ALHAT System Validation

NASA has embarked on a multiyear technology development effort to develop a safe and precise lunar landing capability. The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is investigating a range of landing hazard detection methods while developing a hazard avoidance capability to best field test the proper set of relevant autonomous GNC technologies. Ultimately, the advancement of these technologies through the ALHAT Project will provide an ALHAT System capable of enabling next generation lunar lander vehicles to globally land precisely and safely regardless of lighting condition. This paper provides an overview of the ALHAT System and describes recent validation experiments that have advanced the highly capable GNC architecture

Mars entry navigation performance analysis using Monte Carlo techniques

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.Includes bibliographical references (p. 169-170).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.An atmospheric entry and descent full-state navigation filter is developed and presented. Using this filter a navigation performance analysis is performed to examine the effects of various instrument packages and differing sensor scenarios for the entry and descent phase of the Mars Aerial Regional-scale Environmental Survey (ARES) mission. Deterministic simulation in conjunction with Monte Carlo techniques is used to verify navigation performance of an extended Kalman filter. This analysis specifically compares the performance of four feasible instrument packages. examines navigation performance as it varies with changes to initial sensor activation altitude, and examines error sources and covariance trends for this entry and descent scenario. The results from the analysis show that large attitude uncertainty resulting from the LN200 IMU bias causes a breakdown of the filter algorithm dlue to nonlinearities. The addition of a surface relative velocity measurement, to the altimeter measurement provides only marginal position uncertainty improvement and significant velocity and attitude uncertainty improvement. Increasing the initial altitude for sensor activation provides slight improvements in position uncertainty. but large velocity and attitude uncertainty improvements. Finally, it is shown that initial state uncertainty dominates over all other error sources in this navigation analysis. Error growth within the principal states (position, velocity, and attitude) is predominantly a product of the near-constant attitude uncertainty as it transfers from the innocuous roll attitude channel into the more consequential pitch and yaw attitude channels.by Stephen C. Paschall, II.S.M

GENIE Flight Test Results and System Overview

NASA has envisioned a suite of lander test vehicles that will be flown in Earth s atmosphere to incrementally demonstrate applicable lunar lander performance in the terrestrial environment. As each terrestrial rocket progresses in maturity, relevant space flight technology matures to a higher technology readiness level, preparing it for inclusion on a future lunar lander design.. NASA s "Project M" lunar mission concept flew its first terrestrial rocket, RR1, in June 2010 in Caddo Mills, Texas. The Draper Laboratory built GENIE (Guidance Embedded Navigator Integration Environment) successfully demonstrated accurate, real time, embedded performance of Project M navigation and guidance algorithms in a highly dynamic environment. The RR1 vehicle, built by Armadillo Aerospace, performed a successful 60 second free flight and gave the team great confidence in Project M s highly reliable and robust GNC system design and implementation. This paper provides an overview of the GENIE system and describes recent flight performance test results onboard the RR1 terrestrial rocket

Post2 End-to-End Descent and Landing Simulation for ALHAT Design Analysis Cycle 2

The ALHAT project is an agency-level program involving NASA centers, academia, and industry, with a primary goal to develop a safe, autonomous, precision-landing system for robotic and crew-piloted lunar and planetary descent vehicles. POST2 is used as the 6DOF descent and landing trajectory simulation for determining integrated system performance of ALHAT landing-system models and lunar environment models. This paper presents updates in the development of the ALHAT POST2 simulation, as well as preliminary system performance analysis for ALDAC-2 used for the testing and assessment of ALHAT system models. The ALDAC-2 POST2 Monte Carlo simulation results have been generated and focus on HRN model performance with the fully integrated system, as well performance improvements of AGNC and TSAR model since the previous design analysis cycl

Advances in POST2 End-to-End Descent and Landing Simulation for the ALHAT Project

Program to Optimize Simulated Trajectories II (POST2) is used as a basis for an end-to-end descent and landing trajectory simulation that is essential in determining design and integration capability and system performance of the lunar descent and landing system and environment models for the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. The POST2 simulation provides a six degree-of-freedom capability necessary to test, design and operate a descent and landing system for successful lunar landing. This paper presents advances in the development and model-implementation of the POST2 simulation, as well as preliminary system performance analysis, used for the testing and evaluation of ALHAT project system models

Constitutional Law - First Amendment - Religion Clauses - State Regulation of Religious Organizations

The United States Supreme Court held that a state\u27s nondiscriminatory imposition of sales and use tax of religious on religious organization\u27s sales of religious materials did not violate the Free Exercise or Establishment Clauses. Jimmy Swaggart Ministries v Board of Equalization of California, 493 US __ , 110 S Ct 688 (1990)

Health Care, the Price System and the Conflict Between Access to Care and Cost-Containment

Health policy in the United States struggles with apparently conflicting purposes: (1) access to health care and (2) cost-containment. The failures of policy to resolve this apparent conflict have produced inequities in the health system and the perverse outcomes of high costs and poor access. The failures of policy are associated with the third-party payment system that has become a "rationing transaction" in John R. Commons' hierarchy of transactions. The dominion of private interests over the payment system elevates the financial interests of insurers over the interests of patients. Commons' approach to "reasonable value" as a means of resolving conflicts of interest through a process that engages all participants in the going concern suggests a strengthened role for the public sector in the payment system to achieve the public purposes of the health system.health policy, John R. Commons, health insurance,

Security of Expectations and Freedom of Choice in the Health Insurance Market

The third-party payment system protects security of expectations of providers and patients for payment for medical care. When health insurance coverage is lost through unemployment, security of expectations is threatened. The continuation coverage provisions of the Consolidated Omnibus Budget Reconciliation Act of 1985 ("COBRA") and the Health Insurance Portability and Accountability Act of 1996 ("HIPAA") were adopted to preserve access to medical care through the health insurance market. The author examines COBRA and HIPAA and concludes that these programs are ineffective because they fail to address the economic power of private interests.COBRA, John R. Commons, health insurance, HIPAA,