Aperture Space Research Articles

Numerical simulation study on the construction of cut off walls using high-pressure jet grouting based on SPH method

The optimization of parameters for the construction of cut off walls using high spray method plays a crucial role in improving the permeability stability of hydraulic structures and ensuring the safe operation of water conservancy projects. However, limited by existing research methods, there is currently a lack of systematic research on the influence of construction parameters on the quality of cut off walls. This study fully considers the characteristics of high-speed slurry jet and soil dynamic failure in numerical simulation of the construction of cut off walls using high spray method. Based on the SPH method, a two-dimensional plane strain model of high-pressure jet grouting was established, and the influence of aperture, grouting pressure, and hole spacing on the failure process of soil and the quality of cut off walls is systematically analyzed. The results show that the soil mainly exhibits tensile failure under the continuous action of high-speed cement slurry during the construction of cut off walls using high spray method. Reducing the aperture and grouting pressure, as well as increasing the hole spacing, are not conducive to forming a continuous and dense impermeable wall. Compared to grouting pressure, the influence of aperture and spacing on the quality of cut off walls is more significant. When the aperture is 0.6 m, the grouting pressure is 32 MPa, and the hole spacing is 0.8 m, the quality of cut off walls is great. Finally, the simulation results of this paper were preliminarily verified by combining the construction of cut off walls using high spray method in the flood control project in Luotang Township, Jiangxi Province, China. The findings can provide reference for optimizing the construction parameters of cut off walls using high spray method.

Experimental and numerical study of the cooling characteristics of the double-walled cooling structure on integral support plate

The diffuser, rectifier, fuel injection rod, and flame holder in the afterburner are designed integrally, and a double-layer cooling structure is installed for the integral flame holder. Infrared thermography is employed to carry out the cooling efficiency test experiments under non-afterburner conditions, and the numerical simulation method is used to obtain the flow characteristics inside the integral afterburner. The effects of subtle geometrical parameter changes on the near-wall flow and wall-cooling effect are investigated. The results show that: The cooling air covers the film panel to form a film under the traction of the backflow vortex and spiral vortex behind the support plate, which provides effective cooling for the integral flame holder; the increase of the mass flow ratio will improve the cooling effectiveness of the double-wall, but it will cause additional pressure loss; impact spacing H has a small effect on the cooling effectiveness and relative pressure loss; reduced film aperture diameter df, increased aperture spacing S and aperture row angle β lead to a drop in the cooling capacity of the double-wall, whereas a reduced impact aperture diameter di leads to a certain degree of improvement in the cooling effectiveness of the double-wall.

How porosity can reduce the sound radiation of electrical coils?

High-power electrical coils used in the electricity transmission network can create a noise nuisance for local residents. These industrial coils are made up of a multi-strand cable winding, giving them a cylindrical shell shape. Electromagnetic excitation by Lorentz forces induces coil vibration, creating an undesirable sound field. In this study, we investigate analytically and by numerical simulation the reduction of acoustic radiation using regularly spaced apertures. As the shell becomes porous (with a porosity of less than 10%), acoustic short-circuits appear. We show a reduction in radiation efficiency and the impact of apertures on the structure vibration. Our results offer insights into the design and optimization of apertured electrical coils to mitigate noise generation.

Robotic technologies for in-orbit assembly of a large aperture space telescope: A review

Space telescopes have been instrumental in enlightening our understanding of the universe, from the iconic Hubble Space Telescope to specialized instruments like Chandra and Kepler. Pushing the frontiers of cosmic exploration, the future of space exploration hinges on modular Large Aperture Space Telescopes (LAST), much larger than the recently launched 6.5 m James Webb Space Telescope, necessitating robotic assembly in orbit. This paper introduces a paradigm shift in astronomical observation by featuring robotic in-orbit assembly of a large aperture space telescope. This review paper starts by tracing the evolution of telescopes and presents a comprehensive overview of the state-of-the-art space telescopes. This paper then reinforces the need for LAST to address the constant clamour for higher-resolution astronomy. While current semi-autonomous robotic manipulators operate from the International Space Station, their limited walking capabilities constrain their workspace, making them unsuitable for the LAST mission. This paper presents a detailed trade-off analysis of the challenges associated with the in-orbit assembly of LAST using candidate robots to understand the technological gaps. Further, the evolution of space robotic manipulators is presented, highlighting design features, advantages, and drawbacks for in-orbit spacecraft servicing and assembly missions. To tackle design and modelling challenges for robotic systems in space, amidst the various perturbations in the extreme space environment, linear and non-linear control systems necessary for achieving ultra-high precision performance are also discussed. This paper advances the walking space manipulator technology by introducing the next generation of walking space manipulators – the End-Over-End Walking Robot (E-Walker). The dexterous and modular design of the E-Walker makes it an ideal candidate for missions involving assembly, manufacturing, servicing, and maintenance.

Photon-counting phase-stabilized dual-comb ranging.

Dual-comb ranging (DCR), with its superior overall performance compared to traditional ranging technologies, has recently attracted widespread interest in the research community. Nevertheless, the ranging distance or the material of the targets is limited by the detection sensitivity of optical asynchronous linear sampling. This limitation restricts the application of DCR in several highly significant scenarios. Here, we utilize the photon-counting method to dramatically break through the detection sensitivity to femtowatt. To overcome the impact of fiber-length wandering and achieve Michelson interference based absolute distance measurement, an orthogonal polarization interferometry-arm configuration and a reference-arm based photon-counting trigger protocol are proposed. This photon-counting DCR system can conduct long-period photon-counting coherently, thus, realizing the lowest detection power of phase-stabled DCR to date. The results show that with only 18 femtowatt average power detected, the time-of-flight and multi-wavelength interferometry yields a precision of 22 µm and 8 nm in 3 min, respectively. This work paves the way for the field of large-scale spacecraft formation flying, synthetic aperture space telescope position attitude control, interplanetary positioning, and hard target distance measurement.

Structural design and surface networking analysis of a truss antenna based on hexagonal frustum deployable mechanism units

With the development of space technology, deployable mechanism has been widely applied in large aperture space antennas. In this paper, a hexagonal frustum deployable antenna unit and an innovative modular assembling concept are proposed for large parabolic truss antenna. Screw topology diagram and screw constraint matrix are established to solve degree of freedom (DOF) of the antenna mechanism. By separating column vectors of screw constraint matrix, whole actuations of antenna mechanism are obtained according to unique solution condition. A new hexagon antenna network method based on hexagon frustum units and rotation transformation matrix is proposed, and correctness and efficiency of the modeling principle are proved by simulation. Finally, a prototype of the proposed hexagonal frustum truss deployable antenna mechanism is constructed, and a deployment experiment is conducted, which demonstrate the mobility and deployment performance of the mechanism. The mechanism proposed in this paper provides a theoretical reference for the parabolic truss deployable antenna mechanism, which is potentially valuable in the application of large aperture deployable antennas.

Embedded parallel-actuated technology for deformable space segmented mirror

The deployable segmented space imaging system is an important solution for future ultra-large aperture space optical systems. To achieve the imaging capability of an equivalent aperture monolithic mirror, it requires not only to ensure the positional accuracy in the cophasing process, but also to have extremely high surface accuracy and curvature consistency of the sub-mirrors. However, this work is extremely challenging due to the manufacturing error of the sub-mirrors and the complex space environment. Active optical technology can ensure the surface shape accuracy of the spliced mirror by controlling the mirror surface deformation and compensating for the wavefront aberration. This article compares and analyzes the control ability of two types of deformable mirrors actuated by vertical and parallel methods. We explored the characteristics of the influence function mathematical models of the two types of actuation forms and compared the aberration and curvature correction abilities of them through finite element analysis, summarizing the advantages of the parallel actuation forms. Finally, a 300mm aperture embedded parallel-actuated deformable mirror was designed and manufactured, and relevant experiments were conducted to verify its adjustment ability. By comparing and analyzing the experimental results with the design results, the adjustment ability of the embedded parallel-actuated deformable mirror was verified.

Gravity unloading of a very large spaceborne monolithic SiC mirror.

We formulated a gravity unloading strategy for a monolithic silicon carbide (SiC) mirror with a Φ3m aperture in space. Employing the finite element analysis (FEA) technique, a rapid solution analytical approach for determining optimal support forces during gravity unloading is introduced. This method demonstrates enhanced efficiency and accuracy compared to conventional approaches. A quantitative evaluation methodology for the gravity release error, grounded in the minimum-energy mode, is delineated. The adverse impacts could be expeditiously computed by assessing the maximum deflection of minimum-energy modes generated by various errors. The analytical findings revealed that compliance with the stipulated gravity release error criterion of less than 6 nm (root-mean-square) necessitated the gravity unloading force error to fall within the range of ±0.1N. Additionally, the gravity unloading support position error was required to be within Φ0.5m m, and the measurement error pertaining to the rib thickness of the actual mirror blank had to be within ±0.02m m.

Fiber Optic Sensor-Based Bearing Defect Detection and Its Usages in Computer Vision

This work focuses on the investigation of surface defects in small bearings. Based on the theory of rough surface scattering and the dual-beam ratio measurement method, fiber optic sensing technology is applied in identifying surface defects in bearings. To facilitate the extraction of features for surface defects in bearings, a sensor probe fiber array with three concentric circles around the central emission is determined. A reflective intensity-modulated fiber optic sensor (FOS) is employed to detect surface defects on bearings. The structural parameters of the FOS are simulated through Matlab, considering the inner/outer diameter, numerical aperture, and axial spacing of the sensor. This work involves designing modulation light source excitation circuits, photoelectric conversion module circuits, pre-amplification differential amplifier circuits, infinite gain bandpass filtering circuits, and window function comparison circuits. This effectively amplifies the defect feature signals and eliminates noise interference. In experiments, the sensor probe is fixed on the support of a micro-displacement measurement platform. By adjusting the distance between the probe and the side surface through rotation, initial tests are conducted using standard roughness samples. The results indicate that installing the sensor probe at a distance of 0.92 mm from the side surface provides better measurement of surface roughness. The oscilloscope waveform reveals that the FOS can identify defects on different bearing surfaces. Furthermore, the bearing surface is divided into sections with engraved text (seal cover part) and without engraved text (inner and outer rings of the bearing). Using computer vision (CV) technology, a FOS detection system is designed, achieving a defect recognition rate of 99% for bearings, in line with the intended design goals.

Conceptual Design of an On-Axis 6 m Space Telescope at the Diffraction Limit: Characteristics, Performance and Advantages

This paper presents the conceptual design of an on-axis 6 metre aperture space telescope designed to cover a field of view of ±0.2 degrees with an optical quality at the diffraction limit within a spectral range between 0.5 μm and 2.5 μm. The plate scale is 3 arcsec/mm, and the overall length is less than 12 m. A Korsch layout has been selected based on the superb aberration compensation offered by Three-Mirror Anastigmat systems. The proposed design presents some characteristics: an almost flat response in RMS wavefront error across the field and for the entire spectral range; a flat mirror has been included to reduce the overall volume, and this has been adjusted to be placed at an intermediate pupil position, acting as a baffle for stray light and as a Lyott to restrict background radiation. This mirror presents a central hole, defined to the aperture of the pupil, allowing the transmission of the beam towards the image focal plane, where it can be split for multiple payloads. It also allows the transmission of the central field, at 90 degrees with respect to the science beam, to be used for Active Optics monitoring and correction of the primary mirror in order to ensure optimum optical performance. This on-axis solution significantly reduces the technical complexity for manufacturing, metrology, integration, and tests and has an important impact in the cost of the telescope.

Impact dynamic response of large aperture space deployable antenna supporting structures based on a dual-scale model

This study investigates the joint damage patterns and changes in shape accuracy of large aperture space deployable antenna supporting structures subject to hypervelocity impacts from micro space debris. Based on the dual-scale method, a joint scale model is constructed for a hexagonal prismatic space deployable truss antenna supporting structure with an aperture of six meters and 37 modules. ANSYS/AUTODYN is used for the impact damage analysis, with an equivalent model of impact force integrating the structure's actual damage characteristics in the structure scale model. The dynamic response and deformation performance of the antenna supporting structure under impact velocities from 2.5 to 15.0 km/s, with spherical space debris of 2.5 mm and 5.0 mm diameters, impacting modular central points in both positive and negative directions, are analyzed. The results show that the primary damage to the joint scale model after impact includes cratering, perforation, punch failure, and joint failure. The debris diameter significantly influences joint damage and deformation of the bolt hole diameter. Additionally, the debris cloud post-impact significantly affects the vertical bar's inner wall, spalling the wall and reducing the rod's strength. As the impact point moves towards the structure's centroid, the antenna's overall response increases. With higher impact velocities, the antenna supporting structure's overall deformation first increases, then decreases. At an impact velocity of 12.5 km/s, the impact area of the structure gradually reduces post-impact. Our proposed joint damage forms and three-case damage classification (no effect, repairable, and joint failure) may serve as a valuable reference for designing structural protection and impact identification for space deployable antennas.

Low-frequency still-air acoustic inertia of inclined circular aperture in an infinite flat plate of finite thickness

The acoustic inertia of the canonical configuration of inclined circular aperture(s) in a finite-thickness plate at the low frequency limit is investigated under the inviscid still-air condition. A hybrid approach combining modal expansion and boundary element method is applied to calculate the effective length of the aperture as a quantitative characterisation of its acoustic inertia. These calculations, covering different inclination angles up to 75°, are performed for a single isolated aperture with a selected range of plate thickness and the periodic aperture arrays of aligned and staggered arrangements with a selected range of aperture spacing respectively. The results are validated by the simulations carried out with the commercial software COMSOL. The parametric studies of geometric dimensions included in this work provide representative results for typical acoustic related engineering applications of finite-length inclined apertures. A link for access to the MATLAB programmes implementing the calculations is provided for interested readers. As an example of application, the hybrid method described in this work is used for the acoustic modelling of a representative multi-perforated liner studied in the literature for the problem of thermo-acoustic instability. The results compared well against those obtained from the Computational Fluid Dynamics simulations reported in the literature.

State-of-the-Art: Integrating Fastener Technology and Design Guidelines for Enhanced Performance of Cold-Formed Steel Sections

Cold-formed steel (CFS) elements have gained significant attention in the field of structural engineering due to their numerous advantages, including high strength-to-weight ratio, cost-effectiveness, and ease of assembly and prefabrication. This review paper presents a comprehensive state-of-the-art analysis of the design and analysis of CFS structures, with a specific focus on columns and beams. The primary objectives and aims of this review paper are to provide a detailed assessment of the factors influencing the behavior and performance of CFS elements, including partial composite action, fastener spacing, bolt arrangement, web aperture, stiffeners, and connection spacing, to propose and present various formulas and methodologies that accurately estimate critical buckling loads, strength, and moment resistance for CFS members, and to emphasize the significance of proper screw and bolt placement in preventing premature failure and enhancing the overall load-carrying capacity of CFS structures. Additionally, the impact of temperature on the mechanical properties and performance of CFS members is discussed. The review paper proposes different formulas and methodologies to accurately estimate critical buckling loads, strength, and moment resistance for CFS members. Moreover, the paper highlights the importance of proper screw and bolt placement to prevent early failure and improve the overall load-carrying capacity of CFS structures. The discussion also emphasizes the need for revisions in existing standards and codes to provide more practical guidelines for designers and engineers. Overall, this state-of-the-art review paper provides valuable insights and recommendations for researchers and practitioners involved in the design and analysis of CFS elements.

The Tianlin Mission: A 6 m UV/Opt/IR Space Telescope to Explore Habitable Worlds and the Universe

It is expected that ongoing and future space-borne planet survey missions including Transiting Exoplanet Survey Satellite (TESS), PLATO and Earth 2.0 will detect thousands of small to medium-sized planets via the transit technique, including over a hundred habitable terrestrial rocky planets. To conduct a detailed study of these terrestrial planets, particularly the cool ones with wide orbits, the exoplanet community has proposed various follow-up missions. The currently proposed European Space Agency mission Ariel is the first step for this purpose, and it is capable of characterization of planets down to warm super-Earths mainly using transmission spectroscopy. The NASA Large Ultraviolet/Optical/Infrared Surveyor mission proposed in the Astro2020 Decadal Survey white paper will endeavor to further identify habitable rocky planets, and is expected to launch around 2045. In the meanwhile, China is funding a concept study of a 6 m class space telescope named Tianlin (a UV/Opt/NIR large aperture space telescope) that aims to start its operation within the next 10–15 yr and last for 5+ yr. Tianlin will be primarily aimed at the discovery and characterization of rocky planets in the habitable zones around nearby stars and to search for potential biosignatures mainly using the direct imaging method. Transmission and emission spectroscopy at moderate to high resolution will be carried out as well on a population of exoplanets to strengthen the understanding of the formation and evolution of exoplanets. It will also be utilized to perform in-depth studies of the cosmic web and early galaxies, and constrain the nature of dark matter and dark energy. We describe briefly the primary scientific motivations and main technical considerations based on our preliminary simulation results. We find that a monolithic off-axis space telescope with primary mirror diameter larger than 6 m equipped with a high contrast coronagraph can identify water in the atmosphere of a habitable-zone Earth-like planet around a Sun-like star. More simulations for the detectability of other key biosignatures including O3, O2, CH4 and chlorophyll are coming.

A High-Precision Real-Time Pose Measurement Method for the Primary Lens of Large Aperture Space Telescope Based on Laser Ranging.

The aperture of space telescopes increases with their required resolution, and the transmission optical systems with long focal length and diffractive primary lens are becoming increasingly popular. In space, the changes in the pose of the primary lens relative to the rear lens group have a significant impact on the imaging performance of the telescope system. The measurement of the pose of the primary lens in real-time and with high-precision is one of the important techniques for a space telescope. In this paper, a high-precision real-time pose measurement method for the primary lens of a space telescope in orbit based on laser ranging is proposed, and a verification system is established. The pose change of the telescope's primary lens can be easily calculated through six high-precision laser distance changes. The measurement system can be installed freely, which solves the problems of complex system structure and low measurement accuracy in traditional pose measurement techniques. Analysis and experiments show that this method can accurately obtain the pose of the primary lens in real-time. The rotation error of the measurement system is 2 × 10-5 degrees (0.072 arcsecs), and the translation error is 0.2 μm. This study will provide a scientific basis for high-quality imaging of a space telescope.

The James Webb Space Telescope Mission: Optical Telescope Element Design, Development, and Performance

The James Webb Space Telescope (JWST) is a large, infrared space telescope that has recently started its science program which will enable breakthroughs in astrophysics and planetary science. Notably, JWST will provide the very first observations of the earliest luminous objects in the universe and start a new era of exoplanet atmospheric characterization. This transformative science is enabled by a 6.6 m telescope that is passively cooled with a 5 layer sunshield. The primary mirror is comprised of 18 controllable, low areal density hexagonal segments, that were aligned and phased relative to each other in orbit using innovative image-based wave front sensing and control algorithms. This revolutionary telescope took more than two decades to develop with a widely distributed team across engineering disciplines. We present an overview of the telescope requirements, architecture, development, superb on-orbit performance, and lessons learned. JWST successfully demonstrates a segmented aperture space telescope and establishes a path to building even larger space telescopes.

Design and analysis of a hoop truss deployable antenna mechanism based on convex pentagon polyhedron unit

Hoop truss deployable mechanism is widely applied in large aperture space antennas. In this paper, an integrated assembling concept is proposed for large aperture hoop antennas. First, a new deployable unit with height difference between inner and outer layer is proposed to combine a novel hoop truss deployable mechanism, and the optimization calculation method of the components are conducted based on the reflective cable mesh profile. Second, the degree-of-freedom (DOF) of the deployable unit and the whole mechanism are calculated based on screw theory, the result showed that they all have only one DOF. Then, the kinematic model is established through Lie bracket operation and screw theory, and the actuation allocation of the mechanism is analyzed. Finally, a prototype of the proposed hoop truss deployable mechanism is constructed, and a deployment test is conducted, which demonstrated the mobility and deployment performance of the whole mechanism. The mechanism proposed in this paper provides a theoretical reference for the integrated assembling of the deployable mechanism and reflective cable mesh, which is potentially valuable in the application of large aperture deployable antennas.

Combined endoscopic treatment of patient with «terrible triade»: decompression of brachial plexus in thoracic aperture and interscalene space and arthroscopic subacromial spacer implantation. Clinical case

BACKGROUND: Brachial plexus injury (plexopathy) is a fairly common problem in neurology, neurosurgery, traumatology and orthopedics. Compression of the brachial plexus usually develops in a narrow anatomical space: in the area of the small pectoral muscle, thoracic aperture, interspinous space. In several cases there is a combination of plexopathy and shoulder joint pathology. In a failure of conservative treatment, surgical intervention such as revision and decompression of the brachial plexus can be used. The development of endoscopic methods of decompression allows the minimization of soft tissue trauma, reduces the risk of complications, and accelerates and facilitates the recovery period.
 CLINICAL CASE DESCRIPTION: Our aim was to describe a clinical case and monitor the results of combined endoscopic intervention in a patient with the "terrible triad": endoscopic decompression of the brachial plexus in the thoracic aperture and interlumbar space and arthroscopy of the shoulder joint with subacromial spacer placement at 6 months after surgery. Patient M., aged 64 years, with the consequences of right shoulder joint trauma: dislocation of the humeral head, damage of the shoulder rotator cuff and development of posttraumatic plexopathy of the right brachial plexus. The patient underwent repeated courses of conservative treatment without any pronounced effect for 1 year after injury. To confirm the diagnosis, the patient underwent electroneuromyography and ultrasound examination of the brachial plexus on the right side and magnetic resonance imaging of the right shoulder joint. After the examination, the patient underwent combined endoscopic intervention: arthroscopy of the shoulder joint with subacromial spacer placement and endoscopic decompression of the brachial plexus in the thoracic aperture and interlumbar space. According to the visual analogue scale (VAS) the intensity of pain syndrome before surgery was 7 cm, 6 months after surgery the intensity of pain decreased to 1 cm according to VAS. According to the disabilities of the arm, shoulder and hand scale (DASH), the degree of upper extremity dysfunction before surgery was 48 points; 6 months after surgery, it decreased to 16 points. The British Medical Research Council scale (BMRC) rated the degree of motor impairment at 3 preoperatively and 0 postoperatively. The degree of sensory impairment according to the Seddon Nerve Damage Rating Scale was 2 preoperatively and 3+ postoperatively. Range of motion in the shoulder joint before surgery: flexion 110, abduction 95, external rotation 15. Six months after surgery: flexion 165, abduction 165, external rotation 45.
 CONCLUSION: The findings allow us to characterize the technique of one-stage arthroscopy of the shoulder joint and endoscopic decompression of the brachial plexus in the thoracic aperture and interlumbar space as low-traumatic and effective, creating conditions for restoration of the shoulder joint and upper extremity function as well as elimination of pain syndrome in the upper extremity.

Design and dynamic analysis of a scissors hoop-rib truss deployable antenna mechanism

As the support mechanism of space-borne antennas, space deployable antenna mechanism belongs to complex multi-closed-loop coupling mechanism, configuration design and dynamic analysis are more difficult than general parallel mechanism. In this paper, an unequal-length scissors mechanism (ULSM) is proposed by changing the position of the internal rotational joint through a basic scissors mechanism. A scissors hoop-rib truss deployable antenna mechanism (SHRTDAM) is constructed by replacing the parabolic rib with the ULSM. Kinematic analysis of SHRTDAM is conducted, and the degree of freedom (DOF) of the whole antenna mechanism is analyzed based on screw theory, the result showed that it has only one DOF. Velocity and acceleration characteristics of SHRTDAM are obtained by the screw derivative and rotation transformation. Based on Lagrange equation, dynamic model of this mechanism is established, the torque required to drive the mechanism is simulated and verified by Adams and MATLAB software. In addition, a ground experiment prototype of 1.5-m diameter was fabricated and a deployment test is conducted, which demonstrated the mobility and deployment performance of the whole mechanism. The mechanism proposed in this paper can provide a good reference for the design and analysis of large aperture space deployable antennas.

Design engineering a walking robotic manipulator for in-space assembly missions.

In-Space Services aim to introduce sustainable futuristic technology to support the current and growing orbital ecosystem. As the scale of space missions grows, there is a need for more extensive infrastructures in orbit. In-Space Assembly missions would hold one of the key responsibilities in meeting the increasing demand. In the forthcoming decades, newer infrastructures in the Earth’s orbits, which are much more advanced than the International Space Station are needed for in-situ manufacturing, servicing, and astronomical and observational stations. The prospect of in-orbit commissioning a Large Aperture Space Telescope (LAST) has fuelled scientific and commercial interests in deep-space astronomy and Earth Observation. However, the in-situ assembly of such large-scale, high-value assets in extreme environments, like space, is highly challenging and requires advanced robotic solutions. This paper introduces an innovative dexterous walking robotic system for in-orbit assembly missions and considers the Large Aperture Space Telescope system with an aperture of 25 m as the use case. The top-level assembly requirements are identified with a deep insight into the critical functionalities and challenges to overcome while assembling the modular LAST. The design and sizing of an End-over-end Walking Robot (E-Walker) are discussed based on the design of the LAST and the specifications of the spacecraft platform. The E-Walker’s detailed design engineering includes the structural finite element analysis results for space and earth-analogue design and the corresponding actuator selection methods. Results of the modal analysis demonstrate the deflections in the E-Walker links and end-effector in the open-loop due to the extremities present in the space environment. The design and structural analysis of E-Walker’s scaled-down prototype is also presented to showcase its feasibility in supporting both in-orbit and terrestrial activities requiring robotic capabilities over an enhanced workspace. Further, the mission concept of operations is presented based on two E-Walkers that carry out the assembly of the mirror modules. The mission discussed was shortlisted after conducting an extensive trade-off study in the literature. Simulated results prove the dual E-Walker robotic system’s efficacy for accomplishing complex in-situ assembly operations through task-sharing.