Enrico Stoll

Technische Universität Berlin | TUB

During the 2022/23 winter term, students at the Chair of Space Technology at Technische Universität Berlin developed a multispectral, multi-CubeSat imager formation. The formation was named MIMIR (Multispectral Imager satellite forMation for Inter satellite link and optical downlink demonstRation). A primary mission driver was to address ecological...

As humanity returns to the Moon and establishes a sustained presence, the development of advanced robotics has moved into focus for researchers, industrial companies, and space agencies alike. Among the pioneers of lunar robotics is the NewSpace company NEUROSPACE GmbH. The Berlin-based startup is developing a highly versatile robotics ecosystem ca...

The Moon offers a unique opportunity for space exploration and colonisation due to its proximity to Earth and abundance of resources. Additive manufacturing, also known as 3D printing, has shown promise as a technology for in-situ fabrication of structures and devices using local resources on the Moon. In the project EDAM-R at TU Berlin, molten lun...

Preliminary Results for an Experimental Framework to Characterize Gecko Adhesion under Free-Floating Conditions

The traditional sintering of metallic components shaped via Material Extrusion Additive Manufacturing (MEAM) is a time-consuming process that involves sophisticated energy-intensive heating systems. This work describes a novel induction heater capable of efficiently tailoring temperature profiles to densify MEAM powder compacts. In situ sintering w...

The NanoFF and NanoOOV missions of the Chair of Space Technology at Technische Universität Berlin aim to demonstrate formation flight capabilities using CubeSats in low Earth orbit. In addition to these missions, the presented research analyzes the feasibility of rendezvous and docking using two identical 3U CubeSats equipped with a single-axis ele...

Micropatterned Dry Adhesives, or geckomaterials, offer a lightweight, simple, and passive solution for the capture and docking to objects in space. They can adhere to virtually any surface by means of van-der-Waals forces and their functionality is independent of a surrounding atmosphere. Long-term Investigation of the effects of Zero-gravity, vAcu...

A novel cost effective material extrusion additive manufacturing method for metals and ceramics employs filaments embedded with powdered granules which are shaped, debinded, and sintered sequentially until completion of the part. One well known drawback of the technology lies in the time-consuming debinding process, which often requires handling to...

Avoiding loose powders and resins, material extrusion additive manufacturing is a powerful technique to produce near-net shape parts, being a cheap and safe alternative for developing complex industrial-grade products. Filaments embedded with a high packing density of metallic or ceramic granules are being increasingly used, resulting in almost ful...

Flight dynamics is a topic often overlooked by operators of small satellites without propulsion systems, as two-line elements (TLE) are easily accessible and accurate enough for most ground segment needs. However, the advent of cheap and miniaturized global navigation satellite system (GNSS) receivers and laser retroreflectors as well as modern, ea...

Spaceflight is facing a sustainability problem in Earth orbit, where about 90% of all man-made trackable objects are without functional use. Existing research activities on active debris removal are technologically complex and costly, which are potential reasons why no missions were carried out so far. Micropatterned dry adhesives inspired from cli...

Initial experiments in the design process of a novel 3D printed conformal propellant tank for small satellites are conducted. Contact angle measurements of static colored water droplets on printed PLA, PMMA, and PETG sample plates are performed. Additionally, the optical characteristics of transparent printed tanks of two to five millimeter wall th...

TUBIN is a microsatellite mission tasked with the demonstration of microbolometer technology for the detection of high-temperature events. To this end, the spacecraft employs a set of two microbolometers sensitive in the thermal range of the electromagnetic spectrum as well as a complementary CMOS-based imager for the visible spectrum. Additionally...

Characterisation of space debris has become a fundamental task to facilitate sustainable space operations. Ground-based surveillance provides the means to extract key attributes from spacecraft. However, signal inversion attempts are generally under-constrained, which is why an increase in measurement channels through multispectral observations is...

The launch rate has steeply increased in the last few years. However, the launch success rate in 2020 was the lowest of the last 15 years. Launch failures do not only come at a great economic cost, but also at a large waste of resources on Earth. Moreover, failed upper stages can remain in orbit for long periods of time, adding up to the tonnes of...

Laser melting experiments were carried out with the MOONRISE payload, installed on the mobile manipulator, MIRA3D. The MOONRISE payload was developed to demonstrate the feasibility of additive processing of lunar regolith with the help of lasers on the Moon within a lunar surface mission in the next years. The development of hardware for the flight...

While the quantity of space debris objects is steadily increasing, the necessity for space- or ground-based systems observing and cataloguing these objects grows as well. In principle, observations can be made by radar or optically by telescopes. Optical observations have various advantages over radar, such as low purchase and operating costs combi...

Robotic systems become more and more important for space applications due to the flexibility in tasks they can perform such as docking assistance, supporting extra-vehicular activities (EVA), as well as maintenance tasks. For these purposes multiple different robotic arms have been developed, especially for missions which are intended to demonstrat...

Large scale, on-orbit additive manufacturing (AM) and assembly is being considered as a modular and resource saving approach to facilitate permanent human presence in space. To realise this, a novel AM approach to freeform fabricate large, functional structures in space has been developed. Combining the reach of a free-flying CubeSat with a collabo...

The current paradigm in space robotics is the design of specialized robotic manipulators to meet the requirements for a specific mission profile. This research aims to develop a novel concept of a modular robotic arm for multi-purpose and multi-mission use. The overall approach is based on a manipulator formed by serial connection of identical modu...

A new innovative satellite mission, the Innovative CubeSat for Education (InnoCube), is addressed. The goal of the mission is to demonstrate “the wireless satellite”, which replaces the data harness by robust, high-speed, real-time, very short-range radio communications using the SKITH (SKIpTheHarness) technology. This will make InnoCube the first...

The growing demand for cheaper space access calls for a more economically and environmentally sustainable approach for launchers. Concurrently, the shift to smaller satellites and the rise of constellations necessitate launchers capable of precise multi-payload/multi-orbit injection. ASCenSIon (Advancing Space Access Capabilities-Reusability and Mu...

Reusable Launch Vehicles (RLVs) are not only key for an economically and ecologically sustainable space access but also represent a paramount innovation towards the increasing demand for smaller satellites and mega-constellations. In order to ensure Europe's independent space access capabilities, ASCenSIon (Advancing Space Access Capabilities - Reu...

Reusable Launch Vehicles (RLVs) are not only key for an economically and ecologically sustainable space access but also represent a paramount innovation towards the increasing demand for smaller satellites and mega- constellations. In order to ensure Europe's independent space access capabilities, ASCenSIon (Advancing Space Access Capabilities - Re...

The feasibility of 3D-printed molds for complex solid fuel block geometries of hybrid rocket engines is investigated. Additively produced molds offer more degrees of freedom in designing an optimized but easy to manufacture mold. The solid fuel used for this demonstration was hydroxyl-terminated polybutadiene (HTPB). Polyvinyl alcohol (PVA) was cho...

In this paper, investigations of two types of lunar regolith simulants, called TUBS-M and TUBST, developed by the Institute of Space Systems (IRAS) at TU Braunschweig are presented. These investigations are focused on the thermal properties, namely the specific heat capacity and the thermal conductivity. Several specimen of TUBS-M and TUBS-T were s...

Unmanned aerial vehicles (UAVs) have been used for increasing research applications in atmospheric measurements. However, most current solutions for these applications are based on a single UAV with limited payload capacity. In order to address the limitations of the single UAV-based approach, this paper proposes a new concept of measurements using...

Mankind is setting to colonize space, for which the manufacturing of habitats, tools, spare parts and other infrastructure is required. Commercial manufacturing processes are already well engineered under standard conditions on Earth, which means under Earth’s gravity and atmosphere. Based on the literature review, additive manufacturing under luna...

In view of the upcoming mega-constellations, Collision Avoidance Manoeuvres (CAM) become essential to protect both the space environment and the mission of the constellation. However, satellite constellations are usually bound to tight geometrical constraints, which can be disturbed by these manoeuvres. A communications Walker Delta constellation w...

Orbit Determination is a crucial part of Space Situational Awareness, especially, in the wake of upcoming mega constellations and the general trend towards an increased rate of orbital injection. While there are several initial and statistical orbit determination algorithms, one key aspect is the precise modeling of the process noise to accurately...

Patch antennas are compact, less complex, planar structures and therefore, widely used in small satellite missions for telecommand, data link, and intersatellite link, particularly in S- band and X- band. Improved performance of these patch antennas in terms of gain and compactness will di-rectly affect the communication efficiency of small satelli...

ESA, NASA, and other space institutions are planning the return to the Moon. In the next decades, a human outpost on the lunar surface is going to be established to extend the opportunities for science and economy. For this project, new materials, methods, and processes based on In-Situ Resource Utilization (ISRU) are needed. One aspect is the cast...

The derivation, implementation, and performance assessment of a differential drag based algorithm, designed for spacecraft formation control using a relative orbital elements formulation, is presented. In contrast to similar approaches found in literature, the underlying motion dynamics model used to derive the control law includes J2 perturbation...

Material processing and material transport systems on Earth are designed for Earth's gravity and atmosphere. In order to pave the way for the future colonization of space, production technologies and transport systems are an essential factor in reducing costs and logistical efforts, such as in-situ resource utilization (ISRU). Laser-based additive...

In this Note, we present a potential field-based sliding surface design principle for spacecraft attitude maneuvers. Based on the proposed design principle, we obtain new results of sliding surfaces using different attitude parameterizations. These new results are shown to be general forms of existing classical sliding surfaces in literature. Furth...

The use of lunar hybrid rockets, that connect the Moon surface with a lunar gateway and provide it with resources, are evaluated. Therefore, the composition of lunar regolith and its use for specific rocket subsystems is assessed. In particular, this work evaluates the use of oxygen and aluminum from regolith as oxidant/fuel mixture as well as the...

The trend towards smaller satellites and mega-constellations has enormously changed the space sector and its uti-lisation in the last decades, allowing new players to enter the market and to introduce stringent requirements to enable a variety of novel applications. Alongside, also the launcher market is undergoing a transformation epoch: the devel...

Recent developments have seen a trend towards larger constellations of spacecraft, with some proposals featuring constellations of more than 10.000 satellites. While similar concepts for large constellations already existed in the past, traditional satellite deployments hardly ever feature groups of more than 100 satellites. This trend towards cons...

This is the first of two companion papers that investigate the operations of distributed satellite systems. This first article presents a survey of conventional methods of operations of spacecraft constellations, investigates its scalability for growing number of spacecraft, and identifies operational paradigms shift. The second article focuses on...

The development of hybrid rockets offers excellent opportunities for the practical education of students at universities due to the high safety and relatively low complexity of the rocket propulsion system. During the German educational program Studentische Experimental-Raketen (STERN), students of the Technische Universität Braunschweig obtain the...

The ReDSHIFT (Revolutionary Design of Spacecraft through Holistic Integration of Future Technologies) project was concluded on March 31, 2019. The 3-year project involved 13 European partners and was aimed at studying, implementing and testing novel solutions for space debris mitigation. The focus was on passive means to reduce the impact of Space...

The space industry is undergoing fundamental shifts in paradigms: From few, large satellite buses to many small satellites; from one ground station to many ground stations, from manual telemetry review to an automated treatment; from long in-orbit lifetimes to shorter periods. At the same time, the announcement of large constellations with several...

One of the common challenges of spaceflight and e-mobility is the energy storage. The operational ranges of spacecraft or electric cars as well as operational usability is strongly dependent on the capacity of the energy storage, which is usually constrained by the mass and volume of the vehicle. For example, the battery mass of large communication...

Rising international interest in scientific and commercial Moon exploration programs require cost-efficient logistical solutions regarding raw- and construction materials for a permanent residence on our Earth’s satellite. Lunar regolith soil is the most abundant resource; its technical exploitation would comprise a major leap forward towards the c...

We consider a central challenge that is mission critical for the successful operation of large-scale satellite constellations in Low-Earth Orbit: How can we coordinate the short-term download operations for the enormous amounts of generated data, based on wireless line-of-sight connections to a limited number of stationary ground station? These iss...

There has been a long discussion on how the low-gravity effects that LRUs (Lightweight Rover Units) on the Moon will experience, can affect mission planning and surface operations. In particular, the sinkage observed when regolith soil layers collapse under a normal wheel load has been an important source of contradiction in the field of Terramecha...

This paper proposes an adaptive sliding mode control law based on dual quaternions for six-degree-of-freedom proximity operations between a chaser and a target spacecraft. Dual quaternion, a new parameterization to simultaneously describe the translation and the rotation of a rigid body, is used to model the relative motions during proximity operat...

This paper presents the derivation, implementation, and performance assessment of a differential drag based algorithm, designed for spacecraft formation control. In contrast to similar approaches found in literature, the underlying motion dynamics model used to derive the control law includes J2 perturbation as well as atmospheric drag perturbation...

The area of spaceflight, especially human space flight, experienced a change in the past decades. Due to the privatization of space flight, many advances were provided and human space flight was pushed forward. The number of spaceflight and spaceports has increased as well as the interest in space tourism. General feasibility studies of space touri...

A method to deduce orbit solutions of predetermined accuracy with respect to a reference orbit is presented. The idea is to guarantee the applicability to all orbits and provide both the orbit and the covariance matrix with a constrained method error. Such a solution may be useful, if different users expect different levels of accuracy or have limi...

3D-PIC (Particle In Cell) simulations were performed to emulate the dynamics and collection of plasma particles onto the surface of the UWE-IV, a satellite of miniaturized dimensions (CubeSat) launched in 2018. We review the electrostatic potential, currents collected and plasma disturbances of the CubeSat and characterize them by numerical simulat...

This paper presents the results of a numerical evaluation of the natural lifetime reduction in low Earth orbit, due to dynamical perturbations. The study considers two values for the area-to-mass ratio, a nominal ratio which resembles a typical value of spacecraft in orbit today, and an enhanced ratio which covers the surface augmentation. The resu...

Gain, noise figure (NF), and output power are considered the common performance metrics of an optical fiber amplifier. With an increasing interest of space industry in developing technologies for satellite-ground and intersatellite communication in the optical band, the EDFA (erbium doped fiber amplifier) is needed as power amplifier in space to co...