KEYWORDS: Space operations, Sensors, Satellites, Fluorescence correlation spectroscopy, System integration, Navigation systems, Connectors, Data modeling, Control systems, Computer aided design
The Orbital Express Capture System (OECS) is one of the key technologies successfully demonstrated as part of the
Orbital Express Demonstration System flight operations that took place between March and July, 2007. The OECS
supported all demate, capture and berthing activities throughout the span of on-orbit activities, with no anomalies. This
paper will briefly review the Orbital Express (OE) program, including goals, key milestones & events and other major
subsystems particularly relevant to the OECS performance. A summary of the major activities in the Virtual System
Integration process, as applied to the OECS, to ultimately verify satisfactory pre-flight performance, will be presented.
Finally, actual on-orbit performance of the OECS will be described.
One of the important components of the Virtual System Integration (VSI) process is subsystem testing. The Orbital Express Capture System (OECS), an important subsystem of the DARPA/Boeing Orbital Express Program Demonstration System, was put through 6 DOF testing at the Marshall Space Flight Center Contact Dynamics Simulation Laboratory. Aims of the testing were two-fold: verify proper functionality of the system in a flight-like test to give early indication of any design issues, and provide appropriate test data for correlation and validation of the capture system dynamics analysis model to support OECS verification.
This paper will briefly review the VSI process, the Orbital Express program, the Orbital Express Capture System and describe recent 6 DOF testing of the Orbital Express 6 DOF Capture System.
KEYWORDS: Systems modeling, Data modeling, Content addressable memory, Sensors, 3D modeling, Performance modeling, Aerospace engineering, Satellites, Resistance, Monte Carlo methods
The scope of the analysis was to determine the capability of the Michigan Aerospace Corporation (MAC) Autonomous
Docking Satellite System II (referred to as 'ASDS' for the remainder of this paper), and to develop and mature the concept.
The integrated system model included detailed subsystem models. A cable model was developed from the test data that resulted in good correlation. A high fidelity subsystem model of the cam resistance force was modeled. The integrated system model also includes contact definitions, final latching/locking definition, and various sensors.
Over 3,000 cases were analyzed to identify areas where the MAC docking concept can be improved. Sensitivity and Monte Carlo studies were completed to understand the mechanism’s capture capability, determine subsystem requirements, and evolve the design for improved performance.
The development of autonomous servicing of on-orbit spacecraft has been a sought after objective for many years. A critical component of on-orbit servicing involves the ability to successfully capture, institute mate, and perform electrical and fluid transfers autonomously. As part of a Small Business Innovation Research (SBIR) grant, Starsys Research Corporation (SRC) began developing such a system. Phase I of the grant started in 1999, with initial work focusing on simultaneously defining the parameters associated with successful docking while designing to those parameters. Despite the challenge of working without specific requirements, SRC completed development of a prototype design in 2000. Throughout the following year, testing was conducted on the prototype to characterize its performance. Having successfully completed work on the prototype, SRC began a Phase II SBIR effort in mid-2001. The focus of the second phase was a commercialization effort designed to augment the prototype model into a more flight-like design. The technical requirements, however, still needed clear definition for the design to progress. The advent of the Orbital Express (OE) program provided much of that definition. While still in the proposal stages of the OE program, SRC began tailoring prototype redesign efforts to the OE program requirements. A primary challenge involved striking a balance between addressing the technical requirements of OE while designing within the scope of the SBIR. Upon award of the OE contract, the Phase II SBIR design has been fully developed. This new design, designated the Mechanical Docking System (MDS), successfully incorporated many of the requirements of the OE program. SRC is now completing dynamic testing on the MDS hardware, with a parallel effort of developing a flight design for OE. As testing on the MDS progresses, the design path that was once common to both SBIR effort and the OE program begins to diverge. The MDS will complete the scope of the Phase II SBIR work, while the new mechanism, the Orbital Express Capture System, will emerge as a flight-qualified design for the Orbital Express program.
The Virtual System Integration and Testing (VSIT) paradigm is presented as a means for verification and cost and risk reduction of space system technologies. Components and benefits of the paradigm are explained, accompanied by examples of its application as carried out by the Boeing VSIT team. Particular attention is paid to the current application of VSIT to the Orbital Express (OE) program. Based on examples of the application of VSIT and its latest application to the OE program, the conclusion is drawn that VSIT is a valuable paradigm that can significantly reduce the costs and risks of space system technology development and provide for a cost-effective and thorough means of verification of system level performance.
Proceedings Volume Editor (5)
This will count as one of your downloads.
You will have access to both the presentation and article (if available).
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.