Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020
Europlanet Science Congress 2020
Virtual meeting
21 September – 9 October 2020

Poster presentations and abstracts

MITM3

Together with the recent Discovery and New Frontiers missions’ selections, a good number of ESA, JAXA, ISRO .. planetary missions and flight instruments are either in development or have been proposed and in review. Mission or instrument leads and/or team members are encouraged to present their missions or instruments for wider community awareness, lessons learned or for fostering future collaborations. Abstracts on concept planetary missions and instruments can also be considered for this session

Convener: Brook Lakew | Co-conveners: Olivier Mousis, Geronimo Villanueva, Stephanie A Getty, David H. Atkinson, Sami Asmar, Daniele Durante, Silvia Tellmann, Axel Hagermann, Nicholas Attree, Günter Kargl, Mark Paton

Session assets

Session summary

Chairperson: Olivier Mousis, Stephanie Getty
EPSC2020-429ECP
Mahsa Taheran, René Duffard, Philipp Maier, Angel Colin, Andreas Pahler, Sarah Bougueroua, Lauro Conti, Thomas Mueller, Christian Lockowandt, Jose Luis Ortiz, Maria Ångerman, Lars Hanke, Olle Janson, and Beate Stelzer

For most astronomical measurements, observations in the ultraviolet (UV) at wavelengths below ~320 nm are not possible from the ground because of atmospheric extinction by the atmosphere. Early on, observers started using stratospheric balloons as relatively flexible and affordable means to access ultraviolet wavelengths, thus overcoming most atmospheric limitations.

Balloons offer a flexible and affordable alternative to space telescopes, with short development times and comparably good observing conditions in many wavelength ranges. Yet, the entry burden to use balloon-borne telescopes is high, with research groups typically having to shoulder part of the infrastructure development as well. Aiming to ease access to balloon-based observations, we present the concept of a community-accessible balloon-based observatory, the European Stratospheric Balloon Observatory (ESBO). ESBO aims at complementing the current landscape of scientific ballooning activities by providing a service-centered infrastructure for broad astronomical use, performing regular flights and offering an operations concept that provides researchers with a similar proposal-based access to observation time as practiced on ground-based observatories.

The STUDIO (Stratospheric Ultraviolet Demonstrator ofan Imaging Observatory) mission consists of the development and construction of a versatile prototype gondola (figure 1) and telescope (figure 2), which shall perform technology tests as well as deliver first scientific results from astronomical observations during its maiden flight planned for 2021. Its main optical payload includes a 50 cm aperture telescope to the back of which the Telescope Instruments Platform (TIP) will be attached. STUDIO is the prototype mission and the first objective of the research infrastructure project ESBO DS.

Fig 1: Mechanical Gondola Structure

 

The TIP will include a primary instrument for the ultraviolet to cover a scientific wavelength interval from 180 nm to 330 nm, as well as visible instrument to cover a complementary spectrum up to 1000 nm.

 

Fig 2: Studio Telescope and Telescope Instrument platform

 

 

Two science cases motivate the UV scientific part of STUDIO, namely: (1) The observations of exoplanets hosting stars and (2) UV observations of planetary atmospheres

Technically the prototype will aim to:
- Demonstrate the maturity of critical technologies (e.g. safe landing and recovery)

- Demonstrate a next-generation UV instrument on the prototype

- Ensure the availability of a prototype instrument for scientific use after the end of ESBO DS

How to cite: Taheran, M., Duffard, R., Maier, P., Colin, A., Pahler, A., Bougueroua, S., Conti, L., Mueller, T., Lockowandt, C., Ortiz, J. L., Ångerman, M., Hanke, L., Janson, O., and Stelzer, B.: The STUDIO UV astronomy mission: a step towards a european ballon observatory, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-429, https://doi.org/10.5194/epsc2020-429, 2020.

EPSC2020-498
Cynthia Phillips, Samuel Howell, Robert Pappalardo, David Senske, Haje Korth, Jennifer Kampmeier, Kate Craft, Rachel Klima, and Erin Leonard and the Europa Clipper Science Team

Overview

NASA’s Europa Clipper Mission [1] has as its top-level science goal: Explore Europa to Investigate its Habitability. Scheduled for launch in the next several years, the mission is now in Phase C, with construction begun on the highly capable payload of in situ and remote-sensing instruments. The mission will observe Europa’s ice shell and ocean, study its composition, investigate its geology, and search for and characterize any current activity.

Accommodations for the payload are now being completed. Major milestones from the past year include integration of the Europa Clipper Magnetometer (ECM) and revisions to the VHF antennas for the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) ice-penetrating radar instrument. Figure 1 (below) shows the current spacecraft configuration, including the revised REASON HF and VHF antennas and the ECM boom.  

The Europa Clipper science team continues to perform preliminary planning, including evaluation of potential trajectories and their capability to meet science objectives. Trajectories must also stay within tolerances for engineering parameters, including radiation total integrated dose, total time of flight, and fuel consumption. Through Europa Clipper’s Thematic Working Groups and Focus Groups, the science team is also evaluating the production of standard models for different natural phenomena and their potential observable responses, to be shared across investigations. This includes tools to understand and standardize possible ranges of Europa parameters of phenomena, e.g. potential plumes, the radiation environment, ocean and surface composition, and regolith properties.

The project abides by a “One Team” philosophy, where science team members are considered members of a single integrated science team, to avoid stovepiping of the science effort. The Europa Clipper Rules of the Road document spells out expected behaviors by science team members, including the expectation of inclusiveness, respect, and fair and equal treatment for all team members.

Science Objectives and Instruments

Following from the Europa Clipper goal are three Mission Objectives: (1) Characterize the ice shell and any subsurface water, including their heterogeneity, ocean properties, and the nature of surface-ice-ocean exchange; (2) Understand the habitability of Europa's ocean through composition and chemistry; and (3) Understand the formation of surface features, including sites of recent or current activity, and characterize high science interest localities.

To address the science requirements of the Europa Clipper mission, a highly capable suite of nine instruments comprise the mission's scientific payload. This payload includes four in situ instruments that measure fields and particles: The Europa Clipper Magnetometer (ECM), the Plasma Instrument for Magnetic Sounding (PIMS), the SUrface Dust Analyzer (SUDA), and the MAss Spectrometer for Planetary Exploration (MASPEX). In addition, five remote sensing instruments will observe the wavelength range from the ultraviolet through radio (radar): the Europa Ultraviolet Spectrograph (Europa-UVS), the Europa Imaging System (EIS), the Mapping Imaging Spectrometer for Europa (MISE), the Europa Thermal Imaging System (E-THEMIS), and the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON).

In addition, gravity and radio science will be achieved via the spacecraft's telecommunication system. Moreover, valuable scientific data could come from the spacecraft’s planned radiation monitoring system. For more information on these investigations, see [2] and [3].

Mission Plans

The instruments for the Europa Clipper mission are now in their critical design phase of development. Working together, the payload will provide data to explore Europa to investigate its habitability. Combined with a mission design that provides more than 50 globally distributed flybys over a period of ~3.5 years, it will be possible to access a diverse and widely distributed set of geologic terrains, providing data to constrain and test geophysical and geochemical models of the ice shell and ocean [2, 3]. The Europa Clipper mission is well on its way towards a launch in the next several years, and the science team, as well as the larger science community, eagerly anticipates the future results.

References

[1] Howell, S., and R. Pappalardo, Nat Commun. 11, 1311 (2020). https://doi.org/10.1038/s41467-020-15160-9

[2] Senske, D., et al., EPSC, 15-20 September 2019, Geneva, Switzerland, 2019.

[3] Korth, H. et al., EPSC, 15-20 September 2019, Geneva, Switzerland, 2019.

 

How to cite: Phillips, C., Howell, S., Pappalardo, R., Senske, D., Korth, H., Kampmeier, J., Craft, K., Klima, R., and Leonard, E. and the Europa Clipper Science Team: Europa Clipper: Mission Status and Update, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-498, https://doi.org/10.5194/epsc2020-498, 2020.

EPSC2020-647
Vidhya Pallichadath, Tatiana Bocanegra Bahamon, Giuseppe Cimò, Dominic Dirkx, Dmitry Duev, Leonid Gurvits, Guifré Molera Calvés, and Bert Vermeersen

Introduction

Planetary Radio Interferometry and Doppler Experiment (PRIDE) will exploit the signal recording and processing technology developed originally for Very Long Baseline interferometric (VLBI). The essence of PRIDE is in observing the spacecraft radio signal with a network of Earth-based radio telescopes. The PRIDE technique developed at the Joint Institute for VLBI ERIC (JIVE) together with its partners was used for several experiments with several ESA planetary science missions. It has been chosen by ESA as one of the eleven experiments of the Jupiter Icy Moons Explorer (JUICE), the first Large-class mission in the ESA’s Cosmic Vision 2015–2025 program. The mission is scheduled for launch in 2022.

Figure 1: A typical PRIDE Experiment  

1. PRIDE for JUICE Mission

PRIDE is a multidisciplinary component of the JUICE science suite. The main measured deliverables of PRIDE are lateral coordinates L(φ, θ) of spacecraft and the radial velocity of spacecraft. The former (main) measurable of PRIDE requires the phase-referencing VLBI observations (see Duev et al. [1]).  The latter employs the Doppler extraction technique described in [7,8]. Its prime deliverable will be used primarily for improvement of the Jovian system ephemerides in support to a variety of applications, ranging from gravimetry to geodynamics to fundamental physics. A typical PRIDE experiment is shown in Figure 1.

PRIDE observations are carried out by the ground segment when the spacecraft emits a radio signal for communication or radio science purposes. The methodology of PRIDE has been demonstrated with the ESA's Venus Express & Mars Express by Duev et al. 2012 [1], Molera Calvés et al. 2014 [2], Duev et al. 2016 [4], Molera Calvés et al. 2017 [8], Bocanegra et al. 2018 [7], Bocanegra et al. 2019 [8]. In addition to nominal science objectivities, the team is considering ad hoc observations around the Venus and Mars flybys during the cruise phase. A covariance analysis for a broad scope of the PRIDE measurable and Jovian system parameters have been performed to optimize the observation planning and the overall science impact of the JUICE mission (Dirkx. D et al. 2016 [4] & Dirkx. D et al. 2017 [5]).

2. Ongoing PRIDE observing projects

In 2020, we have begun a campaign to gather PRIDE tracking data of the InSight lander, with up to three tracking epochs scheduled for each of the three 2020 EVN sessions. The primary goal of these experiments is to serve as a preparatory activity for more intensive operations for ExoMars-LaRa [9].

The primary manner in which PRIDE will be able to contribute to the science objectives of LaRa is through the use of the Doppler data obtained by all receiving stations. As shown by the analysis of Bocanegra et al. 2018 [7], PRIDE Doppler data at X-band is similar, and in some cases, higher quality compared to regular closed-loop tracking data. One advantage of PRIDE lies in its diversity of receiving stations, making the data quality much less dependent on the meteorological or operational conditions at a single telescope.

Figure 2:  Frequency detections of Mars Insight (NASA) as seen from the University of Tasmania network of radio telescopes. The spacecraft signal was detected at the sky frequency of 8407.25 MHz and Doppler shift of 50 kHz along 70 minutes of tracking

Besides, we propose to merge the three-way Doppler data generated at each receiving station, to fully exploit the data encoded in all downlinks. This would allow an improved calibration of receiving station noise levels, as the noise incurred locally at the receiving ground station (including Earth tropospheric and ionospheric noise on the downlink) is independent for each station. We will use the InSight tracking data to test different practical approached to achieving this conceptual aim, and apply these ‘lessons learned’ to ExoMars-LaRa data analysis. In particular, we will apply the InSight tracking data to investigate different manners in which to weigh the data, considering the fact that the three-way Doppler noise generated at all receiving stations is highly correlated, and to investigate how inter-station biases and drifts can best be calibrated for. The results of the ongoing PRIDE observations of NASA's InSight probe will be reported elsewhere (Dirkx. D, Le Maistre. S, Dehant. V et al., in preparation).

References

 

 

How to cite: Pallichadath, V., Bahamon, T. B., Cimò, G., Dirkx, D., Duev, D., Gurvits, L., Calvés, G. M., and Vermeersen, B.: PRIDE: Ground-based VLBI observations for Spaceborne Probes , Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-647, https://doi.org/10.5194/epsc2020-647, 2020.

EPSC2020-827ECP
Nozair Khawaja, Jon Hillier, Fabian Klenner, Lenz Nölle, and Frank Postberg

Different mass spectrometric approaches have been used to study the composition of ice and dust particles in space. Mass spectrometers onboard spacecraft such as Cassini, Rosetta and Giotto at Saturn, comet Churyumov-Gerasimenko and comet Halley respectively, have expanded our understanding of these planetary bodies by probing the composition of their dusty environments (Grün et al. 2019). The outstanding results from different space missions prove in situ mass spectrometry to be a reliable analytical tool with which to investigate the Solar System. Many of the mass spectrometers flown through the Solar System have used the impact ionisation technique, and an impact ionisation mass spectrometer, the Surface Dust Analyzer (SUDA), will be a part of NASA’s upcoming Europa-Clipper mission to Jupiter’s moon Europa. During the impact ionisation process, ice and dust grains impinging onto a detector’s solid target plate, at speeds above ≈ 1 km/s, generate a cloud of ions, neutrals and electrons (Srama et al. 2004; Auer & Sitte (1968)). The ions (cations in this work) are accelerated through a drift or reflectron region, towards a detector, from which time of flight mass spectra are generated (Friichtenicht et al. 1971).

Electrostatic accelerators are used to calibrate (Mocker et al. 2012) impact ionization mass spectrometers on Earth, accelerating micron and submicron cosmic dust analogue grains, typically metallic or with a conductive coating, to suitable velocities. As the controlled acceleration of µm-sized ice grains to these hypervelocities is not yet possible in the laboratory, an analogue experiment using Laser Induced Liquid Beam Ion Desorption (LILBID), is employed to simulate the impact ionisation process of ice grains in space (Klenner et al. 2019). In the LILBID process, a thin stream of an aqueous solution of, for example, organic compounds is exposed to laser irradiation in a vacuum. The dissolved compounds, together with the solvent matrix, are ionized and fragment when the matrix, in which charges are stochastically distributed, is dispersed (e.g. Wiederschein et al. 2015). By varying the laser power, as well the ion collection efficiency, it is possible to simulate the spectra which result from impact ionisation at varying impact speeds (Wiederschein et al. 2015, Klenner et al. 2019). The resulting cation time of flight mass spectra then contain mass spectral features corresponding to organic fragments and water cluster species. This technique has been successfully used (Postberg et al. 2009, 2018; Khawaja et al. 2019) to simulate the mass spectra produced when Cassini’s Cosmic Dust Analyzer (CDA) sampled salt- and organic-bearing ice grains emitted into space by Saturn’s moon Enceladus.

In this work we present a comparison between the mass spectral features of organic molecules generated by LILBID simulation of the impact ionisation mass spectra of organic-bearing ice grains, and the widely used standard technique of electron ionization (EI), the results of which can be found in existing databases, such as the National Institute of Standards and Technology (NIST) Chemistry WebBook.  In electron-ionisation (EI), the sample is directly exposed to a beam of high-energy electrons (≈ 70 eV) which converts neutral molecules into molecular ions (M+) with high internal energies. Owing to the generated energies, the structures of the molecular ions become unstable and break up, producing a characteristic population of fragment ions. We have compared the cationic fragments of isomeric carbonyl compounds measured with LILBID and with those from EI obtained from the NIST WebBook database. The tested compounds are divided into three pairs of aldehydes and ketones i.e., propanal & acetone, butanal & 2-butanone, hexanal & 2-hexanone, with 3, 4 and 6 carbon atoms, respectively. To compare the spectral features related to organic fragments, water-cluster features are excluded from the LILBID spectra. In most cases, both the LILBID and EI spectra of the compounds show typical cleavage patterns characteristic of carbonyls.

In ketones and aldehydes, for both LILBID and EI, we observe a correlation between the number of parent molecule carbon atoms and the relative intensities of particular cation fragments. We will present an in-depth comparison of the spectral features obtained from these techniques is currently, using LILBID spectra obtained for a mass spectral database applicable to the SUDA instrument on NASA’s Europa Clipper mission. The mass spectrometers (MASPEX & PEP-NIM) onboard Europa-Clipper, and ESA’s Jupiter Icy Moon Explorer (JUICE) spacecraft, respectively, will employ an EI (70 eV) technique, and the work presented here provides a valuable comparison and cross-calibration between the well-known EI and the more esoteric impact ionization techniques. Understanding the differences between the EI and impact-induced fragmentation and ionization behaviour of organics may also allow large existing libraries of EI spectra to be used to interpret the in situ impact ionization mass spectra of ice-free grains, such as those expected to be returned by JAXA’s Destiny+ mission to the unusual active asteroid 3200 Phaethon, progenitor of the Geminid meteor shower.

References

Grün, E., Krüger, H., & Srama, R. (2019) The dawn of dust astronomy, Space Sci Rev, 2015:46.

Srama, R. et al. (2004). The Cassini cosmic dust analyzer. Space Sci Rev, 114(1– 4), 465–518.

Auer, S., & Sitte, K., (1968). Detection technique for micrometeoroids using impact ionization. Earth and Planetary Sci Lett, 4,178–183

Friichtenicht, J. F., Roy, N. L., & Moede, L. W. (1971). Cosmic Dust Analyzer. Technical Report NASA2CR2140241.

Mocker, A. et al (2012). On the applicability of laser ionization for simulating hypervelocity impacts. Journal of Applied Physics, 112(10).

Klenner, F. (2019), Analogue spectra for impact ionization mass spectra of water ice grains obtained at different impact speeds in space, Rapid Communications in Mass Spectrometry, 33(22), 1751–1760.

Wiederschein, F. et al. (2015) Charge separation and isolation in strong water droplet impacts. Physical Chemistry Chemical Physics. PCCP, 17(10), 6858–64.

Postberg, F. et al. (2009) Sodium salts in E ring ice grains from an ocean below the surface of Enceladus. Nature, 459, 1–4.

Postberg, F. et al. (2018) Macromolecular organic compounds from the depths of Enceladus, Nature, 558(7711), pp. 564–568.

Khawaja, N. et al. (2019) Low-mass nitrogen-, oxygen-bearing, and aromatic compounds in Enceladean ice grains, Monthly Notices of the Royal Astronomical Society, 489(4), pp. 5231–5243.

How to cite: Khawaja, N., Hillier, J., Klenner, F., Nölle, L., and Postberg, F.: Comparative Study of Mass Spectrometry Techniques Relevant to Current and Future Space Missions, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-827, https://doi.org/10.5194/epsc2020-827, 2020.

EPSC2020-1076
Fabian Luedicke, Hauke Hussmann, Kay Lingenauber, Reinald Kallenbach, Keigo Enya, Masanori Kobayashi, Nicolas Thomas, and Kazuyuki Touhara

Exploring the icy moons of Jupiter: The Ganymede Laser Altimeter (GALA) for ESA’s JUICE Mission

 

Fabian Lüdicke (1), Hauke Hussmann (1), Kay Lingenauber (1), Reinald Kallenbach (1), Keigo Enya (2), Masanori Kobayashi (3), Nicolas Thomas (4), Luisa Lara (5), Kazuyuki Touhara (2) and the GALA team.

 

(1) DLR Institute of Planetary Research, Berlin, Germany (fabian.luedicke@dlr.de), (2) ISAS/JAXA, (3) Chiba Institute of Technology, Japan, (4) Physikalisches Institut, University of Bern (UBE), (5) CSIC, Instituto de Astrofísica de Andalucía (IAA), Granada, Spain

 

Abstract

The Ganymede Laser Altimeter (GALA) is one of ten instruments selected for ESA’s Jupiter Icy Moons Explorer (JUICE) mission. We will present an overview on the scientific goals as well as on the status of the instrument development and performance analysis.

ESA’s JUICE mission will explore Jupiter, its magnetosphere and satellites first in orbit around Jupiter before going finally into polar orbit around Ganymede [1]. GALA is one of ten payloads on-board the spacecraft and is developed under responsibility of the DLR Institute of Planetary Research in collaboration with industry and institutes from Germany, Japan, Switzerland and Spain. Its major objectives are to measure the surface topography and the tidal deformation of the satellite.

JUICE (Jupiter Icy Moons Explorer) will be the first orbiter around a moon (other than Earth’s moon) in solar system exploration. Its launch is planned for May/June 2022 followed by an interplanetary cruise of 7.6 years. Jupiter orbit insertion will take place by the end of 2029. An orbit maneuver will bring the spacecraft into a 500-km circular orbit in which it will be staying for at least 132 days until end of nominal mission. The latter phase will be the main period for GALA taking data. In addition data will be taken at Europa, Ganymede, and Callisto at closest approaches of flybys in the Jupiter orbiting phase.

GALA has two main objectives: (1) by range measurements it shall obtain Ganymede’s topography on global, regional and local scales. This will reveal how surface features have formed and how they are connected with the shallow interior ice shell. Global shape measurements will tell us whether the satellite is in hydrostatic state with respect to rotational and tidal forces. (2) Obtaining range measurements distributed in time along the orbital cycle, tidal variations of surface elevations will be measured. The tidal amplitudes are indicative for the presence of a subsurface ocean and would (together with complementary measurements) constrain the ice-I shell thickness [2].

GALA is a single-beam altimeter: a laser pulse (at 1064 nm wavelength) is emitted by using an actively Q-switched Nd:YAG laser firing at 30 Hz in nominal operation. A small fraction of the pulse is guided through fiber optics onto the detector characterizing the outgoing pulse and time of emission. After about 3 msec the Lambertian reflection of the pulse from the surface is received by a aperture telescope and transferred to the detector, an Avalanche Photo Diode. The signal is digitized at a sampling rate of 200 MHz and transferred to the range finder module, which determines (a) the time of flight between the emission and receiving of the pulse (b) the pulse shape, in particular the pulse-width, and (c)  the energy of the received pulse. From the time of flight of the wave-package and the spacecraft position and attitude, the distance for each shot can be converted into height above a reference surface in post-processing of the data.

 

 (1)           (2)