{"project":{"acronym":"","projectId":91653,"title":"Vehicle Staging Analysis of the Transition to Supersonic Retropropulsion During Mars Entry, Descent, and Landing","primaryTaxonomyNodes":[{"taxonomyNodeId":10773,"taxonomyRootId":8816,"parentNodeId":10770,"level":3,"code":"TX09.4.3","title":"System Integration and Analysis for EDL","definition":"EDL system integration and Analysis implements and maintains a flexible simulation structure that evolves with the EDL system definition to enable performance, design, and risk decisions throughout the life cycle.","exampleTechnologies":"Event driven environment simulation","hasChildren":false,"hasInteriorContent":true}],"startTrl":2,"currentTrl":3,"endTrl":3,"benefits":"Extending and sustaining human presence in our solar system will require landing large robotic (~10 mT) and human class payloads (~40-80 mT) on Mars with landed accuracies on the order of meters. To rise to this challenge, new EDL technologies must be developed. The Entry, Descent, and Landing Systems Analysis (EDL \\x13 SA) Study identifies supersonic retropropulsion (SRP) as a promising, mission enabling technology for high mass and human Mars missions. The goal of this project is to develop nominal, detailed designs and requirements for SRP transition architectures for Mars high mass entry vehicles. These configurations are envisioned to guide future SRP technology development and investigation, specifically in the definition of propulsion system requirements, aeroscience configuration-dependent investigations, and further SRP configuration and transition architecture development.","description":"The landing of the Mars Science Laboratory represents the upper limit of current Entry, Descent, and Landing (EDL) capabilities for Mars exploration. The succession from the current state of the art along NASA\u0019s goal of extending and sustaining human presence in our solar system will require landing large robotic (~10 mT) and human class payloads (~40-80 mT) on Mars with landed accuracies on the order of meters. To rise to this challenge, new EDL technologies must be developed. The Entry, Descent, and Landing Systems Analysis (EDL \u0013 SA) Study identifies supersonic retropropulsion (SRP) as a promising, mission enabling technology for high mass and human Mars missions. The goal of my research is to develop nominal, detailed designs and requirements for SRP transition architectures for Mars high mass entry vehicles. These configurations are envisioned to guide future SRP technology development and investigation, specifically in the definition of propulsion system requirements, aeroscience configuration-dependent investigations, and further SRP configuration and transition architecture development. My research into this topic will include an extensive literature review of recent configuration, packaging, and staging analyses applicable to high mass Mars missions as well as review of relevant sub-systems literature such as hypersonic decelerators, SRP sub-systems, terminal descent propulsion and control requirements, previous transition architectures, and transition separation methods. Building off the transition architectures recommend by the EDL-SA study, I will develop six degree-of-freedom models and simulations of aerodynamic and multibody dynamic behavior of high mass entry vehicles relative to their jettisoned masses over nominal Mars EDL trajectories. To aid the multibody dynamics analysis, CFD solvers will be used to determine detailed aerodynamic interactions between entry bodies and jettisoned masses. Specific aerodynamic interactions to be investigated, characterized, and modeled include the suction phenomena occurring between an entry body and an ejected mass shortly after jettison and near and far-field recontact risks. In parallel with aerodynamic and multibody dynamic analyses, ballistic coefficient ratios between entry vehicles and jettisoned masses will be characterized and developed such that recontact risks are minimized. Supersonic ballistic analyses will build off of similar subsonic analyses for previous Mars missions. Detailed design analysis will focus on characterizing and designing separation systems to disconnect and jettison hypersonic decelerators away from the entry body during supersonic flight. Heritage pyro-separation and guide-rail systems will be evaluated for potential feed-forward inclusion into supersonic separation systems. Based on the recommendations of the EDL-SA study, entry vehicle divert maneuvers following jettison events and RCS thrusting maneuvers to dispose of aeroshells after separation will be considered and analyzed as possible methods to minimize jettisoned mass recontact risks. Multi-objective optimization techniques will be used to trade potential recontact risks with transition system complexity, reliability, and cost. To determine contributions to total mission uncertainty due to these transition systems, I will perform Figure of Merit evaluations according to the techniques and weighting schemes defined in the EDL-SA study. As a final component of my research, I will investigate alternatives to configurations considered in the EDL-SA that do not necessarily require a supersonic forebody jettison event. Specifically, aftbody SRP configurations will be investigated. My analysis will focus on defining derived requirements on transitions architectures and systems for these configurations. All previous transition analyses will be reapplied to aftbody SRP configurations so that meaningful comparisons can be drawn between different configuration types.","startYear":2014,"startMonth":8,"endYear":2018,"endMonth":7,"statusDescription":"Completed","principalInvestigators":[{"contactId":237423,"canUserEdit":false,"firstName":"John-Paul","lastName":"Clarke","fullName":"John-paul B Clarke","fullNameInverted":"Clarke, John-paul B","middleInitial":"B","primaryEmail":"johnpaul@utexas.edu","publicEmail":false,"nacontact":false}],"programDirectors":[{"contactId":84634,"canUserEdit":false,"firstName":"Claudia","lastName":"Meyer","fullName":"Claudia M Meyer","fullNameInverted":"Meyer, Claudia M","middleInitial":"M","primaryEmail":"claudia.m.meyer@nasa.gov","publicEmail":true,"nacontact":false}],"programExecutives":[{"contactId":84634,"canUserEdit":false,"firstName":"Claudia","lastName":"Meyer","fullName":"Claudia M Meyer","fullNameInverted":"Meyer, Claudia M","middleInitial":"M","primaryEmail":"claudia.m.meyer@nasa.gov","publicEmail":true,"nacontact":false}],"programManagers":[{"contactId":183514,"canUserEdit":false,"firstName":"Hung","lastName":"Nguyen","fullName":"Hung D Nguyen","fullNameInverted":"Nguyen, Hung D","middleInitial":"D","primaryEmail":"hung.d.nguyen@nasa.gov","publicEmail":true,"nacontact":false}],"projectManagers":[{"contactId":68428,"canUserEdit":false,"firstName":"Charles","lastName":"Campbell","fullName":"Charles H Campbell","fullNameInverted":"Campbell, Charles H","middleInitial":"H","primaryEmail":"charles.h.campbell@nasa.gov","publicEmail":true,"nacontact":false}],"coInvestigators":[{"contactId":104120,"canUserEdit":false,"firstName":"David","lastName":"Blette","fullName":"David Blette","fullNameInverted":"Blette, David","primaryEmail":"dblette.jpl@gmail.com","publicEmail":false,"nacontact":false}],"website":"https://www.nasa.gov/directorates/spacetech/home/index.html","libraryItems":[],"transitions":[{"transitionId":75749,"projectId":91653,"partner":"Other","transitionDate":"2014-08-01","path":"Advanced From","relatedProjectId":12253,"relatedProject":{"acronym":"","projectId":12253,"title":"Non-Invasive Hemodynamic Monitoring in Microgravity","startTrl":4,"currentTrl":6,"endTrl":6,"benefits":"Early detection of cardiovascular changes is of prime importance for assessing astronaut health in space on short and long term missions. This novel non-invasive cardiovascular monitor will benefit future NASA missions and health care providers for ground-based cardiovascular risk assessments.","description":"Microgravity-induced changes in cardiovascular physiology are well-known and significant. Even short duration flights can lead to orthostatic intolerance, syncope, and reduced maximal oxygen uptake upon return to earth. In long-duration spaceflights, these effects can lead to the incapacity to egress the re-entry vehicle without help. Countermeasures, such as exercise or low body negative pressure application, are typically used to mitigate these effects. However, there is still a need for a simple method to monitor and quantify the cardiac de-compensation and the effectiveness of the counter-measures, as shown in the NASA Bioastronautics Roadmap.
Paper (July 2013): Preliminary results from standing ballistocardiography measurements in microgravity
Paper (Aug 2014): Standing ballistocardiography measurements in microgravity Stanford scientists brave the 'vomit comet' to improve astronauts' heart health","startYear":2012,"startMonth":8,"endYear":2015,"endMonth":8,"statusDescription":"Completed","website":"","program":{"acronym":"FO","active":true,"description":"
The President’s 2010 National Space Policy:
“A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship.”
Flight Opportunities directly answers the call of the President’s policy through the acquisition of suborbital launch services on commercial suborbital launch vehicles. By purchasing flight opportunities on U.S. commercial vehicles the Flight Opportunities program is encouraging and facilitating the growth of this market while simultaneously providing pathways to advance the technology readiness of a wide range of new launch vehicle and space technologies.
One of the greatest challenges NASA faces in incorporating advanced technologies into future missions is bridging the mid-technology readiness level (TRL) (4-7) gap (or “valley of death”), between component or prototype testing in a lab or ground facility setting, and the final infusion of a new technology into critical path exploration or science mission development. To cross this gap, the proposed new technology must pass system level testing in a relevant operational environment. Maturing a space technology to flight readiness status through relevant environment testing is a significant challenge from cost, schedule, and technical risk perspectives.
FO has its lineage from the former Innovative Partnership Program (IPP) of FY09, specifically the Facilitated Access to the Space Environment for Technology (FAST) project and the Commercial Reusable Suborbital Research (CRuSR) project. The FAST and CRuSR activities are continued within the FO Program, as the parabolic and suborbital, flight campaigns, respectively. The flights will provide opportunities to expose new technologies to low-g environments and/or high altitude environments. The intent is to demonstrate and mature various technologies for future applications. These emerging technologies will come from the nine other programs within the Space Technology Mission Directorate, from the other Mission Directorates and external sources (other Government Agencies, Academia, and Commercial Industries.
The NASA Flight Opportunities (FO) Program has been established as a part of the Space Technologies Mission Directorate (STMD) to rapidly develop, demonstrate and infuse revolutionary, high-payoff technologies through transparent, collaborative partnerships, expanding the boundaries of the aerospace enterprise by providing the nation’s investments in space technologies to make a difference in the world around us. FO focuses on maturation of technologies that are of benefit to multiple customers, to flight readiness status with an outcome of Technology Readiness Level (TRL) 6 or higher. These crosscutting capabilities are those that advance multiple future aerospace missions, including flight projects where near-space or in-space demonstration is needed before the capability can transition to direct mission application. Maturing technologies to a higher TRL status through relevant flight opportunities testing is a significant challenge from both a cost and risk perspective.
","programId":72,"responsibleMd":{"acronym":"STMD","canUserEdit":false,"city":"","external":false,"linkCount":0,"organizationId":4875,"organizationName":"Space Technology Mission Directorate","organizationType":"NASA_Mission_Directorate","naorganization":false,"organizationTypePretty":"NASA Mission Directorate"},"responsibleMdId":4875,"stockImageFileId":36656,"title":"Flight Opportunities"},"lastUpdated":"2024-2-6","releaseStatusString":"Released","viewCount":113,"endDateString":"Aug 2015","startDateString":"Aug 2012"},"infoText":"Advanced from another project within the program","infoTextExtra":"Another project within the program (Non-Invasive Hemodynamic Monitoring in Microgravity)","dateText":"August 2014"},{"transitionId":75750,"projectId":91653,"transitionDate":"2018-07-01","path":"Closed Out","details":"Planetary exploration of Mars is constrained by the landed payload capabilities of current entry, descent, and landing technologies. To extended landed payload capabilities to allow terrestrial rovers larger than the Mars Science Laboratory and, eventually, human-class payloads, new technologies must be developed that are capable of decelerating these massive payloads. One promising deceleration technology is Supersonic Retropropulsion (SRP) which entails initiating decelerating rocket propulsion at supersonic vehicle velocities rather than subsonic velocities as is used in current missions. To enable the use of SRP, an entry vehicle must perform a supersonic vehicle reconfiguration during descent to the Martian surface to expose SRP rocket nozzles into the oncoming atmospheric flow. The change between the hypersonic entry vehicle configuration and the SRP-ready vehicle configuration will require the supersonic ejection of the vehicle aeroshell. Once ejected, the discarded aeroshell becomes an intact, solid-mass piece of debris traveling in the same direction as the primary vehicle. This debris poses potential catastrophic recontact risks to the primary descent vehicle. Mitigating these debris recontact risks is a significant hurtle to the development of SRP as a mission-ready technology. Prior to the current body of research, the state-of-the-art of descent vehicle reconfiguration architecture analysis was comprised of simplistic pictorials representing a group of engineers' best intuition as to what a potential reconfiguration event should look like, accompanied by a weight feasibility score formed by assigning numeric values to pros and cons of each potential reconfiguration. These primitive assessments did not include any supplemental quantitative analysis to support the weighted feasibility score. More rigorous analysis was inhibited by the sheer size of the feasible design space coupled with the significant time and computational resource requirements of analyzing a single design point. The objective of the current research is to develop a high-level, quantitative, rapid analysis methodology that provides mission designers the capability to assess the initial feasibility of numerous candidate descent vehicle reconfiguration architectures during trade-study-level investigations. The analysis methodology developed through this research assumes that each piece of ejected debris is actively controlled via aerodynamic surfaces or thrusters as the debris separates from the primary descent vehicle and moves a \"safe distance\" away from the primary descent vehicle. After crossing the minimum \"safe\" offset distance threshold, active flight control is terminated and the ejected debris begins to freely tumble. The goal of this analysis methodology is to provide quantitative metrics for a proposed vehicle reconfiguration architecture that facilitate competitive comparison against other proposed architectures. The outputs of this methodology are the minimum required offset distance between the primary descent vehicle and the point at which the debris begins to tumble as well as the accompanying debris flight control subsystem performance requirements (e.g. thrust and propellant mass) necessary to achieve this offset distance. The methodology decomposes the problem into two distinct analysis regimes classified according to the use of active flight control on the ejected debris. The first analysis regime looks at the uncontrolled, tumbling flight of each unique ejected debris geometry. A far-field flight envelope is generated for each debris geometry through a monte-carlo tumbling flight simulation, see Figure 1. The simulation assumes each piece of debris tumbles in isolation, without considering proximity to other debris. The superimposed far-field flight envelopes of all pieces of ejected debris is termed the “debris field envelope”. The debris field envelope is compared to the post-ejection flight trajectory of the primary descent vehicle under the influence of propulsive deceleration from SRP. An initial downrange offset distance between the primary vehicle and the point at which the debris begins to tumble is calculated such that the descent vehicle trajectory will not pass through the debris field envelope, see Figure 2. Figure 1: Illustration of a far-field debris envelope. After ejection, the discarded pieces of the aeroshell may take a number of different tumbling flight trajectories based on variations in the atmosphere, flight dynamic properties, or debris orientation. The blue lines illustrate the extremum trajectories that form the far-field debris envelope. The black like illustrates the primary vehicle’s propulsive descent trajectory. Figure 2: Illustration of a far-field offset distance, . The blue lines illustrate the extremum trajectories that form the far-field debris envelope. The black like illustrates the primary vehicle’s propulsive descent trajectory. The offset distance is calculated such that the primary vehicle’s propulsive descent trajectory does not pass through the debris field envelope. The second analysis regime utilizes the calculated offset distance and a three-step sequential approximation methodology (TSSAM) to prescribe a near-field “transit” trajectory for each piece of ejected debris, see Figure 4. The first step of the TSSAM assumes no aerodynamic forces are acting on any piece of debris and determines the initial separation impulse force that would be required to propel each piece of ejected debris away from the primary descent vehicle by a distance equal to the calculated offset distance. In the second step of the TSSAM, the transit trajectory for each piece of debris is optimized to minimize the required initial separation impulse forces as well as the continuous aerodynamic moment control torques necessary to stabilize the debris during the transit trajectory. The optimization of the transit trajectory utilizes isolated aerodynamics for all pieces of debris. Figure 4: A three-step sequential approximation methodology (TSSAM) is used to prescribe the trajectory of an ejected piece of debris to achieve the initial offset distance . The expanded portion of the figure shows the prescribed transit trajectory of the actively controlled piece of debris relative to the primary descent vehicle. The transit trajectory is prescribed such that an offset distance, , is achieved before each piece of debris begins to freely tumble. In the final step of the TSSAM, interference aerodynamics are calculated along the optimized transit trajectory from the previous step. The interference aerodynamics are not used to modify the transit trajectory route. Rather, they are used to obtain a better approximation of the aerodynamic forces and moments experienced by the debris as it traverses the transit trajectory. Response Surface Methodology (RSM) is used to create models of the difference between isolated and interference aerodynamic coefficients along this transit trajectory. By modeling this difference, investigators may determine the point at which interference aerodynamic coefficients converge to their isolated values. Because interference aerodynamics are exponentially more expensive to compute than isolated aerodynamics, significant resource savings can be realized by only computing interference data where absolutely necessary. This step is one of the key features of the separation analysis methodology that enables its use for rapid, high-level analysis. The substantial time and expense required to calculate interference aerodynamics precludes the creation of a full aerodynamic database due to the high dimensionality of the coupled dynamic motion inherent to supersonic vehicle reconfigurations. By calculating expensive interference aerodynamics only along a defined transit trajectory, we reduce the time and expense required to perform vehicle reconfiguration analyses while still gaining valuable insight that can be used to competitively compare multiple candidate vehicle reconfiguration architectures. This methodology quantitatively approximates required debris ejection impulses and debris transit stability control moments for a descent vehicle reconfiguration architecture. Results can be rapidly computed for several candidate vehicle reconfiguration architectures. The methodology output metrics can be used to quantitatively determine the fittest candidate(s) for further low-level, detailed analysis. This work is being considered for further study by NASA teams investigating supersonic descent vehicle reconfiguration architectures.","infoText":"Closed out","infoTextExtra":"","dateText":"July 2018"}],"responsibleMd":{"acronym":"STMD","canUserEdit":false,"city":"","external":false,"linkCount":0,"organizationId":4875,"organizationName":"Space Technology Mission Directorate","organizationType":"NASA_Mission_Directorate","naorganization":false,"organizationTypePretty":"NASA Mission Directorate"},"program":{"acronym":"STRG","active":true,"description":"\tThe Space Technology Research Grants Program will accelerate the development of "push" technologies to support the future space science and exploration needs of NASA, other government agencies and the commercial space sector. Innovative efforts with high risk and high payoff will be encouraged. The program is composed of two competitively awarded components.
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