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In the history of spaceflight, almost all spacecraft have been manufactured and assembled on the ground, then integrated into a launch vehicle for delivery into orbit. This approach imposes significant limitations on the size, volume, and design of payloads that can be accommodated within the fairing of a single launch vehicle. In particular, fairing diameter limitations restrict the size and number of instruments that can be fielded in orbit for science and national security missions. Current manufacturing and technological limitations are evident in the construction of antennas and mirrors that have to be deployed from a single launch with a single satellite.
To overcome this challenge two technologies are being pursued and On-orbit assembly that refers to aggregation onto a platform of ready-made structures (that were manufactured either on the ground or on-orbit) and On-orbit manufacturing, which is the fabrication of structures (including 3D printing techniques),
On-orbit assembly can be defined as the aggregation onto an orbiting platform of ready-made structures that are manufactured on the ground (they could also be manufactured on-orbit for On-orbit manufacturing). At a conceptual level, on-orbit assembly offers a number of advantages that may enable and enhance various types of space missions. An ability to deploy structures that cannot be launched from Earth because of constraints imposed by launch vehicle fairing size and shape.
ISA is defined as the assembly activities completed in the target orbit and extraterrestrial space (such as: Low Earth Orbit, Geostationary Orbit, Cis-Lunar Space, Mars Orbit, Mars Surface, Lunar Space and interstellar space), which is to assemble modules in space in order to form a larger functional element or to recombine one or more structures after separation. In this process, these modules can be combined using their own power and propellant, or they can be assembled from separate spacecraft.
It is obviously unrealistic to use traditional launch methods for structures with large volumes (diameter greater than 15 m or size greater than 20 m, such as large space telescopes, large space habitats). In-space assembly can enable the construction of much larger orbital structures, for instance for setting up more sensitive radar imaging or for obtaining much higher speed of communications by assembling bigger and more sensitive antennas. It provides many other advantages such as an ability to achieve increased flexibility and resilience of spacecraft assets enabled by assembly involving additions, replacements and technology updates of payloads onto a compliant, orbiting platform. An ability to create structures that cannot be created on Earth at all because of constraints imposed by the terrestrial gravity.
Design of spacecraft built on the ground requires all the components of each spacecraft to be hardened (ruggedized) to withstand the harsh launch environment, which includes severe vibrations, acoustics, acceleration loads, and thermal loads. The hardening processes impose penalties in terms of mass and size that ultimately limit payload capabilities and increase launch costs. At the same time, another consequence of this approach is technology obsolescence due to the long-term ground construction and verification process. On-orbit assembly leads to cost savings by carrying more useful mass — less packaging material (structure) for ruggedization, and less platform material and through reduction in the number and intensity of ground-based tests of space-bound spacecraft and subsystems.
Other possible applications of in-space assembly include artificial gravity or asteroid redirect vehicles, space transportation hubs, space telescopes, in-situ resource utilization for construction, solar electric power and propulsion, sun shields, and atmospheric deccelerators. In the future, robotic construction capabilities could also be applied to create space infrastructure, standing structures such as refueling depots, in-space manufacturing facilities, space-tourism complexes, and asteroid mining stations. Developing a strong and sustainable way of ISA will become the key to human space exploration.
On-orbit manufacturing has recently been demonstrated on the International Space Station (ISS) through additive manufacturing, sometimes referred to as three-dimensional (3D) printing, of small components, such as plastic tools. Many of the technologies and processes required for on-orbit assembly are being developed actively in the areas of on orbit inspection and on-orbit servicing of spacecraft.
Challenges
In the last two decades, robotized On Orbit or In-Space Assembly (OOS / ISA) missions have increasingly gained importance. Every technology comes with a challenge and so does on-orbit satellite servicing. Many on-orbit assembly capabilities face space environment challenges, such as microgravity, atomic oxygen (in LEO), radiation and micrometeoroid impacts. It may therefore be necessary to deploy a protective shell structure in orbit, in which assembly can proceed free from many of these environmental concerns. For LEO operations, there is also the continual significant variation in the lighting environment caused by going in and out of eclipse, which may negatively impact vision-based operations.
And though space construction eliminates the challenge of carrying structures via spacecraft, the supplies and machinery necessary for a build still need to be transported from Earth. The heavy machinery we would typically use for construction projects, like carry deck cranes and scissor lifts, aren’t outfitted to work anywhere other than Earth. Standard design techniques and rules of architecture no longer apply without gravity in the picture.
All of the tools and supplies required need to be small enough to fit on a rocket and strong enough that they won’t break. One building challenge unique to outer space is making something that can withstand the extreme environments of space. One such issue is the need for material that can withstand the bombardment of radiation. Other issues, like being strong enough to exit the Earth’s atmosphere, but light enough so that it doesn’t hinder takeoff must also be addressed.
Technology
According to the complexity of the assembly, the lowest complexity ISA task just involves mating between elements, i.e. two or more independent spacecraft are assembled into a larger space structure and assembled in space with the lowest complexity. The more complex task would be Modular assembly, that is docking and assembly of cabins or modules to make it an independent spacecraft or to expand and reconstruct its functions. The most complex assembly is Assembly from parts: Assembly from initial parts to components needs to go through multiple assembly stages, which is similar to building a computer from the power supply, heat sink and other parts, such as building a truss from a structural member, or installing a mirror segment and alignment on a structural frame mechanism.
According to the different assembly tools used, ISA technologies of the space structure can be divided into: 1) manual assembly by astronauts with assembly assistance, and 2) autonomous assembly by space robots.
The manual assembly technologies by astronaut represented by the United States and Russia, mainly use space shuttle or spacecraft to send astronauts into space, and then complete the assembly task through astronauts wearing extravehicular space suits. The technologies of the United States and Russia have become mature. In addition, since the 1970s, on-orbit servicing by astronauts, such as maintenance of Skylab and the Solar Maximum Mission satellite, the ISS and the Hubble Space Telescope (HST) have laid the foundation for the development of space assembly technology.
An analysis of the potential applications shows that the demanded cross-cutting capabilities are robotic assembly, standardized interfaces, modular design with high stiffness, deployable subsystems, and docking and berthing. These require the availability of dexterous robot systems capable of performing complex assembly tasks. OOS addresses the maintenance of space systems in orbit, including repairing and refueling, using technologies that can be extended to on-orbit robotic assembly.
With the development of ISA, in addition to space remote control robots, researchers began to work on fully autonomous space robot systems for autonomous assembly. The space autonomous assembly robot includes onboard robotics, free-flying assembly agents, and persistent assembly platforms,
The improved technologies are now making it feasible for robotic spacecraft to dock with other spacecraft to handle station keeping or maneuvering, or even perform repairs. Some of these include a advanced sensor suite for careful rendezvous and proximity operations, specialized toolkit with robotic arms for docking, interacting with, and manipulating a client, and software for managing semi-autonomous servicing tasks.
Countries launch In-space Robotic Manufacturing and Assembly programs
Countries represented by the United States, Europe, Japan, Canada, and China have launched a series of space assembly experiments.
In 2001, the Demonstration for Autonomous Rendezvous Technology (DART) introduced by NASA was initiated by the Orbital Science Corporation (OSC). The mission goal of DART is to demonstrate the hardware and software technologies required for autonomous rendezvous in orbit, including testing the main performance of sensors, computers, propulsion systems and related software installed on DART. DART uses advanced video guidance sensors to provide communication when approaching the target satellite. Although the task could not be successfully completed, the autonomous rendezvous technology verified by it played an important role for Orbital Express.
Spacecraft for the Universal Modification of Orbits (SUMO) was a risk reduction program for advanced maintenance spacecraft, which was executed by the Naval Space Technology Center. Developed in 2005, the purpose of this program is to demonstrate the integration of machine vision, robotics, machinery and autonomous control algorithms to achieve OOA, removal of orbital debris, docking with customer satellites and orbital maneuver. SUMO is a modular spacecraft consisting of a high-performance propulsion module and a payload module containing autonomous rendezvous and grab systems . The payload module includes three 7-DOF (7-DOF) universal robotic arms, a variable baseline machine vision system, and a toolbox with multiple end effectors. SUMO could disassemble and install ORUs and supplement propellant and pressure agent.
The “Orbital Express” sponsored by the Defense Advanced Research Projects Agency (DARPA) was initiated in March 2007. ASTRO, the service satellite, can independently capture and dock the target satellite NEXTSat, and replace the modules. While NEXTSat, the target satellite, is responsible for simulating the faulty satellite and the orbital storage platform. The mission successfully demonstrated robot satellite service activities and some activities to replace the orbital replacement unit (ORU) for the first time. During the approximately four-month mission, Orbit Express confirmed that the key technologies required for satellite services had been already in place. The success of the “Orbital Express” showed that the United States had taken the lead in the world in autonomous assembly.
Since 2011, Robonaut 2, developed by NASA and General Motors (GM), has become the first humanoid robot in space. The robot has advanced mechanical control technology, sensitive sensors and visual technology, which are used to assist astronauts to complete sporadic work and maintenance tasks in the international space station after Robonaut. Ground tests have demonstrated the robot’s ability to carry out different tasks, including the assembly of truss structures. In the future, it will be planned to replace astronauts to accomplish extra-vehicular activities (EVA) and other space missions.
DARPA has also made significant investments in developing technologies that are key to orbital manufacturing and assembly. Under the Phoenix program, modular miniature satellites (called satlets) are being developed that can self-assemble on orbit to generate different spacecraft configurations. The Robotic Servicing of Geosynchronous Satellites (RSGS) project aims to increase satellite resilience through development of robotic capabilities for repairing and extending the lifetime of spacecraft in GEO.
China
On October 24, 2017, China’s Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) and UK’s University of Surrey (UoS) led the launch of the ultra-large aperture in-space assembly project. The project would work together to develop a 10 m horizontal aperture space telescope and study the robots and automation key technologies required for assembly.
Cheng et al. of the China Academy of Space Technology proposed a multi-robot collaborative assembly mode with an additional space manipulator arm and a free-flying robot for large space solar power plants, and optimized the assembly sequence and route. Liu et al. of Shenyang Institute of Automation, Chinese Academy of Sciences designed a compact, light-weight, five degree of freedom multi-functional end effector, which can realize the automatic docking of the quick isolator of the refueling pipeline through a single mechanical arm and improve the docking efficiency.
China launched its most recent practice satellite ShiJian-21 (SJ-21) into geosynchronous transfer orbit (GTO) on October 24, 2021, Beijing time and Chinese state media indicated the satellite would “test and verify debris mitigation technology.”SJ-21 has since entered geosynchronous Earth orbit (GEO) and moved into close proximity with another object, which is either its apogee kick motor (AKM) or a sub-satellite, according to the U.S. Space Force’s 18th Space Control Squadron and other space watchers.
SJ-21 is probably going to be China’s second On-Orbit Servicing, Assembly, and Manufacturing (OSAM) practice-series satellite (Shijian) in GEO. One could also reasonably expect SJ-21 to advance work China has already done in lower orbits to practice rendezvous and proximity operations (RPOs) and the use of a robotic arm. According to experts, this time, China might practice using multiple arms, a different type of debris mitigation technology such as that needed for refueling or deorbiting, or a combination of those.
NASA’s In-space Robotic Manufacturing and Assembly
Now, building on the latest robotic technologies available, NASA and its commercial partners seek to transform the way we manufacture, assemble and repair large structures in space, leading us closer to a robust space infrastructure freed from launch window scheduling, launch vehicle mass limitations and astronaut safety concerns. Ultimately, NASA’s new In-space Robotic Manufacturing and Assembly (IRMA) project will enable more frequent science and discovery missions in Earth orbit, across the solar system and beyond.
IRMA is a portfolio of three, ground-based technology development projects, each two years in duration, selected by NASA’s Space Technology Mission Directorate for the agency’s Technology Demonstration Missions (TDM) program, which seeks to mature ground-breaking technologies for infusion into government and commercial programs, dramatically extending human capabilities and opportunities in space. TALISMAN, SAMURAI, and NINJAR are components of CIRAS, part of the In-Space Robotic Manufacturing and Assembly project portfolio, managed by NASA’s Technology Demonstration Missions Program and sponsored by NASA’s Space Technology Mission Directorate.
Engineers will test several components of the Commercial Infrastructure for Robotic Assembly and Services (CIRAS) project at NASA’s Langley Research Center in Hampton, Virginia that may one day be used to build large space structures. The project, aimed at advancing technologies to be able to autonomously construct large platforms in space, is being conducted in collaboration with industry partners. NASA and its partners are pursuing these “tipping point” projects to determine whether they or similar technologies may be sufficiently matured for potential flight demonstration. Each works to meet a series of objectives that will determine which may receive continued funding, advancing toward possible infusion into future exploration missions.
NASA has announced they’re developing technologies and practices to build structures on the surface of other planets using what is known as “in-situ” or on-site resources. Learning how to use these resources can solve many major hurdles to building in space, especially when it comes to transporting the materials necessary for construction. Another major source of construction materials has been recycled old or worn-out items. One of the materials NASA frequently uses on the ISS is called Acrylonitrile butadiene styrene (ABS), a special polymer that can be used to make bolts, wrenches and more. When these items break or run out, they can be recycled and the ABS can be reused.
The actual process of breaking down these tools and other items in order to recycle them can be tricky. In fact, the In-Situ Fabrication and Repair project was created specifically for the sole purpose of finding new ways to fabricate, repair and recycle “tools, parts, and habitats and other structures” using raw lunar materials, recycled spacecraft parts, trash, human waste and a variety of other items. Thanks to specialists like those at the In-Situ Project, new tech now exists to make the salvaging of space materials even more efficient. The Recycler is a machine that reprocesses polymer materials like ABS to be used for the 3-D printer on the International Space Station (ISS).
Crews can feed worn-out tools and materials to the Recycler, which will then transform them back into the polymer base originally used to create them. Then, crews can reuse the polymer to 3-D print other tools and items that can be used for construction and repairs. Another similar machine called the In-Space Refrabicator actually combines the work of the Recycler and a 3-D printer, making it a sort of “one-stop shop” for repurposing old tools. The In-Space Refabricator can even use materials that traditional 3-D printers can’t, like plastic packaging and foam.
NASA’s On-Orbit Servicing, Assembly, and Manufacturing OSAM-1
NASA and its partners are developing robotic technologies to efficiently and autonomously manufacture and assemble hardware, components, and tools in space. Additive manufacturing – better known as 3D printing – can build and assemble complex components in space, deliver on-demand hardware, and allow for structures larger than current rockets can deliver and deploy to orbit.
In 2019, NASA awarded a $73.7 million contract to Made In Space (now Redwire Corporation) to demonstrate this capability in orbit with a spacecraft roughly the size of a refrigerator. The technology demonstration will build, assemble, and deploy a surrogate solar array – a complete solar array that will not be used to power the spacecraft.
In 2020, Redwire demonstrated the capability of their hardware to successfully print a 23-foot (seven-meter), flight-like beam against the conditions expected on orbit. In 2022, Redwire passed the mission Critical Design Review (CDR) marking the end of the design phase and the beginning of the process of building and verifying flight hardware.
Led by NASA’s Goddard Space Flight Center and built by Maxar, the OSAM-1 spacecraft will rendezvous with, grasp, refuel and relocate a government-owned satellite to extend its life. The spacecraft will consist of a servicing payload, provided by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with two robotic arms that will be attached to the spacecraft bus. The bus will also incorporate a payload called Space Infrastructure Dexterous Robot (SPIDER) that will demonstrate in-space assembly and manufacturing. SPIDER will use a third robotic arm to assemble a communications antenna and an element called MakerSat built by Tethers Unlimited to manufacture a beam.
The spacecraft bus and SPIDER are being built by Maxar Technologies. Fitted with a Maxar Space Infrastructure Dexterous Robot (SPIDER) arm, OSAM-1 will also demonstrate on-orbit assembly and manufacturing and validate the use of tools, technologies and techniques that are critical to future exploration missions, including NASA’s Artemis program.
In April 2021, NASA and Maxar Technologies successfully completed the On-orbit Servicing, Assembly, and Manufacturing 1 (OSAM-1) mission spacecraft accommodation Critical Design Review (CDR). This milestone demonstrates that the maturity of the design for the OSAM-1 spacecraft bus is appropriate to support proceeding with fabrication, assembly, integration, and testing.
The 14-foot-tall OSAM-1 spacecraft bus under development will provide OSAM-1 with power and the ability to maneuver in orbit. To make these maneuvers possible, inside the main cylinder are two large bi-propellant tanks, and the upper and lower deck of the spacecraft feature thrusters. The two silver spheres are filled with mono-propellant fuel that will be used to provide OSAM-1’s target client satellite, Landsat 7, with more fuel to demonstrate that robotically refueling a satellite is possible.
Archinaut, a floating factory to manufacture heavy equipment, even full satellites, in orbit
The Archinaut One is a project from Made in Space that combines a 3-D printer and robotic arms to create a single machine capable of building and assembling large structures in outer space. Archinaut seeks to develop in-space hardware capable of building and assembling complex, large components in space on demand. The proposed technology uses additive manufacturing — better known as 3-D printing — to deliver lengthy structures such as beams and struts. The Archinaut is comprised of an industrial sized 3-D printer, cartridges full of plastics and alloys, and robotic arms programmed to assemble the big items extruded by the printer without any human supervision. All of the Archinaut’s components are rugged enough to survive in microgravity and harsh conditions like lunar dust storms and extreme temperatures.
Lead subcontractor Northrop Grumman Corp. of Falls Church, Virginia, provides system integration; Oceaneering Space Systems of Houston, Texas, is developing the hardware’s robotic arm; and NASA’s Ames Research Center in Moffett Field, California, is conducting thermal vacuum testing. Once the Archinaut is finalized, crews on Earth will be able to send it the raw materials and digital design files necessary to build a particular structure. The Archinaut can then print the structure’s components and assemble them to create the finalized structure. According to NASA, this system will be able to do anything from fixing satellites to building gigantic telescopes. The Archinaut One is set to deploy for a test flight no later than 2022.
NASA OSAM-2
Redwire Corporation in April 2022 reached a milestone in a project aimed at developing robotic technologies to build large structures in space by passing the Mission Critical Design Review (CDR). The CDR marks the end of the design phase for the On-Orbit Servicing, Assembly and Manufacturing 2 (OSAM-2) mission and the beginning of the process of building and verifying flight hardware. OSAM-2, also known as Archinaut One, is a $73.7 million contract between Redwire and NASA signed in 2019. OSAM-2 is a technology demonstration mission funded by NASA’s Space Technology Mission Directorate and is scheduled to launch no earlier than 2023.
OSAM-2 is expected to launch no earlier than 2024. The technology demonstration will build two beams and deploy a surrogate solar array utilizing robotic manipulation. Once deployed and positioned in orbit, the small spacecraft will 3D print two beams. While the first beam is being printed, the solar array will be unfurled from the spacecraft. After the 33-foot (ten-meter) beam is completed and locked into place by the robotic arm, the arm will reposition the printer, which will then print a 20-foot (six-meter) beam from the other side of the spacecraft.
OSAM-2 is leveraging Redwire’s Archinaut platform, a customizable suite of manufacturing and assembly technology that can be integrated into free-flying satellites. OSAM-2 will use additive manufacturing technology, also known as 3D printing, and a robotic arm to build and manipulate structures and tools in space, demonstrating critical technologies for producing space infrastructure. After launch, the refrigerator-sized OSAM-2 spacecraft will build and deploy a surrogate solar array in orbit. OSAM-2 will 3D print one beam that extends 10 meters from one side of the spacecraft and a second one that extends six meters from the other side. The Archinaut technologies that OSAM-2 demonstrates have the potential to enable construction of structures that are larger and lighter than what could be launched to orbit by any currently operational rocket.
NASA to Demonstrate First-of-its-Kind In-Space Manufacturing Technique for Telescope Mirrors, reported in 2020
Large telescopes that could be used for detecting and analyzing Earth-like planets in orbit around other stars or for peering back in time to observe the very early universe may not necessarily have to be built and assembled on the ground. In the future, NASA could construct them in space. A NASA engineer was selected for a flight opportunity to show that an advanced thin-film manufacturing technique called atomic layer deposition, or ALD, could apply wavelength-specific reflective coatings onto a sample in space — one of the first steps in ultimately realizing the vision of constructing and assembling large telescopes in microgravity.
“We technologists think next-generation telescopes larger than 20 meters in diameter will be built and assembled in orbit,” said Vivek Dwivedi, an engineer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and an expert in ALD technology. “Instead of manufacturing the mirrors on the ground, why not print them in space? But you don’t have a telescope mirror unless you coat it with a highly reflective material. Our idea is to show that we could coat an optic in space using this technique, which we’ve used on the ground and understand the processes,” Dwivedi said. He and his collaborator, University of Maryland professor Raymond Adomaitis, will now have a chance to demonstrate the concept in space for the first time.
Blue Origin Suborbital Flight Test
Recently, NASA’s Space Technology Mission Directorate’s Flight Opportunities program selected Dwivedi and Adomaitis to fly a football-sized ALD chamber aboard a Blue Origin New Shepard rocket. The launch will provide three minutes of microgravity, long enough for the automated payload to apply a thin film of a well-known ALD material, alumina, onto a two-inch silicon wafer. “Alumina is a bread-and-butter material in ALD applications,” Dwivedi said. “It’s been extensively researched.” Commonly used by industry, ALD involves placing a substrate or sample inside an oven-like reactor chamber and pulsing different types of gases to create a smooth, highly uniform film whose layers are no thicker than a single atom.
ALD-coated Samples in Space
ALD may also have applications for dust mitigation, another challenge NASA is working to solve. Currently, ALD-coated samples are being exposed to plasma from an experiment pallet aboard the International Space Station. Dwivedi and Goddard technologist Mark Hasegawa created these samples to test whether indium tin oxide — an effective compound for dissipating electrical charges — might be applied to paints and other materials to prevent lunar dust from adhering to rovers, instruments, and spacesuits. Mitigating the dust problem is considered one of NASA’s thorniest challenges as the agency plans to establish a sustainable presence on the Moon under the Artemis program.
For in-space manufacturing, ALD offers a distinct advantage, Dwivedi said. ALD chambers scale to any size and can consistently apply smooth layers over very large areas. “If we scaled a silicon wafer to the size of the Washington metropolitan area and placed it inside an ALD chamber, for example, we could deposit a layer of material that varied no more than 60 microns in thickness,” Dwivedi said, illustrating the technique’s precision, which would be essential for developing sensitive optics.
Although Dwivedi and Adomaitis have built several ALD chambers using Goddard Internal Research and Development program funding, they’ve decided to fly a chamber made of commercial off-the-shelf parts during the suborbital test flight. Dwivedi said he and Adomaitis conceived the idea about two years ago. A Goddard colleague, Franklin Robinson, secured a test via Flight Opportunities also on a Blue Origin New Shepard rocket and proved a groundbreaking technology for effectively cooling tightly packed instrument electronics. “We worked very hard to get this opportunity,” Dwivedi said. We can’t wait to get the payload launched to see how well this technique works in space.”
CIRAS for space-based, robotic assembly of flight hardware and space systems
Helmed by Northup Grumman of Los Angeles, CA, the Commercial Infrastructure for Robotic Assembly and Servicing (CIRAS) project is pursuing space-based, robotic assembly of flight hardware and space systems, using innovative technologies including NASA’s Tension Actuated Long-reach In-Space Manipulator (TALISMAN) to reduce the costs and potential human hazards associated with hardware transfer and assembly activities. The work is supported by Orbital ATK’s subsidiary Space Logistics LLC. NASA’s Glenn Research Center in Cleveland is conducting a concept feasibility study; NASA’s Langley Research Center in Hampton, Virginia, is developing TALISMAN for mission applications; and the U.S. Naval Research Laboratory in Washington is developing the project’s robotic software.
CIRAS is made up of several components. TALISMAN, the long-reach robotic arm technology, was developed and patented at Langley. TALISMAN moves SAMURAI, which is like the hand that brings truss segments to NINJAR, the robotic jig that holds the truss segments in place perfectly at 90 degrees while they are permanently fastened using electron beam welding to join together 3D printed titanium truss corner joints to titanium fittings at the strut ends. NINJAR was built almost entirely by interns in the lab. The students have done incredible things, Taylor said.
TALISMAN
Innovative NASA robotic technologies such as TALISMAN, seen here during calibration tests at NASA’s Langley Research Center, are critical to the CIRAS project, which seeks to enable space-based, robotic assembly of flight hardware and space systems.
Dragonfly Project Demonstrates Robotic Satellite Assembly Critical to Future Space Infrastructure Development
Led by Space Systems Loral (SSL) of Palo Alto, California, Dragonfly enables satellites to self-assemble in orbit. A lightweight robotic system with a dexterous 3.5-meter arm that’s able to clamp down, carry items or operate controls — from either end of the “limb” — Dragonfly can install delicate satellite antenna, yet also assemble satellites too massive to be launched to space in their final flight-ready state. These disassembled satellites may be stowed more efficiently or even launched in pieces via multiple flights, enabling mission planners to maximize cargo space and reduce mass. That shift would dramatically reduce launch costs and lead to less expensive, higher-performing satellites.
With optimized reflector stowage, robotic joint assembly and 3-D printed antenna support structures, more powerful satellites will fit within payload space aboard standard launch vehicles, thereby decreasing costs. During the August ground demonstration, Dragonfly’s initial focus was the installation and reconfiguration of large antenna reflectors on a simulated geostationary satellite. The antennas are designed to focus the satellite signal to receivers on the ground. Additional demonstrations are planned through 2018 to further refine its processes and capabilities, including more fluid robotic arm movement and its ability to make even more precise reflector alignments.
Over time, the system will integrate 3-D printing technology enabling the automated manufacture of new antennae and even replacement reflectors as needed. Should a piece of hardware be damaged, or come to the end of its lifecycle, engineers could remotely remove and recycle the outdated component, replacing it with a new one. NASA’s Langley Research Center is developing robotic assembly interfaces; NASA’s Ames Research Center is writing situational awareness software; Tethers Unlimited of Bothell, Washington, is handling in-space truss manufacturing; and MDA US Systems LLC of Pasadena, California, is developing the robotic arm and advanced robotic control software.
“NASA relies on commercial innovation as exemplified by the Dragonfly team,” said Trudy Kortes, TDM program executive at NASA Headquarters in Washington. “Transformative technologies such as these will, in time, lead to more affordable, safer human access to space and more efficient, longer-lasting satellites, probes and other space hardware. Today our future in space looks brighter and more robust than ever.”
NovaWurks Prepares Self Assembling Spacecraft for LEO Demonstration
NovaWurks, a U.S. company that provides high-tech space products and services, is embarking on the demonstration phase of its new modular satellite design set to aid the Defense Advanced Research Projects Agency’s (DARPA) Phoenix program, which aims to scavenge and reuse parts from obsolete spacecraft already in orbit. NovaWurks technology seeks to enable key on-orbit capabilities, including assembly, repair, asset life extension, refueling and more. NovaWurks’ spacecraft, known as Hyper-Integrated Satlets (HISats), draw on areas of biology and engineering in order to create a new low-cost, modular satellite architecture that can scale almost infinitely. The HISats are small independent modules that weigh roughly 15 pounds each and incorporate essential satellite functionality, such as power supplies, movement controls and sensors, among others. The operating system software would be able to aggregate all the modules together on the orbit.
“The HISat is a single unit, cellular in nature — like an embryonic human cell — that works to differentiate itself on demand. In this differentiation it can become whatever tool it needs to become in [the on-orbit] junkyard. In this way you can put them into use and then assign each HISat specific tasks or functions once they are in place,” said Jaeger. The company is using the HISats to demonstrate the ability to rapidly design, build and support payloads of any size and weight. The scalability of the HISat design means that when building a satellite, operators no longer have to adapt to the needs of a spacecraft, cutting back on non-recurring aspects of getting payloads on board and making it more cost-effective to launch a satellite, according to Jaeger.
“If you have an unknown payload that you need to fly, we can wrap it, conform to it and launch it rapidly,” Jaeger explained. “So, instead of a single-commodity bus, you have a variable commodity bus that can scale to the needs of the users on both the launch side and the payload side. That changes the game. It means you don’t always have to modify something or create it from scratch,” said Jaeger. “We can do that because these cells can be attached to rocket launch interfaces and payloads and then, when they are released, can support entire missions because they understand space, how to work together, and how to support payloads at a very low cost and ease of design and capability.”
The company is now in Phase 3 of the program and launched an independent demonstration of the HISat systems onboard the International Space Station (ISS) in December. Next, the company is preparing to take the HISats to flight in Low Earth Orbit (LEO) this summer. NovaWurks is scheduled to demonstrate the technology in GEO in mid-2017. “This is going to open the door for people to not only do the missions they are doing today, but also do the missions they couldn’t even conceive of before,” said Jaeger. “We believe a cellular design allows you to be robust, resilient and survive all sorts of unique challenges that are presented to people as we expand into space, and this design, architecture and hardware allows us to begin getting down that path.”
Other Countries
The typical European Robotic Arm (ERA was designed and assembled by Airbus Defence and Space Netherlands. The robotic arm has 7 degrees of freedom. It was connected to the Russian cabin section of the ISS and mainly used for the installation and deployment of solar panels, replacement of solar panels, and astronaut EVA assistance.
in 2010, Germany launched the Intelligent Building Blocks for On Orbit Satellite Servicing and Assembly (iBOSS). This in-space manufacturing spacecraft project carried out key technologies ground test in 2018. It is a reconfigurable spacecraft that uses standardized interfaces and modular design and manufacturing for on-orbit service and assembly. The goal of iBOSS is to significantly reduce the cost of satellite maintenance through standardization and modularization, which will be used to study the technologies of assembling intelligent modular cubes into modular reconfigurable spacecraft.
During the construction of the ISS, the Shuttle Remote Manipulator System (SRMS) and the Space Station Remote Manipulator System (SSRMS) developed by the Canadian Space Agency (CSA) played important roles in the assembly and maintenance of the ISS. Next-generation Canadarm (NGC) is also under development to support both low earth orbit and deep space missions. The NGC consists of two manipulators: a large manipulator arm with a range of 15 m, and a small manipulator arm with a range of 2.6 m. It adopts the function of a new telescopic arm. The big arm can be used to fold and install the small spacecraft in the future. The small arm can help the satellite operate accurately.
Surrey Space Centre (SSC) has collaborated with the California Institute of Technology, Jet Propulsion Laboratory (JPL) and Indian Institute of Space Science and Technology (IIST) to carry out Autonomous Assembly of the Reconfigurable Space Telescope (AAReST) mission. The main mirror consists of 10 cm diameter circular mirrors, which is used to demonstrate some key technologies of low-cost on-orbit assembly (including close rendezvous and docking) and reconstruction of space telescopes based on multi-mirror components. When the initial calibration and imaging requirements are met, the two mirror segments carried by the independent Cubesats equipped with the propulsion system will be separated from the mirror group, perform orbital manipulation to reposition themselves in a new position in the array.
References and Resources also include:
https://www.sciencedirect.com/science/article/pii/S1000936120304854
