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At least 739 records · Page 41

Automated Management of Small Unmanned Aircraft System (UAS) Communications and Navigation Contingency

The number of small Unmanned Aircraft System (sUAS) operating in the low-altitude of the National Airspace System (NAS) has been rapidly increasing in the past few years and this number is expected to grow in the future. However, aside from a few special cases, all sUAS must fly within visual line-of-sight (VLOS) of their operators and this limitation is blocking highly anticipated beyond visual line-of-sight (BVLOS) sUAS applications such as package delivery from practice. To enable routine low-altitude BVLOS operations, there needs to be a traffic management ecosystem that complements the FAA’s Air Traffic Management (ATM) system, which does not provide air traffic services under 400 feet above ground level (AGL). NASA has been pioneering research and development of this ecosystem under UAS Traffic Management (UTM) project since 2015 in a series of Technical Capability Levels (TCL) activities that are increasingly complex. In TCL1, completed in 2015, visual line-of-sight operations such as agriculture, firefighting, and infrastructure monitoring were addressed with a focus on geofencing and operations scheduling. Technologies and requirements needed for BVLOS operations in sparsely populated areas were examined in TCL2 in 2016, and those for operations over moderately populated areas in TCL3 in 2017 and 2018. TCL4 is building on the earlier TCLs and focuses on technologies and requirements for operations in higher-density urban areas for tasks such as newsgathering and package delivery and for managing large-scale contingencies. To coordinate and facilitate the incremental implementation of the UTM ecosystem in the NAS, a Research Transition Team (RTT) has been formed between the FAA, NASA, and industry. The RTT is divided into four subgroups, concept and use case development, data exchange and information architecture, sense and avoid, and communications and navigation (C&N). This paper focuses on C&N subgroup activities, in particular about the development of automated sUAS communications and navigation contingency management. The goal of this development is to prepare sUAS to display predictable behavior while handling C&N off-nominal events. It is expected that the adoption of the presented automated contingency management by the sUAS community will accommodate and inform rulemaking towards governing low-altitude BVLOS operations.

Unmanned Aviation Systems (UAS) Traffic Management↗

Weather Guidance for UAS Urban Medical Transport Missions

Unmanned aircraft will revolutionize healthcare services by providing efficient and expeditious delivery of life-saving transplant organs and supplies to hospitals in urban environments, where road traffic and congestion can slow delivery times and endanger lives. Bell has developed the Autonomous Pod Transport (APT) vehicle to serve this market, with entry into service in mid-2020s. Adverse weather conditions can introduce risks and inefficiencies in urban environments leading to flight delays and cancellations. In 2018, National Aeronautics and Space Administration (NASA) and Bell entered into a cooperative agreement, under the Systems Integration and Operationalization (SIO) program to tackle key challenges to enable future commercial unmanned aircraft operations. The Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) at the University of Massachusetts, Amherst, joined this team to demonstrate weather avoidance technologies for remotely piloted and autonomous vehicles. CASA has developed the ‘City Warn’ hazard alerting platform to gather weather information from various weather sensors and models, and based on user (or mission) preferences for alerting and on user (or unmanned aircraft) locations, the platform shares timely weather intelligence with users and the systems used by them for remote operations. This presentation discusses the weather avoidance solution developed during this project, leading up to the demonstration of the end-to-end system in Fall 2020. The presentation will cover the following topics: 1) goals related to weather avoidance 2) the design requirements process, including the results of pilot interviews, 3) weather observation and avoidance needs 4) selection of regional and national weather data sets 5) design of the weather graphical interface and 6) considerations for real-time weather alerting. The end-to-end system that was developed will be discussed, along with the results from the demonstration flight. The presentation will conclude with insights from the project team on lessons learned and best practices on weather avoidance technologies for the industry going ahead.

weather avoidance↗

Weather Guidance for UAS Urban Medical Transport Missions

Unmanned aircraft will revolutionize healthcare services by providing efficient and expeditious delivery of life-saving transplant organs and supplies to hospitals in urban environments, where road traffic and congestion can slow delivery times and endanger lives. Bell has developed the Autonomous Pod Transport (APT) vehicle to serve this market, with entry into service in mid-2020s. Adverse weather conditions can introduce risks and inefficiencies in urban environments leading to flight delays and cancellations. In 2018, National Aeronautics and Space Administration (NASA) and Bell entered into a cooperative agreement, under the Systems Integration and Operationalization (SIO) program to tackle key challenges to enable future commercial unmanned aircraft operations. The Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) at the University of Massachusetts, Amherst, joined this team to demonstrate weather avoidance technologies for remotely piloted and autonomous vehicles. CASA has developed the ‘City Warn’ hazard alerting platform to gather weather information from various weather sensors and models, and based on user (or mission) preferences for alerting and on user (or unmanned aircraft) locations, the platform shares timely weather intelligence with users and the systems used by them for remote operations. This presentation discusses the weather avoidance solution developed during this project, leading up to the demonstration of the end-to-end system in Fall 2020. The presentation will cover the following topics: 1) goals related to weather avoidance 2) the design requirements process, including the results of pilot interviews, 3) weather observation and avoidance needs 4) selection of regional and national weather data sets 5) design of the weather graphical interface and 6) considerations for real-time weather alerting. The end-to-end system that was developed will be discussed, along with the results from the demonstration flight. The presentation will conclude with insights from the project team on lessons learned and best practices on weather avoidance technologies for the industry going ahead.

weather avoidance↗

Mars Science Laboratory interplanetary navigaton analysis

The Mars Science Laboratory (MSL) is a NASA rover mission that will be launched in late 2011 and will land on Mars in August of 2012. This paper describes the analyses performed to validate the navigation system for launch, interplanetary cruise, and approach. MSL will use guidance during its descent into Mars in order to minimize landing dispersions, and therefore will be able to use smaller landing zones that are closer to terrain of high scientific interest. This will require a more accurate delivery of the spacecraft to the atmospheric entry interface, and a late update of the state of the spacecraft at entry. During cruise and approach the spacecraft may perform up to six trajectory correction maneuvers (TCMs), to target to the desired landing site with the required flight path angle at entry. Approach orbit determination covariance analyses have been performed to evaluate the accuracy that can be achieved in delivering the spacecraft to the entry interface point, and to determine how accurately the state of the spacecraft can be predicted to initialize the guidance algorithm. In addition, a sensitivity analysis has been performed to evaluate which factors most contribute to the improvement or degradation of the navigation performance, for both entry flight path angle delivery and entry state knowledge.

Wong, Mau C.↗

Evaluation of Opportunistic Contact Graph Routing in Random Mobility Environments

Routing in networks where nodes move randomly is particularly challenging due their potentially unpredictable, and rapidly changing topology. Several routing algorithms have been presented in the literature to address the needs of such networks, most of them implementing variants of controlled network flooding in the hope of successful data delivery. In this note, we compare the results of previous routing algorithms with Opportunistic Contact Graph Routing (OCGR), an enhanced version of Contact Graph Routing (CGR) that is suitable for networks where contacts cannot always be scheduled ahead of time. To perform the benchmark, we simulate a network of nodes moving in a certain space according to the Random Waypoint Mobility Model, and then take measurements of bundle delivery probabilty and overhead ratio as metrics of performance and cost respectively. Through this exercise, we demonstrate that the performance of OCGR is highly dependent on the type of network under consideration (e.g. very sparse vs. densely connected) and the assumed mobility model.

Burleigh, Scott↗

Orbit determination sensitivity analysis for th Europa Clipper Mission tour

This paper will assess the sensitivity of OD delivery and knowledge performance for the current Europa Mission trajectory through parametric variation of a baseline tour navigation strategy.2 Variations of several parameters are run, one at a time, to determine the impact on spacecraft ephemeris uncertainties at OD knowledge, delivery, and encounter reconstruction times. There are two basic categories of sensitivity runs considered: variations of tracking data type and amount, and variations to dynamic parameters. The results of these parameter and data variations are compared against the values necessary to achieve accurate instrument pointing and observation planning.

Young, Brian↗

Delineation of vulnerable areas to water erosion in a mountain region using SDR-InVEST model: A case study of the Ourika watershed, Morocco

The Ourika watershed is characterized by higher than average flood flows, a rugged topography, a sparse vegetation cover and a friable substrate that makes it vulnerable to soil erosion. Soil is an important non-renewable asset capital, providing several ecosystem services that sustain life through physical and biological regulation processes. The loss, or otherwise, redistribution of biota by soil erosion in the Ourika watershed has received little attention and thus constitutes a key knowledge gap that needs to be addressed. This study quantifies the level of erosion and maps its spatial distribution in the watershed using the Sediment Delivery Ratio (SDR) of the Integrated Valuation of Ecosystem Services and Tradeoffs model (InVEST3.6.0). The SDR maps the overland sediment generation and delivery to the stream at the watershed level using rainfall, soil properties, topography, cover management and cropping practices as predefined set of input variables. Recommended internal model calibration was used and results were compared to similar studies carried out in different parts of Morocco for validation. The results reveal that 93% of the watershed is subject to a strong rainfall aggressiveness greater than 50 MJ mm ha–1 h–1 yr1 under an average rainfall intensity of 541 mm/year, rainfall capacity to initiate the detachment and transport of soil particles by runoff, and only 11.5% of the watershed area is protected with vegetative cover. We find that overall, the Ourika watershed is losing its soil to erosion at an alarming average rate of 258.48 ton.ha–1.yr–1, a rate well above the tolerable threshold of 7ton.ha–1.yr–1. The spatial distribution of this loss shows areas that need to be urgently remedied. The primary factors for soil erosion in the Ourika watershed appear to be related to the aggressive nature of local rainfall and the inherent susceptibility of soils, which can be costly to this cash-crop region. Because rainfall intensity, soil properties, and topography are intrinsic characteristics of the watershed, we suggest that seasonally adapted cropping rotations that maintains conservative practices with a high cover management may reduce soil erosion in the Ourika watershed.

Erosion↗

The Lunar Lab Initiative

Analogous to terrestrial Antarctic basecamps at our south pole, space exploration outposts will be a combination of habitation and science-focused assets. The Artemis Exploration Roadmap endeavors to establish a sustained human presence on the lunar south pole starting in 2028. Within the planned Artemis Base Camp, most efforts to date have focused on the habitation assets or a mixture of science and habitation assets . With the recent advent of commercial lunar landing capabilities, the trade space can be further expanded to include dedicated science focused assets that ensure adequate science capability. To that end, the Forge, an innovation team initiative created at the Johnson Space Center (JSC), explored alternative ways to increase the science capabilities within the basecamp. The Forge uses structured brainstorming and facilitation to increase innovation within the assigned team, while executing its process in a rapid turnaround fashion for ideation and design study. As a pilot study for the Forge, a multi-disciplinary team investigated a lunar lab module to augment the lunar surface plans for Artemis. This formulation study evaluated the scientific and operational considerations for this dedicated crew space that would increase the capabilities of lunar surface science operations. The trade space evaluated single lunar lander delivery versus multiple lunar lander delivery for module assembly, alternative structural designs, the science instrument outfitting with mapping to scientific goals to maximize lunar science objectives, and how the lab would be operated. The lab operations options explored a stand-alone facility, as well as a facility integrated into a larger lunar surface complex, while evaluating crew usage and habitability considerations. The resulting alternatives were evaluated by the Forge team with a set of metrics to determine their originality, feasibility, and science performance, and thereby provide a recommendation to the lunar architecture planning team. Lessons learned from the lunar lab study were compiled to improve the process and tools for future Forge studies. Forward work, open issues, and challenges to further refine the design of the various science-focused asset options were also documented. By providing a robust science capability at humanity’s furthest outpost, we can plan for a sustained human lunar presence once the initial lunar surface access capability is well established.

Lunar outpost↗

Enabling New and Innovative Low Cost Mars Science Missions with the Adaptable, Deployable, Entry and Placement Technology (ADEPT)

The Adaptive Deployable Entry and Placement Technology (ADEPT) offers a delivery capability for Small Sat or CubeSat orbiter(s), in-situ elements, or landers. ADEPT can deliver the same science payload to a destination with a stowed diameter a factor of 3-4 times smaller than an equivalent rigid aeroshell, alleviating volumetric constraints on the secondary payload accommodation or primary carrier spacecraft bus. The ADEPT system can support payload over a range of mass and geometries to offer a delivery capability for a single or constellation of spacecraft supporting the goals and objectives of “Low Cost Mars Science Missions.”

ADEPT↗

200 Gbps TBIRD CubeSat Downlink: Pre-Flight Test Results

The Terabyte Infrared Delivery (TBIRD) program will establish an optical communication link from a 6Unanosatellite in low-Earth orbit to a ground station at burst rates up to 200 Gbps. The system is capable of reliable data delivery from a 2 TB storage buffer on the payload to a ground terminal in the presence of atmospheric fading. An overview of the communication architecture for TBIRD is provided as well as results from communications performance testing of the 3U lasercom payload prior to spacecraft integration. Launch is scheduled for mid-year 2022.

space communications↗

Osiris-Rex Shape Model Performance During the Navigation Campaign

The Navigation Campaign of the OSIRIS-REx mission began when the first image of Bennu was recorded by the PolyCam high-resolution imager on Au-gust 17, 2018. In the ensuing months, two teams began building shape models based on imagery taken during the Approach and Preliminary survey phases to be used for the transition to landmark navigation in the Orbital A phase. The orbit determination team began analyzing and characterizing the performance and errors associated with each shape model delivery working closely to iterate on the next shape model delivery. By the end of Orbital A, shape models produced by the Altimetry Working Group and JPL exceeded pre-launch performance re-quirements. This paper provides a summary of the analysis performed during operations.

Leonard, Jason M.↗

Terminal Tracking for the Lucy Trojan Asteroid Mission

The most recent NASA Discovery class mission to fly is the Lucy mission to the Trojan Asteroids of Jupiter. Launched in October of 2021, Lucy’s destination will be the unexplored Jupiter Trojan Asteroids that orbit the Sun at the stable L4 and L5 points ahead of, and behind Jupiter. This 12-yearmission will perform close flybys of 1 main belt asteroid, Donaldjohanson, and 7 Trojans asteroids: Eurybates and its satellite Queta, Polymele, Leucus, Orus, and the near equal mass Trojan binary pair, Patroclus andMenoetius. The large distance from earth for the encounters, the high relative velocities and sun incidence angles on approach,and the limited number of Earth observations of the Trojans,make the delivery knowledge highly uncertain. To reduce the delivery uncertainties and maximize science return, Lucy employs a Terminal Tracking System consisting of optical imaging, centroiding and state estimation of the Trojan asteroids on approach and through close approach. This paper presents the Lucy Terminal Tracking System implementation, a brief overview of the mission and the GN&C subsystem.

Philip G Good↗

Deployable Entry Vehicles for Future Science and Exploration Missions

Deployable Entry Vehicle (DEV) technology has made significant advances over the last decade with ground test development campaigns and flight test demonstrations. DEVs offer benefits over traditional rigid entry vehicles including lower volume and mass, while enabling larger payload delivery and greater landing access. A crucial mission benefit is the DEV capability to transform from a compactly stowed launch configuration to a high drag area entry system for delivery of landers, rovers, aerial platforms, and orbiters (via aerocapture). These benefits span the range of mission classes from Small Satellite to human-class exploration systems. This presentation will describe DEV technology development status, highlight mission concepts, and recommend future investments.

Mission Design↗

Recent Advances in the U.S. in Ablative TPS for In-situ Exploration of Giant Planets

The Decadal Survey report released [1] prioritizes Uranus as the highest priority Flagship class mission to be explored with an orbiter and a probe and it also recommended Saturn Probe under New Frontiers mission class. Thermal protection system (TPS) is essential for Uranus and Saturn probe missions. The two cardinal requirements are that it must be fail-safe and yet be mass efficient. The Decadal Survey report also pointed out the readiness of heatshield for extreme entry environment technology (HEEET) at TRL 6 for probe missions at Gas Giants. HEEET relies on 3-D weaving and is shown to be a robust and mass efficient TPS through ground testing and analysis. HEEET was matured to TRL 6 in 2019. HEEET was reported at the Ice Giant Workshop in 2019 at Marseille. Since 2019, significant advances have been made primarily because of Mars Sample Return (MSR) mission. MSR baselined 3-D Woven TPS as its heatshield for the earth entry system. MSR earth entry system (EES) requirements and the resulting heatshield/TPS requirements are most stringent of all entry missions. This is a result of backward contamination protection which classifies MSR as a “restricted class 5” mission to safeguard the accidental release of potentially hazardous Mars Sample into Earth’s atmosphere. Complex requirements for the heatshield start with micro-meteor impact tolerance followed by the requirement for steep entry to minimize the size of the impact footprint which results in extreme heating. The heatshield is part of the impact attenuation system. The EES architecture does not use a parachute and is designed to tolerate impact loads. Hence heatshield TPS selection and design becomes one of the key challenges. After completion of the HEEET technology maturation in 2019, IRAD efforts focused on assessing the 3-D Woven family of TPS to MSR EES. After nearly two years of evaluation of alternate TPS such as carbon phenolic, C-C hot structure, PICA, and 3-D woven family of TPS, a single layer 3-D woven TPS derived from the dual-layer HEEET was down selected and is currently the baseline. A new loom capable of weaving the single-layer 3-D woven preform at 80” wide has been designed, assembled and is currently on the verge of weaving the MSR EES TPS. During the HEEET maturation and the follow-on development, the single-layer TPS has been tested at extreme heating conditions. As a result, single layer TPS was recommended and evaluated during the Planetary Mission Concept Studies funded by NASA in preparation for the Decadal committee. In addition, in anticipation of Saturn mission proposals, single layer was evaluated as well. Aerocapture can reduce the trip time, also allow bigger payload fraction and in addition, it allows for the possibility of probe delivery once the spacecraft is in orbit. This can lead to obtaining both in-situ data as well as data from orbit simultaneously. Since Aerocapture depletes energy/velocity, probe delivery from orbit reduces the demand on TPS. Aerocapture was mentioned in the Decadal Study report as ready for implementation, but due to perceived risk it is not adopted by the mission designers. Establishing TPS readiness for aerocapture missions will be addressed. Going one step beyond aerocapture is aerogravity assist if fast return is the goal. Recent studies [4] looked at aerogravity assist and the TPS readiness. This talk will highlight both aerocapture and aerogravity assist from a TPS perspective. The main objective of this proposed talk is to present a comprehensive picture of the SOA TPS technology including recent developments. The talk will highlight advances in manufacturing, results from the Decadal White Papers, PMCS and other studies, and aerocapture and aerogravity assist that could play a role in the near or far term in-situ exploration.

E. Venkatapathy↗

Extending the Licklider Transmission Protocol to Multi-Band Links

Most deep space missions return data to Earth using links operating at a single frequency band. Indeed, their data requirements are low enough that bandwidth regulations do not constrain the system. In contrast, spacecraft such as Kepler or Europa Clipper are transitioning to a new operational paradigm where engineering and science data are transmitted through simultaneous links operating at different frequency bands (henceforth termed multi-band links). This ensures, for instance, that critical data is correctly received using a well characterized X-band link, while science data at a much larger data rate can be returned efficiently (both in terms of bandwidth and energy) through a Ka-band link.Having a spacecraft establish two simultaneous links with a ground station opens a large span of potential improvements for space communications and mission operations. In this paper, we consider the problem of running a Licklider Transmission Protocol (LTP) session over a multi-band link. LTP is an implementation of a selective Automatic Repeat reQuest (ARQ) protocol, i.e. it ensures correct delivery of data over an error prone link with potentially long propagation delays. To maximize its efficiency in deep space environments, LTP operates in deferred-ACK mode and is typically included as one of the core protocols in the Delay Tolerant Networking (DTN) suite.The contributions of this paper are as follows: First, we propose an extension to LTP for multi-band links (denoted MBLTP) and sketch how it can be implemented without modifying the current definition of LTP data units. Next, we develop bounds on the performance of MBLTP when transmitting a single data file over a multi-band link. Three metrics are considered, file expected delivery time, total energy spent and bundle jitter. The results of the analytic model are first benchmarked against simulations to ensure validity, and then compared against the performance of both traditional LTP and Parallel LTP (PLTP).We demonstrate that MBLTP can significantly reduce the latency and jitter with which data products are delivered to destination over a deep space link compared to LTP at moderate energy cost. Similarly, we also demonstrate that MBLTP outperforms PLTP in all considered metrics.

Sanchez Net, Marc↗

The Space Superhighway: A Cost Analysis of an In-Space Logistics Resupply Network

The Space Superhighway is a concept for an in-space logistics network for payload delivery and propellant resupply within the Earth-Moon system. It is expected that in the next several years the number of spacecraft in cislunar space will increase significantly. Commercial launch service providers have significantly reduced the cost of access to space and reduced the barrier to entry for private companies to build and operate their own satellites. Many of these newer satellites are being designed to take advantage of future In-space Servicing, Assembly, and Manufacturing (ISAM) capabilities. In addition, the National Aeronautics and Space Administration (NASA) intends to develop and maintain a sustained human presence in cislunar space and on the surface of the Moon. The sustained lunar presence will then serve as a steppingstone for human missions to Mars. The combined demand for propellant resupply and payload delivery in cislunar space for NASA's Moon to Mars campaign in addition to commercial ventures will likely exceed 1,000 t in the upcoming decades. This work presents a concept for an in-space logistics network to fulfill that demand. The network consists of commercial launch vehicles, propellant tankers, orbital depots, and in-space electric propulsion tugs. This work specifically analyzes the cost of developing, producing, and operating such a network at varying levels of customer demand.

nrho↗

The Space Superhighway: A Cost Analysis of an In-Space Logistics Resupply Network

The Space Superhighway is a concept for an in-space logistics network for payload delivery and propellant resupply within the Earth-Moon system. It is expected that in the next several years the number of spacecraft in cislunar space will increase significantly. Commercial launch service providers have significantly reduced the cost of access to space and reduced the barrier to entry for private companies to build and operate their own satellites. Many of these newer satellites are being designed to take advantage of future In-space Servicing, Assembly, and Manufacturing (ISAM) capabilities. In addition, the National Aeronautics and Space Administration (NASA) intends to develop and maintain a sustained human presence in cislunar space and on the surface of the Moon. The sustained lunar presence will then serve as a steppingstone for human missions to Mars. The combined demand for propellant resupply and payload delivery in cislunar space for NASA's Moon to Mars campaign in addition to commercial ventures will likely exceed 1,000 t in the upcoming decades. This work presents a concept for an in-space logistics network to fulfill that demand. The network consists of commercial launch vehicles, propellant tankers, orbital depots, and in-space electric propulsion tugs. This work specifically analyzes the cost of developing, producing, and operating such a network at varying levels of customer demand.

space superhighway↗

Overview of NASA’s Break the Ice Lunar Challenge Phase 1

As NASA works to extend human exploration of the solar system, a sustained presence on the Moon will be critical for developing and testing the technologies and systems needed for future missions to Mars and beyond. In situ resource utilization (ISRU)—the use of lunar materials for life support, fuel, energy, manufacturing, and construction—is necessary to limit the delivery of supplies from Earth. One of the most important of these resources is water. Water supports all life on Earth and will be critical to supporting human exploration beyond Earth. On the Moon, water is trapped in icy regolith at the lunar poles, including inside permanently dark and cold craters. Novel approaches are needed to excavate the icy regolith and transport it for processing in support of permanent human missions on the Moon. To accelerate the development of such approaches and to seek diverse ideas, NASA’s Centennial Challenges launched the Break the Ice Lunar Challenge in November 2020. Phase 1 of the challenge was focused on stimulating innovative approaches for excavating icy regolith and delivering water in extreme lunar environmental conditions. The challenge sought to incentivize solutions for maximizing water delivery while minimizing energy use and the mass of equipment required to be transported to the lunar surface. Submissions for phase 1 of the challenge were due in June 2021 and winners were announced in August 2021. This paper provides details about the execution of the challenge, solutions received, criteria used to select winning solutions, and status of the phase 2 of the challenge.

Naveen Vetcha↗