Non-Intrusive Battery Health Monitoring

The “Non-intrusive battery health monitoring”, developed by Airbus Defence and Space (ADS) in cooperation with the CIRIMAT-CNRS laboratory and supported by CNES, aims at providing a diagnosis of the battery ageing in flight, called State of Health (SOH), using only the post-treatment of the battery telemetries. The battery current and voltage telemetries are used by a signal processing tool on ground to characterize and to model the battery at low frequencies which allows monitoring the evolution of its degradation with great accuracy. The frequential behaviour estimation is based on inherent disturbances on the current during the nominal functioning of the battery. For instance, on-board thermal control or equipment consumption generates random disturbances on battery current around an average current. The battery voltage response to these current random disturbances enables to model the low frequency impedance of the battery by a signal processing tool. The re-created impedance is then compared with the evolution model of the low frequencies impedance as a function of the battery ageing to estimate accurately battery degradation. Hence, this method could be applied to satellites which are already in orbit and whose battery telemetries acquisition system fulfils the constraints determined in the study. This innovative method is an improvement of present state-of-the-art and is important to have a more accurate in-flight knowledge of battery ageing which is crucial for mission and operation planning and also for possible satellite mission extension or deorbitation. This method is patented by Airbus Defence and Space and CNES

MASCOT operations on Ryugu - focus on some specific tasks

Hayabusa2 is an asteroid sample return mission operated by the Japanese space agency, JAXA. It was launched in December 2014. In July 2018, the spacecraft has reached the mission target after a 4-year-long cruise. The objective is a C-type primordial asteroid called Ryugu, in search of organic and hydrated minerals that might give essential clues for the solar system formation. The small lander MASCOT (Mobile Asteroid surface SCOuT) carried aboard Hayabusa2 landed on the surface on the 3rd of October 2018 for reliminary in-situ investigations while the probe is aiming to study Ryugu on a global scale and to return samples to Earth. MASCOT was jointly developed by the German Aerospace Centre (DLR) and the Centre National d'Etudes Spatiales (CNES). It is equipped with a sensor suite consisting of four fully-fledged instruments. DLR was responsible for developing the MASCOT lander and ground segment, and was in charge of planning and conducting lander joint operations from MUSC. CNES supplied the hyperspectral IR spectrometer (MicrOmega, IAS Paris), antennae and power system, provided a support to operations and was in charge of the flight dynamics aspects of the mission. The 17 hours of on-asteroid operations exceeded expectations and the overall landing and operations were a huge success. Indeed, the characteristics of the Ryugu asteroid such as the shape and the gravity were known only after arrival of Hayabusa2 in July 2018 and the operating ccontext was very constrained but did not provide from fulfilling the objectives. This paper is a complement to the overall paper on MASCOT landing and first results. It will focus on several operational tasks such as communication and power subsystems assessments as well as flight dynamics computations needed in real time and for postprocessing

MASCOT—The Mobile Asteroid Surface Scout Onboard the Hayabusa2 Mission

International audienceOn December 3rd, 2014, the Japanese Space Agency (JAXA) launched successfully the Hayabusa2 (HY2) spacecraft to its journey to Near Earth asteroid (162173) Ryugu. Aboard this spacecraft is a compact landing package, MASCOT (Mobile Asteroid surface SCOuT), which was developed by the German Aerospace Centre (DLR) in collaboration with the Centre National d'Etudes Spatiales (CNES). Similar to the famous predecessor mission Hayabusa, Hayabusa2, will also study an asteroid and return samples to Earth. This time, however, the target is a C-type asteroid which is considered to be more primitive than (25143) Itokawa and provide insight into an even earlier stage of our Solar System

MASCOT - a Mobile Lander on-board Hayabusa2 Spacecraft - Operations on Ryugu

MASCOT (‘Mobile Asteroid Surface Scout’) is a 10 kg mobile surface science package part of JAXA’s Hayabusa2 sample return mission. The mission was launched in December 2014 from Tanegashima Space Center, Japan. The Hayabusa2 spacecraft reached the target asteroid in summer 2018. After a mapping phase of the asteroid and a landing site selection process the MASCOT lander was deployed to the surface on the 3rd of October 2018. MASCOT operated successfully for about 17 hours on the surface of Ryugu. It performed three relocation manoeuvres and one “Mini-Move” and returned 128 MBytes of data. MASCOT has been developed by the German Aerospace Center (DLR) in cooperation with the Centre National d’Etudes Spatiales (CNES). The main objectives were to perform in-situ investigations of the asteroid surface and to support the sampling site selection for the mother spacecraft. These objectives could be reached successfully. On 6th December 2020 (JST) Hayabusa returned successfully asteroid samples to the Earth

The MASCOT lander aboard Hayabusa2: The in-situ exploration of NEA (162173) Ryugu

After 3.5 years of cruise, and about 3 months in the vicinity of its target, the MASCOT lander was deployed successfully on October 3, 2018 by the Hayabusa2 spacecraft onto the C-type near-Earth asteroid (162173) Ryugu. After a free-fall of 5 ​min 51 ​s from an altitude of 41 ​m MASCOT experienced its first contact with the asteroid hitting a big boulder. The lander bounced for ~11 ​min 3 ​s before it came to rest. MASCOT was able to perform science measurements with its payload suite at 3 different locations on the surface of Ryugu. It investigated the fine-scale structure, multispectral reflectance, thermal characteristics and magnetic properties. The surface consists of very rugged terrain littered with large surface boulders. The in-situ measurements confirmed the absence of fine particles and dust as already implied by the remote sensing instruments aboard the Hayabusa2 spacecraft. After about 17 ​h of operations, the MASCOT mission terminated with the last communication contact as its primary batteries depleted. This paper summarizes the MASCOT mission covering its four years of in-flight operations, its preparation for the descent, landing and in-situ investigation on the asteroid Ryugu until the end of its operation

A rover for the JAXA MMX Mission to Phobos

The Martian Moons eXploration (MMX) is a mission by the Japan Aerospace Exploration Agency, JAXA,to the Martian moons Phobos and Deimos. It will primarily investigate the origin of this moon by bringing samples back from Phobos to Earth and deliver a small (about 25 kg) Rover to the surface. The Rover is a contribution by the Centre National d’Etudes Spatiales (CNES) and the German Aerospace Center (DLR). Its currently considered scientific payload consists of a thermal mapper (miniRAD), a Raman spectrometer (RAX) a stereo pair of cameras looking forward (NavCAM)and two cameras looking at the interface wheel-surface (WheelCAM) and consequent Phobos’ regolith mechanical properties.The cameras will serve for both, technological and scientific needs. The MMX rover will be delivered from an altitude of <100 m and start uprighting and deploying wheels and a solar generator after having come to rest on the surface. It is planned to operate for three months on Phobos and provide unprecedented science while moving for a few meters to hundreds of meters. MMX will be launched in September 2024 and inserted into Mars orbit in 2025, the Rover delivery and operations are planned for 2026-2027