NASA Automated Rendezvous and Capture Review. Executive summary

In support of the Cargo Transfer Vehicle (CTV) Definition Studies in FY-92, the Advanced Program Development division of the Office of Space Flight at NASA Headquarters conducted an evaluation and review of the United States capabilities and state-of-the-art in Automated Rendezvous and Capture (AR&C). This review was held in Williamsburg, Virginia on 19-21 Nov. 1991 and included over 120 attendees from U.S. government organizations, industries, and universities. One hundred abstracts were submitted to the organizing committee for consideration. Forty-two were selected for presentation. The review was structured to include five technical sessions. Forty-two papers addressed topics in the five categories below: (1) hardware systems and components; (2) software systems; (3) integrated systems; (4) operations; and (5) supporting infrastructure

Autonomous RPOD Technology Challenges for the Coming Decade

Rendezvous Proximity Operations and Docking (RPOD) technologies are important to a wide range of future space endeavors. This paper will review some of the recent and ongoing activities related to autonomous RPOD capabilities and summarize the current state of the art. Gaps are identified where future investments are necessary to successfully execute some of the missions likely to be conducted within the next ten years. A proposed RPOD technology roadmap that meets the broad needs of NASA's future missions will be outlined, and ongoing activities at OSFC in support of a future satellite servicing mission are presented. The case presented shows that an evolutionary, stair-step technology development program. including a robust campaign of coordinated ground tests and space-based system-level technology demonstration missions, will ultimately yield a multi-use main-stream autonomous RPOD capability suite with cross-cutting benefits across a wide range of future applications

The Hera Radio Science Experiment at Didymos

Hera represents the European Space Agency's inaugural planetary defence space mission, and plays a pivotal role in the Asteroid Impact and Deflection Assessment international collaboration with NASA DART mission that performed the first asteroid deflection experiment using the kinetic impactor techniques. With the primary objective of conducting a detailed post-impact survey of the Didymos binary asteroid following the DART impact on its small moon called Dimorphos, Hera aims to comprehensively assess and characterize the feasibility of the kinetic impactor technique in asteroid deflection while conducting in-depth investigation of the asteroid binary, including its physical and compositional properties as well as the effect of the impact on the surface and/or shape of Dimorphos. In this work we describe the Hera radio science experiment, which will allow us to precisely estimate key parameters, including the mass, which is required to determine the momentum enhancement resulting from the DART impact, mass distribution, rotational states, relative orbits, and dynamics of the asteroids Didymos and Dimorphos. Through a multi-arc covariance analysis we present the achievable accuracy for these parameters, which consider the full expected asteroid phase and are based on ground radiometric, Hera optical images, and Hera to CubeSats InterSatellite Link radiometric measurements. The expected formal uncertainties for Didymos and Dimorphos GM are better than 0.01% and 0.1%, respectively, while their J2 formal uncertainties are better than 0.1% and 10%, respectively. Regarding their rotational state, the absolute spin pole orientations of the bodies can be recovered to better than 1 degree, and Dimorphos spin rate to better than 10^-3%. Dimorphos reconstructed relative orbit can be estimated at the sub-m level [...

NASA Capability Roadmaps Executive Summary

This document is the result of eight months of hard work and dedication from NASA, industry, other government agencies, and academic experts from across the nation. It provides a summary of the capabilities necessary to execute the Vision for Space Exploration and the key architecture decisions that drive the direction for those capabilities. This report is being provided to the Exploration Systems Architecture Study (ESAS) team for consideration in development of an architecture approach and investment strategy to support NASA future mission, programs and budget requests. In addition, it will be an excellent reference for NASA's strategic planning. A more detailed set of roadmaps at the technology and sub-capability levels are available on CD. These detailed products include key driving assumptions, capability maturation assessments, and technology and capability development roadmaps

LIDAR-Aided Inertial Navigation with Extended Kalman Filtering for Pinpoint Landing

In support of NASA s Autonomous Landing and Hazard Avoidance Technology (ALHAT) project, an extended Kalman filter routine has been developed for estimating the position, velocity, and attitude of a spacecraft during the landing phase of a planetary mission. The proposed filter combines measurements of acceleration and angular velocity from an inertial measurement unit (IMU) with range and Doppler velocity observations from an onboard light detection and ranging (LIDAR) system. These high-precision LIDAR measurements of distance to the ground and approach velocity will enable both robotic and manned vehicles to land safely and precisely at scientifically interesting sites. The filter has been extensively tested using a lunar landing simulation and shown to improve navigation over flat surfaces or rough terrain. Experimental results from a helicopter flight test performed at NASA Dryden in August 2008 demonstrate that LIDAR can be employed to significantly improve navigation based exclusively on IMU integration

Sequential estimation methods for small body optical navigation

As humans explore further into the solar system, small bodies such as asteroids and comets serve as critical stepping-stone destinations. Highly accurate navigation about these small bodies is critical for any future missions, and as a result is listed prominently among NASA's future goals in the NASA Office of Chief Technologist Roadmap. Due to the long communication light-time delays with the Earth, advances in small body navigation may enable missions currently not feasible, as well as significantly reduce dependence on ground resources. Increased operational agility will enable rapid decisions and opportunistic science measurements not possible in previous missions to small bodies. To assist NASA in accomplishing future small body navigation goals, several important advances are made. First, the effectiveness of modern orbit estimation techniques is investigated, with the higher order Additive Divided-Difference sigma point Filter (ADF) implemented and used along with the standard Extended Kalman Filter (EKF) to estimate the spacecraft state from optical small body surface landmark measurements. The ADF performs consistently better than the EKF in the simulations performed, with increasing improvement for higher levels of initial state error and longer intervals between photos of the surface. Second, a new method is created to improve onboard navigation filter performance in diverse and rapidly changing dynamical environments. The approach is to precompute a process noise profile along a reference trajectory using consider covariance analysis tools and filters. When used in an onboard navigation filter, the precomputed process noise allows the filter to account for time- and state-dependent perturbations in the dynamics. The new method also obviates the need for most or all traditional manual tuning of the filter, and provides significantly improved representation of the state uncertainty. Finally, a Simultaneous Localization And Mapping (SLAM) algorithm is employed to estimate the spin state of a tumbling small body (which are expected to be a significant percentage of the small bodies in the solar system), as well as the spacecraft state and surface landmark locations. For the small body characterization phase of the Rosetta mission, the state estimates converge successfully for large initial state errors. The SLAM algorithm remains effective for a range of small body spin states and masses that correspond to expected tumbling small bodies throughout the solar system. The SLAM algorithm is successfully applied to high fidelity independently simulated imagery of a tumbling small body generated by the European Space Agency, and a method for initializing the small body landmark locations is provided.Aerospace Engineerin

Comet nucleus and asteroid sample return missions

Three Advanced Design Projects have been completed this academic year at Penn State. At the beginning of the fall semester the students were organized into eight groups and given their choice of either a comet nucleus or an asteroid sample return mission. Once a mission had been chosen, the students developed conceptual designs. These were evaluated at the end of the fall semester and combined into three separate mission plans, including a comet nucleus same return (CNSR), a single asteroid sample return (SASR), and a multiple asteroid sample return (MASR). To facilitate the work required for each mission, the class was reorganized in the spring semester by combining groups to form three mission teams. An integration team consisting of two members from each group was formed for each mission so that communication and information exchange would be easier among the groups. The types of projects designed by the students evolved from numerous discussions with Penn State faculty and mission planners at the Johnson Space Center Human/Robotic Spacecraft Office. Robotic sample return missions are widely considered valuable precursors to manned missions in that they can provide details about a site's environment and scientific value. For example, a sample return from an asteroid might reveal valuable resources that, once mined, could be utilized for propulsion. These missions are also more adaptable when considering the risk to humans visiting unknown and potentially dangerous locations, such as a comet nucleus