the performance of DISC simulating the impact with high power pulse laser, in addition to the test performed with real projectiles, useful to cover the range of lower speed. This method is based on the correlation proposed by [Pirri, 1977], which allows to calculate the impact pressure of the laser pulse on a surface, knowing the main operating parameters of the laser: beam radius, pulse time and intensity. In this way, it is possible to reproduce the impact of particles with different size, velocity and contact time.In this study, two different Nd:YAG laser were used, PL2250 and NL300. Both have a wavelength of 1064 nm. Laser PL2250 has a pulse of 80 ps, energy up to 0.1 mJ; Laser NL300 has a pulse of 6 ns, energy up to 1.2 J. Once these parameters are set, it is possible to estimate the range of particles momentum that can be simulated for different values of particle density.

The impact pressure is a function of the impact speed and the particle density, therefore it is possible to correlate the range of interest for DISC calibration. Figure 1 reports the range of impact pressure that DISC must be able to measure, considering a range of particle density of 100 – 2500 kg/m³.

Figure 1: Impact pressure at different speed

Varying the optical energy, it is possible to identify the size and the speed of the particles which we are able to simulate with the lasers. As an example, Figure 2 reports the range of particle diameter and speed achievable with PL2250.

Figure 2: Range of diameter/speed at ρ = 900 kg/m³, PL2250

The use of two lasers with different pulse durations allows to evaluate measurement sensitivity to impact time variation, while maintaining the same transmitted energy.

MGSE development

To perform the simulation of hyper velocity dust impact with pulsed laser, the development of a specific laboratory set-up was required. These test aim at verify DISC expected performance and further verify the consistency between laboratory test and numerical simulations. In addition to the two Nd:YAG laser previously described, the experimental setup, includes a vacuum chamber, a beam expander, a converging lens and a 3D automated movement system. DISC is mounted on the automated movement system and positioned inside the chamber, operating at the pressure of 10^-6 bar.

The lasers are positioned on an optical bench and the pulses are directed through two different optical paths, into a beam expander which increases the pulse width by a factor of 2.5. The pulse, through a window on the vacuum chamber, is directed into a converging lens that focuses it onto the sensitive surface of DISC. The lens has a focal length of 75 mm. By modulating the distance between DISC and the lens on a micrometric scale it is also possible to regulate the spot size and assess the effect of the particle size at a given momentum.

Figure 3: Optical paths to beam expander

The functionality of the Electrical Breadboard of DISC was assessed by mean of impact qualitative test carried out at Leonardo facilities. Metallic spheres of different size, from 0.8 to 2 mm were used as a sample to measure DISC response to the impact from a defined height. The spheres were dropped from the funnel structure represented in Figure 4, to the sensing plate of the EBB. The height was set by mean of a 1-dimension micrometric movement system. Knowing the distance between the drop point and the plate, and the mass of the spheres, it is possible to calculate the momentum of the impact and therefore compare it to the signal response of the PZTs.

All the results obtained from preliminary test, aimed at assessing the functionality of DISC and define sensitivity map of the sensing plate will be shown and discussed in detail.

Figure 4:Set-up for DISC functionality with metal mini-spheres

Acknowledgement: This work has been funded by the ASI-INAF agreement N. 2023-14-HH.0

How to cite: Ruggiero, G., Della Corte, V., Cozzolino, F., Piccirillo, A. M., Rotundi, A., Bertini, I., Inno, L., Fiscale, S., Tonietti, L., Grappasonni, C., Sindoni, G., Ammannito, E., and Longobardo, A.: DISC - Dust impact sensor and counter on-board Comet Interceptor mission: experimental set-up for calibration and preliminary results, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1429, https://doi.org/10.5194/epsc-dps2025-1429, 2025.

The CNSA (China National Space Administration) Tianwen 2 mission [1] will study and sample the Kamo’oalewa near-Earth asteroid and then rendezvous with the 311/PANSTARRS Main Belt Comet (MBC). The mission is scheduled to launch in May 2025, with arrival at Kamo’oalewa in 2026. Then, the spacecraft will land on the asteroid and collect samples of its surface, and deliver them to Earth around 2027. The main spacecraft will then head for 311P/PANSTARRS, which has asteroid-like orbital characteristics but also features comet-like activity. The mission aims at providing insight into the composition and evolution of near-Earth objects and understand the distribution of water and organic molecules and the history of the early Solar System.

The mission includes several instruments, such as multispectral cameras, thermal emission spectrometer, imaging spectrometer, mass spectrometer, a magnetometer and a dust analyser. The dust analyser is a suit of different sensors, including the DIANA (Dust In situ ANAlyser) instrument.

DIANA is based on Quartz Crystal Microbalance (QCM) devices, aiming at detecting dust and volatiles content, as well as assessing contamination on board the spacecraft. This kind of sensors converts mass changes into fundamental resonance frequency variations, according to Sauerbrey equation [2]. DIANA can be heated thanks to the crystals built-in heaters [3] or cooled by a Thermo-Electric Cooler (TEC). Thanks to its customized design [4], DIANA is capable of performing Thermo-Gravimetric Analysis (TGA), a technique widely used to study mas variation processes as a function of temperature, in order to measure the abundance of volatile compounds of astrobiological interests (e.g. water, organics) in the cometary dust and reveal the occurrence of contaminants that could condense on the crystal.

DIANA payload is composed by: 1) a sensor head (DIANA SH1), that works at low temperature (i.e. 225-400K), to measure the dust flux and the amount of physically absorbed water, as well as contamination assessment during Tianwen2 cruise phase; 2) a sensor head (DIANA SH2), that works at higher temperatures (up to 500K), to measure the dust flux and amount of organic components; 3) a Main Electronics Unit (MEU), to read SH1 and SH2 frequencies and temperatures and set the heating ramp rates for TGA.

The technical characteristics of DIANA are shown in Table 1, while the two sensor heads are shown in Figure 1.

Table 1. DIANA technical characteristics.

Figure 1. DIANA sensor heads: SH1 on the left and SH2 on the right.

DIANA was developed by an Italian Consortium led by INAF-IAPS (Istituto Nazionale di AstroFisica-Istituto di Astrofisica e Planetologia Spaziali), in collaboration with CNR-IIA (Consiglio Nazionale delle Ricerche-Istituto sull’Inquinamento Atmosferico) and Politecnico di Milano-MetroSpace Lab. The MEU was developed in collaboration with Shanghai Institute of Technical Physics (SITP).

Acknowledgments: DIANA development activities are funded by the Italian Space Agency through the ASI-INAF Agreement 2022-27-HH.0.

References:

[1] Zhang, X. et al. (2019), LPSC abstracts, 1045

[2] Sauerbrey, G. (1959), Z. Phys, 155, 206–222

[3] Palomba, E. et al. (2016), OLEB, 46, 273-281

[4] Martina, C. et al. (2024), IAC abstracts, 87856

How to cite: Palomba, E., Longobardo, A., Dirri, F., Gisellu, C., Nardi, E., Scaccabarozzi, D., Martina, C., Zampetti, E., Kun, D., Pepe, R., and Pedone, M.: The DIANA instrument for Tianwen 2 mission, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1699, https://doi.org/10.5194/epsc-dps2025-1699, 2025.

The Emirates Mission to the Asteroid Belt (EMA) is set to launch in 2028 to conduct a tour of main belt asteroids. Over a seven-year period, EMA will perform six distinct asteroid flybys and rendezvous with a final seventh asteroid called (269) Justitia, a 54-km diameter object with a uniquely reddened spectrum. The flyby targets consist of a diverse collection of asteroids including (623) Chimaera, the largest remnant of the primitive C-type Chimaera family, and members of the Baptistina, Eos, Erigone, and Euterpe families. Five of the seven targets are C-complex, which form a key piece of the puzzle of early solar system formation and its dynamical evolution. The primary science goal is to probe the origin and evolution of water-rich asteroids, with a focus on three main questions: 1) Where did the volatile-rich asteroids form? 2) Are these asteroids linked to specific meteorites? 3) What does their chemical inventory and volatile abundances tell us about main belt evolution? To answer these questions, the mission will perform science investigations based on the following objectives: A) Determine the geologic history and volatile content of multiple main belt asteroids and investigate the interior structure of the rendezvous target. B) Determine temperatures and thermophysical properties on multiple asteroids to assess their surface evolution and volatile histories. The EMA remote sensing instruments include: 1) Visible color narrow-angle camera (CNAC), 2) Midwave infrared spectrometer (MIST-A), 3) Thermal IR spectrometer (EMBIRS), and thermal IR camera (IR-Cam). MIST-A is provided by the Agenzia Spaziale Italiana (ASI) in partnership with the Italian National Institute for Astrophysics (INAF) and Leonardo S.p.A. The CNAC and IR-cam will be provided by Malin Space Science Systems, and EMBIRS will be provided by Northern Arizona University and Arizona State University. The spectral coverage of the multiple infrared instruments is expected to span 2.0 to > 100 µm, providing opportunities for detailed compositional and thermophysical analyses. Visible images with few meters/pixel resolution will be acquired for (269) Justitia, along with thermal infrared images with 10-100 m/pixel resolution.

Funding of the Emirates Mission to the Asteroid Belt is provided by the UAE Space Agency with support from the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics as its main knowledge partner.

How to cite: AlSaeed, N., AlMazmi, H., and Hayne, P. and the Emirates Mission to the Asteroid Belt science team: Science Overview of the Emirates Mission to the Asteroid Belt, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1435, https://doi.org/10.5194/epsc-dps2025-1435, 2025.

The Emirates Main Belt Infrared Spectrometer (EMBIRS), one of four remote sensing instruments onboard the Emirates Mission to the Asteroid Belt (EMA), is designed to collect data on six main-belt asteroid flybys, ending with proximity operations at 269 Justitia. EMBIRS will measure the emitted spectral radiance of these asteroids providing constraints on the thermophysical properties and spectral character/composition of these asteroids. In combination with the other instruments on the EMA payload, EMBIRS will address the key goals of the mission, specifically evaluating the origins and evolution of water-rich asteroids and their resource potential. EMBIRS measurements address several mission science objectives, including mapping the silicate mineralogy of compositionally diverse, water-rich asteroids, supporting the evaluation of their geologic history, and characterizing the temperature and thermophysical properties of multiple asteroids to assess their formation, surface evolution, and volatile histories.

The EMBIRS instrument is an interferometric thermal infrared spectrometer developed and provided by Northern Arizona University (NAU) and Arizona State University (ASU) in partnership with the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics for inclusion on the United Arab Emirates Space Agency’s EMA mission. It builds on a long heritage of thermal infrared spectrometers designed, built, and managed by ASU's Mars Space Flight Facility. EMBIRS is most directly akin to the Emirates Mars Infrared Spectrometer (EMIRS) on the Emirates Mars Mission (EMM). EMBIRS is a build to print of EMIRS except for minor modifications to the mechanical and thermal interfaces (Figures 1 & 2). EMBIRS is 53x29x32 cm, has a mass of ~12.7 kg, and requires 21 W during operational activities. EMBIRS collects spectral data from 6-40+ µm at 10 and 20 cm^-1 spectral sampling. This instrument utilizes an on-axis deuterated L-alanine doped triglycine sulfate (DLaTGS) detector and a scan mirror to make infrared radiance measurements of the asteroids during flybys and 269 Justitia proximity operations.

Under the current concept of operations, EMBIRS achieves complete global coverage (daytime and nighttime observations) of 269 Justitia within 8 weeks of observing with pixel sizes of <500 m/pixel and emission angles <30˚ (Figure 3). This observation strategy uses a set of pre-canned commands that set the calibration frequency, where space and internal calibration are used to obtain a full aperture calibration on-orbit every 30 minutes. During flyby operations, EMBIRS observes the surface of target asteroids using multiple methods to maximize spatial coverage.  This is accomplished via direct-stare observations for ~10 hours on approach and ~2 hours on departure with ~10-20 minute rasters during the closest approach. Parameters for these close-approach rasters are set by the flyby velocity and object size (Figure 4). EMBIRS is currently undergoing final design changes with assembly, integration, and environmental test that began in November 2024 and delivery to the spacecraft in August 2026.

Figure 1: Fully assembled EMIRS instrument on EMM prior to delivery to the spacecraft (Edwards et al., 2021). EMBIRS is build-to-print, using flight spare hardware from the EMIRS program, with the small interface changes to the mounting interface and thermal control.

Figure 2: The EMBIRS instrument and optical design is identical to the EMIRS instrument with minor changes to the metrology assembly to facilitate alignment (Edwards et al., 2021).

Figure 3: Planned EMBIRS coverage of 269 Justitia (top) after 1 week and (bottom) 8 weeks of observing.

Figure 4: Example flyby coverage from EMIRS observations of Deimos (Edwards et al., 2023).

References:

Edwards, C., Osterloo, M., Fisher, C., Jeppesen, C., Smith, N., Holsclaw, G., Wolff, M., Jonees, A., Knavel, J., & Pilinski, E. (2023). The First Observations of Deimos from the Emirates Mars Mission (EMM) Flybys. Paper presented at the European Geophysical Union.

Edwards, C. S., Christensen, P. R., Mehall, G. L., Anwar, S., Tunaiji, E. A., Badri, K., Bowles, H., Chase, S., Farkas, Z., Fisher, T., Janiczek, J., Kubik, I., Harris-Laurila, K., Holmes, A., Lazbin, I., Madril, E., McAdam, M., Miner, M., O’Donnell, W., Ortiz, C., Pelham, D., Patel, M., Powell, K., Shamordola, K., Tourville, T., Smith, M. D., Smith, N., Woodward, R., Weintraub, A., Reed, H., & Pilinski, E. B. (2021). The Emirates Mars Mission (EMM) Emirates Mars InfraRed Spectrometer (EMIRS) Instrument. Space Science Reviews, 217(7), 77. doi: 10.1007/s11214-021-00848-1

How to cite: Edwards, C. S., Christensen, P. R., Mehall, G. L., Smith, N. M., Anwar, S., Bowles, H., Farkas, Z., Fisher, T., Janiszewska, J., Kubik, I., Ortiz, C., Patel, M., Woodward, R., Reed, H., Hayne, P., Al Mazmi, H., and Al Saeed, N.: The Emirates Main Belt Infrared Spectrometer (EMBIRS) onboard the Emirates Mission to the Asteroid Belt, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-284, https://doi.org/10.5194/epsc-dps2025-284, 2025.

Seven primordial and water-rich asteroids will be investigated by the Emirates Mission to the Asteroid Belt (EMA), which is scheduled to launch in 2028 [1]. Using solar electric propulsion, the spacecraft will cruise for seven years, traveling over five billion kilometers while navigating around Venus, Earth, and Mars with the help of gravity. Six asteroids will be observed by the spacecraft during as many flybys: 10253 Westerwald and 623 Chimaera in 2030, 13294 Rockox in 2031, 88055 and 23871 in 2032, 59980 in 2033. In 2035 EMA will reach 269 Justitia, a 54.4 km diameter object, and one of the few Main Belt (MB) asteroids that exhibits an intense red spectral color in telescopic observations from Earth [2]. After completing a thorough mapping of its surface, a lander will be dropped onto the surface of 269 Justitia at the end of the mission to demonstrate how resources can be reached in the future. With a mass of about 2,300 kg before launch, the EMA spacecraft, called MBR Explorer, will be designed, built, and tested by the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP) as a "knowledge partner" of the UAE Space Agency.

The MWIR Imaging Spectrometer for Target-Asteroids (MIST-A) is designed to gather hyperspectral data on the seven asteroids in order to ascertain their composition and thermal properties. This instrument is Italy's contribution to the EMA science payload [3]. The MIST-A spectral channel optical design is inherited from the JIRAM instrument [4] on board the NASA Juno spacecraft. It is based on a Littrow imaging spectrometer joined to a modified Schmidt off-axis telescope (D=44 mm, f/3.7). The dispersive element of the spectrometer is a flat grating with a blaze angle of 2.56 deg and a groove density of 30.3/mm. A 2D HgCdTe detector with a 36 µm pixel pitch and 2 Me- full well, windowed to a format of 256 spatial samples by 336 spectral bands, is used as focal plane. Two spectral bandpass filters are included in the detector subunit to reject the thermal background of the instrument and sort out grating orders. An exterior radiator passively cools down the optical head to an operating temperature of ≤135 K, while a cryocooler actively cools down the IR infrared detector to ≤85 K.

MIST-A operates with a spectral sampling of less than 10 nm per band within the 2–5 µm spectral range. A one-axis steerable mirror (whose axis is parallel to the slit axis) mounted at the telescope's entrance allows for controlled pointing and scanning capabilities, with offsets up to ±6 degrees from the boresight. Because the position and angular velocity of the scan mirror are pre-set, MIST-A's onboard software and functions enable customizable strategies throughout the mission's several orbital phases, such as close orbits at Justitia and fast target-asteroid flybys.

From a distance of 100 km, the instrument can achieve a swath length of 6.1 km and spatial sampling of 24 m/pixel thanks to its Instantaneous Field of View (IFOV = 238 µrad) and Field of View (FOV = 3.5 degrees). Over time, lateral scans commanded orthogonally to the ground track direction will be used to construct hyperspectral images up to ±6 degrees wide (from the boresight). 

The Internal Calibration Unit (ICU) of the instrument is mounted on the side of the telescope's entrance baffle. It offers a reference infrared signal throughout the spectrometer's whole spectral and spatial range thanks to its diffusive screen, which is lit by two MEMS infrared emitters on which are mounted polystyrene filters. By a specific telecommand sequence, the internal scan mirror is rotated to the ICU reference angle in order to gather the ICU signal. To ensure repeatable fluxes, the IR emitters are driven by carefully regulated current levels. Similar ICU designs used in other spaceborne spectrometers have already been successfully utilized [5]. Finally, at the start of each acquisition sequence, an internal background frame is acquired using the ICU target with sources turned off as a reference.

By operating in the MWIR spectral range, MIST-A can identify and map various classes of compounds relevant for primitive targets, such as organic matter [6,7], carbonates, silicates, phyllosilicates, ammonium salts [8,9,10], and water ice [11]. The instrument can measure surface thermal emission longward of 3 µm [12], from which diurnal temperature and thermal properties can be inferred [13]. Moreover, taking advantage of varying illumination and viewing geometries during flybys and orbits at Justitia, spectrophotometric models can derive regolith composition and physical properties [14]. 

MIST-A will go through a full calibration campaign at INAF-IAPS facilities in Rome following integration and testing at Leonardo Company (Florence). This stage will come before the instrument is finally delivered to LASP in August 2026 where it will be integrated and tested aboard the EMA spacecraft. Phase D2 of the MIST-A project is currently underway after it successfully passed the examination by an independent Critical Design Review board.

INAF/IAPS, Rome, is the MIST-A PI institute and it is responsible for instrument’s calibration, science activities and operations. The primary funding source for the program is the Italian Space Agency (ASI) through science contract 2023-21-HH.0, and industrial contract 2025-33-I.0, with a secondary support from INAF. Leonardo S.p.A. from Campi Bisenzio (Florence) is the MIST-A industrial contractor in charge of the instrument’s design, assembly, qualification and testing.

References: [1] Al Mazmi et al. (2023) AGU id. P44B-01. [2] Hasegawa etal. (2021) ApJL, 916:L6. [3] Filacchione etal. (2023) ACM, 2851. [4] Adriani etal. (2017) SSR, 213, 393-446. [5] Stefani etal. (2025) RSI, 96, id.011301. [6] Raponi etal. (2020) Nat.Astr., 4, 500-504. [7] De Sanctis and Ammannito (2021) Minerals, 11, 799. [8] De Sanctis etal (2016) Nature, 536, 54-57. [9] De Sanctis etal (2020) Nat.Astr., 4, 786-793. [10] Raponi etal. (2019) Icarus, 320, 83-96. [11] Filacchione etal. (2016) Nature, 529, 368-372 [12] Coradini etal. (2011) Science, 334, 492. [13] Formisano etal. (2016) MNRAS, 455, 1892-1904. [14] Ciarniello etal. (2015) A&A, 583, id A31.

How to cite: Filacchione, G., Ciarniello, M., De Sanctis, M. C., Capaccioni, F., Raponi, A., De Angelis, S., Formisano, M., Ferrari, M., Biondi, D., Boccaccini, A., Stefani, S., Piccioni, G., Mura, A., La Francesca, E., Galiano, A., Cencia, C., Tiberia, A., Ammannito, E., and Olivieri, A. and the MIST-A Industrial Team: MIST-A, the MWIR Imaging Spectrometer onboard the Emirates Mission to the Asteroid belt., EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-978, https://doi.org/10.5194/epsc-dps2025-978, 2025.

Introduction and Context

In response to the European Space Agency’s call for an M-Class Mission (M8), we will propose a mission to rendezvous with a short period, Jupiter-Family Comet to interact with its surface and rehearse a touch-and-go (TAG) sampling manoeuvre with in-situ sample analysis. The goal is to study the mechanical properties, stratification, and structural embedding of ice in the upper decimetre(s) of the comet’s surface. With a balanced risk approach, risk and gain are gradually increased from early remote characterisation up to the final TAG manoeuvre with in-situ sample analysis.

Science Goals

The main science goals of the mission are the understanding of 1) comet and planet formation and 2) cometary activity. To achieve this, the focus is put on the stratification of the upper decimetre(s) of the surface, its building blocks, mechanical properties, and the homogeneity or distribution of water ice therein. This requires direct interaction of the spacecraft with the surface.

A comet’s surface is in a complex, dynamic state between its primordial properties and its modification through dust and gas activity driven by solar radiation. Activity models try to bridge between this but need to make strong assumptions on structure, strength, and ice amount and distribution. The upper decimetre determines a comets’s interaction with the environment but many things are uncertain. A selection of specific science questions to address both goals above are the existence and nature of pebbles (Blum et al.) and water-ice-enriched blocks (WEBs; Ciarniello et al.), strength stratification and existence of a sub-surface sinter layer (Biele et al.), or the dust-to-ice ratio (Chokroun et al.).

Mission Design and Instruments

Several steps are planned for the study and interaction with the comet’s surface. Ordered by the gradual increase of the risk, these are a) remote characterisation, b) CubeSat impact experiments, c) TAG rehearsal with back-away thrust interaction, d) TAG manoeuvre with stratified surface removal, and e) TAG manoeuvre with sampling and in-situ analysis. These operations will be performed in this order, but some will be performed multiple times.

Remote sensing implies VIS and NIR study of the surface from ~10 km distance. This covers global spectro-photometric mapping, geologic and compositional characterisation, and many more. Drawing a comparison to previous comets, and in particular 67P will enhance our understanding of the target comet and allow a qualified selection of the interaction sites. To achieve this, the VIS camera (ref. Keller et al., 2007; Sierks et al. 2011) shall feature several colour filters, the NIR instrument must be particularly susceptible for the water ice bands and organics features detection (ref. MIRS; Barucci et al., 2021).

From an altitude in the order of 100 m, a 3u CubeSat is released to impacts into the comet surface with a velocity in the order of 10 m/s. This relatively gentle impact does not pose a threat to the main spacecraft, such that its dynamics can be observed from a low altitude. The impact acceleration shall be recorded via the CubeSat’s Inertial Movement Unit (IMU; ref. Hera/JUVENTAS) and transmitted to the orbiter. A few seconds after impact, it shall be possible to release an extra volume of gas to perform a controlled dust-lift experiment. This CubeSat sequence can be repeated with several CubeSats.

Descending to an altitude of a few metres, a TAG rehearsal shall be performed that uses the back-away thrusters before touching the surface. The OSIRIS-REx and Hayabusa2 interactions with asteroid surfaces showed a visible gas interaction with the surface, which will be repeated with OSIRIS-APEX on asteroid Apophis. This is a direct and controlled interaction with the comet’s surface to measure strength of the material, which is expected in the order of 1 Pa or less (Attree et al., 2018). This manoeuvre will be used to reveal the first centimetre(s) of the cometary subsurface material.

An actual TAG manoeuvre without sampling is planned with a brush-wheel system (BWS; Goldmann et al., 2025), where rotating brushes are successively wiping surface layers to the sides. In contrast to classical BWS, the brushes shall be 180° to allow observation of the surface from above once per revolution with a synchronised camera. This will reveal sub-surface structure and distribution of water ice through albedo and (RGB) colour variations.

For the final TAG manoeuvre, the BWS rotation is reversed, such that a material fountain is lifted into a transparent sampling cup. The sample will be photometrically analysed at different scales and in stereo with different camera systems. Through the pressure increase measured with a pressure sensor the gas production of the sublimating sample can be measured. The concept was proven with Rosetta/COPS (Balsiger et al. 2007, Pestoni et al., 2021), and with the known sample volume it will be possible to measure the dust-to-ice ratio.

All interaction zones (thrust and BWS) will be studied with VIS and NIR remote sensing during ascent. Several CubeSat and BWS interactions are possible, which allows the distribution of risk through the study of multiple interaction sites.

The target comet shall be known from Earth observations and shall show a reasonably low activity level comparable to or less than 67P. This will allow a temporal mission profile comparable to Rosetta with arrival on the order of 12 months prior to perihelion and the sampling attempt at least 6 months before perihelion, i.e., before activity which would make complex operation impossible. With a successful conclusion of this mission phase, the comet shall be followed up to perihelion via remote observation.

References

Attree et al., 2018. A&A 611:A33, 614:C2.
Balsiger et al., 2007. Sp. Sci. Rev., 128:745-801.
Barrucci et al., 2021. Earth, Planets and Space, 73:211.
Biele et al., 2015. Nature 349:6247.
Blum et al, 2017. MNRAS 469:S755–S773.
Choukroun et al., 2020. Sp. Sci. Rev., 216, 3:44.
Ciarniello et al., 2022. Nature Astronomy, 6:546-553.
Keller et al., 2007. Sp. Sci. Rev., 128:433-506.
Goldmann et al., 2025. Apophis T-4 Years, LPI Contrib. 3083:2054.
Pestoni et al., 2021. A&A, 645:A38.
Sierks et al., 2011. Sp. Sci. Rev., 163:263-327.

How to cite: Güttler, C., Gundlach, B., Bockelée-Morvan, D., Cabral, F., Ciarniello, M., Dahmani, F., Fornasier, S., Goldmann, M., Grott, M., Kargl, G., Pajola, M., Patzek, M., Raducan, S., Ritter, B., Rubin, M., Tubiana, C., and Rückriemen-Bez, T.: Proposal for the “Comet Surface Interaction” Mission CoSI, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-854, https://doi.org/10.5194/epsc-dps2025-854, 2025.

Small solar system bodies are remnants of the solar system’s original protoplanetary disk that did not combine to form the more massive planets. These bodies include asteroids (main belt asteroids and Jupiter’s Trojans), trans-Neptunian objects (TNOs), and comets. These objects formed over a wide range of heliocentric distances and have subsequently been distributed across the solar system by dynamical interactions with the giant planets. As such, understanding the provenance and genetic relationships among the solar system’s small bodies is key for constraining the formation and primordial structure of the solar system, and the dynamical events that shaped its subsequent evolution. However, despite their importance, we lack key knowledge about how the distinct small bodies of the solar system are genetically related, how their formation locations varied in time and space, and how their chemical and physical properties have been modified over the history of the solar system. These knowledge gaps reflect that only a very few of these bodies have been visited by spacecrafts and, in particular, the strong bias in the sampling of these bodies by meteorites and past sample return missions. For instance, while the Hayabusa1 and 2 and OSIRIS-Rex missions have demonstrated the enormous scientific potential of sample return missions, and the enhanced scientific value of carefully curated returned samples over meteorites, they were known to return materials represented by meteorites. These all derive from main belt asteroids and as such predominantly represent objects that formed in the vicinity of Jupiter. As such, the next frontier is to return material from the outer solar system, which until now has remained largely unsampled, but which holds the key to understand how the solar system formed and evolved. Here the case is presented that, owing to their primitive nature, D-type asteroids present objects that formed at much greater heliocentric distance that any meteorite parent body. While their closest meteorite analog are carbonaceous chondrites, D-type material does not seem to be present in our meteorite collections, probably because this friable primitive material does not survive atmospheric entry. Moreover, D-type asteroids are predicted to be scattered TNOs, and so they may have originally formed in the far outer disk and derive from the same population of primordial bodies as comets. Thus, analyzing a D-type sample will make it possible to identify the primordial array of materials present in the protoplanetary disk and to test models of solar system formation and evolution by determining the genetic relationships among the most primitive small bodies of the solar system. For these reasons, we propose PRIAMOS (PRImordial Asteroid Mission to understand the Origin of the Solar system), a sample return mission to a D-type near-Earth asteroid (NEA). PRIAMOS would be the first European-led sample return mission and, for the first time, would return a relatively large mass of outer solar system materials to Earth. The investigation of these materials in ground-based laboratories will be transformative for our understanding of early solar system evolution and will pave the way for building a new holistic model of the solar system.

How to cite: Kleine, T., Marschall, R., and Martin, H. and the PRIAMOS team: Introduction PRIAMOS (PRImordial Asteroid Mission to understand the Origin of the Solar system) - a sample return mission to a D-type near-Earth asteroid, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1500, https://doi.org/10.5194/epsc-dps2025-1500, 2025.

The ORIGO mission was submitted in response to the 2025 call for a Medium-size mission opportunity in ESA's Science Programme. The goal of ORIGO is to inform and challenge planetesimal formation theories. Understanding how planetesimals form in protoplanetary disks is arguably one of the biggest open questions in planetary science. To this end, it is indispensable to collect ground truths about the physico-chemical structure of the most pristine and undisturbed material available in our Solar System. ORIGO seeks to resolve the question of whether this icy material can still be found and thoroughly analysed in the sub-surface of comets. Furthermore, ORIGO will quantify the degree of processing that occurs for planetesimals that formed in the outermost part of the protoplanetary disk.

Specifically, ORIGO aims to address the following immediate scientific questions:

• Were cometesimals formed by distinct building blocks such as e.g. "pebbles", hierarchical sub-units, or fractal distributions?
• How did refractory and volatile materials come together during planetesimal growth e.g. did icy and refractory grains grow separately and come together later, or did refractory grains serve as condensation nuclei for volatiles?
• Did the building blocks of planetesimals all form in the vicinity of each other, or was there significant mixing of material within the protoplanetary disk?
• To what degree have comets been modified through evolutionary processes?

To answer these questions, ORIGO will deliver a lander to a comet where we will characterise the first five meters of the subsurface with a combination of remote-sensing and payloads lowered into a borehole. Our instruments will examine the small-scale physico-chemical structure. This approach will allow us to address the following objectives, each of which informs the respective scientific question:

• Reveal the existence of building blocks of a cometary nucleus from the (sub-)micron to metre scale by exploring unmodified material.
• Determine the physical structure of these building blocks, particularly the size distribution of components and how refractory and volatile constituents are mixed and/or coupled.
• Characterise the composition of the building blocks by identifying and quantifying the major ices and refractory components.
• Quantify the amount of processing of near and deep interior material.

Over the past decade, significant theoretical advances have been achieved in working out possible planetesimal formation scenarios.

The two leading hypotheses for how planetesimals formed from sub-micron dust and ice particles in the proto-planetary nebula can be classified into two groups:

• the hierarchical accretion of dust and ice grains to form planetesimals; and
• the growth of so-called pebbles, which are then brought to gentle gravitational collapse to form larger bodies by e.g. the streaming instability.

These competing theories only have indirect proof from observations. Direct evidence, i.e. ground truths, about the building blocks of planetesimals remains hidden. ORIGO will challenge these theories by examining the physico-chemical structure of the most pristine material available in our Solar System.

How to cite: Marschall, R., Vincent, J.-B., Ulamec, S., Thomas, N., Lara, L. M., Ferri, F., Herique, A., Hviid, S., Plettemeier, D., Kereszturi, A., Lavagna, M., Dottori, A., Stöckli, L., Guilbert-Lepoutre, A., Kokotanekova, R., Attree, N., and Groussin, O.: ORIGO - an ESA M-class mission proposal to understand planetesimal formation and evolution., EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1642, https://doi.org/10.5194/epsc-dps2025-1642, 2025.

We present “Pallas Interstellar”, an ESA M8-class mission concept with a dual scientific focus: the detailed exploration of asteroid (2) Pallas and the in-situ investigation of the local interstellar medium beyond 2 AU. By integrating a high-speed flyby of Pallas with a cruise phase optimized for pristine interstellar sampling, remote sensing of the interstellar interface, and using dual-purpose, complementing instrumentation, this mission offers a unique opportunity to address foundational questions in both planetary science and astrophysics within a single mission.

Pallas is a uniquely compelling target as a likely intact protoplanet and the probable parent of an impact family that includes several near-Earth asteroids. It is the third most massive body in the main asteroid belt, containing ~7% of the main belt’s total mass. Pallas is further distinguished by its high orbital inclination (34.8°), primitive B-type spectral classification, and a bulk composition that is likely intermediate in volatile content between that of Ceres and Vesta—the two protoplanets previously explored by the Dawn mission. Spectroscopic data from ground- and space-based observatories indicate the presence of hydrated minerals and carbonates on Pallas, suggesting early aqueous alteration processes. Yet its relatively high albedo and lack of key absorption features hint at substantial surface processing, possibly due to high-energy impacts. These conflicting signals raise fundamental questions about its internal structure, volatile inventory, and thermal evolution—questions that cannot be answered without direct spacecraft observations.

Our proposed flyby, timed near Pallas’ ecliptic crossing, exploits optimal illumination conditions and minimal spacecraft trajectory inclination change. It delivers high-resolution imaging, infrared spectroscopy, neutron spectroscopy, gas and dust mass spectrometry, and radio science to determine the surface composition, map hydrated minerals, detect (potential) outgassing, and constrain Pallas’ bulk structure, porosity, and mass. Crater distribution and basin morphology are analyzed to reconstruct Pallas’ violent collisional history, shaped by its dynamically excited orbit and high-speed impact environment. Together, these data help determine the extent to which Pallas underwent internal differentiation and preserved a primitive volatile inventory—key constraints on models of early planetary accretion. Furthermore, in situ magnetic field and plasma measurements help us to understand how Pallas interacts with the solar wind plasma, constrain the internal conductivity structure and determine whether it retains strong remanent magnetization from a formation among nebular fields in the protoplanetary disk. These observations also constrain the properties of any potential neutral gas envelope and enable the detection of possible outgassing activity.

Beyond the asteroid encounter, the spacecraft traverses a region of the Solar System (>2–3 AU) where heliospheric interference with the interstellar medium is substantially reduced. This cruise phase enables transformative interstellar science. A neutral mass spectrometer is targeted at detecting and characterizing inflowing interstellar neutrals, including species like H, D, O, and others, which are difficult to observe at 1 AU due to solar ionization losses and radiation pressure. A dust analyzer samples interstellar grains with statistically significant numbers, constraining their size distribution, composition, and dynamical filtering processes. An energetic neutral atom (ENA) imager remotely senses the global structure of the heliospheric boundary, benefiting from reduced background levels and improved parallax geometry. A plasma and magnetic field suite provides essential context for solar wind and pickup ion conditions at heliocentric distances rarely visited by dedicated heliophysics missions.

We will further evaluate options for enhancing the mission’s scientific return. Specifically, we will analyze the trade-offs of (i) adding a second Pallas flyby for temporal evolution studies, (ii) targeting a second, potentially active, asteroid in the main belt, and (iii) extending the heliocentric distance to prioritize interstellar measurements. We will also investigate the addition of a kinetic impactor—either passive or active—to excavate and analyze subsurface material during the Pallas flyby, balancing its added complexity against potential breakthroughs in understanding volatile retention and regolith stratigraphy as well as surface material mineral and isotope composition.

By linking the preserved record of planetary accretion on Pallas with direct sampling of our galactic surroundings, this mission illuminates how early Solar System evolution was shaped by both internal processes and external astrophysical environments. It also establishes a pathfinder model for dual-purpose planetary and heliophysics missions operating beyond Earth orbit—critical for advancing ESA’s scientific vision into the 2030s and beyond.

How to cite: Vorburger, A., Barabash, S., Futaana, Y., Jutzi, M., Pommerol, A., Rubin, M., Galli, A., O'Rourke, J., Castillo-Rogez, J., Hener, J., Çelik, O., Srama, R., Tortora, P., Fornasier, S., and Schmid, D.: Pallas Interstellar: A Dual-Purpose Mission to a Primordial Asteroid and the Local Interstellar Medium, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-1753, https://doi.org/10.5194/epsc-dps2025-1753, 2025.

Introduction: We present LUSTER (LUnar-based Survey for Time-domain Exploration and Research), a proposed NASA PRISM-SALSA lunar mission to study comets, asteroids, and exoplanet atmospheres using high-cadence, dual-band photometry from the Moon’s surface. This presentation focuses on LUSTER’s small body science objectives—specifically, its capability to characterize the evolving activity, surface properties, and dynamics of comets and Near-Earth Asteroids (NEAs). Featuring a compact 20-cm telescope deployed via NASA’s CLPS initiative, LUSTER will operate continuously for a full Lunar day (~14 Earth days), enabling uninterrupted near-ultraviolet (NUV) and visible (VIS) observations unconstrained by Earth occultation, diurnal cycles, or atmospheric interference (Fig. 1). It addresses a critical gap in small body research: the scarcity of high-cadence, synchronous NUV-visible data needed to unveil physical properties and track time-variable phenomena.

Figure 1. Dichroic transmission for LUSTER’s NUV and visible channels.

Science Goals - Comets: For comets, LUSTER’s dual-channel capability enables simultaneous imaging of gas and dust in cometary comae. The NUV channel is centered to the OH emission band near 315 nm, a direct tracer of water outgassing via photodissociation of H₂O, while the visible channel captures sunlight scattered by dust grains [1, 2] This configuration enables measurements of dust-to-gas ratio, which is a key diagnostic for understanding the physical and chemical drivers of cometary activity [3]. Additionally, morphological differences in the spatial distribution of gas and dust comae reveal the relative abundance, grain size distribution, and outflow dynamics of volatiles and refractories, which are shaped by nucleus properties and solar heating.  LUSTER will capture coma asymmetries, jets, and fragmenting structures in both bands, providing insight into the mechanisms governing mass loss, including sublimation, localized venting, and structural collapse. These signatures are expected to vary between short-period comets (which have undergone repeated solar processing) and long-period comets (which may retain more pristine volatiles), making LUSTER’s dual-band observations essential for comparative studies [4, 5]. Given a sustained multiple observation-per-day observing cadence, we will track temporal changes in dust and gas emission revealing both steady-state evolution and impulsive activity such as outbursts or fragmentation. LUSTER’s stable platform and uninterrupted viewing avoid the challenges of target visibility windows and Earth occultation that hinder space-based telescopes like HST. In preparation for this science, we are re-analyzing archival comet datasets (e.g., from HST and Swift) to benchmark gas and dust photometry across a variety of activity levels and heliocentric distances. We are also conducting simulated LUSTER observations using empirically motivated models of OH and dust brightness profiles. These simulations test our image extraction and analysis pipelines, particularly for tracking gas-to-dust ratios, assessing coma asymmetries, and detecting transient activity like fragmentation or rapid gas brightening.

Science Goals - NEAs: For Near-Earth Asteroids, LUSTER will generate high-cadence light curves in both NUV and visible bands, enabling the joint modeling of shape, rotation, and surface properties. By capturing light curves over multiple full rotations, LUSTER can resolve the shape and pole orientation of NEAs using light curve inversion techniques [6, 7]. These shape models are critical for refining non-gravitational forces such as the Yarkovsky effect, which depends sensitively on surface temperature distribution and rotation state. This, in turn, improves long-term orbit predictions and impact risk assessments [8]. LUSTER will observe both known and newly discovered NEAs with rapid rotation periods. The reflectance of asteroid surfaces in the NUV is highly sensitive to composition, texture, and degree of space weathering. This spectral range enhances contrast between silicate-rich and carbonaceous material and can identify subtle compositional heterogeneity that is undetectable in visible light alone [9]. Moreover, spectral differences between the NUV and visible light curves can reveal localized mineralogy or hydrated features, advancing our understanding of surface processes and enabling compositional classification at a level rarely achieved by small telescopes. Collectively, these observations will build a robust dataset of NUV-visible color indices, shape models, and light curves for a statistically meaningful sample of small bodies. These data will support both the scientific community and potential mission planning for planetary defense or resource utilization.

Target Selection: The initial small body target list includes >100 comets and asteroids brighter than V = 16 mag, observable at Earth elongations >30° within a potential 2028–2029 launch window. Given the annual discovery rate of >100 comets and >2,000 NEAs, this list is expected to expand significantly. A custom scheduling tool prioritizes exoplanet observations but efficiently interleaves the relatively short (20-minute) small body observations between them. In total, LUSTER will secure dozens of observations per object over the course of a single Lunar day as seen in Figure 2. 

Figure 2. LUSTER’s mock scheduler showing science operations: Exoplanets (39.4%), Comets (42.7%), and NEAs (11.2%).

Conclusion: The Moon provides an unmatched platform for time-domain UV-visible astronomy. Free from atmospheric absorption and weather variability, it allows full spectral access in the NUV and ~14 days of continuous viewing—far exceeding cadences achievable from Earth orbit. LUSTER combines high-cadence, dual-band imaging and a novel lunar vantage point to enable transformative Solar System science. By monitoring cometary activity and asteroid surface evolution over sustained timescales, it will advance our understanding of volatile transport, surface processes, and small body dynamics. Preparatory reanalysis of archival UV datasets, paired with realistic mission simulations, ensures readiness to extract maximum science from the data. As a pathfinder, LUSTER demonstrates the feasibility of lightweight, autonomous lunar telescopes and lays the groundwork for future networks of observatories that can continuously monitor the dynamic Solar System.

References:

[1] Schleicher & A’Hearn (1982), ApJ, 258, 864. doi:10.1086/160133

[2] Bertini et al. (2007), A&A, 461, 351. doi:10.1051/0004-6361:20065461

[3] A’Hearn et al. (2015), AJ, 150, 5. doi:10.1088/0004-6256/150/1/5

[4] Mumma & Charnley (2011), ARAA, 49, 471. doi:10.1146/annurev-astro-081309-130811

[5] Huebner et al. (2006), Heat and Gas Diffusion in Comet Nuclei

[6] Kaasalainen & Torppa (2001), Icarus, 153, 24. doi:10.1006/icar.2001.6673

[7] Kaasalainen et al. (2001), Icarus, 153, 37. doi:10.1006/icar.2001.6674

[8] Hanus et al. (2016), A&A, 592, A34. doi:10.1051/0004-6361/201628666

[9] Rozitis & Green (2011), MNRAS, 415, 2042. doi:10.1111/j.1365-2966.2011.18718.x

How to cite: Graykowski, A., Marchis, F., Hanus, J., Lambert, R., Boyajian, T., and Tanner, A. and the LUSTER Team: The LUSTER Mission Concept for Lunar-Based Asteroid and Comet Monitoring, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-84, https://doi.org/10.5194/epsc-dps2025-84, 2025.

Mass spectrometry significantly contributes to space exploration by uniquely determining the elemental composition of micrometeorites, space dust, or particles from atmospheres and surfaces of distant objects.

HANKA becomes ideal payload candidate for a spectrum of future space missions, ranging from low-budget to ambitious projects. It is a high-resolution mass spectrometer (HRMS) specifically designed for in-situ analyses in resource limited environments like space. The core of the instrument is an electrostatic ion trap mass analyzer, Orbitrap^TM, which has broad applications in biological or environmental research. The first prototype of Orbitrap-based space analyzer was developed in LPC2E Orléans, known as CosmOrbitrap, and the mission of HANKA is to bring this new technology into the space.

A laboratory prototype of HANKA was constructed and tested (Fig.1A). Based on the first data, HRMS requirements were achieved while maintaining a simple instrument design. Mass spectrum of chondrite meteorite (Fig.1B) shows high resolution (50 000 m/Δm_FWHM) at m/z 10-60, and with mass accuracy  <20 ppm. In particular, a broad mass range (2-2000 amu) can be recorded within a short acquisition time (10-1000 milliseconds), providing comprehensive insight into the elemental and isotopic composition of solid particles.

Beyond its functional properties and compact dimensions, further miniaturization is planned, targeting to low-weight (less than 6 kg), and minimal power consumption (5-10 W, mode-dependent). The 4U CubeSat version of HANKA, designed for future in-situ analyses in space, consists of velocity/charge detector, hypervelocity impact ionization source, ion optics, and Orbitrap^TM analyser (Fig.1C)

In summary, HANKA offers a unique combination of high-resolution mass spectrometry, compact design, and low resource demands. It can provide comprehensive and real-time analysis of complex space dust and micrometeorite particles characterization.

Fig.1:  HANKA – laboratory prototype (A), mass spectrum of chondrite meteorite (B), and CubeSat space version (C)

Acknowledgements: This work was supported by the Czech Science Foundation (grant No. 21-11931J)

References

Briois C., Thissen R., Thirkell L., et al.; Planet Space Sci. 2016, 131, 33‐45.

Makarov A.; Anal. Chem. 2000, 72, 1156–1162.

Sanderink A., Klenner F., Zymak I., et.al.; Anal. Chem. 2023, 95, 3621−3628.

Zymak Y., Zabka J., Polášek M., et al.; al.; Aerospace 2023, 10(6), 522.

How to cite: Malečková, M., Žabka, J., Zimak, Y., Polášek, M., Cherville, B., Jašík, J., Spesyvyi, A., Lacko, M., Kashkoul, M., Sanderink, A., Nezvedová, M., Sixtová, N., Abel, B., Charvát, A., and Lebreton, J.-P.: CubeSat Space Dust Analyser "HANKA", EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-120, https://doi.org/10.5194/epsc-dps2025-120, 2025.

Artificial space weathering tests on NWA 10580 CO3, NWA 11469 CO3, NWA 5838 H6, NWA 4560 LL3.2, and Dho 007 Eucrite meteorites using solar wind relevant proton irradiation were performed. The experiments revealed increased iron content, amorphization, water loss, and structural changes that typically reduce the mechanical hardness of the outermost surface layer. Results support both meteorite-asteroid linking and optimization of future infrared detector channel arrangement for cubesat asteroid missions.

Introduction

Artificial space weathering tests in the laboratory of ATOMKI on meteorites using solar wind relevant proton irradiation were performed. The simulation corresponded to 10-100 million years of space weathering exposure, and the resulting changes were detected by infrared, Raman, SEM and XRD measurements before and after the irradiation actions. The aim was to better understand the modifications by surveying the sample with different methods and interpreting the results jointly. The findings are expected to support a better understanding of asteroid spectra, the linking of meteorites to source asteroids, and improved detector band localization for upcoming missions.

Simulated solar wind can induce mineral amorphization, detectable by infrared (IR) spectroscopy (Demyk et al. 2004; Lantz et al. 2015) and Raman spectroscopy (Brucato et al. 2004; Demyk et al. 2004), through band shifts in silicates and compositional changes (Hapke et al. 1975). Nanophase iron-nickel particles have also been identified in CV and CO chondrites post-irradiation (Zhang et al. 2023). These effects are primarily analyzed using Fourier Transform Infrared (FTIR) spectroscopy on bulk samples (Lantz et al. 2017; Brunetto et al. 2014, 2020), and Raman spectroscopy (e.g., olivine: Lantz et al. 2017; polystyrene and olivine: Kanuchova et al. 2015). Beyond scientific interest, understanding the composition and mechanical properties of Near Earth Asteroids - potentially influenced by surface modification of grains within rubble pile structure objects - is essential for developing effective mitigation strategies and improving the spectral correlation with meteorites.

Methods

The meteorite samples (NWA 10580 CO3, NWA 11469 CO3, NWA 5838 H6, NWA 4560 LL3.2, and Dho 007 Eucrite) were irradiated with 1 keV H⁺ protons produced by the ECR ion source (Biri et al. 2021) at the ATOMKI institute under vacuum conditions, up to a fluence of 10¹⁷ ion/cm². The samples were analyzed before and after irradiation actions using the following facilities. For sample analysis FTIR spectroscopy was performed using a Vertex 70 spectrometer with 32 scans in the 400–4000 cm⁻¹ range, measured for 30 s at 4 cm⁻¹ spectral resolution, processed using Bruker Optics’ Opus 5.5. software. Raman spectroscopy was applied using a Morphologi G3-ID instrument (Malvern Instruments; Garzanti et al. 2015) and a Kaiser Optical Systems Inc. Raman Rxn1 Spectrometer with NIR Laser Diode at 785 nm wavelength. Measurements were taken with an exposure time of 30 s at 10 mW laser power over the 150 - 1150 cm^-1 range. The laser spot size was 3 μm at 50× magnification, with a spectral resolution of 1 cm⁻¹ and a focal depth of 1.82 μm. The Scanning Electron Microscope (SEM) used was a JEOL JSM-IT700 HR, operated at a 20 keV voltage and 6 nA beam current, with a 40 s point integration time and 100 s areal integration time.

Results

A range of changes was observed in peak positions, FWHM values, and the disappearance of minor bands, indicating the following sequence of alterations during the series of irradiation and measurement sequences.

• Metastable phases may form ephemerally under conditions differing from those of stability, as shown by Lindsley et al. (1972) in their identification of metastable pyroxferroite related to smectites in cosmic materials, or in specific mineral-like alloys(Lilienfeld et al., 1987), where irradiation modified grain boundaries and dislocations (Chesser et al., 2024). However, such effects have rarely been explored in irradiated meteorites.
• Defect production occurred in the crystalline lattice during the next phase, where vacancy migration was likely influenced by temperature (Campbell et al., 2002, ). These defects could reduce band strength and increase FWHM in general.
• Element migration, replacement, and ion integration occurred, particularly affecting olivine composition, which changed from Fo-50–60 (Hamilton 2010) to Fo-30–35 after irradiation in Frontier Mountain 95,002 and Lancé meteorites (Brunetto et al., 2020), as well as in Tagish Lake sample following ion irradiation (Dukes et al., 2015). We also observed an increase in the Fe/Si ratio during the later stages of the tests at elevated irradiation fluence.
• Amorphization and mineral decomposition were characteristic of the later phase of the tests, occurring at higher levels of irradiation. Excessive defect formation and element loss or implantation were observed. In silicates, depolymerization of SiO₄ tetrahedra and lattice decomposition led to the weakening, and disappearance of spectral bands.

We also evaluated mineral identification possibilities using different spectral resolution, as onboard cubesats simple detectors are expected to be used for asteroid missions frequently in the near future. Spectral coarsening, achieved by artificially lowering the resolution with averaging data points, leads to flattening on a smaller scale. Smaller peaks tend to disappear quickly with the worsening resolution.

Discussion and Conclusion

The experiments revealed increased iron content, amorphization, water loss, and structural changes that typically reduce the mechanical hardness of the outermost surface layer, supporting the linking of meteorites to asteroids; however, one major further step remains: the inclusion of laser-shot-simulated microscopic impact effects, resulting melting, darkening and nanophase iron formation. The major infrared spectra bands are more strongly influenced by spectral coarsening than by space weathering, although both effects should be considered.

A further unexplored topic is the possible mechanical and thermal consequences of space weathering. It may be worth evaluating whether irradiation-induced grain surface alteration (particularly mechanical weakening and reduced heat conduction capacity) could affect the collective behaviour of grain assemblages under YORP-induced forces, where grains are moving next to each other. These forces gradually reshape asteroid bodies and mix their components. The results suggest that both mineralogical and morphological changes may occur over timescales of 10–100 million years. Theoretical implications and open research questions are also discussed.

Acknowledgement

This work was supported by the K_138594 project of NKFIH, support from the Europlanet 2024 RI which has been funded by the European Union’s Horizon 2020 Research Innovation Programme under grant agreement No. 871149.

How to cite: Kereszturi, A., Gyollai, I., Biri, S., Juhász, Z., Kiraly, C., Pál, B., Rácz, R., Rezes, D., Sul, B., Szabo, M., Szalai, Z., and Szavai, P.: Processed meteorites and weathered asteroid spectra analysis for low cost cubesat detector optimization, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–13 Sep 2025, EPSC-DPS2025-926, https://doi.org/10.5194/epsc-dps2025-926, 2025.