The growing frequency of launches and re-entries of space vehicles has increased impact on other ... more The growing frequency of launches and re-entries of space vehicles has increased impact on other users of the National Airspace. Because these activities have a probability of failure far higher than aircraft, the FAA closes airspace proactively to mitigate the potential impact of debris resulting from a breakup event. The FAA Office of NextGen and Office of Commercial Space Transportation have been working to develop a systematic solution to reduce the spatial and temporal extent of airspace closures. A key element of the solution is developing the capability to respond in real-time to a failure. This requires data communication between the space vehicle and the FAA, procedures to communicate air traffic direction to pilots, and software to compute the real-time determination of the hazarded area. A key objective is to maximum the time allotted for aircraft to fly out of the hazarded region. We have developed models, algorithms, and prototype software to compute four-dimensional ai...
Abstract : HAZX is an explosives safety software tool that can be used to assess the hazards and/... more Abstract : HAZX is an explosives safety software tool that can be used to assess the hazards and/or risks when Quantity-Distance (Q-D) safe separation distances are violated. Part 1 of the presentation focuses on the HAZX hazard module which includes a GUI/GIS interface to simplify user inputs, spatial analyses and the display of results and reports. The risk tool is being developed using alternative methods to the algorithms and methods documented in DDESB's Technical Paper No. 14. The underlying fragmentation model performs multiple simulations of drag-corrected fragment throw to account for uncertainties in their characteristics and automate the pseudo-trajectory normal method to compute hazardous fragment density considering 3D bounce/roll other uneven terrain. The hazard tools have been used to support equivalent protection and consequence explosion analyses launch vehicles and conventional weapons by the AF, FAA and Army. The HAZX hazard tool is demonstrated including the capability to compute: a) air blast and hazardous fragment density, and b) consequences of air blast and fragment impacts to ES's (damage, injury and fatality).
48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, 2010
An experimental permit issued by the Federal Aviation Administration’s Office of Commercial Space... more An experimental permit issued by the Federal Aviation Administration’s Office of Commercial Space Transportation (FAA/AST) authorizes reusable suborbital rockets (RLVs) to fly within a predefined operating area. Specifically, an operating area must contain a suborbital rocket’s vacuum instantaneous impact point. This paper will present an update of the work performed since the publishing of the AIAA conference paper titled “Separation Distances for Rocket Launch Operations” at the 2008 AIAA Atmospheric Flight Mechanics Conference. The focus of the above mentioned paper was on the necessary aircraft separation distances from rockets that launched into the national airspace system (NAS). This paper will include updates to the aircraft buffer zone size regarding probability of failure allocation, sensitivity to aircraft vulnerability, effects of wind conditions, and debris catalogue sensitivity, as well as adding information on ground buffer zones for reusable suborbital rockets. In the previously mentioned paper, it is recommended that the probability of failure for each point in time is equal to 1.0 for a reusable suborbital launch. More recent research examines the resulting aircraft buffer zone size if the probability of failure for the overall mission is equal to 1.0 and uniformly allocated to specific times of flight. The sensitivity of the aircraft buffer zone size to the commercial transport aircraft vulnerability model is also reported on in this paper. Day of launch wind conditions and debris catalogue development can significantly change the aircraft buffer zone size and it is important to characterize how these factors can affect the launch operations. The FAA/AST does not require an experimental permit applicant to perform a quantitative risk analysis to obtain a permit and instead has adopted the approach of determining a ground buffer zone around an operating area similar to the aircraft buffer zone. The ground buffer zone protects the public from reusable suborbital rocket explosions near the operating area boundary. Determining the size of the ground buffer zone is a multi step process. This paper will familiarize the reader with these processes and the methodologies that support them along with the results of the aircraft buffer zones in regard to the probability of failure allocation, aircraft vulnerability, wind effects, and debris catalogues.
AIAA Atmospheric Flight Mechanics Conference and Exhibit, 2006
A flight safety analysis quantitatively demonstrates that a launch or reentry vehicle is capable ... more A flight safety analysis quantitatively demonstrates that a launch or reentry vehicle is capable of flying a proposed mission below accepted limits for risk to the uninvolved public. Over time, sophisticated methodologies have been developed to estimate the risks posed by a particular mission by probabilistically modeling the outcomes of multiple potential vehicle failure scenarios and the various influences on those outcomes to a high level of engineering fidelity. However, variations in planned operations, along with limitations in the availability or quality of data, suggest a need for the identification of a broader, more generalized approach. Accordingly, a “tiered” approach to flight safety analysis is explored that advocates the use of simplifying, conservative assumptions in place of complex models as an initial iteration step. Subsequent iterations, if necessary, would employ increasingly less conservative assumptions and more complex modeling techniques until either an acceptable solution is reached or the highest available level of fidelity had been applied. The advantage of such an approach is twofold in that it encourages the design of safer operations for the sake of simplicity in the analysis and it standardizes methodologies for better comparison of results and determination of uncertainties.
Since the STS-114 mission in August of 2005, the FAA has partnered with NASA to protect aircraft ... more Since the STS-114 mission in August of 2005, the FAA has partnered with NASA to protect aircraft flying in the National Airspace System from the potential hazards associated with a catastrophic failure of a reentering Space Shuttle orbiter, similar to that which occurred during ...
With increasing commercial space activities occurring in the National Airspace System (NAS), the ... more With increasing commercial space activities occurring in the National Airspace System (NAS), the Federal Aviation Administration (FAA) has identified a need for more efficient management of the NAS with respect to commercial space operations. Current methods for integration of aviation and space activities employ a segregation approach, in which hazard areas are constructed around launch and reentry operations and sections of airspace are closed to other users. Mission objectives and vehicle characteristics dictate the extent of the closure in terms of location, duration, and volume of airspace affected. Launches, reentries, and other operations have an effect on other NAS stakeholders, causing delays, changes to airlines’ flight plans, and incurred expenses from additional fuel burn caused by reroutes. Likewise, attempts to minimize these effects can be detrimental to launch and reentry operators, leading to additional costs in delays and lost opportunities for mission success. The...
The U.S. Federal Aviation Administration (FAA) has developed an approach to integrating commercia... more The U.S. Federal Aviation Administration (FAA) has developed an approach to integrating commercial space launch and reentry operations into the National Airspace System (NAS). This approach seeks to capitalize on upfront planning in order to minimize the effect of a launch or reentry operation on the system’s performance without jeopardizing the vehicle operator’s opportunity for mission success. The FAA has successfully applied this approach to a number of launch, reentry, and amateur rocket activities. This paper provides an overview of that approach and some of the steps that the FAA has taken to implement it. As enabling technologies are developed and implemented, tactical options will become more broadly applicable and effective. Over time, the FAA is seeking to transition from an approach that protects from failure using preemptive airspace restrictions to an approach that operates for success through limited airspace restrictions, increased mission monitoring capabilities, and the ability to effectively respond to contingencies.
The growing frequency of launches and re-entries of space vehicles has increased impact on other ... more The growing frequency of launches and re-entries of space vehicles has increased impact on other users of the National Airspace. Because these activities have a probability of failure far higher than aircraft, the FAA closes airspace proactively to mitigate the potential impact of debris resulting from a breakup event. The FAA Office of NextGen and Office of Commercial Space Transportation have been working to develop a systematic solution to reduce the spatial and temporal extent of airspace closures. A key element of the solution is developing the capability to respond in real-time to a failure. This requires data communication between the space vehicle and the FAA, procedures to communicate air traffic direction to pilots, and software to compute the real-time determination of the hazarded area. A key objective is to maximum the time allotted for aircraft to fly out of the hazarded region. We have developed models, algorithms, and prototype software to compute four-dimensional ai...
Abstract : HAZX is an explosives safety software tool that can be used to assess the hazards and/... more Abstract : HAZX is an explosives safety software tool that can be used to assess the hazards and/or risks when Quantity-Distance (Q-D) safe separation distances are violated. Part 1 of the presentation focuses on the HAZX hazard module which includes a GUI/GIS interface to simplify user inputs, spatial analyses and the display of results and reports. The risk tool is being developed using alternative methods to the algorithms and methods documented in DDESB's Technical Paper No. 14. The underlying fragmentation model performs multiple simulations of drag-corrected fragment throw to account for uncertainties in their characteristics and automate the pseudo-trajectory normal method to compute hazardous fragment density considering 3D bounce/roll other uneven terrain. The hazard tools have been used to support equivalent protection and consequence explosion analyses launch vehicles and conventional weapons by the AF, FAA and Army. The HAZX hazard tool is demonstrated including the capability to compute: a) air blast and hazardous fragment density, and b) consequences of air blast and fragment impacts to ES's (damage, injury and fatality).
48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, 2010
An experimental permit issued by the Federal Aviation Administration’s Office of Commercial Space... more An experimental permit issued by the Federal Aviation Administration’s Office of Commercial Space Transportation (FAA/AST) authorizes reusable suborbital rockets (RLVs) to fly within a predefined operating area. Specifically, an operating area must contain a suborbital rocket’s vacuum instantaneous impact point. This paper will present an update of the work performed since the publishing of the AIAA conference paper titled “Separation Distances for Rocket Launch Operations” at the 2008 AIAA Atmospheric Flight Mechanics Conference. The focus of the above mentioned paper was on the necessary aircraft separation distances from rockets that launched into the national airspace system (NAS). This paper will include updates to the aircraft buffer zone size regarding probability of failure allocation, sensitivity to aircraft vulnerability, effects of wind conditions, and debris catalogue sensitivity, as well as adding information on ground buffer zones for reusable suborbital rockets. In the previously mentioned paper, it is recommended that the probability of failure for each point in time is equal to 1.0 for a reusable suborbital launch. More recent research examines the resulting aircraft buffer zone size if the probability of failure for the overall mission is equal to 1.0 and uniformly allocated to specific times of flight. The sensitivity of the aircraft buffer zone size to the commercial transport aircraft vulnerability model is also reported on in this paper. Day of launch wind conditions and debris catalogue development can significantly change the aircraft buffer zone size and it is important to characterize how these factors can affect the launch operations. The FAA/AST does not require an experimental permit applicant to perform a quantitative risk analysis to obtain a permit and instead has adopted the approach of determining a ground buffer zone around an operating area similar to the aircraft buffer zone. The ground buffer zone protects the public from reusable suborbital rocket explosions near the operating area boundary. Determining the size of the ground buffer zone is a multi step process. This paper will familiarize the reader with these processes and the methodologies that support them along with the results of the aircraft buffer zones in regard to the probability of failure allocation, aircraft vulnerability, wind effects, and debris catalogues.
AIAA Atmospheric Flight Mechanics Conference and Exhibit, 2006
A flight safety analysis quantitatively demonstrates that a launch or reentry vehicle is capable ... more A flight safety analysis quantitatively demonstrates that a launch or reentry vehicle is capable of flying a proposed mission below accepted limits for risk to the uninvolved public. Over time, sophisticated methodologies have been developed to estimate the risks posed by a particular mission by probabilistically modeling the outcomes of multiple potential vehicle failure scenarios and the various influences on those outcomes to a high level of engineering fidelity. However, variations in planned operations, along with limitations in the availability or quality of data, suggest a need for the identification of a broader, more generalized approach. Accordingly, a “tiered” approach to flight safety analysis is explored that advocates the use of simplifying, conservative assumptions in place of complex models as an initial iteration step. Subsequent iterations, if necessary, would employ increasingly less conservative assumptions and more complex modeling techniques until either an acceptable solution is reached or the highest available level of fidelity had been applied. The advantage of such an approach is twofold in that it encourages the design of safer operations for the sake of simplicity in the analysis and it standardizes methodologies for better comparison of results and determination of uncertainties.
Since the STS-114 mission in August of 2005, the FAA has partnered with NASA to protect aircraft ... more Since the STS-114 mission in August of 2005, the FAA has partnered with NASA to protect aircraft flying in the National Airspace System from the potential hazards associated with a catastrophic failure of a reentering Space Shuttle orbiter, similar to that which occurred during ...
With increasing commercial space activities occurring in the National Airspace System (NAS), the ... more With increasing commercial space activities occurring in the National Airspace System (NAS), the Federal Aviation Administration (FAA) has identified a need for more efficient management of the NAS with respect to commercial space operations. Current methods for integration of aviation and space activities employ a segregation approach, in which hazard areas are constructed around launch and reentry operations and sections of airspace are closed to other users. Mission objectives and vehicle characteristics dictate the extent of the closure in terms of location, duration, and volume of airspace affected. Launches, reentries, and other operations have an effect on other NAS stakeholders, causing delays, changes to airlines’ flight plans, and incurred expenses from additional fuel burn caused by reroutes. Likewise, attempts to minimize these effects can be detrimental to launch and reentry operators, leading to additional costs in delays and lost opportunities for mission success. The...
The U.S. Federal Aviation Administration (FAA) has developed an approach to integrating commercia... more The U.S. Federal Aviation Administration (FAA) has developed an approach to integrating commercial space launch and reentry operations into the National Airspace System (NAS). This approach seeks to capitalize on upfront planning in order to minimize the effect of a launch or reentry operation on the system’s performance without jeopardizing the vehicle operator’s opportunity for mission success. The FAA has successfully applied this approach to a number of launch, reentry, and amateur rocket activities. This paper provides an overview of that approach and some of the steps that the FAA has taken to implement it. As enabling technologies are developed and implemented, tactical options will become more broadly applicable and effective. Over time, the FAA is seeking to transition from an approach that protects from failure using preemptive airspace restrictions to an approach that operates for success through limited airspace restrictions, increased mission monitoring capabilities, and the ability to effectively respond to contingencies.
Uploads
Papers by Daniel Murray