Booster Obsolescence and Life Extension (BOLE) for Space Launch System (SLS): Empowering Deep Space Missions
No abstract available
Engineering topics
Publications and source records attributed to Tobias, Mark.
No abstract available
The Five-Segment Engineering Test Motor (ETM-3) is an extended length reusable solid rocket motor (RSRM) intended to increase motor performance and internal environments above the current four-segment RSRM flight motor. The principal purpose of ETM-3 is to provide a test article for RSRM component margin testing. As the RSRM and Space Shuttle in general continue to age, replacing obsolete materials becomes an ever-increasing issue. Having a five-segment motor that provides environments in excess of normal opera- tion allows a mechanism to subject replacement materials to a more severe environment than experienced in flight. Additionally, ETM-3 offers a second design data point from which to develop and/or validate analytical models that currently have some level of empiricism associated with them. These enhanced models have the potential to further the understanding of RSRM motor performance and solid rocket motor (SRM) propulsion in general. Furthermore, these data could be leveraged to support a five-segment booster (FSB) development program should the Space Shuttle program choose to pursue this option for abort mode enhancements during the ascent phase. A tertiary goal of ETM-3 is to challenge both the ATK Thiokol Propulsion and NASA MSFC technical personnel through the design and analysis of a large solid rocket motor without the benefit of a well-established performance database such as the RSRM. The end result of this undertaking will be a more competent and experienced workforce for both organizations. Of particular interest are the motor design characteristics and the systems engineering approach used to conduct a complex yet successful large motor static test. These aspects of ETM-3 and more will be summarized.
The Five Segment Booster (FSB) concept has been evolving for a number of years as a means to enhance the overall safety and reliability of the Space Shuttle system by minimizing the need to fly the more challenging Return to Launch Site (RTLS) and Transoceanic Abort Landing (TAL) abort profiles. The initial evaluation of the FSB concept was conducted in 1996 to determine the feasibility of the FSB in achieving transatlantic abort leading TAL from the pad, thus eliminating the return to launch site (RTLS) abort mode. The initial study was conducted by ATK Thiokol and did show the potential for the FSB to eliminate the RTLS abort mode. Later Rockwell (now Boeing) conducted a similar study utilizing FSB performance characteristics and verified that the FSB could indeed achieve TAL from the pad, thereby eliminating the necessity for the RTLS abort. The purpose of this paper is to discuss the details of the enhancements achieved through the internally funded study conducted by Boeing and ATK Thiokol. To better understand the enhancements that were addressed as part of this follow-on study, some background on what was achieved in the Phase A study is appropriate.