MASCOT ("Mobile Asteroid Surface SCouT") is a lander that was launched on December 3, 2014 with the Hayabusa2 sample return mission (JAXA). The target of this mission is the near-Earth asteroid (162173) Ryugu. After almost 4 years of flight, MASCOT was separated from the mother ship on October 3, 2018 at 3:58 a.m. (CEST) from an altitude of approx. 42 m above Ryugu's surface. The lander came to rest on the asteroid about 20 minutes after separation and carried out its scientific operations over the next 17 hours or so. Its four scientific instruments (MASCam, MicrOmega, MASMag and MARA) were used to collect data from several locations on the asteroid's surface.
The MASCOT lander was built under the leadership of the German Aerospace Center (DLR) in close cooperation with the French space agency CNES and the Japanese space agency JAXA.
The total mass of the lander is just ten kilograms and also includes the scientific instruments MASCam (camera) and MARA (radiometer) from the DLR Institute of Planetary Research, as well as a hyperspectral infrared microscope (MicrOmega) from the Institut d'Astrophysique Spatiale and the magnetometer (MASMag) from the TU Braunschweig.
The aim of these experiments is to determine the surface structure, the mineralogy, the surface temperature and the magnetic field of the asteroid. All this information, together with the data from the remote sensing instruments on Hayabusa2 and the asteroid samples brought back later, should provide important insights into Ryugu's composition, its formation and development in particular. Based on this, the aim of the Hayabusa2 mission is to expand our knowledge of the early history of the solar system and its evolutionary processes, and to draw possible conclusions about the origin of water and organic materials on Earth via asteroid impacts.
Asteroids, like comets, are small bodies in the solar system. They are not only regarded as remnants of the early phase of planet formation, but are also thought to be the origin of water on Earth: heavy bombardments of the young Earth by asteroids are thought to have brought water and complex molecules to our planet around 3.8 billion years ago. This is said to be the key process for the emergence of life.
Asteroids are distinguished by their orbits (for example, main-belt asteroids, Trojans, near-Earth asteroids) and by characteristics in their reflection spectrum ('asteroid taxonomy').
Ryugu (1999 JU3) belongs to a class of very common near-Earth asteroids. This type of asteroid is of particular interest because its spectrum is similar to that of carbonaceous chondrites and its chemical composition is very close to that of our Sun and the early solar nebula. In addition, minerals containing water have been found on this type. Finding answers to the matter of life, the origin and evolution of our solar system is therefore the main goal of MASCOT as the scientific payload of the Hayabusa2 mission.
The first Hayabusa mission of the Japanese space agency JAXA was already a success: in 2010, the Japanese Hayabusa probe brought asteroid material in its original, unaltered form to Earth in a capsule for the first time. At that time, the DLR Institute of Planetary Research also investigated the rare particles. The Hayabusa2 mission will now bring material back to Earth, but MASCOT will also measure it directly on site. "Among other things, our data will also serve as a reference for investigations in terrestrial laboratories," says DLR project manager Dr. Tra-Mi Ho. The lander will also act as a scout to explore where the Japanese probe is to collect the asteroid material. "The probe and lander will definitely multiply our knowledge of asteroids."
The DLR Institute of Space Systems developed the lander and tested it under space conditions during parabolic flights, in the Bremen drop tower (ZARM) and on the shaking table, as well as in the thermal vacuum chamber at the institute. The DLR Institute of Composite Structures and Adaptive Systems was responsible for the stable structure of the lander. The DLR Robotics and Mechatronics Center developed the swing arm that allows MASCOT to bounce on the asteroid. The DLR Institute of Planetary Research contributed the MASCAM camera and the MARA radiometer. The asteroid lander MASCOT is monitored and operated from the DLR Control Center of the User Center for Space Experiments (MUSC) in Cologne. CNES contributed the power subsystem to MASCOT, part of the telecommunications system including antenna development, descent and landing emission analysis. The magnetometer MASMag was built by TU Braunschweig and the IR Microscope MicrOmega by IAS Paris.
