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Exercise Equipment Usability Assessment for a Deep Space Concept Vehicle

With international aspirations to send astronauts to deep space, the world is now faced with the complex problem of keeping astronauts healthy in unexplored hostile environments for durations of time never before attempted by humans. The great physical demands imparted by space exploration compound the problem of astronaut health, as the astronauts must not only be healthy, but physically fit upon destination arrival in order to perform the scientific tasks required of them. Additionally, future deep space exploration necessitates the development of environments conducive to long-duration habitation that would supplement propulsive vehicles. Space Launch System (SLS) core stage barrel sections present large volumes of robust structure that can be recycled and used for long duration habitation. This assessment will focus on one such conceptual craft, referred to as the SLS Derived Habitat (SLS-DH). Marshall Space Flight Center's (MSFC) Advanced Concepts Office (ACO) has formulated a high-level layout of this SLS-DH with parameters such as floor number and orientation, floor designations, grid dimensions, wall placement, etc. Yet to be determined, however, is the layout of the exercise area. Currently the SLS-DH features three floors laid out longitudinally, leaving 2m of height between the floor and ceilings. This short distance between levels introduces challenges for proper placement of exercise equipment such as treadmills and stationary bicycles, as the dynamic envelope for the 95th percentile male astronauts is greater than 2m. This study aims to assess the optimal equipment layout and sizing for the exercise area of this habitat. Figure 1 illustrates the layout of the DSH concept demonstrator located at MSFC. The exercise area is located on the lower level, seen here as the front half of the level occupied by a crew member. This small volume does not allow for numerous or bulky exercise machines, so the conceptual equipment has been limited to a treadmill and stationary bicycle. With the most current treadmill aboard the International Space Station (ISS), the Combined Operational Load-Bearing External Resistance Treadmill (COLBERT), being located in an International Standard Payload Rack (ISPR), the bottom of the conceptual treadmill features a height of 38in. Making the treadmill flush with the floor would be impossible in this rack configuration, as the distance from the outer wall of the spacecraft to the bottom floor would be too shallow. From preliminary sizing, the 38in required for the bottom of the treadmill combined with a 78in operational envelope for a 95th percentile may not be accommodated in the exercise area in a vertical orientation. Figure 2 demonstrates the volume required (in maroon) for an ISPR-bound treadmill in the concept demonstrator. Early indications as seen in this figure indicate that the crew members would contact the ceiling in such an arrangement. An assessment will be conducted to evaluate various orientations of exercise equipment in the concept demonstrator. Orientations to be tested include putting the bottom of the treadmill on the wall, having the treadmill at an angle in the floor both horizontally and vertically, and having a shorter (non-rack bound) treadmill in a vertical orientation on the floor. This assessment will yield findings regarding sizing of the area and how well participants feel they could exercise in such an environment. Due to the restrictions of assessing a microgravity vehicle in a normal-gravity environment, simulations in MSFC's Virtual Environments Lab (VEL) may be necessary. Final deliverables will include recommendations regarding the location and size of possible exercise equipment aboard the SLS-Derived DSH.

Rhodes, Brooke M.↗

Environmentally Responsible Aviation N plus 2 Advanced Vehicle Concepts NRA Status

The NASA Environmentally Responsible Aviation Project (ERA) has a NASA Research Announcement (NRA) that is performing a systems study and conceptual design. The purpose of the systems study is to determine possible configurations that are capable of simultaneously meeting NASA's Subsonic N+2 Metrics for reducing Noise, Emissions and Fuel Burn. The conceptual design portion of the contract is to perform a conceptual design ofa Subscale Testbed Vehicle to demonstrate and test both the configuration and the technologies that are required to allow that configuration to meet the goals. This briefing is an update on the status of that NRA presented to the Turbo Expo conference in June 2011.

Mangelsdorf, Mark F.↗

Orbital transfer vehicle concept definition and system analysis study. Volume 2: OTV concept definition and evaluation. Book 3: Subsystem trade studies

The technical trade studies and analyses reported in this book represent the accumulated work of the technical staff for the contract period. The general disciplines covered are as follows: (1) Guidance, Navigation, and Control; (2) Avionics Hardware; (3) Aeroassist Technology; (4) Propulsion; (5) Structure and Materials; and (6) Thermal Control Technology. The objectives in each of these areas were to develop the latest data, information, and analyses in support of the vehicle design effort.

Dickman, Glen J.↗

Robotic Mars Sample Return and Earth entry vehicle concept development

NASA has studied potential Mars Sample Return over many decades, and the most recent Planetary Science Decadal Survey recommended making significant progress on this topic one of its highest priority goals. Recent inter-agency discussions and scientific support are lending credence to current Mars Sample Return planning activities, which notionally target launch of Sample Retrieval Lander and Earth Return Orbiter flight elements in 2026, and return of Martian samples to Earth in 2031. As part of the Mars Sample Return architecture under consideration, an Earth Entry Vehicle would perform the final phase by protecting the samples through severe entry environments using a 60-deg. sphere-cone flying on a passive/ballistic trajectory. The Earth Entry Vehicle design activities in particular are considering a variety of potential challenges, including: minimizing vehicle mass due to the need to travel to Mars and back to Earth, vehicle robustness to Micrometeroid and Orbital Debris impacts, capability to withstand severe entry environments while minimizing landing ellipse size, and providing impact load attenuation during a high-speed landing to meet Martian sample tube load limits and ensure sample containment in off-nominal scenarios. The present work provides a snapshot of current study work in progress, and highlights paths being taken to address these various design challenges for the conceptual Earth Entry Vehicle.

Corliss, James↗

Low thrust vehicle concept study

Low thrust chemical (hydrogen-oxygen) propulsion systems configured specifically for low acceleration orbit transfer of large space systems were defined. Results indicate that it is cost effective and least risk to combine the OTV and stowed spacecraft in a single 65 K Shuttle. The study shows that the engine for an optimized low thrust stage (1) does not require very low thrust; (2) 1-3 K thrust range appears optimum; (3) thrust transient is not a concern; (4) throttling probably not worthwhile; and (5) multiple thrusters complicate OTV/LSS design and aggravate LSS loads. Regarding the optimum vehicle for low acceleration missions, the single shuttle launch (LSS and expendable OTV) is most cost effective and least risky. Multiple shuttles increase diameter 20%. The space based radar structure short OTV (which maximizes space available for packaged LSS) favors use of torus tank. Propellant tank pressures/vapor residuals are little affected by engine thrust level or number of burns.

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Space Ops 2002: Bringing Space Operations into the 21st Century. Track 3: Operations, Mission Planning and Control. 2nd Generation Reusable Launch Vehicle-Concepts for Flight Operations

With the successful implementation of the International Space Station (ISS), the National Aeronautics and Space Administration (NASA) enters a new era of opportunity for scientific research. The ISS provides a working laboratory in space, with tremendous capabilities for scientific research. Utilization of these capabilities requires a launch system capable of routinely transporting crew and logistics to/from the ISS, as well as supporting ISS assembly and maintenance tasks. The Space Shuttle serves as NASA's launch system for performing these functions. The Space Shuttle also serves as NASA's launch system for supporting other science and servicing missions that require a human presence in space. The Space Shuttle provides proof that reusable launch vehicles are technically and physically implementable. However, a couple of problems faced by NASA are the prohibitive cost of operating and maintaining the Space Shuttle and its relative inability to support high launch rates. The 2nd Generation Reusable Launch Vehicle (2nd Gen RLV) is NASA's solution to this problem. The 2nd Gen RLV will provide a robust launch system with increased safety, improved reliability and performance, and less cost. The improved performance and reduced costs of the 2nd Gen RLV will free up resources currently spent on launch services. These resource savings can then be applied to scientific research, which in turn can be supported by the higher launch rate capability of the 2nd Gen RLV. The result is a win - win situation for science and NASA. While meeting NASA's needs, the 2nd Gen RLV also provides the United States aerospace industry with a commercially viable launch capability. One of the keys to achieving the goals of the 2nd Gen RLV is to develop and implement new technologies and processes in the area of flight operations. NASA's experience in operating the Space Shuttle and the ISS has brought to light several areas where automation can be used to augment or eliminate functions performed by crew and ground controllers. This experience has also identified the need for new approaches to staffing and training for both crew and ground controllers. This paper provides a brief overview of the mission capabilities provided by the 2nd Gen RLV, a description of NASA's approach to developing the 2nd Gen RLV, a discussion of operations concepts, and a list of challenges to implementing those concepts.

Hagopian, Jeff↗

Design and performance analysis of an aero-maneuvering orbital-transfer vehicle concept

Systems requirements for design-optimized, lateral-turn performance were determined for reusable, space-based applications and low-Earth orbits involving large multiple plane-inclination changes. The aerothermodynamic analysis is the most advanced available for rarefield-hypersonic flow over lifting surfaces at incidence. The effects of leading-edge bluntness, low-density viscous phenomena, and finite-rate flow-field chemistry and surface catalysis are accounted for. The predicted aerothermal heating characteristics are correlated with thermal-control and flight-performance capabilities. The mission payload capacity for delivery, retrieval, and combined operations was determined for round-trip sorties extending to polar orbits. Recommendations are given for future design refinements. The results help to identify technology issues required to develop prototype operational vehicles.

Menees, G. P.↗

Design and performance analysis of an aeromaneuvering orbital-transfer vehicle concept

Systems requirements for design-optimized, lateral-turn performance were determined for reusable, space-based applications and low-earth orbits involving large multiple plane-inclination changes. The aerothermodynamic analysis is the most advanced available for rarefied-hypersonic flow over lifting surfaces at incidence. The effects of leading-edge bluntness, low-density viscous phenomena, and finite-rate flow-field chemistry and surface catalysis are accounted for. The predicted aerothermal heating characteristics are correlated with thermal-control and flight-performance capabilities. The mission payload capacity for delivery, retrieval, and combined operations was determined for round-trip sorties extending to polar orbits. Recommendations are given for future design refinements. The results help to identify technology issues required to develop prototype operational vehicles.

Menees, G. P.↗

Vortex lattice prediction of subsonic aerodynamics of hypersonic vehicle concepts

The vortex lattice method introduced by Lamar and Gloss (1975) was applied to the prediction of subsonic aerodynamic characteristics of hypersonic body-wing configurations. The reliability of the method was assessed through comparison of the calculated and observed aerodynamic performances of two National Hypersonic Flight Research Facility craft at Mach 0.2. The investigation indicated that a vortex lattice model involving 120 or more panel elements can give good results for the lift and induced drag coefficients of the craft, as well as for the pitching moment at angles of attack below 10 to 15 deg. Automated processes for calculating the local slopes of mean-camber surfaces may also render the method suitable for use in preliminary design phases.

Pittman, J. L.↗

Low-thrust vehicles concept studies

Low thrust chemical (hydrogen-oxygen) propulsion systems configured specifically for low acceleration orbit transfer of large space systems were studied in order to provide the required additional data to better compare new, low thrust chemical propulsion systems with other propulsion approaches such as advanced electric systems. Study results indicate that it is cost-effective and least risk to combine the low thrust OTV and stowed spacecraft in a single 65 K shuttle. Mission analysis indicates that there are 25 such missions, starting in 1987. Multiple shuttles (LSS in one, OTV in another) result in a 20% increase in LSS (SBR) diameter over single shuttle launches. Synthesis and optimization of the LSS characteristics and OTV capability resulted in determination of the optimum thrust-to-weight and thrust level. For the space based radar with radial truss arms (center thrust application), the optimum thrust-to-weight (maximum) is 0.1, giving a thrust of 2000 lb. For the annular truss (edge-on thrust application) the structure is not as sensitive, and thrust of 1000 lb appears optimum. For the geoplatform, optimum T/W is .15 (3000 lb thrust). The effects of LSS structure material, weight distribution, and unit area density were evaluated, as were the OTV engine thrust transient and number of burns.

Ketchum, W. J.↗

Shuttle derived vehicle analysis solid booster unmanned launch vehicle concept definition study, volume 2

The technical effort associated with the selection and definition of the recommended SRB-X concept is documented. Included are discussions concerning the trades leading to the selected concept, the analysis that established the concept's basic subsystem characteristics, selected configuration description and performance capabilities, launch site operations and facility needs, development schedule, cost characteristics, risk assessment, and a cursory comparison with other launch systems.

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Orbiter transfer vehicle concept definition and system analysis study. Volume 4: Space station accommodations. Revision 1

A brief summary is given of the key objectives of Task 5 of the Space Station Accommodations Concept Definition. Space station accommodations were assessed and defined for each potential candidate Space-Based OTV concept and for the composite OTV fleet. To accomplish this, the functional and physical interactions between each OTV concept and the space station were defined. Then, conceptual accommodation designs were prepared and optimized for approach and configuration. Initial space station requirements were identified, including the ability to accommodate and support evolution to maturity, and then a time-phasing of accommodations was prepared showing that evolution. In the process of developing physical and functional interactions, operational requirements were defined, together with associated timelines. In that the crew complement is subject to limitations, the operational requirements derivation is biased toward automation wherever possible. For each candidate Ground-Based OTV concept, operating in conjunction with the space station, the above process was repeated.

Randall, Roger M.↗

Space transfer vehicle concepts and requirements, volume 2, book 1

The objective of the systems engineering task was to develop and implement an approach that would generate the required study products as defined by program directives. This product list included a set of system and subsystem requirements, a complete set of optimized trade studies and analyses resulting in a recommended system configuration, and the definition of an integrated system/technology and advanced development growth path. A primary ingredient in the approach was the TQM philosophy stressing job quality from the inception. Included throughout the Systems Engineering, Programmatics, Concepts, Flight Design, and Technology sections are data supporting the original objectives as well as supplemental information resulting from program activities. The primary result of the analyses and studies was the recommendation of a single propulsion stage Lunar Transportation System (LTS) configuration that supports several different operations scenarios with minor element changes. This concept has the potential to support two additional scenarios with complex element changes. The space based LTS concept consists of three primary configurations--Piloted, Reusable Cargo, and Expendable Cargo.

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Space transfer vehicle concepts and requirements. Volume 4: Summary of special studies

Our final report for Phase 1 addressed the future space transportation needs and requirements based on the current assets, at the time, and their evolution through technology/advanced development using a path and schedule that supported the world leadership role of the United States in a responsible and realistic financial forecast. Always, and foremost, the recommendations placed high values on the safety and success of missions both manned and unmanned through a total quality management philosophy at Martin Marietta. The second phase of the STV contract involved the use of Technical Directives (TD) to provide short-term support for specialized tasks as required by the COTR. Three of these tasks were performed in parallel with Phase 1. These tasks were the Liquid Acquisition Experiment (LACE), Liquid Reorientation Experiment (LIRE), and Expert System for Design, Operation, and Technology Studies (ESDOTS). The results of these TD's were reported in conjunction with the Phase 1 Final Report. Cost analysis of existing launch systems has demonstrated a need for a new upper stage that will increase America's competitiveness in the global launch services market. To provide a growth path of future exploration class STV's, near-term low-cost upper stages featuring modularity, portability, scalability, and evolvability must be developed. These recommendations define a program that: leverages ongoing activities to establish a new development environment, develop technologies that benefit the entire life cycle of a system, and result in a scalable hardware platform that provides a growth path to future upper stages.

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Advanced transportation system study: Manned launch vehicle concepts for two way transportation system payloads to LEO. Work breakdown structure and work breakdown structure dictionary

The report describes the work breakdown structure (WBS) and its associated WBS dictionary for task area 1 of contract NAS8-39207, advanced transportation system studies (ATSS). This WBS format is consistent with the preliminary design level of detail employed by both task area 1 and task area 4 in the ATSS study and is intended to provide an estimating structure for parametric cost estimates.

Duffy, James B.↗