The LunaH-Map (LMAP) mission was manifested and launched as a secondary payload on the Artemis 1 mission in November 2022. With a scientific objective of mapping hydrogen concentration at the Lunar South Pole, the mission required a low polar orbit. As a secondary payload, the LMAP mission design had to overcome many unique constraints in order to generate Lunar transfers to reach this desired orbit. This paper will discuss the methods used to overcome all of these challenges and incorporate two sets of three-body weak-stability dynamics into one low-thrust trajectory optimization problem. For operational efficiency, solutions were generated directly in an ephemeris model without needing simplified two- or three-body dynamics. A walkthrough will be provided of the mission design pipeline created to meet tight operational timelines. Instructive trends and results will be presented for the thousands of trajectories generated across the over 400 potential launch opportunities.

The Sample Return Capsule (SRC) onboard the NASA Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) spacecraft is currently carrying samples of the B-type asteroid Bennu for safe return to Earth at the Utah Test and Training Range on September 24, 2023. These samples were collected during the Touch And Go (TAG) sampling event on October 20, 2020, when the spacecraft contacted the surface for a few seconds at a location less than 1 meter from the target. The unprecedented navigation performance achieved during that event was the culmination of experience gained during two years of cruise and two years of increasingly challenging operations at Bennu. As we had hoped, the proximity navigation performance at Bennu exceeded pre-launch analysis. This paper will compare the navigation performance through the proximity operation phases to our pre-launch analysis and will quantify how refinements of the small force models governing the spacecraft motion near Bennu considerably improved the down-track state predictions leading up to the successful TAG event. It was evident to the team and to expert peer reviewers during the design phase that exquisite model fidelity and aggressive operational concepts, which challenged and advanced the state of the art for deep space proximity operations, would be required to meet the mission’s objectives. This paper summarizes the superlative achievements of the team in rising to and overcoming these challenges.

The Origins Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-REx) mission to the asteroid Bennu completed successful two-and-a-half year proximity operations in May 2021. The mission comprehensively mapped Bennu at unprecedented detail and collected a sample of Bennu's surface to return to Earth. Throughout proximity operations, the OSIRIS-REx navigation team used the maps made of Bennu's surface to navigate in the Bennu environment with high accuracy through the use of precise and accurate optical navigation data, radiometric data, and force modelling. The primary type of optical navigation measurements extracted from the images captured by OSIRIS-REx (particularly after first entering orbit around Bennu) were observations of known features on Bennu's surface. Two related but different techniques/tools were used to extract these observations from the images: the Goddard Image Analysis and Navigation Tool Surface Feature Navigation (GIANT SFN) and Stereophotoclinometry (SPC) Autoregister. In this paper we compare the differences between the observables extracted using GIANT SFN and SPC Autoregister, explain the differences, and discuss where each technique is best suited.

Asteroids with diameters less than about 5 km have complex histories because they are small enough for radiative torques (that is, YORP, short for the Yarkovsky-O'Keefe-Radzievskii-Paddack effect)1 to be a notable factor in their evolution2. (152830) Dinkinesh is a small asteroid orbiting the Sun near the inner edge of the main asteroid belt with a heliocentric semimajor axis of 2.19 AU; its S-type spectrum3,4 is typical of bodies in this part of the main belt5. Here we report observations by the Lucy spacecraft6,7 as it passed within 431 km of Dinkinesh. Lucy revealed Dinkinesh, which has an effective diameter of only 720 m, to be unexpectedly complex. Of particular note is the presence of a prominent longitudinal trough overlain by a substantial equatorial ridge and the discovery of the first confirmed contact binary satellite, now named (152830) Dinkinesh I Selam. Selam consists of two near-equal-sized lobes with diameters of 210 m and 230 m. It orbits Dinkinesh at a distance of 3.1 km with an orbital period of about 52.7 h and is tidally locked. The dynamical state, angular momentum and geomorphologic observations of the system lead us to infer that the ridge and trough of Dinkinesh are probably the result of mass failure resulting from spin-up by YORP followed by the partial reaccretion of the shed material. Selam probably accreted from material shed by this event.

NASA's OSIRIS-REx spacecraft successfully collected a sample of asteroid regolith from the surface of near-Earth asteroid Bennu in October of 2020. Subsequent imaging of the sampler head showed material leaking from the collection mechanism, thus stowage of the sample precluded execution of any planned maneuvers in the following days. Optical navigation imaging also ceased in the days following sample collection. The desire to image the sample site to investigate the results of the spacecraft-to-surface interaction led to the Navigation team designing a trajectory to return to Bennu after several months in order to image the surface one final time. After several iterations a trajectory design was created that satisfied the numerous constraints that were levied in order to place utmost importance on the safety of the spacecraft and stowed sample, while also closely emulating previously obtained imaging conditions to provide a close comparison of site pre- and post-contact. Significant analysis was necessary in order to reliably reacquire the asteroid after several months without optical navigation imagery. The final design required five maneuvers to return the spacecraft to Bennu and perform a final flyby of the asteroid at a distance of 3.8 kilometers. Successful execution of the phase provided key insights regarding the performance of the sample collection activities and the subsurface composition of the asteroid.

We summarize a decade of effort by the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission team to build up the unique capabilities, processes, and procedures required to accomplish the unprecedented navigation performance required during proximity operations at asteroid (101955) Bennu. Stereophotoclinometry was a key technology used for digital terrain model (DTM) generation and landmark navigation, enabling estimation of spacecraft trajectories and Bennu’s geophysical parameters. We outline the concept of operations for OSIRIS-REx landmark navigation and the wide array of testing and verification efforts leading up to OSIRIS-REx’s arrival at Bennu. We relate the outcome of these efforts to the experiences during proximity operations. We discuss navigation and DTM performance during operations, including detailed lessons learned to carry forward for future missions.

New Horizons was the first mission with primary science objectives to explore the Pluto-Charon system and, in an extended mission, to observe a Kuiper Belt object (KBO). This article summarizes the challenges in planning and targeting the New Horizons spacecraft for the Pluto encounter and how the team addressed these challenges, reducing mission risk to ensure a successful encounter that fully met its science objectives. It also presents the navigation accuracies achieved and the lessons learned, which were later applied to planning and conducting the flyby of a newly discovered KBO, Arrokoth, during New Horizons' first extended mission.

The New Horizons mission performed a successful flyby of Arrokoth, a distant Kuiper-Belt Object, on January 1, 2019, representing the farthest planetary encounter to date. The navigation strategy and performance required to deliver the spacecraft to the desired flyby target were driven by a number of challenges including those related to Arrokoth’s viewing angle and relatively recent discovery in June 2014. These and other challenges required the New Horizons science and navigation teams to devise a strategy in close collaboration that would substantially reduce the flyby navigation errors. Earth-based astrometry and occultation measurements of Arrokoth were collected and used to estimate Arrokoth’s orbit and its associated uncertainties, which were in turn used to inform and reduce navigation approach and flyby uncertainties. The New Horizons navigation effort used these a priori orbits along with radio metric and optical navigation measurements to first predict the navigation performance in support of the flyby design, and then estimate New Horizons ’ trajectory, maneuvers and other filter state parameters during navigation operations. An overview of the Arrokoth orbit estimation and navigation strategy and predicted performance, as well as the operational results from the initial target search campaign in 2004 through Arrokoth’s successful flyby in 2019 are presented, along with the principal challenges and most important lessons learned along the way.

The Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft was launched in September 2016 and arrived at its target, near-Earth asteroid (101955) Bennu in late 2018. After executing nearly two years of multi-phase proximity operations navigation and mapping campaigns, on October 20, 2020 OSIRIS-REx successfully performed the Touch-And-Go (TAG) maneuver to become the first American mission to collect a sample from an asteroid. As Bennu is one of the smallest objects ever to be visited by a planetary spacecraft, the mission presented many navigational challenges, and optical navigation (OpNav) techniques were essential to the successful execution of the mission. The specific challenges of OSIRIS-REx required nimble OpNav planning, robust data management, and quick, automated analyses and data-product delivery capabilities. In addition to the two primary image processing tools, centroid-based and landmark-based OpNav, a host of support and planning tools and procedures were developed. The multi-year operations timeline, fast maneuver cadence, and multi-phase nature of proximity operations for OSIRIS-REx motivated a streamlined and reactive image planning process. A suite of tools was developed to ensure that the mission navigation requirements were continually satisfied. On approach, the Op-N av Opportunity Analyzer (OpOpp) was used to deconflict the imaging schedule with interference from bright background stars. In-flight instrument calibration was performed using an in-house distortion calibration toolset. An Exposure Time Calculator was used to determine optimal exposure times and verify that the images would produce sufficient OpNav image data. Additionally, Fly-Point-Shoot (FPS) software was used to analyze and mitigate the effect of trajectory and pointing uncertainties on image planning and coverage. This paper describes in further detail the operational challenges of the OSIRIS-REx OpNav subsystem, as well as the tools, procedures, and strategies developed to ensure the satisfaction of navigation requirements.

View Video Presentation: https://doi.org/10.2514/6.2022-2470.vid The NASA Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) spacecraft began close proximity operations at the small (500-m diameter) B-type asteroid (101955) Bennu in December 2018 and concluded in May 2021. Hundreds of grams of pristine surface regolith were collected on October 20, 2020, when the OSIRIS-REx spacecraft successfully executed the Touch and Go (TAG) sample collection sequence. The spacecraft touched down within 1 meter of the targeted site on the surface of Bennu. TAG was the culmination of over 2 years of navigation performance refinement as a result of extraordinary interagency teamwork between the Flight Dynamics System (FDS), science and spacecraft teams while in close proximity to Bennu. This paper will discuss the navigation processes, planning and performance during the proximity operations at Bennu.

Optical navigation (OpNav) is a critical subsystem of the OSIRIS-REx asteroid sample return mission, which operated in the vicinity of near-Earth asteroid (101955) Bennu from August 2018 through April 2021. A substantial amount of mission resources across multiple subsystems and institutions is required to ensure that the OpNav data are successfully acquired. The KinetX OpNav team, part of the Flight Dynamics System (FDS), is responsible for performing required analysis to develop the OpNav operations plans; requesting, reviewing and verifying the plans; and ultimately using the image data for critical navigation operations. The FDS team, responsible for the mission navigation, is operated by KinetX Aerospace with management and operations support from NASA’s Goddard Space Flight Center. The Science Processing and Operations Center (SPOC), located at the University of Arizona’s Lunar and Planetary Laboratory, is responsible for generating the planning products for all science and most OpNav data. These plans are integrated into the spacecraft sequences, tested, and commanded by the Mission Support Area (MSA) at Lockheed Martin Space. To ensure mission-critical navigation image data are successfully acquired, the plan is developed through a waterfall of planning cycles over the course of 3 months prior to onboard plan execution. During the initial strategic planning for a mission phase, detailed analysis is performed by the OpNav team to conceptualize the concept of operations (ConOps) for image data collection. This phase OpNav Narrative is included along with other strategic planning documents for the key ground segment stakeholders to review and provide feedback. The detailed OpNav plans get defined in the tactical planning cycle, which spans 8 to 3 weeks before the week-long integrated sequence is executed on-board the spacecraft. During the tactical cycle, the initial OpNav Request is submitted along with the science requests, kicking off development of the science and OpNav plans. Once the initial plan is drafted, interfaces are exercised so that the plan can be reviewed and iterated, if necessary. A rigorous schedule is followed by the planning teams during the implementation cycle, spanning the last 18 days before uplink, to ensure all the necessary integration, testing, and reviewing can occur on time. The development of the OpNav planning ConOps, including responsibilities, interfaces, timelines, and procedures, took extensive collaboration across mission elements and institutions. The process was robust throughout the 137 weeks of continuous Optical Navigation Operations at Bennu, which concluded on April 9th, 2021.

View Video Presentation: https://doi.org/10.2514/6.2022-1226.vid The Lucy Jupiter-Trojan asteroid mission launched on October 16th, 2021, setting out for the first-ever exploration of the Trojan asteroid clusters at the Jupiter-Sun L4 and L5 points. Between June 2027 and November 2028, Lucy will conduct five consecutive close flybys in the L4 cluster. In 2033, it will return to the Jupiter Trojans to conduct one final close flyby of the Patroclus/Meonetius binary asteroid system in the L5 cluster. In 2025, while enroute to the Trojans, Lucy will perform a flyby of the main belt asteroid (52246) Donaldjohanson. Robust optical navigation (OpNav) capabilities, techniques, and planning will be essential to the navigation efforts of the Lucy mission, enabling precise and accurate navigation relative to the flyby targets. Due to the geometry of the flyby encounters, any improvement in B-plane targeting and time-of-flight (TOF) uncertainty must be obtained using optical navigation. Since most Trojans do not have known moons to provide parallax information, TOF information must be derived from single-body OpNav combined with a priori Hubble Space Telescope-based or ground-based information. To these ends, a concept of operations, and expanded OpNav planning and operations tools have been developed to meet the specific challenges the Lucy mission presents. Additionally, rigorous OpNav operations simulations are ongoing to verify these strategies and procedures. This paper discusses the details of the Lucy OpNav ConOps and capabilities. Details of the planning tools, encounter timelines, and simulation results are presented.

On October 20, 2020, NASA's OSIRIS-REx spacecraft performed its Touch-and-Go (TAG) activity, in which it briefly contacted the surface of the asteroid Bennu and successfully collected a sample of regolith.Subsequent images of the sampling mechanism showed that thousands of small regolith particles were escaping from it, apparently in conjunction with movements of the mechanical arm and wrist joint by which the sampling mechanism is attached to the spacecraft.The escaping particles could be tracked from one image to another, and across multiple images, which allowed the OSIRIS-REx optical navigation team to detect, associate, and track particles using a combination of manual and automated techniques.The associated tracks each represent a unique particle that was further analyzed to estimate its ejection time, 3D trajectory, and velocity, as well as its photometric properties, which were used to compute its brightness, size, and mass.Compiling the aggregate photometric and physical data for all of the particles leads to an estimate of total sample mass lost during the post-TAG imaging sequences.These results further inform an understanding of the sample escape mechanisms and sample loss that occurred before the sample head was stowed in the return capsule on October 28, 2020.

Navigation for spacecraft missions around small bodies requires Optical Navigation (OpNav) to achieve the Orbit Determination (OD) performance necessary to maintain spacecraft safety and achieve mission science objectives. Precise and accurate inertial pointing knowledge in inertial space of the OpNav imager is required to meet this necessary performance. This paper presents results of the OSIRIS-REx OpNav team’s routine trending of the NavCam1 imager pointing with respect to the spacecraft attitude, including analysis of thermal deviations the NavCam boresight correlated with sun-on-deck geometry as well as operation of high-energy instrument payloads. These analyses facilitated the calibration of the imager alignment with respect to the spacecraft and characterized the uncertainties for OpNav pointing. This paper also presents methods and results for a comparison of alternative pointing estimation techniques in order to understand their quality relative to highly accurate star-based pointing solutions. This analysis includes two cases of pointing estimation by the SPC software with different a priori errors and uncertainties, and a third pointing estimate was performed using the OD filter. This analysis characterized the accuracy and precision of these pointing estimation techniques relative to pointing solutions using long-exposure star images. We found that the OD-based pointing solutions performed best when compared to periods where we also had reliable star-based estimates.

The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission conducted nearly two years of proximity operations around asteroid (101955) Bennu. Optical navigation (OpNav)was critical to the success of OSIRIS-REx's mission to collect a sample from asteroid Bennu. Landmark-based OpNav was particularly important for achieving the highest precision mission requirements. This paper assesses the performance of the landmark OpNav after the transition from centroid-based OpNav at the end of the Orbital A phase. An overall evaluation of the landmark performance is presented as well as analysis of potential sensitivities to viewing conditions and a priori state information.

Carbonaceous asteroids, such as (101955) Bennu, preserve material from the early Solar System, including volatile compounds and organic molecules. We report spacecraft imaging and spectral data collected during and after retrieval of a sample from Bennu’s surface. The sampling event mobilized rocks and dust into a debris plume, excavating a 9-meter-long elliptical crater. This exposed material is darker, spectrally redder, and more abundant in fine particulates than the original surface. The bulk density of the displaced subsurface material was 500 to 700 kilograms per cubic meter, which is about half that of the whole asteroid. Particulates that landed on instrument optics spectrally resemble aqueously altered carbonaceous meteorites. The spacecraft stored 250 ± 101 grams of material, which will be delivered to Earth in 2023.

During its initial orbital phase in early 2019, the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) asteroid sample return mission detected small particles apparently emanating from the surface of the near-Earth asteroid (101955) Bennu in optical navigation images. Identification and characterization of the physical and dynamical properties of these objects became a mission priority in terms of both spacecraft safety and scientific investigation. Traditional techniques for particle identification and tracking typically rely on manual inspection and are often time-consuming. The large number of particles associated with the Bennu events and the mission criticality rendered manual inspection techniques infeasible for long-term operational support. In this work, we present techniques for autonomously detecting potential particles in monocular images and providing initial correspondences between observations in sequential images, as implemented for the OSIRIS-REx mission.

OSIRIS-REx began observing particle ejection events shortly after entering orbit around near-Earth asteroid (101955) Bennu in January 2019. For some of these events, the only observations of the ejected particles come from the first two images taken immediately after the event by OSIRIS-REx's NavCam 1 imager. Without three or more observations of each particle, traditional orbit determination is not possible. However, by assuming that the particles all ejected at the same time and location for a given event, and approximating that their velocities remained constant after ejection (a reasonable approximation for fast-moving particles, i.e., with velocities on the order of 10 cm/s or greater, given Bennu's weak gravity), we show that it is possible to estimate the particles' states from only two observations each. We applied this newly developed technique to reconstruct the particle ejection events observed by the OSIRIS-REx spacecraft during orbit about Bennu. Particles were estimated to have ejected with inertial velocities ranging from 7 cm/s to 3.3 m/s, leading to a variety of trajectory types. Most (>80%) of the analyzed events were estimated to have originated from midlatitude regions and to have occurred after noon (local solar time), between 12:44 and 18:52. Comparison with higher-fidelity orbit determination solutions for the events with sufficient observations demonstrates the validity of our approach and also sheds light on its biases. Our technique offers the capacity to meaningfully constrain the properties of particle ejection events from limited data.

The Touch And Go Camera System (TAGCAMS) is a three-camera-head instrument onboard NASA’s OSIRIS-REx asteroid sample return mission spacecraft. The purpose of TAGCAMS is to facilitate navigation to the target asteroid, (101955) Bennu; confirm acquisition of the asteroid sample; document asteroid sample stowage; and provide supplementary imaging for OSIRIS-REx science investigations. During the almost two-year OSIRIS-REx outbound cruise phase we pursued nine TAGCAMS imaging campaigns to check, calibrate and characterize the camera system’s performance before asteroid arrival and proximity operations began in late 2018. The TAGCAMS in-flight calibration dataset provides the relevant information to enable the three cameras to complete their primary observation goals during asteroid operations. The key performance parameters that we investigated in flight included: linearity, responsivity (both point source and extended body), dark current, hot pixels, pointing, image geometry transformation, image quality and stray light. Analyses of the in-flight performance either confirmed the continued applicability of the TAGCAMS ground test results or substantially improved upon the ground test knowledge. In addition, the TAGCAMS calibration observations identified the source of a spacecraft outgassing feature that guided successful remediation efforts prior to asteroid arrival.

The Lunar Polar Hydrogen Mapper (LunaH-Map) mission will map the distribution of hydrogen around the lunar South Pole using a miniature neutron spectrometer. The mission builds upon a decade of lunar science, which has revealed both regional and more localized enrichments of water ice near the lunar poles. Localized enrichments are primarily within permanently shadowed regions (PSRs) and craters throughout the South Pole. The spatial extent of these regions is often below the resolution of previous neutron instruments that have flown on lunar missions. The neutron leakage spectrum from planetary surfaces is primarily sensitive to hydrogen abundance in the top meter of regolith, however, for neutron spectrometers with omnidirectional sensitivity, the spatial resolution is limited by the spacecraft orbital altitude above the surface. A low altitude measurement from a distance on the same scale of the PSRs could spatially isolate and constrain the hydrogen enrichments both within and around within those regions. A small spacecraft mission is ideally suited to acquire the low-altitude measurements required to localize hydrogen enrichments using neutron spectroscopy at the lunar South Pole. LunaH-Map will use a solid iodine ion propulsion system, X-Band radio communications through the NASA Deep Space Network, star tracker, Command & Data Handling System, and EPS systems from Blue Canyon Technologies, solar arrays from MMA Designs, LLC, mission design and navigation by KinetX. Spacecraft systems design, integration, qualification, test, and mission operations are performed by Arizona State University, AZ Space Technologies and Qwaltec.