Evaluation of the National Aerospace Initiative (2004) / Chapter Skim
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3 Access to Space
3 Access to Space
Pages 53-86
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From page 53... ...
The proliferation of terrestrial fiber optics and increasingly capable and longer life satellites (both commercial and military) have tended to reduce launch rates, thereby inhibiting large new investments in launch vehicles and associated infrastructure.
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From page 54... ...
Included are reusable rocket propulsion, tanks, and airframes; thermal protection systems (TPS) ; integrated vehicle health management (IVHM)
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From page 55... ...
55 %51 2025 - and (3X)
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From page 56... ...
to enable a decision on a rocket-based reusable launch system by 2008. Air-breathing hypersonic technology is not baselined for any near-term space access application but is under consideration for a long-term, crewed launch vehicle (Rogacki, 2003)
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From page 57... ...
, and Space Control (SC) may require both rapid-launch, expendable systems and reusable launch systems capable of turnaround times measured in hours rather than weeks or months.
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From page 58... ...
The only reusable launch capability, NASA's Space Transportation System, is scheduled to be retired by the end of the decade. Owing to the loss of the shuttle Columbia and the resulting Presidential Vision announcement, the plans for crewed flights are undergoing extensive revision.
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From page 59... ...
An individual table is devoted to each NAI-designated vehicle system: · Airframe · Propulsion · Flight subsystems · Launch operations · Mission operations · Software Each table further divides the vehicle system into major technology areas, which are in turn broken down into the constituent technologies defined (for the most part)
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From page 60... ...
Airframe Depending on their configuration, the airframes of launch vehicles can serve several purposes, including thermal protection; enabling favorable lift-to-drag and thrust-to-drag ratios; housing and protection of onboard electrical equipment, pumps, feed systems, and engine systems; and fuel storage. The airframe is expected to be fully active in aerodynamic control of the vehicle.
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From page 61... ...
Vehicle CFD/aerothermal 2 Extreme Low Structural design 3 Moderate Medium Cost and safety analyses 2 Moderate Low xxx materials initiative addressing thermal protection for bearings, nozzles, thrust chambers, gas generators, hot gas ducting, and turbomachinery (Brockmeyer, 2003)
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From page 62... ...
NAI should support programs to validate numerical tools using groundbased and/or airborne testing. Summary Lightweight reusable fuel tanks and highly integrated structures are significant contributors to increasing the overall system margin and the payload fraction of launch vehicles.
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From page 63... ...
. It should be noted that the NASA NGLT program not only targets reduced cost, faster turnaround time, and more reuse than the current shuttle capability but also specifies a lift capability of 30 to 50 metric tons.
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From page 64... ...
3/5a Significant Low Medium (oxidizer/fuel) LOx/LH2 5 Significant Medium H2O2/HC 2 Little Low High-energy green fuels 1 Little Low Propellant Turbine pumps 3 Extreme Low High management devices Engine lines 3 Extreme Low Engine ducts 3 Extreme Low Engine valves 3 Extreme Low Cryo level sensors 4 Significant Medium Combustion and Chambers 3 Extreme Low High energy conversion Nozzles 3 Extreme Low devices Injectors 3 Extreme Low Gas generators 3 Extreme Low Preburners 3 Extreme Low Controls Sensors 4 Moderate Medium Medium Health management 2 Significant Low Software 4 Significant High Engine controls 4 Significant Medium Materials O2-rich compatible 3 Significant Low High High temperature 2 Significant Low a3 for U.S.
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From page 65... ...
Finding 3-11. Advances in materials and design can reduce cost, increase chemical compatibility, enable higher operating temperatures, reduce weight, and increase the operating life of propellant management systems.
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From page 66... ...
Advances in materials and designs of combustion and energy conversion devices are needed to reduce cost, increase chemical compatibility, increase operating temperature, reduce weight, and increase operating life. Controls Of all the engine components, controls (except for health management systems)
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From page 67... ...
Future visions of aerospace vehicles in both the civilian and military sectors are based on plans that require wide-ranging evolutionary changes. In accessing space, the significant difference between future requirements for commercial/civil vehicles and those for the military space plane system is the military requirement for a responsive space lift capability (Sega, 2003)
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From page 68... ...
Not only must the key technologies be matured, but photonic optics must be integrated with the vehicle management system. Flight test will ultimately be dependent on the critical reliability of the
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From page 69... ...
As such, a number of programs in the vehicle management system (VMS) , integrated vehicle health management (IVHM)
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From page 70... ...
Thus, in the context of flight subsystems, thermal cooling technologies can be effectively leveraged from other R&D programs. Vehicle Health Similar to the engine health monitoring discussed in the section on propulsion, a vehicle subsystem health management system to continuously monitor, diagnose, and prognosticate the vehicle status will be critical to improving vehicle availability.
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From page 71... ...
Because some of the biggest launch process drivers are unique to specific launch vehicles, it is difficult to imagine a complete set of generic areas where advances (cost reductions) can be made independent of the vehicle configuration.
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From page 72... ...
It is assumed that achieving or approaching these goals would result in reducing marginal sortie costs. Reusable launch vehicle (RLV)
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From page 73... ...
High) Weather Winds aloft 4 Little High Medium prediction Lightning prediction and 2 Significant Low control Automated ops Umbilical 3 Significant High High Hypergolic fuels 2 Significant Medium System calibrations 4 Moderate High Ground and range ops design 4 Moderate High and analysis tools Integrated range Onboard range safety 4 Extreme High Medium network architecture Responsive reconfiguration 3 Moderate Medium Intelligent TPS acreage 1 Extreme Low High inspection Health management 2 Significant Low Security Physical N/A Low unauthorized penetration Electronic N/A xxx system from approximately $300 million per sortie to $10 million per sortie (DDR&E, 2002)
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From page 74... ...
NAI plans to correct this situation using the X-42 flight test vehicle. In addition to being an environment simulator for airframe and flight subsystems technologies, NAI advertises that the X-42 will be used to evaluate improved technologies and approaches for fighterlike operability in a military space plane (MSP)
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From page 75... ...
Likewise, if the X-43 series (discussed previously) includes enabling durable, intelligent TPS, an all-electric launch system with health management, and a space-based launch tracking system, as advertised by NASA (Lyles, 2003)
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From page 76... ...
A space-based range architecture would provide a flexible network of tracking and communication links, enabling global launch operations. Furthermore, the only precision landing aid available at the Eastern Range is an antiquated microwave landing system used by the shuttle.
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From page 77... ...
Integrated vehicle health management (IVHM) systems not only perform those functions but also should identify part degradation and assist in vehicle maintenance.
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From page 78... ...
is currently tied to fixed range systems for launch vehicles, but there is a desire to make the tracking of launch and landing independent of fixed locations to provide flexibility in launch and landing location and to facilitate rapid response (Morrish, 2003)
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From page 79... ...
Software All aspects of the National Aerospace Initiative rely heavily on the use of software for successful applications. These include the three NAI major pillars: hypersonics, access to space, and space technology.
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From page 80... ...
High) Rapid mission Integrated mission planning 2 Moderate Medium High planning -- tools mission-unique constraints and Mission unique constraints 1 Significant Medium analysis and analysis Rapid mission Range tracking 3 Moderate High Medium response Launch and landing 2 Significant Medium flexibility Command and control 3 Moderate Medium Air traffic management 4 Little High On-orbit Autonomous GNC 3 Extreme Medium Medium operations Proximity operations 4 Significant High Grapple, soft dock 2 Moderate High Fuel/consumable transfer 2 Little Medium ORU transfer 1 Little Medium Orbit-assembly-compatible 4 Significant High structures Rapid sensor initialization 3 Extreme Medium xxx committee.
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From page 81... ...
High) Open Secure wireless 3 N/A High Medium architectures communications Modularity Plug-and-play interface 4 N/A High High Engineering Combustion flow analysis 3 Significant Medium Medium design software issues Simulation of aero control, 4 Significant Medium stability, and autopilot design Hypersonic inlet/ nozzle design 4 Significant Medium Thermal structural testing 4 Significant Medium Propulsion system design 2 Significant Low Quick 3 N/A Medium Medium modification Verification and Parallel processing 2 Little Low High validation Prediction of vehicle 2 Significant Low performance Autonomous Vehicle to vehicle 2 Moderate Low Medium flight control transportability (transportable)
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From page 82... ...
Technologies having the greatest probability of enhancing the near-term goals of NAI are advanced materials for use in propulsion and thermal protection systems, electrical/hydraulic power generation and management, software transportability, integrated structures, and error-free software generation and verification. Furthermore, the development of computational analysis tools and methodologies should be emphasized -- especially when coupled to test analysis and ground test facilities.
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From page 83... ...
Recommendation 3-23. DoD and NASA should develop time-phased, reusable, rocket-based flight demonstration programs to move these and other near-term, unproven technologies through flight test; specify and disseminate the technology readiness levels and specific exit criteria necessary to support the operational decision points; ensure that research is directed toward obtaining the specified data and that the demonstrations -- both flight and ground -- are structured to obtain the required information and data; concentrate on technologies that contribute to reusability; and fund multiple copies of each design to mitigate potential loss of the entire program if a single vehicle is lost.
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From page 84... ...
Projected specific and related funding of AFRL space access efforts averages more than $100 million per year through FY 2009 without additional NAI-designated funds. This funding encompasses both upgrades to current expendable launch vehicles and technology for reusable systems.
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From page 85... ...
It is projected that the military space plane, as currently conceived, can perform the PGS, ORS, and Space Control missions in a very cost effective manner. The United States and several other countries currently possess the capability to develop the technology to produce this weapon system in the near term.
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From page 86... ...
Briefing by Garry Lyles, NASA Marshall Space Flight Center, to the Committee on the National Aerospace Initiative. October 7.
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