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Journal Article

Orion Emergency Mask Approach

2009-07-12
2009-01-2460
As mission duration increased, some sort of emergency breathing apparatus was used to provide safe breathing air in emergency situations. The Orion vehicle has a unique set of emergency breathing apparatus design challenges: the vehicle is small compared to shuttle and station, the vehicle does not have a pressurized supply of breathing air, the vehicle has a 30% oxygen design limit, no airlocks or alternate habitable volumes, and during lunar missions the crew members need to remain in the vehicle for many hours after an emergency. ...A filtering respirator shows special promise to address the needs of Orion, but a filtering respirator for combustion products has never been built and qualified for space. ...This paper describes the emergency breathing apparatus needs for Orion and reports the results of some filtering respirator development tests.
Technical Paper

Avionics System Architecture for the NASA Orion Vehicle

2009-11-10
2009-01-3276
The inception of NASA's Orion Crew Exploration Vehicle (CEV) spacecraft offers the opportunity to leverage the latest integrated avionics technologies into crewed space vehicle architecture. ...Historically, aircraft and spacecraft have very similar avionics requirements. Both aircraft and spacecraft must have high reliability. ...However, there are several key differences between aircraft and spacecraft avionics. Typically, the overall spacecraft operational time is much shorter than aircraft operation time, but the typical mission time (and hence, the time between preventive maintenance) is longer for a spacecraft than an aircraft.
Journal Article

The Orion Air Monitor; an Optimized Analyzer for Environmental Control and Life Support

2008-06-29
2008-01-2046
This paper describes the requirements for and design implementation of an air monitor for the Orion Crew Exploration Vehicle (CEV). The air monitor is specified to monitor oxygen, nitrogen, water vapor, and carbon dioxide, and participates with the Environmental Control Life Support System (ECLSS) pressure control system and Atmosphere Revitalization System (ARS) to help maintain a breathable and safe environment. ...The sensing requirements are similar to those delivered by the International Space Station (ISS) air monitor, the Major Constituent Analyzer or MCA (1, 2 and 3), and the predecessors to that instrument, the Skylab Mass Spectrometer (4, 5), although with a shift in emphasis from extended operations to minimized weight. The Orion emphasis on weight and power, and relatively simpler requirements on operating life, allow optimization of the instrument toward the mass of a sensor assembly. ...The Air Monitor is more integral with Orion's ARS, simplifying the sampling system relative to the MCA, the verification assembly has been greatly simplified, and the electronics have been redesigned around a simple controller, allowing the design to come in at under 15 pounds.
Journal Article

A Comparison of the Apollo and Early Orion Environmental Control, Life Support and Active Thermal Control System's Driving Requirements and System Mass

2008-06-29
2008-01-2081
The Orion Crew and Service Modules are often compared to the Apollo Command and Service Modules due to their similarity in basic mission objective: both were dedicated to getting a crew to lunar orbit and safely returning them to Earth. ...The Orion Crew and Service Modules are often compared to the Apollo Command and Service Modules due to their similarity in basic mission objective: both were dedicated to getting a crew to lunar orbit and safely returning them to Earth. Both spacecraft rely on the environmental control, life support and active thermal control systems (ECLS/ATCS) for the basic functions of providing and maintaining a breathable atmosphere, supplying adequate amount of potable water and maintaining the crew and avionics equipment within certified thermal limits. ...This evaluation provides a top level assessment of the efficacy of the Orion ECLS/ATCS, as well as identifies areas that could benefit from a more careful examination as the Orion project approaches the preliminary design review milestone.
Standard

Spacecraft Thermal Balance

2011-07-25
CURRENT
AIR1168/12A
In the design of spacecraft, heat transfer becomes a criterion of operation to maintain structural and equipment integrity over long periods of time. ...In the design of spacecraft, heat transfer becomes a criterion of operation to maintain structural and equipment integrity over long periods of time. The spacecraft thermal balance between cold space and solar, planetary, and equipment heat sources is the means by which the desired range of equipment and structural temperatures are obtained. ...With the total spacecraft balance set, subsystem and component temperatures can be analyzed for their corresponding thermal requirements.
Standard

Spacecraft Equipment Environmental Control

2011-07-25
CURRENT
AIR1168/13A
This part of the manual presents methods for arriving at a solution to the problem of spacecraft inflight equipment environmental control. The temperature aspect of this problem may be defined as the maintenance of a proper balance and integration of the following thermal loads: equipment-generated, personnel-generated, and transmission through external boundary.
Standard

Spacecraft Life Support Systems

2012-10-15
CURRENT
AIR1168/14A
A life support system (LSS) is usually defined as a system that provides elements necessary for maintaining human life and health in the state required for performing a prescribed mission. The LSS, depending upon specific design requirements, will provide pressure, temperature, and composition of local atmosphere, food, and water. It may or may not collect, dispose, or reprocess wastes such as carbon dioxide, water vapor, urine, and feces. It can be seen from the preceding definition that LSS requirements may differ widely, depending on the mission specified, such as operation in Earth orbit or lunar mission. In all cases the time of operation is an important design factor. An LSS is sometimes briefly defined as a system providing atmospheric control and water, waste, and thermal management.
Technical Paper

Overview of Potable Water Systems on Spacecraft Vehicles and Applications for the Crew Exploration Vehicle (CEV)

2007-07-09
2007-01-3259
Providing water necessary to maintain life support has been accomplished in spacecraft vehicles for over forty years. This paper will investigate how previous U.S. space vehicles provided potable water. ...The water source for the spacecraft, biocide used to preserve the water on-orbit, water stowage methodology, materials, pumping mechanisms, on-orbit water requirements, and water temperature requirements will be discussed. ...The Crew Exploration Vehicle (CEV or Orion) water systems will be generically discussed to provide a glimpse of how similar they are to water systems in previous vehicles.
Technical Paper

Spacecraft Life Support System Process Technology Maturation using Stage Gate Methodology

2007-07-09
2007-01-3045
The National Aeronautics and Space Administration (NASA) faces significant challenges to evolve and mature life support system process technologies for insertion into the Orion and Constellation programs. The challenge is not a lack of experience with crewed spacecraft design and development but the varied mission operational concepts and rapid developmental schedules that compress the time allotted to identifying, selecting, and maturing the best mix of technologies to meet flight program needs.
Technical Paper

First Human Testing of the Orion Atmosphere Revitalization Technology

2009-07-12
2009-01-2456
A system of amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and is baselined for the Orion Atmosphere Revitalization System (ARS). In two previous years at this conference, reports were presented on extensive Johnson Space Center (JSC) testing of the technology, which was performed in a representative environment with simulated human metabolic loads. ...This first instance of human testing of a new Orion ARS technology included several cases run in a sealed Orion-equivalent free volume and three cases using emergency breathing masks connected directly to the ARS loop, Significant test results presented in this paper include a comparison between the standard metabolic rates for CO2 and water vapor production published in Orion requirements documents and metabolic rate ranges observed with the human test subjects. ...This first instance of human testing of a new Orion ARS technology included several cases run in a sealed Orion-equivalent free volume and three cases using emergency breathing masks connected directly to the ARS loop, Significant test results presented in this paper include a comparison between the standard metabolic rates for CO2 and water vapor production published in Orion requirements documents and metabolic rate ranges observed with the human test subjects. Qualitative assessments of the tolerability of various process flow rates and closed-loop pressure-cycling while using the emergency masks are also included.
Technical Paper

Design and Performance of the Sorbent-Based Atmosphere Revitalization System for Orion

2007-07-09
2007-01-3070
Validation and simulations of a real-time dynamic cabin model were conducted on the sorbent-based atmosphere revitalization system for Orion. The dynamic cabin model, which updates the concentration of H2O and CO2 every second during the simulation, was able to predict the steady state model values for H2O and CO2 for long periods of steady metabolic production for a 4-person crew.
Standard

Spacecraft Boost and Entry Heat Transfer

2011-07-25
CURRENT
AIR1168/11A
The prediction of vehicle temperatures during ascent through the earth’s atmosphere requires an accurate knowledge of the aerodynamic heating rates occurring at the vehicle surface. Flight parameters required in heating calculations include the local airstream velocity, pressure, and temperature at the boundary layer edge for the vehicle location in question. In addition, thermodynamic and transport air properties are required at these conditions. Both laminar and turbulent boundary layers occur during the boost trajectory. Experience has shown that laminar and turbulent heating are of equivalent importance. Laminar heating predominates in importance in the stagnation areas, but the large afterbody surfaces are most strongly affected by turbulent heating. Once the local flow conditions and corresponding air properties have been obtained, the convective heating rate may be calculated for a particular wall temperature.
Standard

Fluid Couplings for Spacecraft Servicing, Preparation of Specification for, Metric

2015-08-21
CURRENT
MAP2261
This SAE Metric Aerospace Recommended Practice (MAP) establishes the requirements for preparing a specification for fluid couplings for spacecraft servicing. The objective of this document is to provide design, development, verification, storage, and delivery requirement guidelines for the preparation of specifications for fluid couplings and the ancillary hardware for use with serviceable spacecraft designed for use in the space environment. ...The objective of this document is to provide design, development, verification, storage, and delivery requirement guidelines for the preparation of specifications for fluid couplings and the ancillary hardware for use with serviceable spacecraft designed for use in the space environment. The couplings shall be capable of resupplying storable propellants, cryogenic liquids, and gases to a variety of spacecrafts. ...The couplings shall be capable of resupplying storable propellants, cryogenic liquids, and gases to a variety of spacecrafts.
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