Space mechanisms needs for future NASA long duration space missions

The capabilities of maximising standard payload modules’ functionalities for applications such as on-orbit satellite servicing or planetary exploration depend critically on the creation and availability of a standard interface (IF). Standard interface should provide, aside from the necessary mechanical interconnections, electrical power and data connections, as well as thermal transfer between “building block” payload modules. The overall flexibility enabled by such IF will allow endless reconfigurations of payload and other modules for different functional requirements. This can be considered a game changer technology, enabling transformation from the current approach to space missions, deploying single-use system with pre-planned and limited functionalities, to a radically new approach with multi-use, dynamically reconfigurable and multi-functional systems. Hence, SIROM aims to set a new research agenda for future affordable space missions. Within this context, the partners of the SIROM (Standard Interface for Robotic Manipulation of payloads in future space missions) project are developing the first standard IF solution that combines the four required functionalities in an integrated and compact form for future space missions. With a mass lower than 1.5 kg and having an external diameter of 120 mm and a height of 30 mm, this novel interface permits not only mechanical coupling but also electrical, data and thermal connectivity between so called Active Payload Modules (APMs), as well as other modules such as the robotic end-effectors. This multi-functional IF features an androgynous design to allow for replacement and reconfiguration of the individual modules in any combination desired. It consists of the following sub-assemblies: mechanical IF, electrical IF, data IF, thermal IF and IF controller. A clear advantage of SIROM design is that its mechanical IF consists of a latching and guiding systems for misalignment correction, capable of withstanding certain robotic arm positioning inaccuracies: ± 5 mm translation and ± 1.5° rotation in all axes. Regarding the electrical and data IFs, SIROM transfers up to 150 W electrical power and provides a data transfer rate of 100 Mbit/s via SpaceWire, plus command communication with speeds up to 1Mbit/s via CAN bus. The thermal IF provides fluidic ports for flow transfer and has the potential to transfer 2500 W between APMs accordingly provided with the corresponding close-loop heat exchange system. Although not envisaged for SIROM current design, a possible variation could be to use these ports for satellite re-fuelling. Apart from that, SIROM exhibits redundant coupling capabilities: it can match and couple another completely passive SIROM. It is provided with main and redundant connectors for thermal, electrical, data and control flow in case of one of the lines fails. All in all, SIROM will enable long duration missions with no logistic support, refurbishing, maintenance and reconfiguration of satellites, cost efficiency and simplification of the tool exchange in scientific exploration missions. SIROM is designed to be a common building block for European and possibly world future space robotics enabled missions.

Formation °ying spacecraft has been identied as an enabling technology for many future NASA and DoD space missions. However, this is still, as yet, an unproven technology. Thus, to minimize the risk associated with using this new technology on future missions, testbeds are required that enable a com- prehensive simulation and validation. This paper presents an innovative hardware-in-the-loop testbed that can be used to analyze estimation and control architectures for formation °ying spacecraft. The testbed consists of multiple computers that each em- ulate a spacecraft in the °eet. These computers are restricted to communicate via serial cables to emu- late the actual inter-spacecraft communications ex- pected on-orbit. All estimation and control algo- rithms are implemented in MATLAB, which greatly enhances its °exibility/recongurability and provides an excellent environment for rapidly comparing nu- merous control and estimation algorithms and ar- chitectures. A multi-tasking/multi-thread software environment is simulated by simultaneously running several instances of MATLAB on each computer. The paper presents the initial simulation results us- ing a highly distributed estimation, coordination, and control architecture for a °eet of 4 spacecraft.

Dr. Charles Dukes is an Aerospace psychiatrist working with NASA’s behavioral health and performance operations group under the human health and performance contract at Johnson Space Center in Houston Texas....

Magnetic resonance imaging (MRI) and isokinetic dynamometry was used to assess lower leg skeletal muscle characteristics from crewmembers (n=9; 45±2 y) that averaged 181-d aboard the International Space Station (ISS). While on the ISS, crewmembers had access to a running treadmill, cycle ergometer and resistance exercise device. The exercise regimen varied among the individuals with groups identified as high treadmill users (HT; n=4) and low treadmill users (LT; n=5). On average, all crewmembers lost 13±2% (p<0.05) of their lower leg muscle mass. HT lost less (p<0.05) muscle mass (8±2%) compared to LT (15±2%). Maximal isometric strength was reduced similarly for all crewmembers (14±2%; p<0.05). Isokinetic strength at six speeds was reduced 20–29% (p<0.05) with no differences between HT and LT. These data show that lower leg muscle volume and strength are significantly reduced after 6 months in space. These data also indicate that the level of treadmill use in space may aid in preserving lower limb muscle mass. Future long duration space missions should consider modifications to the current ISS exercise prescription and/or hardware that would preserve human skeletal muscle mass and function. Supported by NASA grant NCC9-116.

Photoabsorption in Ganymede’s atmosphere

In-situ connectability among modules of a space system can provide significantly enhanced flexibility, adaptability, and robustness for space exploration and servicing missions. Connection of modules in extra-terrestrial environment is hence a topic of rising importance in modern orbital or planetary missions. As an example, the increasing number of satellites sent to space have introduced a large set of connections of various type, for transferring mechanical loads, data, electrical power and heat from one module to another. This paper provides a comprehensive review of published work in space robotic connections and presents the different transfer types developed and used to date in robotic applications for orbital and extra-terrestrial planetary missions. The aims of this paper are to present a detailed analysis of the state of the art available technologies, to make an analysis of and comparison among different solutions to common problems, to synthesize and identify future connectability research, and to lay the foundation for future European space robotic connectability effort and work for a complex and growing important future space missions. All types are described in their base characteristics and evaluated for orbital and planetary environments. This analysis shows that despite the large number of connectors developed for each of the four functionalities (mechanical, thermal, data, and electrical power) here considered, the trend is that researchers are integrating more than one functionalizes into a single equipment or device, to reduce costs and improve standardization. The outcomes of this literature review have contributed toward the design of a future multifunctional, standard and scalable interface at the early stage of the Standard Interface for Robotic Manipulation of Payloads in Future Space Missions (SIROM) project, a European Commission funded Horizon 2020 project. SIROM interfaces will be employed by European prime contractors in future extra-terrestrial missions.

The Astrophysics Data Facility at NASA Goddard Space Flight Center supports the processing, management, and dissemination of data obtained by past, current, and future NASA and international astrophysics missions, and promotes the effective use of those data by the astrophysics community, educators, and the public. Our Multiwavelength Milky Way poster was printed for broad distribution. It depicts the Galaxy at radio, infrared, optical, X-ray, and gamma-ray wavelengths. In particular, the poster contains images of the Galactic 21-cm and CO (J = 1 → 0) line emission, and IRAS 12, 60, and 100 μm, COBE/DIRBE 1.25, 2.2, and 3.5 μm, Digitized Sky Survey optical wavelength, ROSAT/PSPC 0.25, 0.75, and 1.5 keV X-ray, and CGRO/EGRET E &gt; 100 MeV gamma ray broadband emission. All of the data sets are publicly available. Captions describe the Milky Way and what can be learned about the Galaxy from measurements made in each segment of the electromagnetic spectrum. The poster is intended to be an educational tool, one that will stimulate heightened awareness by laypersons of NASA's contribution to modern astronomy.Through an interface available on the World Wide Web at http://adf.gsfc.nasa.gov/adf/adf.html one may view the images that appear on the poster, read the poster captions, and locate the archived data and references.

The potential of spaceborne lidar to monitor aerosol layering and mixing with high vertical resolution is reviewed. An overview is presented on aerosol lidar techniques of past, present, and future NASA and ESA lidar missions. The potential of a standard backscatter lidar (LITE, 1994), a backscatter/polarization lidar (CALIPSO, since 2006), a polarization High Spectral Resolution Lidar (HSRL, ATLID, EARTHCARE), and of a multiwavelength polarization HSRL are discussed regarding their ability to derive height profiles of optical and microphysical properties of aerosols and to resolve aerosol types and mixtures as a function of height. The important role of ground-truth activities is emphasized. Measurement examples taken with ground-based lidars illustrate that these systems provide a detailed characterization of complex aerosol scenarios in contrast to the snapshot-like observations with spaceborne lidars.

Integrated system health management (ISHM) technologies have been developed to address safety, replace time-based maintenance with condition-based maintenance, and to reduce life cycle costs. Traditional space system designs have focused on safety to minimize the risk to crew and to protect the public, astronauts and pilots, the NASA workforce, and high-value equipment and property. Systems have relied on high reliability components to provide the necessary safety margins and avoid operational mission failures. The current vision for future manned and unmanned space missions to the International Space Station, the Moon, Mars, and beyond, will require longer duration missions and will rely on complex assemblages of components. Increased mission duration and complexity increase the probability of operational mission failures that must be mitigated without jeopardizing safety or the objectives of the current or future missions that might reuse critical mission components. ISHM technology will be essential for providing near-real-time assessments of system capability, safety margins, and maintenance and sustainment requirements. The Applied Research Lab has conducted a series of workshops for NASA which focused on defining requirements for integrated system health monitoring and for the integration of health monitoring and control to provide intelligent self situational awareness (ISSA). The results of these workshops indicate that the benefits of ISHM and greater integration between ISHM and control include increased safety and mission assurance, the ability to rapidly respond to system failures, and decreased operator workload. Emerging open system standards such as OSA-EAI provide a framework for integrating system health monitoring with control functionality in spacecraft avionics systems. The purpose of this paper is to describe areas where system health monitoring can impact safety, reliability and sustainment in space applications and present the results of workshops conducted for NASA to identify requirements for the integration of health monitoring and control in future space systems

Among the numerous technological advances sought in order to facilitate human exploration and habitation outside of earth’s atmosphere, solutions and innovations are needed for processing local resources to support sustainable and long duration space missions. Such in-situ resource utilization (ISRU) is aimed at reducing the payload mass during launch and eliminate the need for ground support for long-term missions and ultimately space colonization. One particular need for habitation and deep space exploration is the continuous supply of oxygen for life support and for propellants in the form of liquid oxygen. As mission duration is extended, the availability of a consistent supply of oxygen will become critical. The entire lunar surface is covered by regolith which is approximately 45% oxygen by mass, making it a very large reservoir. However, this oxygen is in the form of metal and mineral oxides. NASA thus recognizes the need to develop approaches to utilize this oxygen and material resource.Faraday Technology Inc. and RoCo Global are addressing this unique challenge by demonstrating the feasibility of an efficient ionic liquid-assisted electrochemical system for oxygen recovery from SiO2 that can be employed on lunar surfaces for oxygen extraction from lunar regolith. Accordingly, Faraday and RoCo Global have successfully: 1) Developed a scalable bifluoride based IL with reduced process complexity that can enable direct solubilization of SiO2; 2) Developed an experimental approach utilizing an electrochemical Liquid-Liquid-Solid (LLS) process [i],[ii] [iii] [iv] for the extraction of oxygen and deposition of Si from the solubilized SiO2 in the bifluoride based IL; 3) Demonstrated feasibility to recover oxygen and electrodeposit Si from SiO2 solubilized in bifluoride based IL electrolyte; 4) Demonstrated feasibility of reutilizing IL electrolyte for multiple SiO2 solubilization cycles; 5) Prepared a preliminary semi-continuous alpha-scale design (Figure 1). Acknowledgements: Financial support of NASA Contract 80NSSC-20-C-0338 is acknowledged.

During long duration space missions, crewmembers are exposed to a variety of incessant noises and acoustic conditions, as well as brief, but very loud, sound levels during launch, descent, and possible abort scenarios. Some common sources of these sounds are payloads (science experiments), ventilation fans, thermal control systems, and equipment within the limited confines of spacecraft (Goodman and Grosveld. Acoustics and noise control in space crew compartments. National Aeronautics and Space Administration, Houston; 2015). Crewmembers have reported that the monotony of adverse acoustic conditions can degrade habitability, especially with inadequate acoustic respite during long duration missions. More specifically, the impact of acoustics on human health and performance during space flight has been associated with disruptions of sleep, interference with speech communications, reduced audible detection of caution or warning alarms, and reduced human performance in demanding tasks. Because excessive noise conditions may also be a risk for temporary or permanent hearing loss, crewmembers must frequently wear hearing protection. In an effort to prevent hearing loss and improve habitability during space missions, multidisciplinary teams have been established to control acoustical noise using hardware design and reviews, acoustical measurements, noise controls, and hearing conservation practices. This chapter offers a summary of the impact of spacecraft noise on human health and performance, as well as options for remediation and crew protection.

Low frequency electromagnetic tomography such as the capacitance tomography (ECT) has been proposed for monitoring and mass-gauging of gas-liquid two-phase system under microgravity condition in NASA's future long-term space missions. Due to the ill-posed inverse problem of ECT, images reconstructed using conventional linear algorithms often suffer from limitations such as low resolution and blurred edges. Hence, new efficient high-resolution nonlinear imaging algorithms are needed for accurate two-phase imaging. The proposed Iterative Nonlinear Tikhonov-regularized Algorithm with Constraints (INTAC) is based on an efficient finite element method (FEM) forward model of quasi-static electromagnetic problem. It iteratively minimizes the discrepancy between FEM simulated and actual measured capacitances by adjusting the reconstructed image using the Tikhonov regularized method. More importantly, it enforces the known permittivity of two phases to the unknown pixels which exceed the reasonable range of permittivity in each iteration. This strategy does not only stabilize the converging process, but also produces sharper images. Simulations show that resolution improvement of over 2 times can be achieved by INTAC with respect to conventional approaches. Strategies to further improve spatial imaging resolution are suggested, as well as techniques to accelerate nonlinear forward model and thus increase the temporal resolution.

This paper describes a program initiated by the NASA Johnson Space Center to investigate vapor‐liquid flow regimes and pressure drops in pipe components and variable gravity conditions. This program supports the Space Station Freedom External Active Thermal Control System design and future space missions, including the Space Exploration Initiative activities. The objectives for this program include studying two‐phase flow behavior in fluid components (smooth pipes, bellows lines, quick‐disconnect fittings), expanding the two‐phase database for zero‐g conditions, developing a database for low‐g conditions (for example, Moon‐g, Mars‐g), and validating models for two‐phase flow analyses. Zero‐g and low‐g data will be gathered using a Freon‐12 flow loop during four test series on the KC‐135 aircraft beginning in August 1991.

Modelling approaches for an ultrasonic percussion drill

During this seminar, I will talk about three of the projects I’ve been involved with at NASA in the last few years: 1. **The Human Exploration Research Analog (HERA)** is a ground-based astronaut analog mission run at NASA’s JSC in Houston to study and evaluate impacts on the crew due to isolation, remoteness, and confined habitation. NASA scientists use the collected data to develop and verify countermeasures to reduce or mitigate psychological and physiological effects for future Deep Space missions. This simulation was a 45-day trip to Mars’s moon Phobos and back with the goal of performing geological operations with complete communications delays in effect. 2. **Astrobee** is a new class of free-flying robots that operates in the interior of the International Space Station (ISS). In addition to being a research platform for microgravity free-flying robotics, Astrobee improves the efficiency of ISS operations by providing flight and payload controllers with a mobile camera and a sensor platform. 3. NASA is developing new deployable structures and material technologies for solar sail propulsion systems destined for future low-cost deep space missions. NASA’s Advanced Composite Solar Sail System (ACS3) uses composite materials in its novel, lightweight booms that deploy from a Cubesat. Data obtained from ACS3 will guide the design of future larger-scale composite solar sail systems that could be used for several deep space exploration missions.