The second Venus flyby of BepiColombo mission reveals stable atmosphere over decades

Studies of the Venusian mesosphere provide important information about the current state of the entire Venusian atmosphere. This includes information about the dense cloud structure, its vertical thermal profile, temperature fields, and the resulting dynamical and meteorological processes that contribute to a deeper understanding of the climatologically different evolutionary paths of Earth and Venus. However, the last measurements were acquired in 1983 during Venera-15 mission. In this paper, results of mid-infrared spectral measurements of the Venusian atmosphere are presented. Here we show Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) measurements of the Venusian atmosphere during the second flyby of BepiColombo mission on its way to Mercury. Our Venus measurements provide reliable retrievals of mesospheric temperature profiles and cloud parameters between 60 and 75 km altitude, although MERTIS was only designed to operate in Mercury environment. Our results are in good agreement with the Venera-15 mission findings. This indicates the stability of the Venusian atmosphere on time scales of decades

Transparent Conducting Oxides for Photovoltaics: Manipulation of Fermi Level, Work Function and Energy Band Alignment

Doping limits, band gaps, work functions and energy band alignments of undoped and donor-doped transparent conducting oxides Zn₀, In₂O₃, and SnO₂ as accessed by X-ray and ultraviolet photoelectron spectroscopy (XPS/UPS) are summarized and compared. The presented collection provides an extensive data set of technologically relevant electronic properties of photovoltaic transparent electrode materials and illustrates how these relate to the underlying defect chemistry, the dependence of surface dipoles on crystallographic orientation and/or surface termination, and Fermi level pinning

Infrared Mapper (IRMA) for Support of Comet Sample Return Missions

Comets are remnants from the formation of the Solar System, and contain the most pristine material available today for deciphering the physical and chemical conditions of this process. As such, they are very interesting candidates for sample return missions, as indicated for example by the recent mission proposals CAESAR, CONDOR, and CORSAIR to the NASA New Frontiers 4 call. For maximizing the science return from such a mission the optimum selection of sampling site(s) is crucial. To support this selection we propose a remote sensing instrument working in the thermal infrared (TIR) wavelength range

OPTICAL DESIGN AND BREADBOARD OF THE RAMAN SPECTROMETER FOR MMX

This paper reports the laboratory confirmation of an optical design for a 0.2 numerical aperture confocal miniaturized, ruggedized Raman visible light spectroscope (RAX) to be borne by an autonomous rover landed on the martian moon, Phobos

In situ science on Phobos with the Raman spectrometer for MMX (RAX): preliminary design and feasibility of Raman meausrements

Mineralogy is the key to understanding the origin of Phobos and its position in the evolution of the Solar System. In situ Raman spectroscopy on Phobos is an important tool to achieve the scientifc objectives of the Martian Moons eXploration (MMX) mission, and maximize the scientifc merit of the sample return by characterizing the mineral composition and heterogeneity of the surface of Phobos. Conducting in situ Raman spectroscopy in the harsh environment of Phobos requires a very sensitive, compact, lightweight, and robust instrument that can be carried by the compact MMX rover. In this context, the Raman spectrometer for MMX (i.e., RAX) is currently under development via international collaboration between teams from Japan, Germany, and Spain. To demonstrate the capability of a compact Raman system such as RAX, we built an instrument that reproduces the optical performance of the fight model using commercial of-the-shelf parts. Using this performance model, we measured mineral samples relevant to Phobos and Mars, such as anhydrous silicates, carbonates, and hydrous minerals. Our measurements indicate that such minerals can be accurately identifed using a RAX-like Raman spectrometer. We demonstrated a spectral resolution of approximately 10 cm−1, high enough to resolve the strongest olivine Raman bands at ~820 and ~850 cm−1, with highly sensitive Raman peak measurements (e.g., signal-to-noise ratios up to 100). These results strongly suggest that the RAX instrument will be capable of determining the minerals expected on the surface of Phobos, adding valuable information to address the question of the moon’s origin, heterogeneity, and circum-Mars material transport

Conception and State of the Radiometric Analysis Breadboard (RAB) for the Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS)

As a part of the ESA deep space mission to mercury - BepiColombo - investigations of mercury´s surface layer using a push-broom thermal infrared imaging spectrometer (MERTIS) with a high spectral resolution is planned. One of the scientific goals is the measurement of Christiansen Features which are emissivity maxima resulting from rapid changes in the real part of the mineral´s refractive index. Their positions within the spectral range of 7-14µm deliver information about mineralogical compositions. For these measurement MERTIS needs to have a high spectral resolution of 90nm. The planet will be mapped with a resolution of 500m and a S/N ratio of at least 100. For the measurement of the surface radiation a micro-bolometer detector array will be used. A detectivity of 1.0E9 is required. High sensitive TIR systems commonly use cooled detectors with a large mass budget and high electrical power consumption. One of the challenges of MERTIS is the use of an uncooled micro-bolometer detector. The development of MERTIS is currently in an early phase but a breadboard concept will be presented. Special attention is payed to the first of two phases of the breadboard concept: - The Radiometric Breadboard (RAB) has been configured for the development of the opto-electronical components and for the investigation of radiometric calibration methods and algorithms. The design of the RAB is already a spectrometer configuration but it cannot reach the performance the technical and scientific requirements demand. - The Spectro-Radiometric Breadboard (SRB) will be implemented for investigations of the performances of the optics and detector of MERTIS. Relevant components have to be developed and validated particularly in the spectral domain. The SRB will be the prototype of MERTIS

Developing of MERTIS as an advanced process from the study up to the flight model

ESA’s mission BepiColombo will be launched in 2016. MERTIS (Mercury Radiometer and Thermal imaging Spectrometer) is one of the key instruments. MERTIS is an imaging infrared spectrometer and radiometer using an uncooled detector technology with very small resources in terms of mass and power. The incentive of the MERTIS development is scientific requirements to study the surface composition and temperatures of Mercury under the extreme environmental condition at Mercury. Therefore, the state-of-the-art optical performance of MERTIS is unique. Components based on innovative technologies have been developed and qualified to realize the project. This approach required an advanced model philosophy and development process from the study up to the flight model completed in 2013. This paper describes the development process as well as challenges from the management and system engineering point of view up to a lessons learnt that lead to important conclusions