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At least 667 records · Page 37

Integratable propulsion systems for the Space Station

Oxygen/hydrogen propulsion system options for space station orbit maintenance and attitude control were developed and evaluated relative to monopropellant and storable bipropellant propulsion systems. Space station propulsion requirements were analyzed with reference to such considerations as station size, altitude, power, crew size, and orbit transfer vehicle and orbital maneuvering vehicle servicing requirements. The evolutionary growth of oxygen/hydrogen bipropellant propulsion as an integral part of several interrelated space station functions, e.g., life support, power, and thermal management was considered. Propellant resupply evolves from resupply based on transport of liquid oxygen and liquid hydrogen to water. The advantages of the operation of the space station based on an oxygen/hydrogen economy are presented and discussed.

Rosenberg, S. D.↗

Space architecture monograph series. Volume 4: Genesis 2: Advanced lunar outpost

This research and design study investigated advanced lunar habitats for astronauts and mission specialists on the Earth's moon. Design recommendations are based on environmental response to the lunar environment, human habitability (human factors and environmental behavior research), transportability (structural and materials system with least mass), constructability (minimizing extravehicular time), construction dependability and resilience, and suitability for NASA launch research missions in the 21st century. The recommended design uses lunar lava tubes, with construction being a combination of Space Station Freedom derived hard modules and light weight Kevlar laminate inflatable structures. The proposed habitat includes research labs and a biotron, crew quarters and crew support facility, mission control, health maintenance facility, maintenance work areas for psychological retreat, privacy, and comtemplation. Furniture, specialized equipment, and lighting are included in the analysis and design. Drawings include base master plans, construction sequencing, overall architectural configuration, detailed floor plans, sections and axonometrics, with interior perspectives.

Fieber, Joseph P.↗

A Comparison Between Orion Automated and Space Shuttle Rendezvous Techniques

The Orion spacecraft will replace the space shuttle and will be the first human spacecraft since the Apollo program to leave low earth orbit. This vehicle will serve as the cornerstone of a complete space transportation system with a myriad of mission requirements necessitating rendezvous to multiple vehicles in earth orbit, around the moon and eventually beyond . These goals will require a complex and robust vehicle that is, significantly different from both the space shuttle and the command module of the Apollo program. Historically, orbit operations have been accomplished with heavy reliance on ground support and manual crew reconfiguration and monitoring. One major difference with Orion is that automation will be incorporated as a key element of the man-vehicle system. The automated system will consist of software devoted to transitioning between events based on a master timeline. This effectively adds a layer of high level sequencing that moves control of the vehicle from one phase to the next. This type of automated control is not entirely new to spacecraft since the shuttle uses a version of this during ascent and entry operations. During shuttle orbit operations however many of the software modes and hardware switches must be manually configured through the use of printed procedures and instructions voiced from the ground. The goal of the automation scheme on Orion is to extend high level automation to all flight phases. The move towards automation represents a large shift from current space shuttle operations, and so these new systems will be adopted gradually via various safeguards. These include features such as authority-to-proceed, manual down modes, and functional inhibits. This paper describes the contrast between the manual and ground approach of the space shuttle and the proposed automation of the Orion vehicle. I will introduce typical orbit operations that are common to all rendezvous missions and go on to describe the current Orion automation architecture and contrast it with shuttle rendezvous techniques and circumstances. The shuttle rendezvous profile is timed to take approximately 3 days from orbit insertion to docking at the International Space Station (ISS). This process can be divided into 3 phases: far-field, mid-field and proximity operations. The far-field stage is characterized as the most quiescent phase. The spacecraft is usually too far to navigate using relative sensors and uses the Inertial Measurement Units (IMU s) to numerically solve for its position. The maneuvers are infrequent, roughly twice per day, and are larger than other burns in the profile. The shuttle uses this opportunity to take extensive ground based radar updates and keep high fidelity orbit states on the ground. This state is then periodically uplinked to the shuttle computers. The targeting solutions for burn maneuvers are also computed on the ground and uplinked. During the burn the crew is responsible for setting the shuttle attitude and configuring the propulsion system for ignition. Again this entire process is manually driven by both crew and ground activity. The only automatic processes that occur are associated with the real-time execution of the burn. The Orion automated functionality will seek to relieve the workload of both the crew and ground during this phase

Ruiz, Jose O,↗

Integration Process for the Habitat Demonstration Unit

The Habitat Demonstration Unit (HDU) is an experimental exploration habitat technology and architecture test platform designed for analog demonstration activities. The HDU previously served as a test bed for testing technologies and sub-systems in a terrestrial surface environment. in 2010 in the Pressurized Excursion Module (PEM) configuration. Due to the amount of work involved to make the HDU project successful, the HDU project has required a team to integrate a variety of contributions from NASA centers and outside collaborators The size of the team and number of systems involved With the HDU makes Integration a complicated process. However, because the HDU shell manufacturing is complete, the team has a head start on FY--11 integration activities and can focus on integrating upgrades to existing systems as well as integrating new additions. To complete the development of the FY-11 HDU from conception to rollout for operations in July 2011, a cohesive integration strategy has been developed to integrate the various systems of HDU and the payloads. The highlighted HDU work for FY-11 will focus on performing upgrades to the PEM configuration, adding the X-Hab as a second level, adding a new porch providing the astronauts a larger work area outside the HDU for EVA preparations, and adding a Hygiene module. Together these upgrades result in a prototype configuration of the Deep Space Habitat (DSH), an element under evaluation by NASA's Human Exploration Framework Team (HEFT) Scheduled activates include early fit-checks and the utilization of a Habitat avionics test bed prior to installation into HDU. A coordinated effort to utilize modeling and simulation systems has aided in design and integration concept development. Modeling tools have been effective in hardware systems layout, cable routing, sub-system interface length estimation and human factors analysis. Decision processes on integration and use of all new subsystems will be defined early in the project to maximize the efficiency of both integration and field operations. In addition a series of tailored design reviews are utilized to quickly define the systems and their integration into the DSH configuration. These processes are necessary to ensure activities, such as partially reversing integration of the X-Hab second story of the HDU and deploying and stowing the new work porch for transportation to the JSC Rock Yard and to the Arizona Black Point Lava Flow Site are performed with minimal or no complications. In addition, incremental test operations leading up to an Integrated systems test allows for an orderly systems test program. For FY-11 activities, the HDU DSH will act as a laboratory utilizing a new X-Hab inflatable second floor with crew habitation features. In addition to the day to day operations involving maintenance of the HDU and exploring the surrounding terrain, testing and optimizing the use of the new X-Hab, work porch, Hygiene Module, and other sub-system enhancements will be the focus of the FY-11 test objectives. The HDU team requires a successful integration strategy using a variety of tools and approaches to prepare the DSH for these test objectives. In a challenging environment where the prototyping influences the system design, as well as Vice versa, results of the HDU DSH field tests will influence future designs of habitat systems.

Gill, Tracy↗

SpaceX Dragon Air Circulation System

The Dragon capsule is a reusable vehicle being developed by Space Exploration Technologies (SpaceX) that will provide commercial cargo transportation to the International Space Station (ISS). Dragon is designed to be a habitable module while it is berthed to ISS. As such, the Dragon Environmental Control System (ECS) consists of pressure control and pressure equalization, air sampling, fire detection, illumination, and an air circulation system. The air circulation system prevents pockets of stagnant air in Dragon that can be hazardous to the ISS crew. In addition, through the inter-module duct, the air circulation system provides fresh air from ISS into Dragon. To utilize the maximum volume of Dragon for cargo packaging, the Dragon ECS air circulation system is designed around cargo rack optimization. At the same time, the air circulation system is designed to meet the National Aeronautics Space Administration (NASA) inter-module and intra-module ventilation requirements and acoustic requirements. A flight like configuration of the Dragon capsule including the air circulation system was recently assembled for testing to assess the design for inter-module and intra-module ventilation and acoustics. The testing included the Dragon capsule, and flight configuration in the pressure section with cargo racks, lockers, all of the air circulation components, and acoustic treatment. The air circulation test was also used to verify the Computational Fluid Dynamics (CFD) model of the Dragon capsule. The CFD model included the same Dragon internal geometry that was assembled for the test. This paper will describe the Dragon air circulation system design which has been verified by testing the system and with CFD analysis.

Hernandez, Brenda↗

Thermal Components Boost Performance of HVAC Systems

As the International Space Station (ISS) travels 17,500 miles per hour, normal is having a constant sensation of free-falling. Normal is no rain, but an extreme amount of shine.with temperatures reaching 250 F when facing the Sun. Thanks to a number of advanced control systems onboard the ISS, however, the interior of the station remains a cool, comfortable, normal environment where astronauts can live and work for extended periods of time. There are two main control systems on the ISS that make it possible for humans to survive in space: the Thermal Control System (TCS) and the Environmental Control and Life Support system. These intricate assemblies work together to supply water and oxygen, regulate temperature and pressure, maintain air quality, and manage waste. Through artificial means, these systems create a habitable environment for the space station s crew. The TCS constantly works to regulate the temperature not only for astronauts, but for the critical instruments and machines inside the spacecraft as well. To do its job, the TCS encompasses several components and systems both inside and outside of the ISS. Inside the spacecraft, a liquid heat-exchange process mechanically pumps fluids in closed-loop circuits to collect, transport, and reject heat. Outside the ISS, an external system circulates anhydrous ammonia to transport heat and cool equipment, and radiators release the heat into space. Over the years, NASA has worked with a variety of partners.public and private, national and international. to develop and refine the most complex thermal control systems ever built for spacecraft, including the one on the ISS.

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Payload accommodations. Satellite servicing support

The proposed technology studies discussed at the Space Transportation Avionics Symposium in Williamsburg, VA on 7 to 9 November 1989, are discussed. The discussions and findings of the Payload Accommodations Subpanel are also summarized. The major objective of the proposed focused technology development is to develop and demonstrate (ground and flight) autonomous rendezvous, proximity operations, and docking/berthing capabilities to support satellite servicing. It is expected that autonomous rendezvous and docking (AR and D) capabilities will benefit both the users (e.g., satellite developers and operators) and the transportation system developers and operators. AR and D will provide increased availability of rendezvous and docking services by reducing the operational constraints associated with current capabilities. These constraints include specific lighting conditions, continuous space-to-ground communications, and lengthy ground tracking periods. AR and D will provide increased cost efficiency with the potential for reduced propellant expenditures and workloads (flight and/or ground crews). The AR and D operations will be more consistent, allowing more flexibility in the design of the satellite control system and docking/berthing mechanisms.

Lee, Roscoe↗

Space transfer concepts and analysis for exploration missions. Implementation plan and element description document (draft final). Volume 6: Lunar systems

NASA's two Office of Space Flight (Code M) Space Transfer Vehicle (STV) contractors supported development of Space Exploration Initiative (SEI) lunar transportation concepts. This work treated lunar SEI missions as the far end of a more near-term STV program, most of whose missions were satellite delivery and servicing requirements derived from Civil Needs Data Base (CNDB) projections. Space Transfer Concepts and Analysis for Exploration Missions (STCAEM) began to address the complete design of a lunar transportation system. The following challenges were addressed: (1) the geometry of aerobraking; (2) accommodation of mixed payloads; (3) cryogenic propellant transfer in Low Lunar Orbit (LLO); (4) fully re-usable design; and (5) growth capability. The leveled requirements, derived requirements, and assumptions applied to the lunar transportation system design are discussed. The mission operations section includes data on mission analysis studies and performance parametrics as well as the operating modes and performance evaluations which include the STCAEM recommendations. Element descriptions for the lunar transportation family included are a listing of the lunar transfer vehicle/lunar excursion vehicle (LTV/LEV) components; trade studies and mass analyses of the transfer and excursion modules; advanced crew recovery vehicle (ACRV) (modified crew recovery vehicle (MCRV)) modifications required to fulfill lunar operations; the aerobrake shape and L/D to be used; and some costing methods and results. Commonality and evolution issues are also discussed.

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Commercial Space with Technology Maturation

To provide affordable space transportation we must be capable of using common fixed assets and the infrastructure for multiple purposes simultaneously. The Space Shuttle was operated for thirty years, but was not able to establish an effective continuous improvement program because of the high risk to the crew on every mission. An unmanned capability is needed to provide an acceptable risk to the primary mission. This paper is intended to present a case where a commercial space venture could share the large fixed cost of operating the infrastructure with the government while the government provides new advanced technology that is focused on reduced operating cost to the common launch transportation system. A conceivable commercial space venture could provide educational entertainment for the country's youth that would stimulate their interest in the science, technology, engineering, and mathematics (STEM) through access at entertainment parks or the existing Space Visitor Centers. The paper uses this example to demonstrate how growing public-private space market demand will re-orient space transportation industry priorities in flight and ground system design and technology development, and how the infrastructure is used and shared.

McCleskey, Carey M.↗

NASA's Integrated Space Transportation Plan

Abstract NASA's Integrated Space Transportation Plan (ISTP) is the basis of the agency's new Space Launch Initiative (SLI). ISTP was developed to provide a structured methodology and framework to enable the next generation of reusable launch systems which will operate at orders of magnitude lower operating costs and higher levels of reliability and safety. Created in the fall of 1999, ISTP is the culmination of a series of Space Transportation Architecture Studies (STAS I, II, and III) which identified requirements, developed candidate architectures, and identified sets of technologies required to enable those architectures. The studies were conducted as a partnership between NASA and industry. Both new designs and shuttle-derived concepts were examined. Architectures were identified for 2" Generation Reusable Launch Vehicles (RLV), which would reach first operational capability in 2010, and 3rd Generation RLV, which will become operational in the 2025 timeframe, Second Generation RLV's have a goal of placing payloads in low earth orbit (LEO) at a cost of S 1,000/Ibm, and a safety goal of 1/10000 probability of loss of crew, The Third Generation RLV launch system will deliver payloads to LEO at $ 100/Ibm and approach airline-like reliability and safety, with a 1/ 10(exp 6) probability of loss of crew.

Anderson, David M.↗

Cell Maintenance Systems

Living human cells require attachment to a suitable surface and special culture conditions in order to grow. These requirements are modified and amplified when cells are taken into a weightless environment. Special handling and maintenance systems are required for routine laboratory procedures conducted in the Orbiter and in the Spacelab. Methods were developed to maintain cells in special incubators designed for the Orbiter middeck, however, electrophoresis and other experiments require cells to be harvested off of the culture substrate before they can be processed or used. The cell transport assembly (CTA) was flown on STS-8, and results show that improvements are required to maintain adequate numbers of cells in this device longer than 48 hours. The life sciences middeck centrifuge probably can be used, but modifications will be required to transfer cells from the CTA and keep the cells sterile. Automated systems such as the Skylab SO-15 flight hardware and crew operated systems are being evaluated for use on the Space Shuttle, Spacelab, and Space Station research modules.

Morrison, D. R.↗

Advanced cockpit technology for future civil transport aircraft

A review is presented of advanced cockpit technology for future civil transport aircraft, covering the present state-of-the-art and major technologies, including flat-panel displays, graphics and pictorial displays. Pilot aiding/automation/human-centered design and imaging sensor/flight systems technology (for low-visibility operations) are also presented. NASA Langley Research Center's recent results in pictorial displays and on future developments in large-screen display technologies are discussed. Major characteristics foreseen for the future high-speed civil transport include fault-tolerant digital avionics and controls/displays with extensive human-centered automation, and unusually clean, uncluttered interface with natural crew interaction via touch, voice/tactile means.

Hatfield, Jack J.↗

BioBot: Innovative Offloading of Astronauts for More Effective Exploration

The BioBot concept consists of a robotic rover which is capable of traversing the same terrain as a spacesuited human. It carries the primary life support system for the astronaut, including consumables, atmosphere revitalization systems (e.g., CO2 scrubbing, humidity and temperature management, ventilation fan), power system (e.g., battery, power management and distribution),and thermal control system (e.g., water sublimator, cooling water pump), along with umbilical lines to connect to the supported astronaut. Although not technically part of life support, it would be logical for the BioBot to also provide long-range communications, video monitoring, tool and sample transport, and other functions to enable and enhance EVA productivity in planetary surface exploration.The design reference scenario for this concept is that astronauts involved in future lunar or Mars exploration will be on the surface for weeks or months rather than days, and will be involved in regular EVA operations. It is not unreasonable to think of geologists spending several days inEVA exploration each week over a prolonged mission duration, with far more ambitious operational objectives than were typical of Apollo. In this scenario, each astronaut will be accompanied by a "BioBot", which will transport their life support system and consumables, an extended umbilical and umbilical reel, and robotic systems capable of controlling the position and motion of the umbilical. The astronaut will be connected to the robot via the umbilical, carrying only a small emergency open-loop life support system similar to those contained in every PLSS. The robotic mobility base will be designed to be capable of traveling anywhere the astronaut can walk, and will also be useful as a transport for the EVA tools, science instrumentation, and collected samples. In addition, the BioBot can potentially carry the astronaut on traverses as well. Such a system will also be a significant enhancement to public engagement in these future exploration missions, as the robotic vehicles can also support high-resolution cameras and high bandwidth communications gear to providehigh-definition video coverage of each crew throughout each EVA sortie.

Akin, David L.↗

NASA Exploration Launch Projects Systems Engineering Approach for Astronaut Missions to the Moon, Mars, and Beyond

The U.S. Vision for Space Exploration directs NASA to design and develop a new generation of safe, reliable, and cost-effective transportation systems to hlfill the Nation s strategic goals and objectives. These launch vehicles will provide the capability for astronauts to conduct scientific exploration that yields new knowledge from the unique vantage point of space. American leadership in opening new fi-ontiers will improve the quality of life on Earth for generations to come. The Exploration Launch Projects office is responsible for delivering the Crew Launch Vehicle (CLV) that will loft the Crew Exploration Vehicle (CEV) into low-Earth orbit (LEO) early next decade, and for the heavy lift Cargo Launch Vehicle (CaLV) that will deliver the Lunar Surface Access Module (LSAM) to LEO for astronaut return trips to the Moon by 2020 in preparation for the eventual first human footprint on Mars. Crew travel to the International Space Station will be made available as soon possible after the Space Shuttle retires in 2010.

Cook, Stephen A.↗

NASA Exploration Launch Projects Systems Engineering Approach for Astronaut Missions to the Moon, Mars, and Beyond

The U.S. Vision for Space Exploration directs NASA to design and develop a new generation of safe, reliable, and cost-effective transportation systems to hlfill the Nation s strategic goals and objectives. These launch vehicles will provide the capability for astronauts to conduct scientific exploration that yields new knowledge from the unique vantage point of space. American leadership in opening new fi-ontiers will improve the quality of life on Earth for generations to come. The Exploration Launch Projects office is responsible for delivering the Crew Launch Vehicle (CLV) that will loft the Crew Exploration Vehicle (CEV) into low-Earth orbit (LEO) early next decade, and for the heavy lift Cargo Launch Vehicle (CaLV) that will deliver the Lunar Surface Access Module (LSAM) to LEO for astronaut return trips to the Moon by 2020 in preparation for the eventual first human footprint on Mars. Crew travel to the International Space Station will be made available as soon possible after the Space Shuttle retires in 2010.

Dumbacher, Daniel L.↗

Updated Mars Mission Architectures Featuring Nuclear Thermal Propulsion

Nuclear thermal propulsion (NTP) can potentially enable routine human exploration of Mars and the solar system. By using nuclear fission instead of a chemical combustion process, and using hydrogen as the propellant, NTP systems promise rocket efficiencies roughly twice that of the best chemical rocket engines currently available. The most recent major Mars architecture study featuring NTP was the Design Reference Architecture 5.0 (DRA 5.0), performed in 2009. Currently, the predominant transportation options being considered are solar electric propulsion (SEP) and chemical propulsion; however, given NTP's capabilities, an updated architectural analysis is needed. This paper provides a top-level overview of several different architectures featuring updated NTP performance data. New architectures presented include a proposed update to the DRA 5.0 as well as an investigation of architectures based on the current Evolvable Mars Campaign, which is the focus of NASA's current analyses for the Journey to Mars. Architectures investigated leverage the latest information relating to NTP performance and design considerations and address new support elements not available at the time of DRA 5.0, most notably the Orion crew module and the Space Launch System (SLS). The paper provides a top level quantitative comparison of key performance metrics as well as a qualitative discussion of improvements and key challenges still to be addressed. Preliminary results indicate that the updated NTP architectures can significantly reduce the campaign mass and subsequently the costs for assembly and number of launches.

Rodriguez, Mitchell A.↗

Advanced transportation system study: Manned launch vehicle concepts for two way transportation system payloads to LEO

The purpose of the Advanced Transportation System Study (ATSS) task area 1 study effort is to examine manned launch vehicle booster concepts and two-way cargo transfer and return vehicle concepts to determine which of the many proposed concepts best meets NASA's needs for two-way transportation to low earth orbit. The study identified specific configurations of the normally unmanned, expendable launch vehicles (such as the National Launch System family) necessary to fly manned payloads. These launch vehicle configurations were then analyzed to determine the integrated booster/spacecraft performance, operations, reliability, and cost characteristics for the payload delivery and return mission. Design impacts to the expendable launch vehicles which would be required to perform the manned payload delivery mission were also identified. These impacts included the implications of applying NASA's man-rating requirements, as well as any mission or payload unique impacts. The booster concepts evaluated included the National Launch System (NLS) family of expendable vehicles and several variations of the NLS reference configurations to deliver larger manned payload concepts (such as the crew logistics vehicle (CLV) proposed by NASA JSC). Advanced, clean sheet concepts such as an F-1A engine derived liquid rocket booster (LRB), the single stage to orbit rocket, and a NASP-derived aerospace plane were also included in the study effort. Existing expendable launch vehicles such as the Titan 4, Ariane 5, Energia, and Proton were also examined. Although several manned payload concepts were considered in the analyses, the reference manned payload was the NASA Langley Research Center's HL-20 version of the personnel launch system (PLS). A scaled up version of the PLS for combined crew/cargo delivery capability, the HL-42 configuration, was also included in the analyses of cargo transfer and return vehicle (CTRV) booster concepts. In addition to strictly manned payloads, two-way cargo transportation systems (CTRV's) were also examined. The study provided detailed design and analysis of the performance, reliability, and operations of these concepts. The study analyzed these concepts as unique systems and also analyzed several combined CTRV/booster configurations as integrated launch systems (such as for launch abort analyses). Included in the set of CTRV concepts analyzed were the medium CTRV, the integral CTRV (in both a pressurized and unpressurized configuration), the winged CTRV, and an attached cargo carrier for the PLS system known as the PLS caboose.

Duffy, James B.↗

STS-79 Flight Day 5

On this fifth day of the STS-79 mission, the flight crew, Cmdr. William F. Readdy, Pilot Terrence W. Wilcutt, Mission Specialists, Thomas D. Akers, Shannon Lucid, Jay Apt, and Carl E. Walz, in the first full day of joint Shuttle/Mir operations begin in with the transfer of a biotechnology investigation and logistical supplies from Atlantis to Mir. The Biotechnology System, an investigation that will study the long-term development of cartilage cells in microgravity, was transported to Mir early this morning. During his planned four-month stay on Mir, John Blaha will take weekly samples of the culture which may provide researchers with information on engineering cartilage cells for possible use in transplantation. They also took time out of their schedules to talk with Good Morning America's Elizabeth Vargas in a brief interview. Prior to beginning the day's transfer activities, all nine astronauts and cosmonauts participated in a joint planning session to outline the day's schedule.

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