The Psyche project was selected in January 2017 to send a spacecraft to orbit and investigate the (16) Psyche asteroid, which is the largest Class-M metallic asteroid in the solar system, and is believed to be mostly composed of iron and nickel metal. The Psyche project is a new partnership for the Jet Propulsion Laboratory (JPL) and the NASA community with Maxar Space, formally Space Systems Loral. It also represents a new concept for the development and production of a spacecraft for JPL in that it represents a hybrid combination of the organizations' key competencies. Maxar is a leading provider of high-power GEO spacecraft for the telecommunications industry, and is a world leader in the utilization of Solar Electric Propulsion (SEP) for satellite orbit raising and station-keeping. JPL has a long history of deep space missions and is considered a center of excellence in deep space communications, guidance and navigations, flight software, and autonomy. The Psyche spacecraft combines these core-capabilities from each organization to provide a high-power SEP vehicle capable of autonomous deep space operation out to the asteroid belt. The Psyche architecture follows the Dawn mission that sent a SEP spacecraft to Vesta and Ceres. In order to ensure the mission fits within a Discovery Class budget, the Psyche Spacecraft utilizes high heritage systems based on Maxar's 1300 solar electric propulsion geo-communications satellite from their production line. JPL is providing the telecommunications system, avionics suite, and software/autonomy systems, which have evolved from the Juno mission and multiple Mars missions. The purpose of this paper is to describe the Jet Propulsion Laboratory/Maxar collaboration, with a fixed-price contractual setup, present the key decisions, including lessons learned from this new partnership. This paper will involve all aspects of this process from the implementation stage of the Project PMSR through the current stage of the project as we get ready for the environmental test campaign

In January 2017, “Psyche: Journey to a Metal World” was selected for implementation as part of NASA's Discovery program. The Psyche mission will utilize electric propulsion with SPT-140 Hall thrusters to rendezvous and orbit the metal-rich asteroid (16) Psyche, in the main asteroid belt between Mars and Jupiter. The Psyche spacecraft requires no chemical propulsion and, when launched in 2022, will be the first mission to use Hall thrusters beyond lunar orbit. The Psyche spacecraft is a hybrid development with Jet Propulsion Laboratory (JPL)-provided deep-space avionics and communications equipment mounted on a high-heritage MAXAR (formerly Space Systems Loral) Solar-Electric Propulsion (SEP) Chassis, based on their 1300 series of GEO communications satellites. The spacecraft is equipped to support a suite of science instruments, as well as a demonstration of the Deep Space Optical Communications (DSOC) technology. The spacecraft has sufficient onboard resources, autonomy, redundancy, and operability to complete a 3.5-year cruise to 16 Psyche, followed by a 20-month campaign of science investigations while orbiting the asteroid. The mission's early concept design and progress through Preliminary Design Review (PDR) has been described in previous work. The paper will cover the recent mission progress from the Critical Design Review (CDR) through the start of Spacecraft Environmental Testing, which took place during the COVID pandemic. The authors will highlight the successful remote collaboration between the major partners: ASU, JPL, MAXAR, and the Payload teams that led to the initiation of the Assembly, Test, Launch, Operations Phase (ATLO) in early March 2021. Emphasis will be placed on the effects that the COVID-19 pandemic had on the work environment over the last 16+ months, including challenges to delivery of flight hardware and test equipment. In addition to the COVID-19 challenges, other significant anomalies discovered during design and test will be described along with any impacts to the overall science capability of the mission.

One of the obstacles to achieving a cost-effective high-reliability paradigm has been the need to reinvent the command and data handling infrastructure on a spacecraft by spacecraft basis. The availability of a family of commercial spacecraft avionics units with extensive reliable flight heritage offers an attractive approach to efficiently implement a spacecraft bus tailored to support specific mission needs without the concomitant redesign, redevelopment, or requalification of the avionics framework. In 2019 P. Lord et al. [1] defined Technology Readiness Levels (TRL) 10 and TRL 11 by expanding upon the need identified by J. Straub in 2015 [2] for a TRL beyond level 9. They extended TRL 9 ("Flight Proven Technology") by defining TRL 10 as "Reliable Flight Proven Technology" and level 11 as "Mature Flight Proven Technology". Maxar's avionics units, with extensive flight heritage in the commercial GEO market, offer TRL 10 and TRL 11 building blocks enabling a customized architecture to accommodate varied missions, from a deep space asteroid rendezvous (Psyche), to robotic servicing in LEO (Restore-L), to forming the basis of the Lunar Gateway with the Power and Propulsion Element (PPE). The Maxar catalog includes a RAD750 based central processor and a hardware level commanding unit as well as units specialized for temperature sensor acquisition, analog voltage measurement, digital control and monitoring, pyrotechnic device control and monitoring, heater control, generic relay control, launch vehicle umbilical discharge event isolation, and ESD hazard mitigation. The Maxar avionics family is integrated via a highly scalable serial data bus architecture. Every unit offers redundancy and full cross-strapping may be implemented for even higher mission reliability. This paper illustrates the scalability of the Maxar avionics family and includes details of unit capabilities on-orbit data based failure rate estimates, and TRL level as well as their itemization on the Psyche, Restore-L, and PPE spacecraft.

1.5 kW Solar Electric Propulsion (SEP) systems in commercial production for over a decade enable cost-effective and mass-efficient in space transportation. Today's Second Generation 5 kW class Hall Effect thrusters, share a common flight proven design and production legacy that has been carefully evolved by a factor of three. Providing 300% more thrust these flight proven systems are suitable for Discovery class exploration missions carrying significant sensors and/or targeting faraway objects. The recent emergence of a third generation of commercial technology is being achieved through a second 300% growth in scale making possible low-risk steps toward 15-kW class thrusters. When combined with large scale, high power solar arrays and higher voltage power processing equipment, large in space mass transportation missions can be achieved at dramatically lower cost compared to chemical propulsion missions. Fielding these highly reliable technologies for exploration missions is made possible by commercial bottom line driven product development approaches which are strongly focused on early product configuration decisions, modularity and scalability. To succeed in the highly competitive global market, commercial practices demand high reliability features be demonstrated over 15 year missions with rigorous qualification to an envelope of application environments and products designed for manufacturability. To date Maxar has flown well over 100 hall thruster engine systems on commercial spacecraft, without a system level failure impacting Spacecraft performance. Anchoring these emerging technologies in ongoing commercial production across the full SEP power spectrum is vital to maintaining the legacy of low cost and high reliability introduced by the 1st generation of commercial SEP. In addition to a commercial SEP roadmap covering the evolution of smaller planetary, and enhanced large space transportation capabilities, two examples are highlighted of exploration missions enabled by commercial SEP optimized for deep space operations. One illustrates how the Psyche Discovery mission's 20kW SEP chassis design was extracted from Maxar's Space Solutions commercial product line for the exploration of then main belt asteroid 16 Psyche. The second features the much larger third generation Power Propulsion Element (PPE) or “space tug” being developed for the Deep Space Gateway. PPE is a 50 kW class state of the art SEP spacecraft that is capable of Cislunar and Mars missions.

Psyche is a Discovery mission that will visit the asteroid (16) Psyche to determine if it is the metallic core of a once larger differentiated body or otherwise was formed from accretion of unmelted metal-rich material. The spacecraft will launch in August 2022 and arrive at the asteroid in January 2026. Psyche will carry three science instruments: a gamma ray and neutron spectrometer, a magnetometer, and a multi-spectral imager. Additionally, the spacecraft will host the Deep Space Optical Communications payload, which is a technology demonstration not required to meet Psyche's science objectives. The magnetometer is composed of two identical high-sensitivity magnetic field fluxgate sensors mounted in a gradiometer configuration that enables the rejection of meter-scale stray fields from the spacecraft. The instrument is key to meeting mission objectives since measurements of a strong asteroid remanent magnetic field will unambiguously indicate that (16) Psyche is an iron core. The magnetic signature from the spacecraft is the main source of noise for the magnetometer, both for DC and AC magnetic fields. Limiting and characterizing spacecraft-generated magnetic fields is therefore essential to the mission. This is the objective of the Psyche's magnetics control program described in this paper. The first step towards a successful program was to establish a set of magnetic cleanliness requirements directly derived from the magnetometer science performance and Psyche's range of expected fields. Test and modeling efforts of DC and AC fields of spacecraft components were then put in place to characterize and understand the spacecraft fields and enable verification of the cleanliness requirements. In this paper we describe the derivation of these requirements, test and analyses methods, and more generally the processes and procedures that govern the magnetics program for Psyche. The paper concludes with a discussion of the challenges and work to go and a comparison with the magnetic control processes of other missions with similar magnetic cleanliness constraints.

In January 2017, Psyche was one of two mission concepts selected by NASA for flight as part of the 14th Discovery mission competition. The project has been staffing up and maturing the spacecraft, instrument and mission system baseline designs on the path towards a 2022 launch. During much of 2018, the Project has been executing the lifecycle stage called Phase B, “Preliminary Design and Technology Completion,” one key element of which is the development and management of requirements at various levels. In the case of the Psyche project, this process has been particularly unique for several reasons. The project utilizes a Solar Electric Propulsion (SEP) Chassis from Space Systems Loral (SSL), a high volume manufacturer of commercial geostationary (GEO) telecom spacecraft based on the 1300 satellite bus. While SSL has an extensive, well-vetted set of requirements based on their very successful Earthorbiting product line, translating that heritage to a deep space science mission required special care. In addition to the differences associated with the deep space environment and longer communication times, new interfaces had to be incorporated. While a substantial portion of the Flight System consists of the SEP Chassis, there were several new interfaces within various subsystems between SSL components and those provided by JPL and other contractors. Managing these interfaces through requirements at a relatively higher level than normally seen on internal or external builds proved challenging. Finally, the Psyche spacecraft plans to host the flight terminal of the Deep Space Optical Communications (DSOC) technology demonstration, which is itself a separate project with its own requirements that must be flowed down and managed. This paper will present an overview of the requirement development and management process for the Psyche project. It will discuss in detail the various challenges summarized above, the methods and decisions chosen to address them, and evaluate their overall effectiveness at this stage in the project.

On its web site NASA defines Technology Readiness Level (TRL) 9 as: "Actual systems 'flight proven through successful mission operations". It's the gold standard for the development and implementation of new technologies on NASA spacecraft, and originates from the idea that technologies that have flown can be expected to fly successfully again. While the risks associated with developing a new technology and using it in space are considered by NASA and most of the space community to have been retired by a first flight, there is no guarantee of reliability or success the next time the technology is used in space. In a recent paper, Straub [1] proposed establishing a TRL 10 level that indicates "proven technology demonstrated through extended operations". After extensive discussion on the need for this and the possible definition, he suggested that a TRL definition higher than 9 would be useful in recognizing and taking advantage of higher maturity space hardware. Multiple other papers have made the case that hardware that has flown successfully and essentially unchanged multiple times will certainly have higher reliability and lower implementation risk than single flight units. The Psyche mission provides a unique case for testing these arguments about higher maturity hardware and extending the TRL scale beyond TRL 9. NASA's Psyche mission is procuring the majority of its spacecraft bus from SSL's commercial communication product line, which features spacecraft components and technologies with tens to hundreds of successful flights. In many cases, multiple generations of this hardware have been matured based on lessons learned, which guarantees reliability greatly in excess of one-shot hardware. This paper takes another look at the development of the TRL scale, arguments for its extension, and its application to NASA missions in the light of the flight proven, highly reliable commercial hardware described in this paper. We propose two additional TRL levels adopting and refining prior efforts to define levels of hardware maturity beyond TRL 9. This allows NASA to recognize and utilize the benefits of more mature technologies to build better spacecraft that can reliably explore the solar system; better, faster and cheaper than ever before.

In January 2017, Psyche and a second mission concept were selected by NASA for flight as part of the 14th Discovery mission competition. Assigned for an initial launch date in 2023, the Psyche team was given direction shortly after selection to research the possibility for earlier opportunities. Ultimately, the team was able to identify a launch opportunity in 2022 with a reduced flight time to its destination. This was accomplished in large part to crosscutting trades centered on the electrical power subsystem. These trades were facilitated through the Psyche mission's planned use of Solar Electric Propulsion (SEP), which enables substantial flexibility with respect to trajectory design. In combination with low-thrust trajectory analysis tools, the team was able to robustly converge to solutions with a higher fidelity and accuracy of results. These trades also took advantage of the 1300 series product line produced by Space Systems Loral (SSL), which enabled power growth while maintaining strong system-level heritage through its modular design that has been utilized on a large number of geostationary (GEO) communications satellites. This paper presents an overview of the Psyche mission concept, and the unique architecture that enables the use of commercially developed electric propulsion and space power systems from Space Systems Loral to provide flexibility in mission design. This paper then discusses the trades that allowed the Psyche team to meet a 2022 launch date.

Solar Electric Propulsion (SEP) has become vital in several commercial space applications and is well positioned to lower the cost and risk of important space exploration and science missions. The success of commercial SEP in the global satellite market provides a production base that produces cost-effective hardware. Well-established commercial approaches are in place for scaling and tailoring SEP systems to US government missions. An evolutionary roadmap is discussed, illustrating how these capabilities have emerged from the privately funded commercial technology branching into two new applications to government exploration missions. One is the adaptation for deep space exploration as illustrated by the NASA Discovery class mission to the main belt asteroid 16 Psyche that will use currently-available commercial SEP technologies with only minor modifications. The second enables the emergence of large scale space transportation as embodied by the Power Propulsion Element (PPE), derived from the Asteroid Redirect Robotic Mission (ARRM) spacecraft concept and planned as the bus foundation of the Deep Space Gateway (DSG). The PPE could use high-power third generation SEP derived from commercial capabilities to transport and maintain large habitats and modules within the Earth-Moon system.

In January 2017, the proposed mission Psyche: Journey to a Metal World, led by principal investigator Dr. Lindy Elkins-Tanton of Arizona State University (ASU), was selected for implementation as part of NASA’s Discovery Program. The planned Psyche mission is enabled by electric propulsion and would use SPT-140 Hall thrusters to rendezvous and orbit the largest metal asteroid in the solar system. The spacecraft requires no chemical propulsion and, when launched in 2022, would be the first mission to use Hall thrusters beyond lunar orbit. This paper describes the ongoing development of the Psyche mission concept and describes how Psyche would use commercially provided solar power and electric propulsion to meet its mission’s science requirements. It describes the mission’s scientific objectives and low thrust mission trajectory, the spacecraft architecture, including its power and propulsion systems, and the all-electric attitude control strategy that allows Psyche to fly without the use of chemical propulsion. Together, these elements provide a robust baseline design that maximizes heritage, leverages the strongest experience bases within the partner organizations, and minimizes risk across the design; providing a firm basis for implementation of the Psyche mission.

L.T. Elkins-Tanton, E. Asphaug, *James F Bell, D. Bercovici, B.G. Bills, R.P. Binzel, W.F. Bottke, G.M. Brown, J. Goldsten, R. Jaumann, I. Jun, D.J. Lawrence, P. Lord, S. Marchi, T. McCoy, D. Oh, R.S. Park, P.N. Peplowski, C.A. Polanskey, D. Potter, T.H. Prettyman, C.A. Raymond, C.T. Russell, S. Scott, H. Stone, K.G. Sukhatme, N.Z. Warner, B.P. Weiss, D.D. Wenkert, M. Wieczorek, D. Williams, M.T. Zuber

In September 2015, NASA selected five mission concepts from a field of 27 to proceed to the next stage (step 2) of the latest Discovery mission competition. Each team submitted a Mission Concept Study to NASA in August 2016, and in January of 2017 NASA selected Psyche and a second mission for flight. This paper describes Psyche, a unique investigation of a metal world, which is the only one of the original five mission concepts studied in detail to propose the use of Electric Propulsion (EP) to accomplish its mission objectives. Psyche will harness commercially developed EP and space power systems with strong system-level heritage to accomplish a deep space NASA science mission at comparatively low technical-risk and cost-risk. This paper describes the Psyche mission concept and the unique Solar Electric Propulsion (SEP) architecture that allows the use of SSL's commercial SPT-140 Hall thruster propulsion system at solar distances of up to 3.3 AU with only minimal modifications. Building on previous work analyzing SEP systems for Discovery-class missions, this paper describes the heritage, design, and testing which have been conducted on the power and propulsion systems to develop the Psyche mission, addresses the differences between GEO and deep-space environments, and describes actions taken to ensure that GEO heritage systems can be operated reliably in deep-space.