acm-header
Sign In

Communications of the ACM

Collaborative Virtual Design Environments

Design Engineering in Virtual Environments


The current Space Shuttle Orbital Maneuvering System (OMS) and the related Reaction Control System (RCS) make use of hydrazine as a propellant. Hydrazine, while high in energy content, is both corrosive and poisonous. As a result, its use in the OMS/RCS dictates that extreme caution be used in both the initial charging of the systems before launch and in their safetying after landing. Not only does the use of hydrazine increase the risk for those preparing and maintaining the Space Shuttle, but the procedures required for personnel safety during these processes add significant time to the preparation of each Space Shuttle for launch. As a result, the Space Shuttle Upgrade Board approved the design of a new OMS/RCS utilizing a non-toxic propellant. At the same time, this engineering design effort was recognized as an ideal opportunity to assess the overall maintainability of the OMS/RCS and to incorporate, where possible, design and vehicle integration features that would significantly reduce the personnel and time requirements for processing these systems between flights.

In an effort to reduce the overall engineering design time and costs, a partnership between the Propulsion Division and the Automation, Robotics, and Simulation Division of the NASA/Johnson Space Center (JSC) was formed to adapt and implement virtual environment technologies to reduce the length and cost of the engineering design process. At the heart of this effort was the use of real-time, 3D graphics to allow engineering teams to visualize the complex systems under development and to rapidly explore alternative design options.

Figure 1. A portion of the Space Shuttle with one of the OMS pods made transparent.

In addition, the virtual environments used for this purpose incorporated accurate human models to assess the visibility and accessibility of system elements that required routine inspection, removal, and/or replacement. Moreover, in the interest of improving the overall maintainability of the new systems, teams from NASA/Marshall Space Flight Center and NASA/Kennedy Space Center (KSC) participated materially in the design process, especially in design reviews intended to achieve the maximum possible quality in the finished design.

Figure 2. EAI Transom Jack human figure models were used to assess how many technicians were required to handle an OMS access panel.

Technologies developed and integrated by the Virtual Environments Research Institute of the University of Houston were employed to provide for high performance, 3D visualizations for the engineering design on platforms that ranged from the engineer's desktop computer to a fully immersive CAVE. The EAI Transom Jack human model was integrated into this software environment to permit evaluation of inspection and access capabilities by technical staff over a range of human variability in height and arm length. Finally, with support from the Intelligent Synthesis Environment teams from both NASA/JSC and NASA/KSC, two or more display/interaction systems could be connected via existing communication channels to permit teams in different locations to be simultaneously involved in both the design and design review processes. The use of collaborative virtual environments was intended to achieve a significant reduction in the time and travel costs normally associated with the traditional engineering design process and a major improvement in the maintainability of the new systems.

Back to Top

Author

R. Bowen Loftin (bloftin@odu.edu) is a professor of electrical and computer engineering, a professor of computer science, and director of simulation programs in the Virginia Modeling, Analysis and Simulation Center at Old Dominion University, Norfolk, VA.

Back to Top

Footnotes

CAVE is a registered trademark of the Board of Trustees of the University of Illinois. EAI Transom Jack is a registered trademark of Engineering Animation, Inc.

Back to Top

Figures

F1Figure 1. A portion of the Space Shuttle with one of the OMS pods made transparent.

F2Figure 2. EAI Transom Jack human figure models were used to assess how many technicians were required to handle an OMS access panel.

Back to top


©2001 ACM  0002-0782/01/1200  $5.00

Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee.

The Digital Library is published by the Association for Computing Machinery. Copyright © 2001 ACM, Inc.


 

No entries found

Sign In for Full Access
» Forgot Password? » Create an ACM Web Account
Article Contents: