Search NASA⌕ Search

SEARCH · Search NASA

Results for “PRESSURIZED CABIN”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2

Crew Exploration Vehicle Environmental Control and Life Support Emergency Gas Consumable Sizing

As part of preparing for the Crew Exploration Vehicle (CEV), the National Aeronautics and Space Administration (NASA) worked on developing the requirements that drive the emergency gas consumables. Emergency gas is required to support Extravehicular Activities (EVA), maintain the cabin pressure during a cabin leak for the crew to don their suits, and to recover the cabin following a toxic even or a fire.

Lewis, John F.↗

A Dual-Chamber Hybrid Inflatable Suitlock (DCIS) for Planetary Surfaces or Deep Space

The Habitat Demonstration Unit (HDU) Project in conjunction with the NASA Extravehicular Activity (EVA) team has identified a need for a hybrid inflatable and hard shell suitlock that can be used for planetary surface and deep space human exploration missions. Through ongoing analog studies at NASA Desert Research and Technologies Studies (D-RATS) and in NASA's Prototyping Testbed Facility, it has been determined that a compactly stowed, deployable suitlock unit is needed to accommodate advanced EVA egress and ingress operations for various environments with only minor modification.The Dual-Chamber Inflatable Suitlock (DCIS) consists of three hard in-line bulkheads, separating two cylindrical membrane-walled compartments. A dual-compartment suitlock will allow for dust and contaminant control, suit maintenance, and efficient egress / ingress; and the inflatable aspect of the design will allow the unit to stow in a compact package for transport. This paper describes the DCIS functionality, subsystems, and operational scenarios.The novel concepts included in the DCIS are the triple bulkhead, dual-chamber that has one compartment that is continuously pressurized (either at cabin pressure, or may be used for transitional pressure from high-pressure habitats), and a nominal unpressurized second compartment where the suits will be kept for normal operations. The advantages include quicker egress / ingress, capacity for 'shirt sleeve' suit maintenance, and portability of the entire unit.

habitat demonstration unit (HUD)↗

Mass Estimation Relationships for Conceptual Design of Blended-Wing-Body Cabin with Advanced Structures

Blended-Wing-Body (BWB) achieve a higher L/D than conventional tube and wing aircraft due to aerodynamic shaping of the non-circular pressure vessel that is made feasible through advanced composite technologies such as Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS). Due to the relatively new nature of the BWB, sufficient historical data does not exist for conceptual aircraft designers to base their structural weight estimations on, especially for estimating weights of the pressurized cabin center body. This paper describes general parametric Mass Estimation Relationships (MERs) based on high fidelity finite element analysis using PRSEUS for estimating the weight of a BWB pressurized cabin structure that includes cabin area, center body sweep, fineness ratio, and take-off gross weight.

BWB↗

Mass Estimation Relationship for Conceptual Design of Blended-Wing-Body Cabin with Advanced Structures

Blended-Wing-Body (BWB) aircraft concepts achieve higher lift-to-drag ratios (L/D) than conventional tube and wing aircraft due to aerodynamic shaping of the non-circular pressure vessel that is made feasible using advanced composite technologies such as Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS). Due to the relatively new nature of the BWB configuration, sufficient historical data is not readily available for conceptual aircraft designers to base their structural weight estimations on, especially for estimating weights of the pressurized cabin center body. This paper describes a general parametric Mass Estimation Relationship (MER) based on high fidelity Finite Element Analysis (FEA) using PRSEUS for conceptual weight estimation of a BWB pressurized cabin structure that includes cabin area, center body sweep, fineness ratio, span ratio, and take-off gross weight as parametric design variables.

PRSEUS↗

Mass Estimation Relationship for Conceptual Design of Blended-Wing-Body Cabin with Advanced Structures

Blended-Wing-Body (BWB) aircraft concepts achieve higher lift-to-drag ratios (L/D) than conventional tube and wing aircraft due to aerodynamic shaping of the non-circular pressure vessel that is made feasible using advanced composite technologies such as Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS). Due to the relatively new nature of the BWB configuration, sufficient historical data is not readily available for conceptual aircraft designers to base their structural weight estimations on, especially for estimating weights of the pressurized cabin center body. This paper describes a general parametric Mass Estimation Relationship (MER) based on high fidelity Finite Element Analysis (FEA) using PRSEUS for conceptual weight estimation of a BWB pressurized cabin structure that includes cabin area, center body sweep, fineness ratio, span ratio, and take-off gross weight as parametric design variables.

BWB↗

Shuttle Orbiter Atmospheric Revitalization Pressure Control Subsystem

The Atmospheric Revitalization Pressure Control Subsystem (ARPCS) provides oxygen partial pressure and total pressure control for the habitable atmosphere of the Shuttle for either a one atmosphere environment or an emergency 8 PSIA mode. It consists of a Supply Panel, Control Panel, Cabin Pressure Relief Valves and Electronic Controllers. The panels control and monitor the oxygen and nitrogen supplies. The cabin pressure relief valves protect the habitable environment from overpressurization. Electronic controllers provide proper mixing of the two gases. This paper describes the ARPCS, addresses the changes in hardware that have occurred since the inception of the program; the performance of this subsystem during STS-1 and STS-2; and discusses future operation modes.

Walleshauser, J. J.↗

Analysis of a Hybrid Wing Body Center Section Test Article

The hybrid wing body center section test article is an all-composite structure made of crown, floor, keel, bulkhead, and rib panels utilizing the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) design concept. The primary goal of this test article is to prove that PRSEUS components are capable of carrying combined loads that are representative of a hybrid wing body pressure cabin design regime. This paper summarizes the analytical approach, analysis results, and failure predictions of the test article. A global finite element model of composite panels, metallic fittings, mechanical fasteners, and the Combined Loads Test System (COLTS) test fixture was used to conduct linear structural strength and stability analyses to validate the specimen under the most critical combination of bending and pressure loading conditions found in the hybrid wing body pressure cabin. Local detail analyses were also performed at locations with high stress concentrations, at Tee-cap noodle interfaces with surrounding laminates, and at fastener locations with high bearing/bypass loads. Failure predictions for different composite and metallic failure modes were made, and nonlinear analyses were also performed to study the structural response of the test article under combined bending and pressure loading. This large-scale specimen test will be conducted at the COLTS facility at the NASA Langley Research Center.

Wu, Hsi-Yung T.↗

Viability of Small Dimension Crew Quarters for Surface Habitation

During early planning for the Artemis program’s sustained phase of lunar activity, NASA planners have been held to work towards a NASA reference lunar lander concept. With this activity taking place prior to the awarding of a lander contract, NASA planners cannot assume which of several potential landers will be available. This has limited habitation team engineers to a 12-metric ton mass limit for the reference concept of the lunar Surface Habitat. Consequently, minimal approaches have been applied to many habitat systems and it is important to determine acceptable volume for crew quarters. A number of both NASA and non-NASA surface habitat concepts have proposed relatively small crew quarters due to this constraint. Consequently, there is a need to collect objective test data to confirm or refute the validity of small crew quarters. NASA-STD-3001 is looked to for guidance in its many standards but offers little to no help. While prior versions called for private habitation, the current version – Revision B – calls for “individual privacy” to “accommodate social retreat.” Proposed Revision C modifications change the language slightly to “accommodate sleep and social retreat.” This is not enough guidance to determine the size of a crew quarters or even its capabilities. Unfortunately, only a small number of US spacecraft have included crew quarters, primarily the International Space Station and the Skylab Space Station. The space shuttle orbiter sometimes flew a set of private bunks that some might consider a crew quarters. All of these are dramatically smaller than US standards for minimum jail cells. The first opportunity for NASA to test a small crew quarters in a surface habitat application has been created through the Exploration Atmospheres test series, which is evaluating human performance under reduced cabin pressures. The test is converting the 20-Foot Vacuum Chamber at Johnson Space Center into a habitat, with the lower level outfitted as an EVA test area and the upper two levels for human habitation. The test will place eight people (six test subjects and two technicians) inside the chamber for eleven days. All eight will sleep in private quarters during the test. Volume limitations in the chamber forced extremely small crew quarters, measuring approximately 2 meters in length, 0.85 meters in height, and 0.9 meters in width. The test cabin pressure of 8.2 psi and elevated oxygen also introduces significant material limitations, limiting outfitting options. Nonetheless, the crew quarters design requirements were to accommodate visual separation, auditory separation, olfactory separation, tactile separation, air flow control, lighting control, single person personal computing, physical work surface access, sleep accommodations, non-sleep rest/relaxation, meditation, stretching, two-person meetings, snacking, changing clothes, viewing appearance, video communication, and audio communication. This paper will detail the acceptability of the crew quarters as measured in the October 2021 Exploration Atmosphere test. Based on this data, the viability of the type of crew quarters used in the 20 Foot Chamber will be assessed. Design recommendations for a 30-60-day Surface Habitat crew quarters will be provided, along with recommendations for future testing.

Crew Quarters↗

Development of the PRSEUS Multi-Bay Pressure Box for a Hybrid Wing Body Vehicle

NASA has created the Environmentally Responsible Aviation Project to explore and document the feasibility, benefits, and technical risk of advanced vehicle configurations and enabling technologies that will reduce the impact of aviation on the environment. A critical aspect of this pursuit is the development of a lighter, more robust airframe that will enable the introduction of unconventional aircraft configurations that have higher lift-to-drag ratios, reduced drag, and lower community noise. Although such novel configurations like the Hybrid Wing Body (HWB) offer better aerodynamic performance as compared to traditional tube-and-wing aircraft, their blended wing shapes also pose significant new design challenges. Developing an improved structural concept that is capable of meeting the structural weight fraction allocated for these non-circular pressurized cabins is the primary obstacle in implementing large lifting-body designs. To address this challenge, researchers at NASA and The Boeing Company are working together to advance new structural concepts like the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS), which is an integrally stiffened panel design that is stitched together and designed to maintain residual load-carrying capabilities under a variety of damage scenarios. The large-scale multi-bay fuselage test article described in this paper is the final specimen in a building-block test program that was conceived to demonstrate the feasibility of meeting the structural weight goals established for the HWB pressure cabin.

Jegley, Dawn C.↗

Overview of the Life Sciences Glovebox (LSG) Facility

The Life Sciences Glovebox (LSG) is a rack-level payload facility designed to house biological investigations in a "workbench" type environment aboard the International Space Station (ISS). The facility is scheduled to be launched in September 2018 and will be installed in the Japanese Experiment Module (JEM) of the ISS. LSG is comprised of an extendable work volume, an airlock, an avionics package, a laptop, and supporting structure. The 450L work volume provides two levels of containment for investigations via the physical barrier of its structure and an internal, filtered airflow that results in a negative pressure relative to ISS cabin pressure. The facility provides many other resources for investigation use including 28 VDC power, 120 VAC power, heat rejection, data connections, and video. Portions of the interior surfaces of the work volume are ferrous, allowing investigations and supporting hardware to be magnetically affixed to these surfaces. A UV decontamination system and a variety of ancillary hardware are available for investigations to use while occupying LSG. An engineering unit on the ground is used for payload development and integrated verification testing. Once the facility is installed and commissioned, it will be managed by the same team that manages the Microgravity Science Glovebox (MSG), another rack-level payload facility that has been operating aboard the ISS since 2002. Experienced Investigation Payload Integration Managers (IPIMs), who also support MSG payloads, will be available to assist payload developers through the integration process. This presentation will provide an overview of the LSG facility and the planned investigation flow for the near future.

Jordan, Lee↗

The variation in pressure in the cabin of an airplane in flight

The pressure in the cabin of a Fairchild cabin monoplane wa surveyed in flight, and was found to decrease with increased air speed over the fuselage and to vary with the number and location of openings in the cabin. The maximum depression of 2.2 inches of water (equivalent pressure altitude at sea level of 152 feet) occurred at the high speed of the airplane in level flight with the cabin closed.

Gough, Melvin N↗

Ozone concentration in the cabin of a Gates Learjet measured simultaneously with atmospheric ozone concentrations

A Gates Learjet Model 23 was instrumented with monitors to measure simultaneously the atmospheric and the cabin concentrations of ozone at altitudes up to 13 kilometers. Six data flights were made in February 1978. Results indicated that only a small amount of the atmospheric ozone is destroyed in the cabin pressurization system. Ozone concentrations measured in the cabin near the conditioned-air outlets were only slightly lower than the atmospheric ozone concentration. For the two cabin configurations tested, the ozone retention in the cabin was 63 and 41 percent of the atmospheric ozone concentration. Maximum cabin ozone concentration measured during these flights was 410 parts per billion by volume.

Briehl, D.↗

Environmental control and life support system: Analysis of STS-1

The capability of the orbiter environmental control and life support system (ECLSS) to support vehicle cooling requirements in the event of cabin pressure reduction to 9 psia was evaluated, using the Orbiter versions of the shuttle environmental consumbles usage requirement evaluation (SECURE) program, and using heat load input data developed by the spacecraft electrical power simulator (SEPS) program. The SECURE model used in the analysis, the timeline and ECLSS configuration used in formulating the analysis, and the results of the analysis are presented. The conclusion which may be drawn drom these results. is summarized. There are no significant thermal problems with the proposed mission. There are, however, several procedures which could be optimized for better performance: setting the cabin HX air bypass and the interchanger water bypass to the zero flow position is of questionable efficacy; the cabin air pressure monitoring procedure should be re-evaluated; and the degree of equipment power down specified for this analysis and no problems were noted.

Steines, G.↗

Structural Configuration Analysis of Crew Exploration Vehicle Concepts

Structural configuration modeling and finite element analysis of crew exploration vehicle (CEV) concepts are presented. In the structural configuration design approach, parametric solid models of the pressurized shell and tanks are developed. The CEV internal cabin pressure is same as in the International Space Station (ISS) to enable docking with the ISS without an intermediate airlock. Effects of this internal pressure load on the stress distribution, factor of safety, mass and deflections are investigated. Uniform 7 mm thick skin shell, 5 mm thick shell with ribs and frames, and isogrid skin construction options are investigated. From this limited study, the isogrid construction appears to provide most strength/mass ratio. Initial finite element analysis results on the service module tanks are also presented. These rapid finite element analyses, stress and factor of safety distribution results are presented as a part of lessons learned and to build up a structural mass estimation and sizing database for future technology support. This rapid structural analysis process may also facilitate better definition of the vehicles and components for rapid prototyping. However, these structural analysis results are highly conceptual and exploratory in nature and do not reflect current configuration designs being conducted at the program level by NASA and industry.

Mukhopadhyay, V.↗

Advanced ETC/LSS computerized analytical models, CO2 concentration. Volume 1: Summary document

Computer simulations have been prepared for the concepts of C02 concentration which have the potential for maintaining a C02 partial pressure of 3.0 mmHg, or less, in a spacecraft environment. The simulations were performed using the G-189A Generalized Environmental Control computer program. In preparing the simulations, new subroutines to model the principal functional components for each concept were prepared and integrated into the existing program. Sample problems were run to demonstrate the methods of simulation and performance characteristics of the individual concepts. Comparison runs for each concept can be made for parametric values of cabin pressure, crew size, cabin air dry and wet bulb temperatures, and mission duration.

Taylor, B. N.↗

Design development and test: Two-gas atmosphere control subsystem

An atmosphere control subsystem (ACS) was developed for NASA-IBJSC which is designed to measure the major atmospheric constituents in the manned cabin of the space shuttle orbiter and control the addition of oxygen and nitrogen to maintain the partial pressures of these gases within very close limits. The ACS includes a mass spectrometer sensor (MSS) which analyzes the atmosphere of a shuttle vehicle pressurized cabin, and an electronic control assembly (ECA). The MSS was built and tested to meet the requirements for flight equipment for the M-171 Metabolic Analyzer experiment for the Skylab flight program. The instrument analyzes an atmospheric gas sample and produces continuous 0-5 vdc analog signals proportional to the partial pressures of H2, O2, N2, H2O, CO2 and total hydrocarbons having a m/e ratio between 50 and 120. It accepts signals from the MSS proportional to the partial pressures of N2 and O2 and controls the supply of these gases to the closed cabin.

Jackson, J. K.↗

Flight test evaluation of an RAF high altitude partial pressure protective assembly

A partial pressure suit was evaluated during tests in an F-104 and F-15 as a protective garment for emergency descents. The garment is an pressure jerkin and modified anti-g suit combined with an oronasal mask. The garment can be donned and doffed at the aircraft to minimize thermal buildup. The oronasal mask was favored by the pilots due to its immobility on the face during high g-loading. The garment was chosen to provide optimum dexterity for the pilot, which is not available in a full pressure suit, while protecting the pilot at altitudes up to 18,288 meters, during a cabin decompression, and subsequent aircraft descent. During cabin decompressions in the F-104 and F-15, cabin pressure altitude was measured at various aircraft angles of attack, Mach numbers, and altitudes to determine the effect of the aerodynamic slipstream on the cabin altitude.

Ashworth, G. R.↗

Full scale GLARE fuselage panel tests

A GLARE fuselage panel, representative of the crown section of the Fokker 100 fuselage in front of the wing, was tested. The panels were loaded by air pressure resulting in tangential stress in the panel by axial loading, representative of both the cabin pressure and the fuselage bending due to taxiing and gust loading. A fatigue test, simulating 180000 flights, followed by static tests were performed. The panel was loaded to failure at 1.32 ultimate load. The test set-up, the uniform strain distribution of the panel, and the fatigue loads applied at high test frequency are described. The use of GLARE leads to a substantial weight reduction without affecting the fatigue static strength.

Vercammen, Roland W. A.↗