Mobile Asteroid Surface Scout (MASCOT) - Design, Development and Delivery of a Small Asteroid Lander Aboard Hayabusa2

MASCOT is a small asteroid lander launched on December 3rd, 2014, aboard the Japanese HAYABUSA2 asteroid sample-return mission towards the 980 m diameter C-type near-Earth asteroid (162173) 1999 JU3. MASCOT carries four full-scale asteroid science instruments and an uprighting and relocation device within a shoebox-sized 10 kg spacecraft; a complete lander comparable in mass and volume to a medium-sized science instrument on interplanetary missions. Asteroid surface science will be obtained by: MicrOmega, a hyperspectral near- to mid-infrared soil microscope provided by IAS; MASCAM, a wide-angle Si CMOS camera with multicolour LED illumination unit; MARA, a multichannel thermal infrared surface radiometer; the magnetometer, MASMAG, provided by the Technical University of Braunschweig. Further information on the conditions at or near the lander‘s surfaces is generated as a byproduct of attitude sensors and other system sensors. MASCOT uses a highly integrated, ultra-lightweight truss-frame structure made from a CFRP-foam sandwich. It has three internal mechanisms: a preload release mechanism, to release the structural preload applied for launch across the separation mechanism interface; a separation mechanism, to realize the ejection of MASCOT from the semi-recessed stowed position within HAYABUSA2; and the mobility mechanism, for uprighting and hopping. MASCOT uses semi-passive thermal control with Multi-Layer Insulation, two heatpipes and a radiator for heat rejection during operational phases, and heaters for thermal control of the battery and the main electronics during cruise. MASCOT is powered by a primary battery during its on-asteroid operational phase, but supplied by HAYABUSA2 during cruise for check-out and calibration operations as well as thermal control. All housekeeping and scientific data is transmitted to Earth via a relay link with the HAYABUSA2 main-spacecraft, also during cruise operations. The link uses redundant omnidirectional UHF-Band transceivers and patch antennae on the lander. The MASCOT On-Board Computer is a redundant system providing data storage, instrument interfacing, command and data handling, as well as autonomous surface operation functions. Knowledge of the lander’s attitude on the asteroid is key to the success of its uprighting and hopping function. The attitude is determined by a threefold set of sensors: optical distance sensors, photo electric cells and thermal sensors. A range of experimental sensors is also carried. MASCOT was build by the German Aerospace Center, DLR, with contributions from the French space agency, CNES. The system design, science instruments, and operational concept of MASCOT will be presented, with sidenotes on the development of the mission and its integration with HAYABUSA2

Planetary Defense Ground Zero: MASCOT's View on the Rocks - an Update between First Images and Sample Return

At 01:57:20 UTC on October 3rd, 2018, after 3½ years of cruise aboard the JAXA spacecraft HAYABUSA2 and about 3 months in the vicinity of its target, the MASCOT lander was separated successfully by from an altitude of 41 m. After a free-fall of only ~5m51s MASCOT made first contact with C-type near-Earth and potentially hazardous asteroid (162173) Ryugu, by hitting a big boulder. MASCOT then bounced for ~11m3s, in the process already gathering valuable information on mechanical properties of the surface before it came to rest. It was able to perform science measurements at 3 different locations on the surface of Ryugu and took many images of its spectacular pitch-black landscape. MASCOT’s payload suite was designed to investigate the fine-scale structure, multispectral reflectance, thermal characteristics and magnetic properties of the surface. Somewhat unexpectedly, MASCOT encountered very rugged terrain littered with large surface boulders. Observing in-situ, it confirmed the absence of fine particles and dust as already implied by the remote sensing instruments aboard the HAYABUSA2 spacecraft. After some 17h of operations, MASCOT‘s mission ended with the last communication contact as it followed Ryugu’s rotation beyond the horizon as seen from HAYABUSA2. Soon after, its primary battery was depleted. We present a broad overview of the recent scientific results of the MASCOT mission from separation through descent, landing and in-situ investigations on Ryugu until the end of its operation and relate them to the needs of planetary defense interactions with asteroids. We also recall the agile, responsive and sometimes serendipitous creation of MASCOT, the two-year rush of building and delivering it to JAXA’s HAYABUSA2 spacecraft in time for launch, and the four years of in-flight operations and on-ground testing to make the most of the brief on-surface mission

Development of hardware-in-the-loop facility for optical navigation with the study of insect inspired algorithm for spacecraft landing

The thesis objective was to develop a real-time interface to the robot controller and related software components in the hardware-in-the-loop simulation facility for optical navigation. For demonstration of the developed components, an insect-inspired landing algorithm using a camera was chosen to study along with the hardware-in-the-loop simulation development. The testing of the algorithm in the hardware-in-the-loop simulation provided the evaluation of the algorithm itself as well as the functional test of the hardware-in-the-loop software components. In this thesis, two simulation platforms were presented. First, the simulation platform using planetary image generation software was setup. The landing algorithm acquired image data from the image generation software by providing spacecraft dynamics information to the software. After image processing, the algorithm provided the feedback control to control the spacecraft. Second, the hardware-in-the-loop simulation software components were setup in the facility in German Aerospace Centre (DLR). The robotic arm carrying a camera was controlled to approach the scaled terrain model. Simple spacecraft dynamics was performed and transformed to the robotic arm movement. Reference frames for the transformation were defined. The real-time control software for the robotic arm was developed and the closed-loop control in the hardware-in-the-loop simulation was setup. Finally, control signals from the image processing module were transferred to change spacecraft dynamics in the simulation resulted in changing the movement of the robotic arm. An insect-inspired algorithm using optical flow from a camera for controlling the spacecraft during the landing was presented. The image processing for the optical flow determination and interpretation were described. The characteristics of the optical flow were studied. The control law for controlling the spacecraft velocity according to the optical flow was designed according to the optical flow characteristics. The delay in the control system was considered in the design of the control rule. The implementation of the algorithm with the tests in software-in-the-loop simulation and in the hardware-in-the-loop facility was presented. The landing algorithm can slow down the spacecraft and land softly both with image generation software and in hardware-in-the-loop simulation. The system with the delay was studied. The developed control rule can control the delayed system effectively. The thesis has shown that the insect- inspired landing algorithm using only the optical flow calculation is feasible for the landing of the spacecraft.Validerat; 20101217 (root

Concurrent AIV and Dynamic Model Strategy in Response to the New Normal of so called Death March Projects: The Engineering Venture as Experienced in the DLR MASCOT and Hayabusa-2 Project

As today’s projects increase quickly in complexity and development times are shortened to save budgets, the term “Death March Project” has been recently used to describe projects which schedules are so compressed that current and well established processes cannot be followed in order to finalize the project in the given time. MASCOT, a small 11 kg Asteroid Landing Package on-board JAXA’s Hayabusa-2 space probe is currently being finalized at DLR. Its last stages during the Assembly, Integration and Verification (AIV) process show that by applying a unique mix of conventional and tailored Model Philosophies it is possible to dynamical adapt the test program, limited by a fixed launch date, to accomplish for the shortest planning and a suitable weighing of costs and risks. Introducing “Concurrent AIV” to identify and mitigate design and manufacturing issues shortened the MASCOT project timeline further from a general 4 year AIV phase to less than 2 years

Going Beyond the Possible, Going Beyond the “Standard” of Spacecraft Integration and Testing!

MASCOT, a small 10kg Asteroid landing package on-board Hayabusa-2 is currently finalizing Phase-C of its development and after official go-ahead during the Critical Design Review it will undergo a final verification program at DLR before send to JAXA to be integrated into the mother spacecraft. Its last stages during the Assembly, Integration and Verification (AIV) process show that by applying a unique mix of conventional and tailored Model Philosophies it is possible to dynamical adapt the test program, limited by a fixed launch date, to accomplish for the shortest planning and a suitable weighing of costs and risks. In addition, this paper introduces the term Concurrent AIV to express the many simultaneous running test and verification activities

MASCOT - a Mobile Lander on-board Hayabusa2 Spacecraft - Operations and Status after Launch

MASCOT (‘Mobile Asteroid Surface Scout’) is a 10 kg mobile surface science package on board JAXA’s Hayabusa2 spacecraft, currently on its way to the near-Earth asteroid (162173) Ryugu. MASCOT has been developed by the German Aerospace Center (DLR) in cooperation with the Centre National d’Etudes Spatiales (CNES). The concept of MASCOT is to perform in-situ measurements on the asteroid’s surface and to support the Hayabusa2 mission in the sampling site selection. MASCOT is equipped with 4 scientific instruments, a wide angle camera, a hyperspectral IR microscope, a radiometer and a magnetometer. MASCOT is powered by a primary battery which shall enable MASCOT to investigate the asteroid surface for up to 2 asteroid days. An internal mobility mechanism shall relocate MASCOT on the asteroid surface to investigate different landing sites in detail

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—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

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