MASCOT, the small mobile package on its piggyback journey to 1999JU3: pre-launch and post-launch activities

Since December 2014 the Japanese spacecraft Hayabusa2 is on its journey to asteroid (162173) 1999 JU3. Like its famous predecessor it is expected to study and return samples from its target body. This time, the mother spacecraft has several small passengers. One of them is a compact landing package called MASCOT (Mobile Asteroid surface SCOuT), which has been developed by the German Aerospace Centre (DLR) and the Centre National d'Etudes Spatiales (CNES). Once having been released from its mother spacecraft's cradle, MASCOT will descend to the asteroid and after a few bounces will come to rest at a certain location on the surface. Sitting on the surface, it will perform its scientific investigations of the asteroids surface structure, mineralogical and physical properties, thermal behaviour and magnetic effects by using its suite of four scientific instruments: a spectrometer (MicrOmega, IAS Paris), a camera (CAM, DLR Berlin), a radiometer (MARA, DLR Berlin) and a magnetometer (MAG, TU Braunschweig). These payload operations are made possible by, amongst others, a clever thermal subsystem design specifically devised to cope with the contrasting requirements of cold cruise and hot on-surface operations and a primary battery optimizing mass versus energy output. A mobility mechanism realizes locomotion on the surface supported by an attitude and motion sensing system. An intelligent autonomy manager which is implemented in the onboard software can operate MASCOT when ground intervention is not available. In a nutshell, with its many challenging technical hurdles that have been solved, the MASCOT lander can serve as a benchmark for extremely lightweight (10 kg), highly integrated mobile small body landing systems with onboard autonomy and high science output. This paper will summarize the mission and system development. We will provide an overview of the final capabilities of the system as well as discuss the last challenging pre-launch activities and tests. Further a summary and an outlook regarding the already performed as well as upcoming post-launch activities will follow. Lessons have been learned and will be told to be ready for future upcoming missions for small solar system body exploration

MASCOT - a Mobile Lander on-board Hayabusa2 Spacecraft - Status and Operational Concept for the Asteroid Ryugu

MASCOT (‘Mobile Asteroid Surface Scout’) is a 10 kg mobile surface science package on board JAXA’s Hayabusa2 sample return mission, currently on its way to the near-Earth asteroid (162173) Ryugu. The mission was launched in December 2014 from Tanegashima Space Center, Japan. The Hayabusa2 spacecraft will reach the target asteroid in summer 2018. Hayabusa2 will return its samples to Earth in December 2020. After arrival at the target asteroid ‘Ryugu’ a detailed mapping phase will be performed and the landing site of MASCOT will be selected. The deployment of MASCOT to the asteroids surface is planned for the beginning of October 2018. MASCOT has been developed by the German Aerospace Center (DLR) in cooperation with the Centre National d’Etudes Spatiales (CNES). The main objective of MASCOT is to perform in-situ investigations of the asteroid surface and to support the sampling site selection for the mother spacecraft. Mascot is equipped with four scientific instruments a wide angle camera, a hyperspectral infrared microscope, a radiometer and a magnetometer. The camera (MasCam) provides ground truth for the orbital measurements of the Hayabusa2 orbiter instruments and the in-situ MASCOT sensor suite as well as geological context of the samples. The radiometer (MARA) determines the surface brightness temperature, the thermal inertia of the surface material and the spectral slope in infrared. The radiometer field of view is correlated with the wide angle camera field of view. The magnetometer (MasMAG) observes the magnetic field profile during descent and bouncing and determines any global and local magnetization of the asteroid

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