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NASA NTRS2003

The NASA Materials Science Research Program - It's New Strategic Goals and Plans

In 2001, the NASA created a separate science enterprise, the Office of Biological and Physical Research (OBPR), to perform strategical and fundamental research bringing together physics, chemistry, biology, and engineering to solve problems needed for future agency mission goals. The Materials Science Program is one of basic research disciplines within this new Enterprise's Division of Physical Sciences Research. The Materials Science Program participates to utilize effective use of International Space Station (ISS) experimental facilities, target new scientific and technology questions, and transfer results for Earth benefits. The program has recently pursued new investigative research in areas necessary to expand NASA knowledge base for exploration of the universe, some of which will need access to the microgravity of space. The program has a wide variety of traditional ground and flight based research related types of basic science related to materials crystallization, fundamental processing, and properties characterization in order to obtain basic understanding of various phenomena effects and relationships to the structures, processing, and properties of materials. A summary of the types and sources for this research is presented and those experiments planned for the space. Areas to help expand the science basis for NASA future missions are described. An overview of the program is given including the scope of the current and future NASA Research Announcements with emphasis on new materials science initiatives. A description of the planned flight experiments to be conducted on the International Space Station program along with the planned facility class Materials Science Research Rack (MSRR) and Microgravity Glovebox (MSG) type investigations.

Schlagheck, Ronald A.↗
NASA NTRS2003

Propulsion Ground Testing: Planning for the Future

Advanced planners are constantly being asked to plan for the provision of future test capability. Historically, this capability is provided either by substantial investment in new test facility capabilities, or in the substantial investment in the modification of pre-exiting test facilities. The key words in the previous sentence are 'substantial investment.' In the evolving environment of increasingly constrained resources, how is an advanced planner to plan for the provisions of such capabilities? Additionally, the conundrum exists that program formulation decisions are being made based on both life cycle cost decisions in an environment in which the more immediate challenge of front-end capital investment oftentimes is the linchpin upon which early decisions are made. In such an environment, how are plans and decisions made? This paper cites examples of decisions made in the past in the area of both major test facility upgrades, as well as major new test facility investment.

Bruce, Robert↗
NASA NTRS2004

Test Planning Approach and Lessons

As NASA began technology risk reduction activities and planning for the next generation launch vehicle under the Space Launch Initiative (SLI), now the Next Generation Launch Technology (NGLT) Program, a review of past large liquid rocket engine development programs was performed. The intent of the review was to identify any significant lessons from the development testing programs that could be applied to current and future engine development programs. Because the primary prototype engine in design at the time of this study was the Boeing-Rocketdyne RS-84, the study was slightly biased towards LOX/RP-1 liquid propellant engines. However, the significant lessons identified are universal. It is anticipated that these lessons will serve as a reference for test planning in the Engine Systems Group at Marshall Space Flight Center (MSFC). Towards the end of F-1 and J-2 engine development testing, NASA/MSFC asked Rocketdyne to review those test programs. The result was a document titled, Study to Accelerate Development by Test of a Rocket Engine (R-8099). The "intent (of this study) is to apply this thinking and learning to more efficiently develop rocket engines to high reliability with improved cost effectivenes" Additionally, several other engine programs were reviewed - such as SSME, NSTS, STME, MC-1, and RS-83- to support or refute the R-8099. R-8099 revealed two primary lessons for test planning, which were supported by the other engine development programs. First, engine development programs can benefit from arranging the test program for engine system testing as early as feasible. The best test for determining environments is at the system level, the closest to the operational flight environment. Secondly, the component testing, which tends to be elaborate, should instead be geared towards reducing risk to enable system test. Technical risk can be reduced at the component level, but the design can only be truly verified and validated after engine system testing.

Parkinson, Douglas A.↗
NASA NTRS2004

Compiling Planning into Scheduling: A Sketch

Although there are many approaches for compiling a planning problem into a static CSP or a scheduling problem, current approaches essentially preserve the structure of the planning problem in the encoding. In this pape: we present a fundamentally different encoding that more accurately resembles a scheduling problem. We sketch the approach and argue, based on an example, that it is possible to automate the generation of such an encoding for problems with certain properties and thus produce a compiler of planning into scheduling problems. Furthermore we argue that many NASA problems exhibit these properties and that such a compiler would provide benefits to both theory and practice.

Bedrax-Weiss, Tania↗
NASA NTRS2004

Scaling Up Decision Theoretic Planning to Planetary Rover Problems

Because of communication limits, planetary rovers must operate autonomously during consequent durations. The ability to plan under uncertainty is one of the main components of autonomy. Previous approaches to planning under uncertainty in NASA applications are not able to address the challenges of future missions, because of several apparent limits. On another side, decision theory provides a solid principle framework for reasoning about uncertainty and rewards. Unfortunately, there are several obstacles to a direct application of decision-theoretic techniques to the rover domain. This paper focuses on the issues of structure and concurrency, and continuous state variables. We describes two techniques currently under development that address specifically these issues and allow scaling-up decision theoretic solution techniques to planetary rover planning problems involving a small number of goals.

Meuleau, Nicolas↗
NASA NTRS2003

Physical sciences research plans for the International Space Station

The restructuring of the research capabilities of the International Space Station has forced a reassessment of the Physical Sciences research plans and a re-targeting of the major scientific thrusts. The combination of already selected peer-reviewed flight investigations with the initiation of new research and technology programs will allow the maximization of the ISS scientific and technological potential. Fundamental and applied research will use a combination of ISS-based facilities, ground-based activities, and other experimental platforms to address issues impacting fundamental knowledge, industrial and medical applications on Earth, and the technology required for human space exploration. The current flight investigation research plan shows a large number of principal investigators selected to use the remaining planned research facilities. c2003 American Institute of Aeronautics and Astronautics. Published by Elsevier Science Ltd. All rights reserved.

manned↗
NASA NTRS2003

Propulsion Ground Testing: Planning for the Future

Advanced planners are constantly being asked to plan for the provision of future test capability. Historically, this capability is provided either by substantial investment in new test facility capabilities, or in the substantial investment in the modification of pre- existing test capabilities. The key words in the previous sentence are "substantial investment". In the evolving environment of increasingly constrained resources, how is an advanced planner to plan for the provisions of such capabilities? Additionally, the conundrum exists that program formulation decisions are being made based upon both life cycle cost decisions in an environment in which the more immediate challenge of "front-end" capital investment? Often times is the linch-pin upon which early decisions are made. In such an environment, how are plans and decisions made? This paper cites examples of decisions made in the past in the area of both major test facility upgrades, as well as major new test facility investment.

Aerospace Systems↗
NASA NTRS1995

NASA science utilization plans for the Space Station

The Mir-1 and International Space Station Alpha capabilities present the science community with unique long duration platforms to conduct a wide range of scientific research in the microgravity and life sciences as well as in the observational sciences, NASA is developing plans to use the capabilities of Mir and Space Station as they emerge during the development of the orbital program. In both cases the planned science utilization programs take advantage of the volume, crew, power, microgravity and logistics resupply unique to each phase. The paper will present these utilization plans in the context of an evolving scientific program.

manned↗
NASA NTRS2004

Model-based Executive Control through Reactive Planning for Autonomous Rovers

This paper reports on the design and implementation of a real-time executive for a mobile rover that uses a model-based, declarative approach. The control system is based on the Intelligent Distributed Execution Architecture (IDEA), an approach to planning and execution that provides a unified representational and computational framework for an autonomous agent. The basic hypothesis of IDEA is that a large control system can be structured as a collection of interacting agents, each with the same fundamental structure. We show that planning and real-time response are compatible if the executive minimizes the size of the planning problem. We detail the implementation of this approach on an exploration rover (Gromit an RWI ATRV Junior at NASA Ames) presenting different IDEA controllers of the same domain and comparing them with more classical approaches. We demonstrate that the approach is scalable to complex coordination of functional modules needed for autonomous navigation and exploration.

Finzi, Alberto↗
NASA NTRS2004

Global Precipitation Measurement (GPM) Ground Validation: Plans and Preparations

The Global Precipitation Measurement (GPM) program is an international partnership led by the National Aeronautics and Space Administration (NASA) and the Japan Aerospace Exploration Agency (JAXA). GPM will improve climate, weather, and hydro-meteorological forecasts through more frequent and more accurate measurement of precipitation across the globe. This paper describes the concept, the planning, and the preparations for Ground Validation within the GPM program. Ground Validation (GV) plays an important role in the program by investigating and quantitatively assessing the errors within the satellite retrievals. These quantitative estimates of retrieval errors will assist the scientific community by bounding the errors within their research products. The two fundamental requirements of the GPM Ground Validation program are: (1) error characterization of the precipitation retrievals and (2) continual improvement of the satellite retrieval algorithms. These two driving requirements determine the measurements, instrumentation, and location for ground observations. This paper outlines GV plans for estimating the systematic and random components of retrieval error and for characterizing the spatial p d temporal structure of the error and plans for algorithm improvement in which error models are developed and experimentally explored to uncover the physical causes of errors within the retrievals. This paper discusses NASA locations for GV measurements as well as anticipated locations from international GPM partners. NASA's primary locations for validation measurements are an oceanic site at Kwajalein Atoll in the Republic of the Marshall Islands and a continental site in north-central Oklahoma at the U.S. Department of Energy's Atmospheric Radiation Measurement Program site.

Schwaller, M.↗
NASA NTRS1990

A Plan for the Development and Demonstration of Optical Communications for Deep Space

In this article, an overall plan for the development and demonstration of optical communications for deep-space applications is presented. The current state of the technology for optical communications is presented. Then, the development and demonstration plan is presented in two parts: the overall major systems activities, followed by the generic technology developments that will enable them. The plan covers the path from laboratory subsystems demonstrations out to a full-scale flight experiment system for the proposed Mars Communications Relay Orbiter mission.

Lesh, J. R.↗
NASA NTRS1952

An Approximate Method of Calculating the Deformations of Wings Having Swept, M or W, A, and Swept-Tip Plan Forms

An approximate method of calculating the deformations of wings of uniform thickness having swept, M or W, Delta, and swept-tip plan forms is presented. The method employs an adjustment to the elementary beam theory to account for the effect of the triangular root portion of a swept wing on the deformation of the outboard section of the wing. To demonstrate the general applicability of the method, the modified elementary theory is applied to the more complex M or W, Delta, and swept-tip plan forms as well as to swept plan forms. For the purpose of calculating angles of attack, it is shown that the unmodified elementary beam theory applied to that part of the wing outboard of the root triangle produces satisfactory results. However, for calculating deflections it is necessary to include the effects of the root-triangle deformation.

Zender, George W.↗
NASA NTRS2005

Validation for the Tropical Rainfall Measuring Mission: Lessons Learned and Future Plans

The Tropical Rainfall Measuring Mission (TRMM) was launched in November 1997 and is a highly regarded and successful mission. A major component of the TRMM program was its Ground Validation (GV) program. Through dedicated research and hard work by many groups, both the GV and satellite-retrieved rain estimates have shown a convergence at key GV sites, lending credibility to the global TRMM estimates. To be sure, there are some regional differences between the various satellite estimates themselves, which still need to be addressed; however, it can be said with some certainty that TRMM has provided a high-quality, long-term climatological data set for researchers that provides errors on the order of 10-20%, rather than pre-TRMM era error estimates on the order of 50-100%. The TRMM GV program's main operational task is to provide rainfall products for four sites: Darwin, Australia (DARW); Houston, Texas (HSTN); Kwajalein, Republic of the Marshall Islands (KWAJ); and, Melbourne, Florida (MELB). A comparison between TRMM Ground Validation (Version 5) and Satellite (Version 6) rain intensity estimates is presented. The gridded satellite product (3668) will be compared to GV Level II rain-intensity and -type maps (2A53 and 2A54, respectively). The 3G68 product represents a 0.5 deg x 0.5 deg data grid providing estimates of rain intensities from the TRMM Precipitation Radar (PR), Microwave Imager (TMI) and Combined (COM) algorithms. The comparisons will be sub-setted according to geographical type (land, coast and ocean). The convergence of the GV and satellite estimates bodes well for expectations for the proposed Global Precipitation Measurement (GPM) program and this study and others are being leveraged towards planning GV goals for GPM. A discussion of lessons learned and future plans for TRMM GV in planning for GPM will also be provided.

Wolff, David B.↗
NASA NTRS2005

Mixed-Initiative Activity Planning for Mars Rovers

One of the ground tools used to operate the Mars Exploration Rovers is a mixed-initiative planning system called MAPGEN. The role of the system is to assist operators building daily plans for each of the rovers, maximizing science return, while maintaining rover safety and abiding by science and engineering constraints. In this paper, we describe the MAPGEN system, focusing on the mixed-initiative planning aspect. We note important challenges, both in terms of human interaction and in terms of automated reasoning requirements. We then describe the approaches taken in MAPGEN, focusing on the novel methods developed by our team.

Bresina, John↗
NASA NTRS2005

Mixed-Initiative Planning in MAPGEN: Capabilities and Shortcomings

MAPGEN (Mixed-initiative Activity Plan GENerator) is a mixed-initiative system that employs automated constraint-based planning, scheduling, and temporal reasoning to assist the Mars Exploration Rover mission operations staff in generating the daily activity plans. This paper describes the mixed-initiative capabilities of MAPGEN, identifies shortcomings with the deployed system, and discusses ongoing work to address some of these shortcomings.

Bresina, John L.↗
NASA NTRS2005

Addendum to Air Quality: Decision Support Tools, Partner Plans, Working Groups, Committees

In the original report dated February 11, 2005, the utility of NASA Earth science data in the air quality activities of other agencies and organizations was assessed by reviewing strategic and mission plans and by conducting personal interviews with agency experts to identify and investigate agencies with the potential for partnership with NASA. The overarching agency strategic plans were reviewed and commonalities such as the desire for partnerships and technology development were noted. This addendum to the original report contains such information about the Tennessee Valley Authority and will be inserted as Section 2.6 of "Air Quality: Decision Support Tools, Partner Plans, Working Groups, Committees."

Holekamp, Kara↗
NASA NTRS2005

Activity Scratchpad Prototype: Simplifying the Rover Activity Planning Cycle

The Mars Exploration Rover mission depends on the Science Activity Planner as its primary interface to the Spirit and Opportunity Rovers. Scientists alternate between a series of mouse clicks and keyboard inputs to create a set of instructions for the rovers. To accelerate planning by minimizing mouse usage, a rover planning editor should receive the majority of inputted commands from the keyboard. Thorough investigation of the Eclipse platform's Java editor has provided the understanding of the base model for the Activity Scratchpad. Desirable Eclipse features can be mapped to specific rover planning commands, such as auto-completion for activity titles and content assist for target names. A custom editor imitating the Java editor's features was created with an XML parser for experimenting purposes. The prototype editor minimized effort for redundant tasks and significantly improved the visual representation of XML syntax by highlighting keywords, coloring rules, folding projections, and providing hover assist, templates and an outline view of the code.

Abramyan, Lucy↗