This paper reports on EMC issues of the laser transmitter, the photodiode receiver, and the communication port of the BepiColombo Laser Altimeter BELA during integration on ESA's Mercury Planetary Orbiter MPO. Parasitic currents originating in the active Q-switch electronics of BELA's diode-laser pumped Nd:YAG laser and from the high-power laser diode driver electronics interfered with the sensitive Si avalanche photodiode sensor operating at a noise floor of about 0.3 pA/VHz in a bandwidth of 20 MHz, and with BELA's Spacewire port, corrupting about 3% of telemetry data to the MPO memory. The problems had been eliminated by implementing multi-point grounding.

Thermal and mechanical material properties determine comet evolution and even solar system formation because comets are considered remnant volatile-rich planetesimals. Using data from the Multipurpose Sensors for Surface and Sub-Surface Science (MUPUS) instrument package gathered at the Philae landing site Abydos on comet 67P/Churyumov-Gerasimenko, we found the diurnal temperature to vary between 90 and 130 K. The surface emissivity was 0.97, and the local thermal inertia was 85 ± 35 J m −2 K −1 s -1/2 . The MUPUS thermal probe did not fully penetrate the near-surface layers, suggesting a local resistance of the ground to penetration of >4 megapascals, equivalent to >2 megapascal uniaxial compressive strength. A sintered near-surface microporous dust-ice layer with a porosity of 30 to 65% is consistent with the data.

The Ganymede Laser Altimeter (GALA) is one of 11 instruments selected by ESA for the JUICE mission payload. GALA will focus on geodetic and geophysical investigations of the icy satellites Europa, Callisto and, in particular, Ganymede. The instrument design is described.

The implementation and results from thermal mathematical modelling of a Stavroudis-type reflective baffle for the BepiColombo laser altimeter (BELA) are presented. BELA and other instruments on board the European Space Agency's Mercury Planetary Orbiter are exposed to a harsh environment in Mercury orbit. This environment is briefly discussed and the detailed design solution for the baffle is presented. Special attention has been paid to the implementation of the thermal model because specific approximations were required. The results of the thermal mathematical models show the temperature behaviour in orbit and the feasibility of the solution. The work has applications to future missions which will go inside the orbit of Venus (e.g. ESA's Solar Orbiter).

We have designed and constructed an original facility to characterize the VIS–NIR Bidirectional Reflectance Distribution Function (BRDF) and some complementary bulk physical properties of planetary analog samples containing water ice. The central part of the facility is a highly accurate gonio-radiometer (PHIRE-2) operating in the VIS–NIR spectral range (400–1100nm) installed in a large laboratory freezer. Its development was based on the experience gained on the gonio-radiometer PHIRE-1 (Gunderson et al., 2006). The PHIRE-1 design was modified to permit operations at sub-zero temperatures and to optimize the performance of the instrument. The photometric measurements are complemented by a detailed simultaneous characterization of the physical state and possible temporal evolution of the samples using a combination of macro- and micro-imaging, thermal, electrical and sample mass measurements. The modified design will support the interpretation of current and future remote sensing and in-situ datasets on icy planetary objects with a special emphasis on cometary nuclei, Martian polar regions and Jovian satellites.

It is widely accepted that lunar volcanism started before the emplacement of the mare fills (≈3.1–3.9Ga b.p.) and lasted for probably more than 3.0Ga. While the early volcanic activity is relatively easy to understand from a thermal point of view, the late stages of volcanism are harder to explain, because a relatively small body like the Earth's Moon is expected to cool rapidly and any molten layer in the interior should solidify rather quickly. We present several thermal evolution models, in which we varied the boundary conditions at the model surface in order to evaluate the influence on the extent and lifetime of a molten layer in the lunar interior. To investigate the influence of a top insulating layer we used a fully three-dimensional spherical shell convection code for the modelling of the lunar thermal history. In all our models, a partial melt zone formed nearly immediately after the simulation started (early in lunar history), consistent with the identification of lunar cryptomare and early mare basalt volcanism on the Moon. Due to the characteristic thickening of the Moon's lithosphere the melt zone solidified from above. This suggests that the source regions of volcanic rock material proceeded to increasing depth with time. The rapid growth of a massive lithosphere kept the Moon's interior warm and prevented the melt zone from fast freezing. The lifetimes of the melt zones derived from our models are consistent with basalt ages obtained from crater chronology. We conclude that an insulating megaregolith layer is sufficient to prevent the interior from fast cooling, allowing for the thermal regime necessary for the production and eruption of young lava flows in Oceanus Procellarum.

The surface heat flow of a planet is a fundamental measure for its overall energy balance, and is somewhat indicative of its total radionudlide inventory and its internal dynamics. However, this quantity depends not only on the heat flow from the deep interior (core, mantle) into the crust, but also from the the radiogenic heat that is produced in the crust. Furthermore, the topography and the thermal properties of the near surface layers influence the heat flow. Therefore, it is not straightforward to determine the global surface heat flow from single measurements, unless a correction for topography effects is applied. Here, we study the effect of several generic geological features such as basins, craters, shield volcanos, grabens and ridges, on the heat flow at the surface, and determine the subsurface temperatures. It will be shown that the influence of the topography is substantial.

Dynamical processes in the Martian boundary layer provide the means of communication between surface ice deposits and the free atmosphere, and the means of lifting dust from the surface. The boundary layer is therefore one of the most important components of the Martian climate system. The Martian boundary layer differs from that of the Earth in that it is more strongly forced, it is deeper, and the relative importance of radiative and convective heat fluxes in the lower boundary layer can be quite different. In order to understand the Martian boundary layer, a combination of theoretical, modeling and observational studies are necessary. Interactions between theorists, modelers, and observational scientists are needed to make progress and to provide a basis for analysis of data expected from Phoenix, Mars Science Laboratory, ExoMars and other future landed missions (such as a surface network mission), or missions such as balloons or other aircraft operating in the neutral atmosphere. The prime goal of this project under the auspices of the International Space Science Institute (ISSI) is to review and assess the current knowledge and understanding of Martian planetary boundary layer and its interactions with the surface and free atmosphere. We aim to promote international communication and collaboration to enhance the rate of acquisition of knowledge and understanding. This will be achieved through an International Study Team and publication of overview papers and individual reports on recent advances in this area.

The BepiColombo Laser Altimeter (BELA) is the first European Laser Altimeter for planetary exploration which has been selected by ESA for flight aboard of ESA's BepiColombo mission to planet Mercury. A consortium led by the Physikalisches Institut Bern and Institute for Planetary Research at the German Aerospace Center (DLR) will develop a laser altimeter based on the classical principle of laser pulse time of flight measurement. The instrument is based on a longitudinally pumped Nd:YAG laser with 50mJ pulse energy and pulses of about 3 ns pulse duration, operating nominally at 10 Hz repetition rate. BELA performs global topographic mapping with high accuracy of 1m and a surface shot to shot spacing in the range of 300m. Laser Ranging will be done at a distance up to 1000 km with a detection probability >70%. The ground footprint of the laser beam amounts to about 100m.

The Bepi-Colombo Laser Altimeter (BELA) is the first European Laser Altimeter for planetary exploration which has been selected by ESA for flight aboard of ESA's BepiColombo mission to planet Mercury. A consortium led by the Physikalisches Institut Bern and Institut fur Planetenforschung (DLR-Berlin, Germany) will develop a laser altimeter based on the classical principle of laser pulse time of flight measurement. The instument is based on a longitudinally pumped Nd:YAG laser with 50mJ pulse energy and pulses of about 3ns pulse duration, operating nominally at 10Hz repetition rate. The BELA-requirements, the conceptional design, the technical development activities and their status are presented during the workshop.

The BepiColombo Laser Altimeter (BELA) has been selected for flight aboard the MPO (Mercury Planetary Orbiter) of ESA´s BepiColombo mission to Mercury. From the spacecraft’s elliptic (pericenter: 400 km) near-polar orbit, the instrument will carry out range measurements to the surface along orbit tracks. The measurements will ultimately form a global geodetic map grid, which is fundamental for studies of the interior structure of the planet. BELA also aims at measurements of tidal flexing and planet librations. In addition, the analysis of the returning laser pulses will reveal details on the character of the surface, as morphology, reflectivity, and roughness. This first European planetary laser altimeter will be developed by a consortium led by the Physikalische Institut (Universitat Bern, Switzerland) and the Institut fur Planetenforschung (Deutsches Zentrum fur Luft- und Raumfahrt, Berlin, Germany). The spacecraft is scheduled for launch in 2013.

The BepiColombo Laser Altimeter (BELA) is a proposed experiment for the BepiColombo mission to the planet Mercury. BELA is intended to provide payload-to-surface ranging data from a spacecraft in a polar Hermean orbit by measuring the time-of-flight of outgoing laser pulses and their echoes. As proposed, BELA also will provide small-scale surface variation and reflectivity data via characterization of return pulse forms. Primary instrument components include a low frequency pulsed Nd:YAG laser transmitter and a reflective receiver telescope feeding a silicon avalanche photodiode to capture pulse echoes with a direct detection approach. To assist with the evaluation of various design strategies, we have developed a numerical model of the instrument that returns a signal-to-noise-ratio figure of merit, as well as simulated return pulses, according to a diverse set of hardware specifications and viewing geometries as input parameters. An analysis of large sets of simulated pulses assists with the estimation of measurement accuracy. This model has been used to investigate the performance of a variety of instrument configurations, and some tradeoffs leading to the favored design will be described.