Providing Goal-Based Autonomy for Commanding a Spacecraft

A computer program for use aboard a scientific- exploration spacecraft autonomously selects among goals specified in high-level requests and generates corresponding sequences of low-level commands, understandable by spacecraft systems. (As used here, “goals” signifies specific scientific observations.) From a dynamic, onboard set of goals that could oversubscribe spacecraft resources, the program selects a non-oversubscribing subset that maximizes a quality metric. In an early version of the program, the requested goals are assumed to have fixed starting times and durations. Goals can conflict by exceeding a limit on either the number of separate goals or the number of overlapping goals making demands on the same resource.

Posted in: Briefs, TSP, Information Sciences, Automatic pilots, Computer software and hardware, Spacecraft guidance, Logistics

Optimal Planning and Problem-Solving

CTAEMS MDP Optimal Planner is a problem- solving software designed to command a single spacecraft/rover, or a team of spacecraft/ rovers, to perform the best action possible at all times according to an abstract model of the spacecraft/rover and its environment. It also may be useful in solving logistical problems encountered in commercial applications such as shipping and manufacturing.

Posted in: Briefs, TSP, Information Sciences, Computer software and hardware, Spacecraft guidance, Logistics, Manufacturing processes, Materials handling

Attitude-Control Algorithm for Minimizing Maneuver Execution Errors

A G-RAC attitude- control algorithm is used to minimize maneuver execution error in a spacecraft with a flexible appendage when said spacecraft must induce translational momentum by firing (in open loop) large thrusters along a desired direction for a given period of time. The controller is dynamic with two integrators and requires measurement of only the angular position and velocity of the spacecraft. The global stability of the closed-loop system is guaranteed without having access to the states describing the dynamics of the appendage and with severe saturation in the available torque.

Posted in: Briefs, Information Sciences, Mathematical models, Attitude control, Booster rocket engines, Spacecraft

Grants Document-Generation System

The Grants Document- Generation System (GDGS) software allows the generation of official grants documents for distribution to the appropriate parties. The documents are created after the selection and entry of specific data elements and clauses. GDGS is written in Cold Fusion that resides on an SQL2000 database and is housed on-site at Goddard Space Flight Center. It includes access security written around GSFC’s (Goddard Space Flight Center’s) LIST system, and allows for the entry of Procurement Request information necessary for the generation of the resulting Grant Award.

Posted in: Briefs, Information Sciences, Computer software and hardware, Documentation, Financial management

Automated Production of Movies on a Cluster of Computers

Processing is faster, easier, more flexible, and more collaborative than before.

A method of accelerating and facilitating production of video and film motion- picture products, and software and generic designs of computer hardware to implement the method, are undergoing development. The method provides for automation of most of the tedious and repetitive tasks involved in editing and otherwise processing raw digitized imagery into final motion-picture products. The method was conceived to satisfy requirements, in industrial and scientific testing, for rapid processing of multiple streams of simultaneously captured raw video imagery into documentation in the form of edited video imagery and video derived data products for technical review and analysis. In the production of such video technical documentation, unlike in production of motion-picture products for entertainment, (1) it is often necessary to produce multiple video derived data products, (2) there are usually no second chances to repeat acquisition of raw imagery, (3) it is often desired to produce final products within minutes rather than hours, days, or months, and (4) consistency and quality, rather than aesthetics, are the primary criteria for judging the products.

Posted in: Briefs, Information Sciences, Computer software and hardware, Imaging and visualization, Collaboration and partnering, Data management, Automation

Lossless, Multi-Spectral Data Compressor for Improved Compression for Pushbroom-Type Instruments

A modified data compression algorithm could be used on commercial satellites or other applications with multispectral imaging instruments.

A low-complexity lossless algorithm for compression of multispectral data has been developed that takes into account pushbroom-type multispectral imagers’ properties in order to make the file compression more effective. These types of imagers use a detector array to acquire data in spatial-spectral slices. Each detector element corresponds to a specific spectral band and cross-track position. Because the characteristics of detector elements generally vary somewhat from element to element, cross-track adjacent samples in a given spectral band are not as similar as they are in an instrument that uses the same detector for all samples in a given spectral band (e.g. in a whiskbroom-type instrument). Along-track adjacent samples will tend to be very similar.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Data acquisition and handling, Imaging and visualization

Measuring Positions of Objects Using Two or More Cameras

This method could determine the causes of accidents.

An improved method of computing positions of objects from digitized images acquired by two or more cameras (see figure) has been developed for use in tracking debris shed by a spacecraft during and shortly after launch. The method is also readily adaptable to such applications as (1) tracking moving and possibly interacting objects in other settings in order to determine causes of accidents and (2) measuring positions of stationary objects, as in surveying. Images acquired by cameras fixed to the ground and/or cameras mounted on tracking telescopes can be used in this method.

Posted in: Briefs, TSP, Information Sciences, Imaging and visualization, Particulate matter (PM), Mountings, Entry, descent, and landing, Spacecraft

Reduced-Order Kalman Filtering for Processing Relative Measurements

A Kalman filter can be propagated using fewer computations.

A study in Kalman-filter theory has led to a method of processing relative measurements to estimate the current state of a physical system, using less computation than has previously been thought necessary. As used here, “relative measurements” signifies measurements that yield information on the relationship between a later and an earlier state of the system. An important example of relative measurements arises in computer vision: Information on relative motion is extracted by comparing images taken at two different times.

Posted in: Briefs, Information Sciences, Measurements, Imaging and visualization

Aerobraking Maneuver (ABM) Report Generator

abmREPORT Version 3.1 is a Perl script that extracts vital summarization information from the Mars Reconnaissance Orbiter (MRO) aerobraking ABM build process. This information facilitates sequence reviews, and provides a high-level summarization of the sequence for mission management.

Posted in: Briefs, Information Sciences, Computer software and hardware, Data acquisition and handling, Spacecraft

ABM Drag_Pass Report Generator

dragREPORT software was developed in parallel with abmREPORT, which is described in the preceding article. Both programs were built on the capabilities created during that process. This tool generates a drag_pass report that summarizes vital information from the MRO aerobreaking drag_pass build process to facilitate both sequence reviews and provide a high-level summarization of the sequence for mission management. The script extracts information from the ENV, SSF, FRF, SCMFmax, and OPTG files, presenting them in a single, easy-to-check report providing the majority of parameters needed for cross check and verification as part of the sequence review process.

Posted in: Briefs, Information Sciences, Computer software and hardware, Data acquisition and handling, Spacecraft

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