Space Operations

In September 2019, the Interagency Operations Advisory Group (IOAG) Spacecraft Emergency Cross Support (SECS) Working Group presented the SECS Standard Operating Processes and Procedures (SOP) to the annual IOAG conference (IOAG-23). The SOP presents a harmonised approach for emergency recovery support entailing processes and services that reduce response times related to critical emergency situations. The implementation of these services will be achieved by:

The SOP provides guidance to agency Service Users, i.e. any agency mission, current or future, that may require additional support beyond their routine and contingency support, in order to recover from an Emergency Condition that threatens the life of the spacecraft. Initially, support is limited to IOAG member Agencies; however, the support, as defined, has the potential to expand the “service user” and “service provider” base. In addition, the IOAG is surveying interest from Commercial Service Providers for participation. The SECS SOP defines three specific categories of standard support that can be made available by service providers.

The SOP describes the “recovery” services that service providers may perform, covering a wide variety of contingency situations, including:

These services require the support of various branches of a service provider’s infrastructure, namely:

The SOP deals with items of particular interest to mission managers, including what constitutes a spacecraft emergency, radio frequency (RF) licensing, points of contact, and the SECS asset database. As a “Proof of Concept”, various demonstration exercises were performed utilising stations from multiple agencies tracking spacecraft which, although not actually in emergency, require preparation activities in line with a contingency acquisition. Completion of this SOP is a major milestone for this working group. The document focuses on emergency support for robotic missions. The working group plans to expand its scope to encompass emergency support for human spaceflight missions. More information on the IOAG can be found on the following website: https://​www.​ioag.​org. The SOP can be located on the IOAG by following the “Documents” link then the “Public” link, or can be found directly on the website: https://​www.​ioag.​org/​Public%20​Documents/​IOAG%20​Spacecraft%20​Emergency%20​Cross%20​Support%20​SOP.​pdf.

Avanti is a British operator of geostationary communications spacecraft. From its inception in 2002, the company evolved into a significant regional operator (Fogg et al. [1]), which continues to be at the forefront of technological advancement in the industry. Nimbleness to relocate its satellites in order to respond to shifting business needs is part of Avanti's success story. Satellite relocations are non-routine operations that—by their own nature—raise more risks than the routine activities. Avanti has developed a framework to assess the operational and regulatory risks associated with these operations and mitigate them through careful planning and meticulous execution. In our experience, regulatory requirements often translate into operational constraints, and operational risks often require regulatory support for an effective mitigation. For this reason, safe non-routine operations require transparency, clear communications, and a cooperative mindset among all teams. Similarly, communications to third parties is crucial to ensure the safety of non-routine operations. Disseminating operational products to fellow operators, watchdogs, and service providers allows Avanti to mitigate both the risk of close approach and the risk of radio-frequency interference. Avanti happily shares its experience in order to foster collaboration among players, promote industry best practices, and contribute to the safety of the space environment.

Launched on a Delta IV-Heavy rocket from Cape Canaveral on August 12, 2018, NASA’s Parker Solar Probe (PSP) will travel closer to the Sun than any other spacecraft. PSP is designed to complete 24 solar encounters over its seven-year mission. During the 24 orbits, PSP gradually shrinks its orbit around the Sun, coming as close as 3.83 million miles using a series of seven Venus flybys. The spacecraft will explore the inner region of the heliosphere and perform in-situ and remote sensing observations of the magnetic field, plasma, and accelerated particles. The spacecraft was designed and built by the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, where mission operations are currently conducted. This paper describes the development and execution of the mission operations “Orbit-in-the-Life” and early operations mission simulations performed using the spacecraft during thermal vacuum testing. The author will first discuss selection and organization of activities and events to be tested and effects of the spacecraft engineering team’s desire to use mission operations tests to also perform spacecraft performance requirement testing. Next, the author will discuss selecting the orbit to be performed during the “Orbit-in-the-Life” test and the challenges for condensing a one-hundred-and-twenty-day orbit into a ten-day test. Then, preparing for the test, including executing an accelerated version of the orbit planning process with the four instrument teams and pre-testing the tests using the hardware-in-the-loop simulator will be described. Last, executing the test will be discussed including dealing with anomalies and lessons learned.

Since 1995, Canadians and international users have benefited from the high-resolution imagery captured by three generations of RADARSAT satellites: RADARSAT-1, RADARSAT-2 and the RADARSAT Constellation Mission (RCM). RADARSAT imagery is used for coastal water surveillance, ice formation in shipping lanes, disaster zone observation and ecosystem monitoring. The technology incorporated into these satellites has progressed over the past two decades. Significant technological advancements were made between RADARSAT-1 and its successors: RADARSAT-2 and RCM. The constellation of three RCM satellites has significant differences over its predecessors: RADARSAT-1 and RADARSAT-2. With three equally spaced RCM spacecraft on the same orbital plane, imagery of Canada and large maritime areas of the coasts can now be acquired daily instead of every three days. The orbit of the three RCM satellites is controlled within a 120-m tube in order to provide Coherent Change Detection (CCD) and Differential Interferometric SAR capabilities. The length of the SAR antenna has been reduced from 15 m to 7.5 m and the size of the solar panels and batteries have been reduced significantly because of evolving battery technology and more efficient solar cells. Another significant difference is RCM satellites include Automatic Identification System (AIS) receivers in order to track ship traffic in maritime regions, where the AIS-generated data can be correlated with the SAR images to identify ships of interest. Ground control of all three generations of RADARSAT satellites is based at the Saint-Hubert (SHUB) mission control facility at the Canadian Space Agency (CSA) headquarters at Saint-Hubert, Quebec, Canada. RCM operations are performed at a newly constructed Primary Control Facility (PCF) that includes image order handling, mission planning, flight dynamics, satellite control, image product generation and image quality subsystems. Independent S-band and X-band ground stations have been available for RADARSAT-1 and RADARSAT-2; however, RCM Canadian Ground Stations have been upgraded for simultaneous S-band and X-band communication. In order to receive and process AIS data and augment SAR imagery in Canada's maritime regions, two additional ground terminals have been established by the Canadian Department of National Defence. This paper will compare and contrast the three generations of RADARSAT satellites and provide overviews of their designs. It will also summarize the evolution of the Ground Segment, and how technological advancements and lessons learned have impacted the concept of operations for this new fleet.

The Psyche Mission is a mission to the asteroid “(16) Psyche”, featuring three science instruments and gravity science. (16) Psyche, located in the asteroid belt between Mars and Jupiter, will be the first potential metal world—instead of rock or ice—visited by the National Aeronautics and Space Administration (NASA). This Jet Propulsion Laboratory (JPL) managed mission will explore Psyche for 21 months after an earliest launch date of August 2022 and a 3.5 year cruise. In this paper, the End-to-End Information System’s (EEIS) concept, architecture, and the Consultative Committee for Space Data Systems (CCSDS) standards implementation of Psyche are studied and analyzed for fulfilment of mission requirements and for satisfaction of operational constraints. The EEIS is a virtual system comprising distributed data system functions through the subsystems. The system is defined by how the flight, mission, and launch systems work together to enable Psyche’s data flows (uplink, downlink, spacecraft, and ground), as well as validate, account for, process, distribute, and store Psyche’s data. This data includes spacecraft commands, spacecraft health, and instrument science data. EEIS Engineers are specifically responsible for the concept formulation of the information system, its design architecture, as well as implementing the CCSDS standards in the flight to ground interface from a high-level project system engineering perspective. This includes evaluating the mission’s operational constraints and requirements, as well as inherited mission infrastructure. Criteria for evaluating mission information include the quantity, quality, latency, and continuity (QQCL) of the data. In this paper, the Psyche EEIS will be evaluated in relation to these four criteria. Thus, this paper focuses on: the driving EEIS design requirements based on program, project, science, and operability requirements; the views and analysis of the EEIS conceptual design; the CCSDS standards implementation; and the EEIS layered architecture comprising its data flows, flight assets, mission operations system (MOS), ground/science data systems (SDS), and multi-mission services. The possible advantages and limitations of the Psyche EEIS architecture and suggestions for future space missions are also discussed.

With a voice command or a few taps on the console, the spacecraft pivots on a dime at high velocity and gently docks to an orbiting space platform. This is the image most people have of the complex software computations and integrated hardware performance necessary for a spacecraft to successfully perform an automated launch, rendezvous, and docking. Today’s reality is that while computer operations are advancing rapidly, science fiction over-simplifies and over-sells current capabilities. This paper discusses the integration of spacecraft computer automation into the operation of one of the United States’ new Commercial Crew vehicles—the Boeing CST-100 Starliner. Lessons learned by the Boeing Mission Operations team, a unique private–public partnership with NASA, from conceptual design through real-time operation of the first test flight will be discussed along with evolution of the system to prepare for the second uncrewed test flight. Focus will center on how operations have learned to use the automated software to their advantage while also knowing how to adjust the automation in response to spacecraft anomalies. One goal of advanced spacecraft automation is the ability to reduce both the crew workload and the ground control footprint while at the same time increasing spacecraft and mission flexibility. Historically, crewed spacecraft required many operators on the ground to use a plethora of tools to compute nominal and contingency mission trajectories. Moving those sophisticated software tools to being onboard the vehicle can reduce the need for such complex ground support. Given that today’s spacecraft software is not yet as capable or as flexible in all circumstances as the computers depicted in movies, there is usually a trade-off between software automation cost and the flexibility of that software resulting in compromises between what is performed on the spacecraft and what is left to onboard crew or ground control. An additional challenge discussed in this paper is the added complexity when the system is still evolving in a developmental program. For missions that go beyond the Moon, software that autonomously controls nearly every aspect of a crewed mission will become a necessity, given the long-time delays between the spacecraft and Earth’s ground control teams. The lessons learned by Boeing and its Mission Operations team, through the design and implementation of Starliner’s hardware and software automation, will be able to inform future public and private spacecraft design. As the technologies and capabilities evolve, incorporating lessons learned in successful low Earth orbit commercial crew vehicle missions, spacecraft designs will continue to improve and be able to better enable safe execution of human missions to the Moon and beyond.

The launch of SpaceX’s Crew Dragon Demo-2 Capsule generated a wave of new technology and inspiration for innovation within the space industry, especially in function and design. One major difference observed by those that watched the launch was the prominent use of a touch screen console. The question this research addresses: are touch screen consoles superior to those that use mechanical switches and controls? With implementing new technology, concerns have been made about both the safety of the new design and its efficiency. Through the utilization of journal articles and public information released by space agencies, this research focuses in survey of current and past console design through an industrial engineering lens. As there are many factors to consider that are atypical to traditional touch screen when considered for use in a spacecraft including g-forces, vibrations, redundancy requirements and user traditionally wearing multi-layer protective equipment, many aspects of the usefulness were evaluated. Additionally, assumptions about current technological advancements like autonomous navigation are considered being a part of the ultimate spacecraft system. Recommendations on how the console design should be conducted in the future are included in this paper. Ultimately, it is determined that a hybrid solution would be the best path for a dual-fault tolerant system. This would allow for the infusion of technology, enabling a more diverse space traveler, while prioritizing safety in this path of exploration and operations.

The Ten-Year Innovation Plan (2008–2018) of the Department of Science and Innovation (DSI) identified space science and technology as one of the five grand challenges for South Africa to become a key contributor to global space science and technology, with a National Space Agency, a growing satellite industry, and a range of innovations in space sciences, earth observation, communications, navigation, and engineering. The South African National Space Agency (SANSA) was established in 2008 and opened its doors to serve humanity on April 1, 2011. SANSA absorbed the Council for Scientific and Industrial Research (CSIR) Satellite Applications Centre (SAC) and the National Research Foundation (NRF) Hermanus Magnetic Observatory (HMO). Two SANSA divisions, Space Operations, and Earth Observation (EO), were created from CSIR SAC at Hartebeeshoek (HBK) and Pretoria, respectively. The SANSA 2015–2020 Strategy identified strategic goal 3 to develop national human capacity and ensure transformation of the South African space sector. SANSA’s EO established the Science Advancement Services (SAS) unit in January 2013 in order to develop and implement the National Space Awareness Programme (NSAP) to stimulate youth interest in science. The DSI established the Science Engagement Strategy (SES) in January 2015 to develop the national science engagement programme. The SANSA NSAP is aligned to the DSI SES objectives. This paper reflects on the national achievements of the SANSA EO SAS NSAP spanning the period of 2013–2014 to 2019–2020. The paper reflects on the impact of the DSI SES on the SANSA EO SAS NSAP activities, the achievement of national footprint during National Science Week 2019, and the importance of developing youth entrepreneurial mindset in science, technology, engineering and mathematics (STEM) education. Last, this paper showcases the alternative approach for sustainable space awareness in the 52 districts of South Africa and the Human Capital Development Pipeline Model that forms the connecting bridge between learners in the school system and the professionals in the space industry.

More and more countries are operating their own national satellites. In recent years, states like Peru, Angola, Bangladesh and Qatar have launched their very first satellite missions. Many of these states aim for multiple socio-economic benefits: the mission tasks typically cover disaster management, agricultural monitoring, water management, fisheries and national security. With their own ground stations and a mission control system, the corresponding national institution can fully control such satellites after launch. A problem that emerging space nations often face is that of knowledge transfer to their respective local industry and academia, especially in the area of onboard computers, onboard software and operations. In 2016, the University of Stuttgart and the University of Cape Town (UCT) decided to strengthen and deepen the cooperation in research and education in the field of space sciences and technologies between both institutions. This partnership, supported by additional industrial sponsors Cobham Gaisler, Sweden and Terma B.V Netherlands, and Airbus, provided UCT with a fully representative satellite simulation, a digital twin of the “Flying Laptop” mission. This comprises the simulator, the flight software and a real mission control system—namely the Satellite Control and Operation System CCS5. The CCS5 runs together with the spacecraft simulation software on a single high-performance workstation. The third application is the flight software development environment. Multiple monitors allow users to simultaneously display the different parts of the simulation as it is running: The Airbus simulator SimTG (Simulator Third Generation) itself, the hardware emulator for the onboard software called TSIM, and a visualization of the satellite in orbit. This equipment enables now satellite software development and operator training at UCT. For UCT, this is a significant step in academic excellence, research and development (R&D) and innovation and capacity building in the field of space sciences and technology. Students who gained experience at Stuttgart University and further insights from Airbus Defense and Space in Fridrichafen will perform the training in Cape Town. This ensures that the personnel in Cape Town will be fully trained in the system’s operation. In addition, phone support from experienced Airbus engineers is available. At the time of writing this abstract, the system is being established. The team at UCT will simulate a flight scenario which covers vegetation monitoring using optical payload instruments and a detailed explanation on how to model a satellite and its subsystems and the effects of the simulator on local capacity growth. This will be an impactful demonstration of South African academic competence in mission operations and spacecraft modelling.

In order to better support the Telemetry monitoring of both current and future missions at EUMETSAT, flight control teams have developed semi-supervised Outlier Detection algorithms which compliment traditional monitoring techniques such as Out of Limit Monitoring. This Outlier Detection has now been in use for several years. Through the process of developing and utilising the Outlier Detection algorithms, it has been found that the main challenges are not related to the choice, tuning or development of the algorithm. Instead, they are related to the more practical aspects surrounding the presentation of results, choice of parameters to be monitored, filtering of results and the labelling of Nominal Data. Moreover, these practical problems are largely algorithm independent and so once an adequate algorithm was developed, it was realised that chasing a better algorithm before these practical had been addressed would simply lead to a delay in the use of this technique. This paper discusses the Outlier Detection algorithm and its development, but the main focus is on the lessons learned from this process which led to the identification of practical problems and solutions to them. In particular, the Outlier Detection results are presented in a way which allows users to understand why outliers have been flagged, which minimises the “Black Box” effect. This, however, implies limiting the number of dimensions used when performing Outlier Detection. Another issue observed was floods of outliers being reported during non-nominal operations or anomalies. Not only does this mask real issues, but being since Outlier Detection is a relatively new technique, it also serves to erode trust in the process. This has mainly been resolved by a conditional Outlier Detection method which has been developed by categorising parameters hierarchically as Influencers and Followers, and also by careful selection of parameters. Finally, the main sticking point for any semi-supervised Outlier Detection techniques is keeping up to date with the labelling of Nominal Data. Again, this is partially addressed through careful selection of parameters in order to avoid having too many datasets to maintain, however it is the one area where development is still on-going within EUMETSAT, and so this paper describes the future plans to facilitate the labelling of Nominal Data.

This paper presents some research works based on the PhD thesis of B. Pilastre (B. Pilastre, Estimation Parcimonieuse et Apprentissage de Dictionnaires pour la détection d’Anomalies Multivariées dans des Données Mixtes de Télémesure Satellite, PhD Thesis of the university of Toulouse, Nov. 6, 2020.), supported by CNES and Airbus Defence & Space, on a new Anomaly Detection algorithm based on a sparse decomposition into a DICTionary (ADDICT). The proposed method addresses two main challenges related to anomaly detection for satellite telemetry parameters, namely the multivariate processing of these parameters and the mixed continuous and discrete nature of the data. Different variations of the ADDICT algorithm, referred to as C-ADDICT and W-ADDICT, have been investigated differing by the data decomposition term defined using a linear combination of the atoms or its convolutional equivalent. The resulting ADDICT, C-ADDICT and W-ADDICT algorithms have been evaluated on a small representative dataset containing satellite anomalies with an available ground-truth and have shown competitive results with respect to the state-of-the-art. They have also been tested on industrial use-cases, especially regarding online processing (i.e., sequential learning taking into account the feedback of users). The results of these tests are presented in this paper.

The paper introduces the Health Monitoring System (HMS) for the European Space Agency (ESA) Euclid mission. Euclid, due for launch early 2023 and implementing an extragalactic sky survey relies on tight monitoring of its instrument performance in order to understand and prevent systematics. This requires not only access to a single data source as HouseKeeping Telemetry (HKTM) but also to other input sources that can allow to perform data correlation and cross-matching. The HMS, part of the Science Operations Centre (SOC), covers use cases for the off line monitoring of the health and performance of the instruments but also is a key component in the generation of the entry products for the scientific processing in the mission. It allows storage, access and analysis of time based parametric data and is designed using as baseline the ESA’s Analysis and Reporting System (ARES), that provides support for storage, analysis and display of many types of operational house-keeping time based data series. The simplicity of the system architecture and data enhancement is the key for its strength. This concept is being explored by other mission’s Science Operations Centres, as BepiColombo, XMM or PLATO, thus hinting new avenues and use cases where cross mission data can be easily exchanged. The paper shows how synergies across different operational areas at ESA create tools and use cases that provide overall added value. HMS is heavily based on excellent collaboration across ESA’s Directorates, and merges know-how and technologies from different operational environments (Mission and Science) into a wider system. The paper will describe the concept and technology of Euclid’s HMS and ARES, the data sources, structures and interfaces, and the different operational use cases, focusing highly on the novelty of its use at a Science Operations Centre.

The 16th of July 2019, the ESA’s Gaia satellite started his first mission extension after 5 years of producing operational observations (since 25th of July 2014). This mission is the successor of Hipparcos ESA’s satellite with the same objective of publishing a catalogue of stars and objects (galaxies, asteroids, etc.) but up to 1 billion objects (against 2.5 million). Gaia catalogue will determine the position, the distance and the movement of each object. To achieve this goal, a consortium, called DPAC, has been created to process all the satellite’s data composed of more than 450 people mostly in Europe (including scientists and engineers). 9 Coordination Units (CU) corresponding to dedicated themes and 6 data processing centres (DPCs) have been created. CNES is in charge of 3 scientific CUs (with 7 scientific pipelines) in operations, called DPCC. CNES is in DPAC an important DPC. The first catalogue has been released in September 2016, based on the first year of Gaia observations (2014/2015). The second catalogue has been published on the 25th of April 2018. Over one billion of sources have been processed. Operations are ongoing to prepare the third version of the catalogue (with an early release containing astrometric positions and photometry published on the 3rd of December 2020). This new version of the catalogue will include three years of Gaia observations. All CUs will produce data and the existing scientific algorithms will be improved. This catalogue will be available for the entire scientific community in 2021. DPCC will manage the processing of all delegated CUs for the first time, meanwhile performing daily operations, in a limited time.

Within the Operations Directorate large amounts of data are produced daily. Their proper visualization is the bridge between the quantitative information in the data and the human intuition and understanding. The Space Weather System in Space Safety Programme produces huge amounts of data products from hundreds of sensors on ground and in space, based on which the Space Weather forecasters make qualitative and quantitative nowcasts and forecasts. Despite the constantly advancing numerical simulation techniques and advanced analysis of the data, human interpretation of the outputs is still pivotal in providing good forecasts. Intuitive data visualisation tools are one of the key techniques to improve their accuracy in the near future. Today, the main means of visualization are 2D graphs projecting the propagation of heliospheric plasma on two orthogonal planes. In this paper, we present the proof-of-concept prototype we have implemented where historic data of Coronal Mass Ejections come to life in an interactive tool based on a Virtual Reality game engine. Employing VR technology, we offer an immersive experience to the forecaster and support educational and promotion activities. The 3D visualisation tool is an innovation that brings new technology in SWE forecasting closely linked to mission operations in ESOC.

In the recent years, the “Program for INteractive Timeline Analysis” PINTA, developed at the German Space Operation Center (GSOC), was continuously improved and experienced several evolution steps. PINTA is a GUI application running on Windows-based computer systems, whose main purpose is to serve as the anchor tool for a mission planning operation’s engineer when generating, modifying or analysing a mission timeline. This is supported by calling automatic planning algorithms of the embedded generic planning library “PLAnningTOol” PLATO, using input of the embedded orbit propagation and event calculation library “SpaceCraft Orbit and GroundTrack Analysis Tool” SCOTA, or its expandability through plugins. PINTA is the generic basis of many semi-automated mission planning systems for past, current and future spacecraft projects operated at GSOC. It is used or has been used for the missions Grace, TET-OOV, FireBird, Grace-FollowOn, Eu:CROPIS and is currently prepared for CubeL. Furthermore, PINTA serves as the timeline analysis tool for validating the TerraSAR-X/TanDEM-X mission planning system. The variety of use cases was further extended to support Launch and Early Orbit Phases (LEOPs) in its special “SoEEditor” configuration as the new generic editing tool for the so-called “Sequence of Events”. It was successfully used for the satellites Biros, HAG-1, PAZ, Grace-FollowOn 1 and Grace-FollowOn 2, Eu:Cropis, EDRS-C and is currently in preparation for EnMAP. In addition to LEOP’s, the SoEEditor was also capable of supporting the constellation maneuvers for the TerraSAR-X/TanDEM-X mission. Besides all these use cases, the paper at hand will especially describe how PINTA was even further extended to not only tackle spacecraft-based but also ground-based scheduling. On the one hand it serves as an “On-Call Tool” to support the on-call shifts by automatically generating conflict-free role-based shift plans for all subsystems by considering various constraints like person outages, working hours, role-conflicts, etc. The plan can then be further adapted manually to cope with user change-requests. On the other hand it is used as a “Multi-Mission-Control-Room-and-pass-Scheduler” (MuMiCoRoS) to coordinate the ground-station booking of all LEO (low-earth orbit) satellites: TerraSAR-X, TanDEM-X, TET, Biros, Grace-FollowOn 1 & 2 and Eu:CROPIS. In order to avoid ground-station and operator conflicts between the missions, an automatic and combined plan for all satellites is generated which can then be further modified manually if necessary. As another use case, PINTA (a.k.a. GPT; Galileo Planning Tool) supports the Galileo Service Operation (GSOp). The planning process involves three timelines: a Short-Term Plan (STP), covering the next ten days, two Mid-Term Plans (MTP) for the Operational (OPE) and the Validation (VAL) chain), covering the next 15 weeks, and a Long-Term Plan (LTP), covering the next 15 months. The activities in these timeframes cover all subsystems of Galileo: Flight Ops, Control segment, Mission segment, remote sites, service operations, hardware, software, hosting, network, etc. In order to support the GSOp, numerous additional features, like importers, exporters, interfaces and plugins had to be added to PINTA.

Combining the output signals from two or more ground station antennas can increase the gain of the received signal, providing the critical flexibility to increase the science data rate from space missions. NASA’s Near Space Network (NSN) has developed a gigabits/sec high rate antenna arraying system, based on the coherent combination of signals derived from multiple directive antennas. This arraying system is called the “High Data Rate Signal Combiner (HDRSC).” This arraying design approach/technology has been used previously at very low data rates. This work, however, focuses on gigabits/sec high rate antenna arraying system architecture. When coherently combining just two signals there is ideally a doubling of power, i.e., a 3 dB signal-to-noise improvement. Arraying of small antennas can easily outperform a single large aperture antenna not only in radio-frequency performance but also in a substantial reduction of cost. This paper covers the design transition for the arraying approach from post- to pre-detection, hardware architecture starting from separate and distinct analog-to-digital converters to integrated tiles within a single semiconductor chip package, a rigorous and evolving test philosophy, and results.

Communication networks are prone to disruption due to inherent uncertainties such as environmental conditions, system outages, and other factors. However, current communication protocols for state-of-the-art disruption-tolerant networks (DTNs) designed to withstand such conditions are not yet optimized for high performance over long distances, such as those encountered in deep space. Current DTN communication protocols have been documented in the literature as inherently assuming relatively low levels of signal loss, not accounting for end-to-end error rate, and presuming a lack of performance constraints governing optimal communication function. However, these assumptions and constraints frequently do not hold true outside of theoretical scenarios; therefore, there is a need for an improved communication protocol that has the ability to minimize data loss to tolerable levels over an unstable and error-prone communication link. Furthermore, any novel communication protocol should also be able to optimize transmission time: this is because current communication networks for parts of space prone to signal disruptions, particularly deep space, are fairly slow and have a low data rate, since transmitters have to trade speed for accuracy when transmitting data at a particular power level directly from deep space to Earth. Bundle protocol (BP) is an experimental protocol for handling packet transmission through DTN networks that has a number of vocal proponents in the academic and the aerospace community; however, as noted by authors of the protocol, there are a number of key areas of concern associated with BP approach, including, but not limited to, high vulnerability to denial of service (DoS) attacks and issues efficiently handling congestion and flow control schemes implemented across highly variable delay environments. BP, as a protocol which “sits at the application layer of some number of constituent internets”, also utilizes internet protocols such as Transmission Control Protocol/Internet Protocol (TCP/IP) and similar alternatives to handle lower-level management of data transfer, and thus inherits the limitations associated with the implementations of such approaches (as well as those that emerge at the interface of protocols at each level), creating further vulnerabilities for potential exploitation by nefarious agents or reductions in system performance due to poor environmental conditions. This work concerns the development of a novel protocol for data transmission across delay/disruption-tolerant networks, which is presented as an alternative to the bundle protocol standard. The alternative proposed herein seeks to address some of the limitations seen in bundle protocol and provide a DTN networking option with wider usability, better reliability, and improved immunity to DoS attacks. In particular, the efficacy of the proposed approach, in terms of maintaining both data integrity and transmission speed, was evaluated via simulation against BP and a set of other alternative DTN data handling methodologies from the literature and demonstrated a statistically significant improvement in performance compared to BP and other canonical communication protocols. The result is presented herein in terms of its ramifications for future DTN implementations.

Compact and inexpensive Earth observation satellites in low Earth orbit are now routinely developed by universities, “New Space” businesses, and space agencies. They enable new opportunities for fast turnaround times of imaging data takes, which is e.g. particularly important for disaster response. For this kind of satellites and the missions enabled by them a ground system exhibiting the same characteristics, namely being compact and mobile, yet inexpensive and flexible, is desired. We present DLR’s approach for the provisioning of a ground segment fit for these kinds of “Responsive Space” missions. The objective of this project consists of the engineering, delivery, and demonstration of a compact and yet complete Mission Operations System, runnable on commodity mobile hardware, enabling fully automated workflow-driven operations of alike missions from anywhere in the world with access to a ground station or ground station network. Just as disasters strike suddenly, the ground segment needs to be set up and spun up in a timely manner. This leads to the requirement of being able to quickly roll out the system on new hardware, possibly even several of these systems in parallel. Our paper provides insight on how we perform the automatic deployment and provisioning. Because the system is supposed to be decentralized and used in the field, particular challenges need to be overcome resulting from the lack of all of the infrastructure typically present in conventional control centers, such as network connectivity. An embedded Flight Dynamics System is taking care of automated orbit determination and related event generation to support the mission needs and maneuver capabilities. Special effort is made to cope with auxiliary data that may not be updated on a regular basis in a closed mission environment. The feasibility of the concept is demonstrated by a first system deployment as drop-in replacement for the existing conventional Mission Operations System for DLR’s BIROS satellite at the GSOC control center. A second demonstration campaign is performed from a remote location without access to control center infrastructure.

The Consultative Committee for Space Data Systems (CCSDS) presents several standards and informational reports concerning the security of the space to ground data link, in particular through the specification of a Space Data Link Security (SDLS) Protocol, which enables authentication and encryption for missions utilising standard Space Data Link Protocols (SDLP). SDLS Extended Procedures (EP) specify services, procedures and data structures to manage, monitor and control associated security primitives. A flexible and representative test environment is required in order to assess the suitability of these protocols and also of standard terrestrial secure communication technologies in order to de-risk and promote their uptake for future missions. This paper presents work undertaken to design and implement a representative testbed laboratory for the testing of CCSDS secure protocols and the suitability of IP-based terrestrial network and security components for protection of the space datalink and improved communications flexibility. The developed Secure Communications Laboratory (SEC_LAB) is a virtual testbed which simulates a real space link based on ESA’s mission control (MICONYS) and test and validation (TEVALIS) software infrastructure. Several use cases, tests and scenarios have been explored and quantified test results provide insights and recommendations. The feasibility of utilising encapsulated terrestrial networking technologies including encapsulated IP/IPSec over CCSDS protocols, Virtual Private Networks (VPN), Software Defined Networking (SDN) and host fingerprinting is demonstrated. Several lightweight encryption and authentication algorithms are tested to measure overheads and performance impacts, identifying the symmetric block ciphers SPECK and Advanced Encryption Standard (AES) as suitable options. Optimization of on-board processors for particular algorithms is identified as a potentially important factor. Simulated disruption tests indicate that terrestrial protocols are susceptible to disruption, in particular those with handshake authentication operations. Throughput testing for implementations of Galois/Counter Mode (GCM) and Cipher-based Message Authentication (CMAC) indicate optimal sizes for Telecommand (TC) and Telemetry (TM) transfer frame throughput. SDLS EP procedures are validated and a number of risks and mitigation measures are discussed. The output of the activity supports de-risking and informed decision making for investments in adapting existing control systems and securing the data link, thereby addressing a key security threat for future space missions. Next steps and potential future work in the domain include maturation of the testbed and implementation and testing of secure protocols for the next generation of mission control software (European Ground Operations System–Common Core (EGS-CC)).

The onset of the COVID-19 pandemic brought a dramatic and rapid transformation to almost every aspect of humanity. The world’s space agencies and their missions were not immune to the wide-sweeping changes. One discipline principally affected was mission operations and the various groups supporting that function. Mission support teams, especially for complex and crewed missions like the International Space Station (ISS) were forced to rethink how and where control center staff performed their vital work. Operations training—an essential element to mission ops, had unique hurdles to overcome. Operations training is responsible for preparing astronaut crews for their missions, training and certifying flight controllers, as well as ensuring that new team members are ready to join their colleagues. Every element of training was impacted during the pandemic. From orientation and introductory classes for new controllers, simulations, and advanced lessons, On the Job Training (OJT) and final evaluations; all aspects faced challenges. Trainers at NASA’s Marshall Space Flight Center in Huntsville, Alabama were forced to become more efficient with trainees and resources to continue supporting ISS payload operations. The pandemic arrived in the USA in March 2020. Immediately, NASA mandated that the support for ISS real-time operations was critical. As a result, physical access to key facilities was restricted. Trainers and trainees had to quickly shift to 100% remote learning. In the short term, this was not a problem. However, instructors discovered lessons they were accustomed to delivering in a classroom environment often did not translate to remote teaching. Another hurdle to operations training was the mandate that all simulations could only be held remotely. The logistics of even small simulations proved to be challenging due to Information Technology (IT) restrictions and public internet limitations. With simulations essentially halted, as well as the restrictions on most OJT, trainees were essentially stopped in their advancement towards certification. Once limitations were identified, trainers prioritized new options. Transitioning to all electronic learning materials was a relatively easy fix. Teaching to large groups took additional shifts in the training paradigm. Methods for preparing astronauts for their missions were revised. Simulation supervisors found efficient techniques to provide realistic training experiences. Communication and coordination with management was essential. In every case, the payload operations instructors found novel solutions to all functions listed. This paper discusses the factors and solutions payloads operations trainers found to keep scientific research on the ISS flying forward to mission success.

The two satellites for the GRACE (Gravity Recovery And Climate Experiment) Follow-On mission were successfully launched in May 2018 into a polar orbit at an altitude of 491 km. Its predecessor GRACE was operated by the same partners from 2002 until 2017). The mission continues the measurements of the gravity field of the Earth (with emphasis on the time variability) and also delivers radio occultation measurements. The twin satellites are kept at a relative distance of 170 to 270 km and act as probes in the gravity field of the Earth. The inter-satellite distance is measured by a microwave tracking system to an accuracy of 1 μm. A laser ranging interferometer is added as a technology demonstration. Stable and accurate relative pointing, as well as the minimization of disturbance torques, is required in order to optimize scientific results. This poses stringent demands upon attitude control. The performance of the GRACE Follow-on attitude control system will be presented, as well as the special actions and changes that became necessary as the mission evolved. A short description of the sensors and actuators used for attitude control is given and improvements with respect to GRACE are discussed in some more detail. The operational modes are described with a focus on the so-called nominal fine-pointing mode, in which the front ends point towards each other in order to enable microwave- and laser-ranging. The third section opens with a description of special tasks, such as the fine-tuning of the control and monitoring parameters and the complex determination of the satellite’s center of gravity. A comparison is made with a tracking model based upon the fuel expenditure from the two tanks that can be determined independently. Several series of involved tests with manual thruster firings were performed in order to characterize the response of the accelerometers to thruster actuations. A description of the design of the tests, their execution and results is presented. A switch to the redundant instrument was made five months after launch on one of the satellites. The consequences for attitude control are discussed in Sect. 4. A method that was developed to cope with a situation where also the redundant GPS receiver would become unavailable is discussed in detail. Conclusions and an outlook for the upcoming years of operations are presented in the last section.

Ariane 6 is the next heavy European launch system of the Ariane family. It is being developed with the objectives to provide users with high mass performance, mission versatility, operational flexibility, high launch rate and low launch service cost. The flight segment (Launcher System), the ground segment (Launch Base) and the whole Launch System Architecture have already performed the respective Critical Design Reviews. ESA, in its role of Launch System Architect (LSA), is in charge of ensuring the coherence between the Launcher and the Launch Base, validating the Launch System performances and verifying the Launch System requirements so as to reach the above-mentioned objectives. With this goal, the LSA (ESA), the Launcher System Design Authority (ArianeGroup) and the Launch Base Design Authority (CNES) work together on building up an optimised launch operations plan to be validated during the so called Ariane 6 Launch System Combined Tests. The Combined Tests bring together the Ariane 6 Launcher, its Launch Complex and the Launch Range for the first time. The intended test sequences cover one by one all the operations and system configurations (including degraded cases) encountered during the launch campaigns. They will end with the launch facilities revalidation and reconfiguration in view of carrying out the Ariane 6 Maiden Flight. This paper presents the operational logic established to perform the Ariane 6 Combined Tests, the related Launch System, Launcher System and Launch Base tests objectives and the rational for the selected test sequences. The preliminary combined tests, dubbed “Early Combined Tests”, which main objective is to mitigate specific risks before the first interfacing between the Launcher Combined Tests Models and the Launch Complex, will be also presented as well as the specific adaptations of the Launch Complex in order to be able to carry out the Combined Tests.

The Spectr-RG space observatory was launched from Baikonur on July 13, 2019, and today is orbiting in the vicinity of the Sun-Earth libration point L2. The planned lifetime of the mission is 6.5 years and includes all-sky survey and pointed observations in the 0.3–15 keV band with the goal to create an X-ray map of the universe. This paper describes technical constraints of the mission, covering launch scenario, spacecraft design, ground data relay network, orbital and attitude control systems. First, the orbit correction scheme, applied for communication requirements, is presented. Then, the analysis focuses on a trade-off solution between attitude and orbit control operations. The proposed strategy allows mission to minimize the total propellant consumption by coordinated reaction wheels offloading and reducing the number and cost of the station-keeping manoeuvres to maintain the nominal orbit.

MASCOT (‘Mobile Asteroid Surface Scout’) is a 10 kg mobile surface science package part of JAXA’s Hayabusa2 sample return mission. The mission was launched in December 2014 from Tanegashima Space Center, Japan. The Hayabusa2 spacecraft reached the target asteroid in summer 2018. After a mapping phase of the asteroid and a landing site selection process the MASCOT lander was deployed to the surface on the 3rd of October 2018. MASCOT operated successfully for about 17 h on the surface of Ryugu. It performed three relocation manoeuvres and one “Mini-Move” and returned 128 MBytes of data. MASCOT has been developed by the German Aerospace Center (DLR) in cooperation with the Centre National d’Etudes Spatiales (CNES). The main objectives were to perform in-situ investigations of the asteroid surface and to support the sampling site selection for the mother spacecraft. These objectives could be reached successfully. On 6th December 2020 Hayabusa2 successfully returned asteroid samples to the Earth.

The National Aeronautics and Space Administration’s (NASA’s) Robotics Operations branch at the Johnson Space Center is entrusted with the planning and execution of operations on-board the International Space Station (ISS) using the Canadarm2, Dextre, and Mobile Transporter robots. While the most exciting part of the team’s work (the aspect most often shown on television or portrayed in movies) is the actual execution of the mission, a significantly greater portion of a robotics flight controller’s time is spent performing pre-operations planning. Myriad aspects of each robotic task must be considered in detail prior to execution, including overall task choreography, robot configurations and trajectories, writing of operational procedures, incorporation of protections against operational risks, adherence to flight rules, and advance development of contingency response plans. Recognizing the time demands associated with executing pre-operations planning and struggling to meet increasing call for extra-vehicular robotics operations on-board the ISS, NASA’s Robotics Operations branch sought to automate their pre-operations planning process with the goal of decreasing process execution time while preserving (or ideally, improving) the process’ level of safety and mission success. To achieve this objective the team employed an agile software development model and prioritized software features that would reduce the process’ inherent human risk by allowing the software to autonomously execute those tasks most often performed incorrectly by human operators. This chapter provides an overview of the Robotics Operations branch’s pre-operations planning process followed by a description of the automation project and associated software mechanisms and algorithms. Also discussed are several challenges that were addressed during the software development and adoption phases and the results of the effort.

Flight and ground system operability has been a focus area on the Europa Clipper Project since early in its formulation phase. This has given the operations team the opportunity to influence the design, with a goal of increasing overall system operability. This paper presents example operability challenges, opportunities, and solutions arising from the Critical Design Review (CDR) system design. The integrated wing assembly design directly couples a scientific instrument (the REASON sounding radar) to the spacecraft’s power source (solar array wing panels). Impacts to mission operations of this design include: increased slew durations; solar array pointing constraints during inner cruise, Europa flybys, and orbit trim maneuvers; and stray light intrusions into the stellar reference units’ keep out zones. The use of CCSDS File Delivery Protocol (CFDP) Class-2 for reliable downlink of the large volume of Europa Clipper science data is described, along with nominal and off-nominal use cases. The effort to improve post-launch spacecraft visibility by adding a third low-gain antenna to the spacecraft is detailed. The design of the bulk data store has necessitated the implementation of accountable data products (ADPs), accountability identifiers (AIDs), and metadata packets to provide end-to-end science data accountability. To streamline and automate the flight rules generation and checking process, a first order and temporal logic-based solution of expressing flight rules without ambiguity, and whose programmatic implementation can be automated, is proposed. The focus on operability has had a positive influence on Europa Clipper design decisions, although cost, schedule, budget, heritage, and other technical concerns have many times outweighed operability concerns. However, experience to date demonstrates that this approach to operability results in more thorough, balanced consideration of the effect of early design trades and decisions on the operations phase of a mission than seen in many previous missions, and provides operations development insight into prioritizing work to go.

Plan repair is more preferred over replanning when the agent suffers from plan failures. Most of the existing research work on autonomous plan repair regards the planned action as an instantaneous point, preventing it from being directly applied to the field of spacecraft operation, where is full of concurrent actions with varying duration and resource consumption. In this chapter, a reactive rapid autonomous plan repair algorithm based on retargetable goals, Retargetable Goals Plan Repair Method (ReGPR), is proposed. In ReGPR, a mechanism for transforming a mission plan into a state queue and a method of determining the optimal states, i.e., retargetable goals, based on evaluation are proposed. For transformation, ReGPR discretizes the concurrent actions into two state nodes distributed at their beginnings and ends, which encapsulates much information such as logic, numeric, and duration. Then, the plan repair problem is transformed into the puzzle of state transition by mapping them into the same timeline, which forms the retargetable goals. To determine the optimal goal for recovery, an evaluation criterion including goal reachability and search time estimation is designed. With the help of evaluation, ReGPR gets rid of searching for the recovery plan by the try-error method and finds the possible solution quickly. Several experiments with either logic failures or energy shortage or both were done in the modified Satellite Complex domain to show the performance of ReGPR by comparing it with the corresponding results of the replanning methods and other plan repair methods. And the results desmonstrate that in the repair progress, ReGPR explores fewer state nodes in no more than one round, and its advantage is greater when the plan repair problem becomes more complex.

On November 26, 2018, the NASA InSight spacecraft successfully landed on Mars. This paper describes the operations that took place on Mars after that landing, focusing on deployment with the SEIS (Seismic Experiment for Interior Structure) seismometer instrument’s robotic arm, followed by the associated wind and thermal shield. This is the first time an instrument has ever been deployed on another planet. The operations led by NASA-JPL lasted several weeks, until February 2019. CNES, the French Space Agency, is leading the operations concerning the SEIS instrument. The SEIS instrument consists of two independent 3-axis seismometers: an ultra-sensitive very broad band (VBB) oblique seismometer, and a miniature, short period (SP) seismometer. These sensors measure movements at the surface of Mars and will enable the planet’s interior structure to be characterized for the first time. The mission will last for two years (one Martian year). This paper is divided into two parts. The first part describes how the CNES team prepared for the SEIS deployment operations on Mars, through a yearlong training course with NASA-JPL and a rigorous certification process. The many lessons learned during this training process will be mentioned here, especially how operational issues encountered during the tests were taken into account to update the operational processes and the ground tools before the real operations began. The second part of the paper describes the real deployment operations on Mars in detail. The SEIS team was responsible for performing a health assessment on SEIS using the telemetry received, preparing SEIS activities while taking available resources and flight constraints into account, and delivering sequences to be run on Mars. The entire team was operating remotely from JPL, far from home for a long period of time. This paper therefore also includes a section on the management of French teams operating from NASA-JPL in California over a three-month period, especially in relation to the human and technical challenges encountered during that critical phase, and how lessons learned from the phase could benefit future missions.

Reaction wheels are commonly used to provide precision control for spacecraft that require fine pointing. However, vibration disturbances from the mechanical structure of reaction wheels such as stiction and resonance can cause attitude errors that are difficult to compensate. By using an optimal reaction wheel control that keeps the wheel speeds away from the disturbance-related wheel speeds, the effects of these disturbances can be minimized. This paper proposes an optimal control algorithm for reaction wheel assemblies with four or more wheels that minimizes the impact of stiction and resonance by implementing an intelligent wheel torque distribution algorithm. The null space provided by redundant wheels is utilized as an extra degree of freedom for controlling the wheel speeds. The formulated optimization problem is solved by Particle Swarm Optimization (PSO) and the numerical simulations of a 4-wheel spacecraft are carried out to validate the proposed algorithm.