Thermal and Mechanical Investigation of a Preload Release Mechanism for a Space Probe under Laboratory Conditions

Der Vorspannungsabbau-Mechanismus der Asteroidenlandeeinheit MASCOT soll auf seine Funktionalität untersucht werden. Dazu muss ein Teststand entwickelt werden. Zusätzlich soll der Mechanismus derart verändert werden, dass der Erfolg des Abbauvorganges während des Fluges überprüft werden kann

Special Testing and Test Strategies for Unique Space Hardware Developments

Hardware developments for new and innovative space applications require extensive testing in order to demonstrate the functionality under the expected environmental conditions. Within several projects the German Aerospace Center (DLR), Institute of Space Systems used its test capabilities for unique tests campaigns that went beyond standard qualification testing

EDEN Versatile End-effector (EVE): An Autonomous Robotic System to Support Food Production on the Moon

Spacefaring nations have already expressed their plans for a sustainable human and robotic exploration on the Moon. This endeavor highlighted in the Global Exploration Roadmap (GER) foresees the development of infrastructures such as habitats, greenhouses, science labs, power plants, and mining facilities. Following this long-term vision, the German Aerospace Center (DLR) EDEN LUNA Project presents a Moon-analogue greenhouse facility which can demonstrate nearly closed-loop bio-regenerative life support systems technology and aim to produce fresh food for astronauts on the Moon in the near future. To optimize the food production and overcome challenges inherent to space missions, the EDEN Versatile End-effector (EVE) is integrated to the EDEN LUNA Greenhouse. This support system is a valuable payload which will automatize the tasks of the entire plant cultivation process: from germination to harvesting. The automatization is particularly relevant when the food production is intensified either seasonally or in a future scaled-up scenario. The EVE system encompasses a linear rail system installed on the ceiling of the greenhouse, a 7-Degrees of Freedom (DOF) autonomous robotic arm with high precision joint configuration, a sensorized robotic hand which can grasp delicate objects, and a sophisticated computer vision camera with plant monitoring capabilities. When in operation, the EVE system uses shared autonomy features. Thus, while it maintains the human in the loop for some of the decision-making processes, it can also function with some level of autonomy. A set of tasks previously defined by an astronaut in the end of an operational day and carried out autonomously during the night by the EVE system is one example of this human-robot collaboration. In addition, an optimized motion planning will ensure that the EVE system can perform constrained manipulation tasks in a limited workspace observing energy efficiency and safety requirements. This is explained in the paper with the abstraction of the different robotic control levels which range from the high-level view for non-experts in robotics to the motion planning level and their interconnections. The EVE system is currently in development at the DLR Robotic and Mechatronics Center (RMC) in Oberpfaffenhofen. In 2024, it will be integrated to the EDEN LUNA Greenhouse at the DLR Institute of Space Systems in Bremen. Finally, by the end of 2025, it will start operations in the ESA/DLR LUNA facility at the European Astronaut Centre (EAC) in Cologne

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

Mechanical design of a modular experiment carrier for a terrestrial analog demo mission and its potential for future space exploration

The ROBEX (Robotic Exploration under Extreme Conditions) alliance formed by the German Helmholtz Association has the aim to find and use areas of overlapping competencies between institutions involved with the exploration of deep sea and space environment. To demonstrate the developed systems and technologies two test campaigns are conducted, one for the deep sea in the area of Svalbard, Norway and one on the volcano Mt. Etna in Sicily, Italy as an Moon environment analog test ground. The objective of the volcano mission is to demonstrate seismic experiments built-up and conducted autonomously by robotic elements. It shall serve as scientific benchmark to validate concepts reproducing and extending experiments from the Apollo program and at the same time demonstrate robotic capabilities to do so without direct human interaction. The overall test infrastructure consisting of a stationary lander, a mobile element and instrument carriers has been developed within the ROBEX alliance. The modular instrument carrier, referred to as Remote Unit (RU), is deployed and positioned by a robotic system and supplies the payload, in this case the seismometer, with power, data-handling and communication. It also provides mechanical interfaces to the lander and a grapple interface for robotic handling. The RU’s primary structure is a differential carbon-fiber-reinforced-plastic (CFRP) framework with a dedicated payload and bus compartment. Two types of RUs have been developed: one basic version that complies with a mass limitation of 3 kg (RU3) and one extended version of 10 kg (RU10). While the basic version has a fixed seismometer as well as limited lifetime due to the lack of photovoltaics, the extended version is equipped with a self-levelling seismometer, photovoltaics and an inductive power/data interface for unit charging and telemetry/telecommand (TT&C). Both designs use the identical main structure to meet the envisaged modularity approach. Even though the hardware was never meant to enter the space environment, the design approach for the units was always driven by principles which could be functional under space conditions while respecting the peculiarities and the financial framework of this terrestrial demonstration. This paper presents the functionalities of the RU with a special focus on the overall configuration, structural concept as well as included mechanisms. Moreover, starting with the baseline design for the terrestrial application, it analyses the differences and derives necessary changes and modifications to further develop the system towards a usage in an actual Moon mission

Upcoming DLR Reusability Flight Experiment

After the successful hypersonic flight experiments SHEFEX I and II, the German Aerospace Center (DLR) is now investigating the realization of the Reusability Flight Experiment (ReFEx). This successor mission shall be launched on a Brazilian VSB-30 sounding rocket in 2021 and shall achieve a reentry velocity of more than Mach 5. The main goal is the demonstration of a controlled autonomous re-entry flight from hypersonic velocity down to subsonic range and to test key technologies required for future reusable booster systems. So far, two Concurrent Engineering (CE) studies were conducted to investigate the feasibility of this sophisticated project. The required subsystems, including sensors and actuators as well as their interfaces have been defined and different options were assessed regarding matters like the scientific output, complexity, risk, and cost. The current configuration of ReFEx has a re-entry mass of about 450 kg, a length of 2.7 m, and a wingspan of 1.1 m. This paper provides a system overview, addresses systems engineering aspects and main challenges regarding the mission realization. For example, to meet the VSB-30 launcher flight stability requirement, the wings of the ReFEx experiment were designed foldable. Therefore, special attention was paid to a passive and reliable lock mechanism for the wings

The MASCOT Separation Mechanism - A Reliable, Low-Mass Deployment System for Nano-Spacecraft

The Mobile Asteroid Surface Scout (MASCOT), an Asteroid Lander carried by the Hayabusa2 spacecraft, successfully landed on the Near-Earth Asteroid (162173) Ryugu on October 03, 2018. Hereby accomplishing the first ever landing of a European spacecraft on the surface of this type of celestial body. MASCOT was a prototype design of a new class of nano-size surface science packages for the exploration of small solar system bodies. The very low gravity (thus, very low escape velocity) of the target body required the design of a miniaturized deployment mechanism with a relatively small, well reproducible separation velocity. In addition, the mechanism also had to safely restrain the lander to the mother spacecraft during the launch and its 3.5 years cruise phase. In this paper, we describe in detail the design, numerical analysis and test of this newly developed separation mechanism. Furthermore, we compare the mechanism to other existing deployment systems and verify its performance with two independent analysis methods using actual flight data taken during the ultimate flight activation event, which initiated the successful delivery and surface operation of the MASCOT asteroid lande

DLR Reusability Flight Experiment ReFEx

The German Aerospace Center (DLR) is currently developing the Reusability Flight Experiment (ReFEx). The successor of the already performed hypersonic flight experiments SHEFEX I and II shall be launched on a Brazilian VSB-30 sounding rocket in 2022 and shall achieve a re-entry velocity of more than Mach 5. The main goals of the project are the demonstration of a controlled autonomous re-entry flight from hypersonic velocity down to subsonic range and the testing of the key technologies required for future reusable first stage systems. Utilizing Concurrent Engineering (CE) approach the fundamental feasibility of this sophisticated flight experiment has been investigated by the entire ReFEx team. All required systems, including sensors and actuators as well as their interfaces have been defined and different options were assessed regarding matters such as the scientific output, complexity, risk and cost. The current configuration of ReFEx has a re-entry mass of about 400 kg, a length of 2.7 m and a wingspan of 1.1 m. This paper provides a system overview and addresses the Reusable Launch Vehicles (RLV) technologies Guidance, Navigation and Control as well as Flight Instrumentation. Furthermore the mission design (launch & re-entry) and the main challenges regarding the mission realization are addressed

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