The aim of the M experiments is to move to a more level of complexity for the experiment set-up. Typically more than one partner and multiple instruments will be involved.
M1 - CoPhyLab Dust
In order to study the physics of comets we need to use analog materials that have physical properties as close as possible to the ones known for cometary nuclei. The composition of the comet can be divided in two main groups: volatiles like water and CO2 ice and refractories like dust and organics. This project aims at creating a recipe for the refractory part. For this we will be mixing mineral components (such as silica dust) with some organic materials. The end product should be a dark dust whose physical properties (mechanical, thermal, spectral...) are close to those known for comets. Once this CoPhyLab dust is created it will be used in our multiple experiments as an analog of cometary material.
M2 - Thermophysical Model Calibration Experiments
The first aim of this experiment campaign is to measure the thermal conductivity of solid and granular water ice. Further the specific heat, the heat capacity and the absorption coefficient of both materials shall be measured. After this campaign we shall have our measurements and our theoretical models in full agreement for these samples inside this chamber. This will be an important baseline for the modelling of more complex samples. Further the thermal properties of granular water ice should be a result of this campaign.
M3 - Thermal Properties
This is an extension of the S3 Thermal Conductivity project. It aims at determining the thermal properties of large mixtures of CoPhyLab dust and water ice. The thermal properties of the individual components are well known but the properties of mixtures often deviate from the expected values. Additionally the temperature of the sample will be measured by a whole suite of instruments in addition to the infrared camera. This will allow us to better understand the thermal processes taking place in these more complex samples. This project will enhance even more our understanding of the thermal evolution of cometary nuclei and will prove to be very helpful for building future numerical models of comets.
M4 - Long-term Sample Evolution
The M4 project aims at observing, estimating and measuring the activity of a sample (a mixture of CoPhyLab dust and ice) left to sublimate under the beam of a sun simulator or simply on its own. Multiple instruments shall investigate throughout the experiments, not only the physical properties of the sample (its mass, temperature, cohesive strength, etc.), but its surface composition as well as the local conditions surrounding the sample (pressure, presence and amount of ejected dust, etc.). Building on the results of the S-projects, the M4 project will allow to perform the first thorough sublimation measurements with most CoPhyLab instruments running simultaneously and thus to serve as a guide during subsequent large experiments.