Object-Oriented Design for Authoring and Executing Spacecraft 
Operating Procedures

T. J. Grant, I. van Dreumel, E. Lammers, T. Ott de Vries, R. Potze
Tim.Grant@nlnwgfsc.origin.nl
Origin/BSO Nieuwegein b.v., Computer Resource International A/S

Abstract:
This paper summarises a decade of experience in designing and integrating 
software for the end-to-end support of the authoring and execution of spacecraft 
operating procedures. Applications cover crew and automated procedures for 
payloads and subsystems, and for in-orbit and ground operations.
Manned and remote-sensing missions are emphasised, covering BSO's:

- integration of DLR's OPIS into the Crew Support Computer now flying on MIR.

- Advanced Crew Terminal (ACT) project for ESTEC and CRI's subcontract.

- Crew Procedure Language Interpreter for the International Space Station (ISS) 
  Russian segment's Data Management System (DMS-R).

- Recipe Editor and Despatcher for the Earth Monitoring Work Station.

Experience includes unmanned, ground-based, and non-space missions. Systems have 
been implemented using Oracle, Lisp, Smalltalk, C++, Ada, MS-Word, and HTML with 
Booch, OOSE, OMT, Coad and Yourdon, and HOOD methods.

The purpose of the paper is to present a generic object-oriented design supporting 
the complete procedure life-cycle, including authoring/generation, storage, 
verification and validation, selection and retrieval,instantiation, resource 
allocation, execution, and post-use evaluation. User-interface and functionality 
issues are separated.

Implementers are free to choose whether or not to:

- implement branching, nesting, iteration, preconditions, and variables.
- make links to FDIR, synoptics, timelining, multimedia documentation,
  annotations, simulators, and external databases.
- mix crew and automated procedures.

Suitable choices enable (eg) ISS-standard Automated Crew Procedure scripts to be 
implemented.

The paper:

- summarises project experience leading to the generic design.
- lists trade-offs in implementing procedure systems.
- presents key patterns found in the generic design.
- outlines experience in adapting it for specific projects.
- identifies possible future enhancements.

The development of a generic design is significant in that it enables:

- re-use across a wide range of systems and applications, with attendant cost and 
  time savings.
- development of COTS products.