Tech Briefs

flexplan: Mission Planning System for the Lunar Reconnaissance Orbiter

The tool can be configured for any mission without the need to modify or re-compile code.

flexplan is a mission planning and scheduling (MPS) tool that uses soft algorithms to define mission scheduling rules and constraints. This allows the operator to configure the tool for any mission without the need to modify or re-compile code. In addition, flexplan uses an ID system to track every output on the schedule to the input from which it was generated. This allows flexplan to receive feedback as the schedules are executed, and update the status of all activities in a Web-based client. flexplan outputs include various planning reports, stored command loads for the Lunar Reconnaissance Orbiter (LRO), ephemeris loads, and pass scripts for automation.

flexplan covers the end-to-end loop of MPS and allows users to adapt the system to their requirements quickly and easily. At the core of flexplan’s scheduling process is a soft algorithm generation engine that requires no recompiling of the tool whenever flight rules change. This engine is largely responsible for the ease of adaptability of flexplan to the different mission phases, requirements, and styles of planning and scheduling operations. flexplan’s modular architecture allows its components to interact with each other via the database. This allows different components to be run at different times or concurrently by different operators. This architecture also allows flexplan to be easily extended with additional modules to support specific mission requirements or needs. The LRO MPS uses flexplan’s core modules plus additional modules developed using existing flexplan capabilities to support LRO’s flight software memory loads generation and modeling, a slew maneuver planning tool, and Web-based mission status reporting.

The flexplan components are divided into two categories: core components that are modules responsible for the generation of conflict-free schedules, and supporting components that are modules supporting additional requirements for the LRO and for the status awareness of planned activities.

flexplan offers three advantages over existing systems:

1. Use of soft algorithms to define mission scheduling rules and constraints. This allows the operators to define how planning and scheduling is accomplished, without the need for manufacturer modification to the software. All scheduling rules and constraints can be placed under configuration management, allowing the operation team to easily create and use rules for different phases of the mission.

2. Tracking ID. All inputs and outputs into and from flexplan are assigned a unique ID. This allows the operations team to identify the source of scheduled activities. It also allows flexplan to receive execution feedback for all schedule activities and update the activities status on a Webbased client for improved mission awareness.

3. Open XML format for all scheduling inputs. A single XML structure is used to ingest all scheduling inputs, regardless of the nature or source of the input. This allows new scheduling inputs to be processed without the need to configure the external interface to a specific input format.

flexplan is also used in the scheduling operations of the LDCM (Landsat Data Continuity Mission) spacecraft, also at GSFC, which is currently undergoing final mission and ground readiness testing to prepare for upcoming launch in January of 2013, and undergoing customization for operational use in the TDRS (Tracking and Data Relay Satellites) Space Network upgrade project, SGSS, a joint venture between NASA GSFC and WSC.

This work was done by Assaf Barnoy and Theresa Beech of GMV USA for Goddard Space Flight Center. GSC-15558-1

This Brief includes a Technical Support Package (TSP).

flexplan: Mission Planning System for the Lunar Reconnaissance Orbiter (reference GSC-15558-1) is currently available for download from the TSP library.

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