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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.

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At least 145 records · Page 8

All sources NASA NTRS DOE OSTI

NASA NTRS1993

Testing of ROMPS robot mechanical interfaces and compliant device

The Robot Operated Materials Processing System (ROMPS) has been developed at Goddard Space Flight Center (GSFC) under a flight project to investigate commercially promising in-space material processes and to design reflyable robot automated systems to be used in the above processes for low-cost operations. The ROMPS is currently scheduled for flight in 1994 as a Hitchhiker payload in a Get Away Special (GAS) can. An important component of the ROMPS is a three degree-of-freedom (DOF) robot which will be responsible for carrying out the required tasks of in-space processing of selected materials. This report deals with testing of the mating capability of the ROMPS robot fingers with its various mechanical interfaces. In particular, the test plan will focus on studying the capability of a compliance mechanism mounted on the robot fingers in accommodating misalignments between the robot fingers and the interfaces during the mating. The report is organized as follows: Section 2 represents the main components of the ROMPS robot and briefly describes its operations. Section 3 presents the objectives of the test and outlines the test plan. The testbed comprising a Steward Platform-based high precision manipulator and associated data acquisition and control systems is described in Section 4. Section 5 presents results of numerous experiments conducted to study the mating capability of the robot fingers with its various interfaces under misalignments. The report is concluded with observations and recommendations based on the test results.

Nguyen, Charles C.↗

NASA NTRS1995

Shielded, Automated Umbilical Mechanism

Umbilical mechanism automatically connects and disconnects various fluid couplings and/or electrical contacts while shielding mating parts from debris. Reacts mating and demating loads internally, without additional supporting structures. All functions - extension of plug, mating, and movement of debris shields - actuated by single motor. If mechanism jams or fails at any point in sequence, override feature in drive train allows manual operation. Designed for service in outer space, where its shields protect against micrometeoroids, debris, ultraviolet radiation, and atomic oxygen. Used on Earth to connect or disconnect fluid or electrical utilities in harsh environments like those of nuclear powerplants or undersea construction sites, or in presence of radioactive, chemical, or biological hazards, for example.

Barron, Daniel R.↗

NASA NTRS2005

Concepts to Automate Fluid Transfer Capability of Low Impact Docking System (LIDS)

The capability to transfer mass between spacecraft is necessary for many mission scenarios. Docking and berthing operations have enabled fluid, electrical, crew and equipment transfers to some degree on all manned space operations since the Gemini program. The Apollo program performed some sophisticated docking maneuvers to land men on the moon and return them safely to Earth. These programs primarily transferred crew, equipment, and pressurized atmosphere between docked spacecraft. The International Space Station (ISS) U.S. modules are connected by Common Berthing Mechanism (CBM) portals. They provide many feed-through ports for electrical, and fluid transfer between modules, as well as a large diameter crew and equipment tunnel. Fluid and electrical jumpers are manually installed after the CBM sealing surfaces have been securely mated to maintain the pressurized cabin environment. CBM berthing and subsequent fluid transfer capability requires a lengthy manual process involving an active interface that mates with a passive half. The Androgynous Peripheral Attach System (MAS) a Russian technology that docked the Russian Zarya module to Unity, or Node 1, is a more complex system that also is capable of fuel transfer, enabling refueling of the Russian re-boost engines on ISS. For several years, a Low Impact Docking System (LIDS) has been under development at Johnson Space Center (JSC). This docking technology has a requirement to be androgynous in order to allow the fabrication of a single configuration that can dock with all other LIDS units. It is desired to make electrical and fluid coupling mating an automated process to enable routine docking and undocking operations to support future exploration missions. It is envisioned that modular design and vehicle assembly will require an efficient LIDS for fuel, electrical, crew, and equipment transfer. Marshall Space Flight Center (MSFC) has joined the LIDS development effort and plans to employ fluid transfer concepts and technology from previous development programs, such as the Automated Fluid Interface System (AFIS) and the Ohital Fluid Transfer System (OFTS) that were developed and tested by MSFC. Orbital Expressderived robotic satellite servicing technology is scheduled to fly soon to demonstrate fluid transfer technology developed for the Air Force. This paper will compare known technology against possible fluid transfer requirements for LIDS to develop design strategies for automated fluid transfer.

Miernik, Janie H.↗

NASA NTRS2008

Experimental Investigation of Elastomer Docking Seal Compression Set, Adhesion, and Leakage

A universal docking and berthing system is being developed by the National Aeronautics and Space Administration (NASA) to support all future space exploration missions to low-Earth orbit (LEO), to the Moon, and to Mars. An investigation of the compression set of two seals mated in a seal-on-seal configuration and the force required to separate the two seals after periods of mating was conducted. The leakage rates of seals made from two silicone elastomer compounds, S0383-70 and S0899-50, configured in seal-on-seal mating were quantified. The test specimens were sub-scale seals with representative cross-sections and a 12 inch outside diameter. The leakage rate of the seals manufactured from S0899-50 was higher than that of the seals made from S0383-70 by a factor of 1.8. Similarly, the adhesion of the 50 durometer elastomer was significantly higher than that of the 70 durometer compound. However, the compression set values of the S0899-50 material were observed to be significantly lower than those for the S0383-70.

Daniels, Christopher C.↗

NASA NTRS2008

Alignment Pins for Assembling and Disassembling Structures

Simple, easy-to-use, highly effective tooling has been devised for maintaining alignment of bolt holes in mating structures during assembly and disassembly of the structures. The tooling was originally used during removal of a body flap from the space shuttle Atlantis, in which misalignments during removal of the last few bolts could cause the bolts to bind in their holes. By suitably modifying the dimensions of the tooling components, the basic design of the tooling can readily be adapted to other structures that must be maintained in alignment. The tooling includes tapered, internally threaded alignment pins designed to fit in the bolt holes in one of the mating structures, plus a draw bolt and a cup that are used to install or remove each alignment pin. In preparation for disassembly of two mating structures, external supports are provided to prevent unintended movement of the structures. During disassembly of the structures, as each bolt that joins the structures is removed, an alignment pin is installed in its place. Once all the bolts have been removed and replaced with pins, the pins maintain alignment as the structures are gently pushed or pulled apart on the supports. In assembling the two structures, one reverses the procedure described above: pins are installed in the bolt holes, the structures are pulled or pushed together on the supports, then the pins are removed and replaced with bolts. The figure depicts the tooling and its use. To install an alignment pin in a bolt hole in a structural panel, the tapered end of the pin is inserted from one side of the panel, the cup is placed over the pin on the opposite side of the panel, the draw bolt is inserted through the cup and threaded into the pin, the draw bolt is tightened to pull the pin until the pin is seated firmly in the hole, then the draw bolt and cup are removed, leaving the pin in place. To remove an alignment pin, the cup is placed over the pin on the first-mentioned side of the panel, the draw bolt is inserted through the cup and threaded into the pin, then the draw bolt is tightened to pull the pin out of the hole.

Campbell, Oliver C.↗

NASA NTRS2007

Build-Up Approach to Updating the Mock Quiet Spike Beam Model

When a new aircraft is designed or a modification is done to an existing aircraft, the aeroelastic properties of the aircraft should be examined to ensure the aircraft is flight worthy. Evaluating the aeroelastic properties of a new or modified aircraft can include performing a variety of analyses, such as modal and flutter analyses. In order to produce accurate results from these analyses, it is imperative to work with finite element models (FEM) that have been validated by or correlated to ground vibration test (GVT) data, Updating an analytical model using measured data is a challenge in the area of structural dynamics. The analytical model update process encompasses a series of optimizations that match analytical frequencies and mode shapes to the measured modal characteristics of structure. In the past, the method used to update a model to test data was "trial and error." This is an inefficient method - running a modal analysis, comparing the analytical results to the GVT data, manually modifying one or more structural parameters (mass, CG, inertia, area, etc.), rerunning the analysis, and comparing the new analytical modal characteristics to the GVT modal data. If the match is close enough (close enough defined by analyst's updating requirements), then the updating process is completed. If the match does not meet updating-requirements, then the parameters are changed again and the process is repeated. Clearly, this manual optimization process is highly inefficient for large FEM's and/or a large number of structural parameters. NASA Dryden Flight Research Center (DFRC) has developed, in-house, a Mode Matching Code that automates the above-mentioned optimization process, DFRC's in-house Mode Matching Code reads mode shapes and frequencies acquired from GVT to create the target model. It also reads the current analytical model, as we11 as the design variables and their upper and lower limits. It performs a modal analysis on this model and modifies it to create an updated model that has similar mode shapes and frequencies as those of the target model. The Mode Matching Code output frequencies and modal assurance criteria (MAC) values that allow for the quantified comparison of the updated model versus the target model. A recent application of this code is the F453 supersonic flight testing platform, NASA DFRC possesses a modified F-15B that is used as a test bed aircraft for supersonic flight experiments. Traditionally, the finite element model of the test article is generated. A GVT is done on the test article ta validate and update its FEM. This FEM is then mated to the F-15B model, which was correlated to GVT data in fall of 2004, A GVT is conducted with the test article mated to the aircraft, and this mated F-15B/ test article FEM is correlated to this final GVT.

Herrera, Claudia Y.↗

NASA NTRS2008

Split-Block Waveguide Polarization Twist for 220 to 325 GHz

A split-block waveguide circuit that rotates polarization by 90 has been designed with WR-3 input and output waveguides, which are rectangular waveguides used for a nominal frequency range of 220 to 325 GHz. Heretofore, twisted rectangular waveguides equipped with flanges at the input and output have been the standard means of rotating the polarizations of guided microwave signals. However, the fabrication and assembly of such components become difficult at high frequency due to decreasing wavelength, such that twisted rectangular waveguides become impractical at frequencies above a few hundred gigahertz. Conventional twisted rectangular waveguides are also not amenable to integration into highly miniaturized subassemblies of advanced millimeter- and submillimeter-wave detector arrays now undergoing development. In contrast, the present polarization- rotating waveguide can readily be incorporated into complex integrated waveguide circuits such as miniaturized detector arrays fabricated by either conventional end milling of metal blocks or by deep reactive ion etching of silicon blocks. Moreover, the present split-block design can be scaled up in frequency to at least 5 THz. The main step in fabricating a splitblock polarization-rotating waveguide of the present design is to cut channels having special asymmetrically shaped steps into mating upper and lower blocks (see Figure 1). The dimensions of the steps are chosen to be consistent with the WR-3 waveguide cross section, which is 0.864 by 0.432 mm. The channels are characterized by varying widths with constant depths of 0.432, 0.324, and 0.216 mm and by relatively large corner radii to facilitate fabrication. The steps effect both a geometric transition and the corresponding impedance-matched electromagnetic-polarization transition between (1) a WR-3 rectangular waveguide oriented with the electric field vector normal to the block mating surfaces and (2) a corresponding WR-3 waveguide oriented with its electric field vector parallel to the mating surfaces of the blocks. A prototype has been built and tested. Figure 2 presents test results indicative of good performance over nearly the entire WR-3 waveguide frequency band.

Ward, John↗

NASA NTRS2010

Inline Electrical Connector Mate/Demate Pliers

Military and aerospace industries use Mil-Spec type electrical connections on bulkhead panels that require inline access for mate and demate operations. These connectors are usually in tight proximity to other connectors, or recessed within panels. The pliers described here have been designed to work in such tight spaces, and consist of a mirrored set of parallel handles, two cross links, two return springs, and replaceable polyurethane-coated end effectors. The polyurethane eliminates metal-to-metal contact and provides a high-friction surface between the jaw and the connector. Operationally, the user would slide the pliers over the connector shell until the molded polyurethane lip makes contact with the connector shell edge. Then, by squeezing the handles, the end effector jaws grip the connector shell, allowing the connector to be easily disconnected by rotating the pliers. Mating the connector occurs by reversing the prescribed procedure, except the connector shell is placed into the jaws by hand. The molded lip within the jaw allows the user to apply additional force for difficult-to-mate connectors. Handle design has been carefully examined to maximize comfort, limit weight, incorporate tether locations, and improve ergonomics. They have been designed with an off-axis offset for wiring harness clearance, while placing the connector axis of rotation close to the user s axis of wrist rotation. This was done to eliminate fatigue during multiple connector panel servicing. To limit handle opening width, with user ergonomics in mind, the pliers were designed using a parallel jaw mechanism. A cross-link mechanism was used to complete this task, while ensuring smooth operation.

Yutko, Brian↗

NASA NTRS2010

Compliant, low profile, independently releasing, non-protruding and genderless docking system for robotic modules

An apparatus for coupling with a mating coupling module to facilitate the joining of two disjoined structures without requiring precise alignment between the disjoined structures during the coupling of them may include a rotating drive mechanism, a hollow cylindrical body operatively connected to the rotating drive mechanism, wherein the hollow cylindrical body has at least one internal spiral channel, and at least one connector claw positioned within the hollow cylindrical body and guided by the internal spiral channel, wherein the at least one connector claw is configured to extend outwardly from the coupling module to engage the mating coupling module when brought in close proximity but not necessarily in precise alignment with the mating coupling module.

Khoshnevis, Behrokh↗

NASA NTRS2010

Full-Scale System for Quantifying Loads and Leak Rates of Seals for Space Applications

NASA is developing advanced space-rated vacuum seals in support of future space exploration missions to low-Earth orbit and other destinations. These seals may be 50 to 60 in. (127 to 152 cm) in diameter and must exhibit extremely low leak rates to ensure that astronauts have sufficient breathable air for extended missions to the International Space Station or the Moon. Seal compression loads must be below prescribed limits so as not to overload the mechanisms that compress them during docking or mating, and seal adhesion forces must be low to allow two mated systems to separate when required. NASA Glenn Research Center has developed a new test apparatus to measure leak rates and compression and adhesion loads of candidate full-scale seals under simulated thermal, vacuum, and engagement conditions. Tests can be performed in seal-on-seal or seal-on-flange configurations at temperatures from -76 to 140 F (-60 to 60 C) under operational pressure gradients. Nominal and off-nominal mating conditions (e.g., incomplete seal compression) can also be simulated. This paper describes the main design features of the test apparatus as well as techniques used to overcome some of the design challenges.

Dunlap, Patrick H., Jr.↗

NASA NTRS2010

NASA Docking System (NDS) Interface Definitions Document (IDD)

The NASA Docking System (NDS) mating system supports low approach velocity docking and provides a modular and reconfigurable standard interface, supporting crewed and autonomous vehicles during mating and assembly operations. The NDS is NASA's implementation for the emerging International Docking System Standard (IDSS) using low impact docking technology. All NDS configurations can mate with the configuration specified in the IDSS Interface Definition Document (IDD) released September 21, 2010. The NDS evolved from the Low Impact Docking System (LIDS). The acronym international Low Impact Docking System (iLIDS) is also used to describe this system. NDS and iLIDS may be used interchangeability. Some of the heritage documentation and implementations (e.g., software command names) used on NDS will continue to use the LIDS acronym. The NDS IDD defines the interface characteristics and performance capability of the NDS, including uses ranging from crewed to autonomous space vehicles and from low earth orbit to deep space exploration. The responsibility for developing space vehicles and for making them technically and operationally compatible with the NDS rests with the vehicle providers. Host vehicle examples include crewed/uncrewed spacecraft, space station modules, elements, etc. Within this document, any docking space vehicle will be referred to as the host vehicle. This document defines the NDS-to-NDS interfaces, as well as the NDS-to-host vehicle interfaces and performance capability.

Source record↗

NASA NTRS2004

Advanced Docking System With Magnetic Initial Capture

An advanced docking system is undergoing development to enable softer, safer docking than was possible when using prior docking systems. This system is intended for original use in docking of visiting spacecraft and berthing the Crew Return Vehicle at the International Space Station (ISS). The system could also be adapted to a variety of other uses in outer space and on Earth, including mating submersible vehicles, assembling structures, and robotic berthing/handling of payloads and cargo. Heretofore, two large spacecraft have been docked by causing the spacecraft to approach each other at a speed sufficient to activate capture latches - a procedure that results in large docking loads and is made more difficult because of the speed. The basic design and mode of operation of the present advanced docking system would eliminate the need to rely on speed of approach to activate capture latches, thereby making it possible to reduce approach speed and thus docking loads substantially. The system would comprise an active subsystem on one spacecraft and a passive subsystem on another spacecraft with which the active subsystem will be docked. The passive subsystem would include an extensible ring containing magnetic striker plates and guide petals. The active subsystem would include mating guide petals and electromagnets containing limit switches and would be arranged to mate with the magnetic striker plates and guide petals of the passive assembly. The electromagnets would be carried on (but not rigidly attached to) a structural ring that would be instrumented with load sensors. The outputs of the sensors would be sent, along with position information, as feedback to an electronic control subsystem. The system would also include electromechanical actuators that would extend or retract the ring upon command by the control subsystem.

Lewis, James L.↗

NASA NTRS2012

Cumulative Measurement Errors for Dynamic Testing of Space Flight Hardware

Located at the NASA Johnson Space Center in Houston, TX, the Six-Degree-of-Freedom Dynamic Test System (SDTS) is a real-time, six degree-of-freedom, short range motion base simulator originally designed to simulate the relative dynamics of two bodies in space mating together (i.e., docking or berthing). The SDTS has the capability to test full scale docking and berthing systems utilizing a two body dynamic docking simulation for docking operations and a Space Station Remote Manipulator System (SSRMS) simulation for berthing operations. The SDTS can also be used for nonmating applications such as sensors and instruments evaluations requiring proximity or short range motion operations. The motion base is a hydraulic powered Stewart platform, capable of supporting a 3,500 lb payload with a positional accuracy of 0.03 inches. The SDTS is currently being used for the NASA Docking System testing and has been also used by other government agencies. The SDTS is also under consideration for use by commercial companies. Examples of tests include the verification of on-orbit robotic inspection systems, space vehicle assembly procedures and docking/berthing systems. The facility integrates a dynamic simulation of on-orbit spacecraft mating or de-mating using flight-like mechanical interface hardware. A force moment sensor is used for input during the contact phase, thus simulating the contact dynamics. While the verification of flight hardware presents unique challenges, one particular area of interest involves the use of external measurement systems to ensure accurate feedback of dynamic contact. The measurement systems for the test facility have two separate functions. The first is to take static measurements of facility and test hardware to determine both the static and moving frames used in the simulation and control system. The test hardware must be measured after each configuration change to determine both sets of reference frames. The second function is to take dynamic measurements during hardware motion and contact. While performing dynamic testing of an active docking system, researchers found that the data from the motion platform, test hardware and two external measurement systems exhibited frame offsets and rotational errors. While the errors were relatively small when considering the motion scale overall, they substantially exceeded the individual accuracies for each component. After evaluating both the static and dynamic measurements, researchers found that the static measurements introduced significantly more error into the system than the dynamic measurements even though, in theory, the static measurement errors should be smaller than the dynamic. In several cases, the magnitude of the errors varied widely for the static measurements. Upon further investigation, researchers found the larger errors to be a consequence of hardware alignment issues, frame location and measurement technique whereas the smaller errors were dependent on the number of measurement points. This paper details and quantifies the individual and cumulative errors of the docking system and describes methods for reducing the overall measurement error. The overall quality of the dynamic docking tests for flight hardware verification was improved by implementing these error reductions.

Winnitoy, Susan↗

NASA NTRS2011

NASA Docking System (NDS) Interface Definitions Document (IDD)

Lewis, James↗

NASA NTRS2012

Seal with integrated shroud for androgenous docking and berthing in contaminated environments

The present invention is directed to a specially configured seal system which provides a barrier to gas leakage flow between a pressurized module and its external environment. The seal includes a shroud covering which protects the sealing interface from its environment when not in use, and retracts to expose the sealing interface when mated. The seal system is constructed and arranged to mate with a seal of identical construction and arrangement or to mate with a flat surface.

Daniels, Christopher C.↗

NASA NTRS2012

A Comparison of Candidate Seal Designs for Future Docking Systems

NASA is developing a new docking system to support future space exploration missions to low Earth orbit, the Moon, and other destinations. A key component of this system is the seal at the main docking interface which inhibits the loss of cabin air once docking is complete. Depending on the mission, the seal must be able to dock in either a seal-on-flange or seal-on-seal configuration. Seal-on-flange mating would occur when a docking system equipped with a seal docks to a system with a flat metal flange. This would occur when a vehicle docks to a node on the International Space Station. Seal-on-seal mating would occur when two docking systems equipped with seals dock to each other. Two types of seal designs were identified for this application: Gask-O-seals and multi-piece seals. Both types of seals had a pair of seal bulbs to satisfy the redundancy requirement. A series of performance assessments and comparisons were made between the candidate seal designs indicating that they meet the requirements for leak rate and compression and adhesion loads under a range of operating conditions. Other design factors such as part count, integration into the docking system tunnel, seal-on-seal mating, and cost were also considered leading to the selection of the multi-piece seal design for the new docking system. The results of this study can be used by designers of future docking systems and other habitable volumes to select the seal design best-suited for their particular application.

Dunlap, Patrick, H., Jr.↗

NASA NTRS2016

Apparatus, Systems, and Methods for Reconfigurable Robotic Manipulator and Coupling

A robotic manipulator arm is disclosed. The arm includes joints that are attachable and detachable in a tool-free manner via a universal mating adapter. The universal mating adapter includes a built-in electrical interface for an operative electrical connection upon mechanical coupling of the adapter portions. The universal mating adapter includes mechanisms and the ability to store and communicate parameter configurations such that the joints can be rearranged for immediate operation of the arm without further reprogramming, recompiling, or other software intervention.

Burridge, Robert Raven↗

NASA NTRS2016

International Docking Standard (IDSS) Interface Definition Document (IDD) : Revision - E

This International Docking System Standard (IDSS) Interface Definition Document (IDD) is the result of a collaboration by the International Space Station membership to establish a standard docking interface to enable on-orbit crew rescue operations and joint collaborative endeavors utilizing different spacecraft. This IDSS IDD details the physical geometric mating interface and design loads requirements. The physical geometric interface requirements must be strictly followed to ensure physical spacecraft mating compatibility. This includes both defined components and areas that are void of components. The IDD also identifies common design parameters as identified in section 3.0, e.g., docking initial conditions and vehicle mass properties. This information represents a recommended set of design values enveloping a broad set of design reference missions and conditions, which if accommodated in the docking system design, increases the probability of successful docking between different spacecraft. This IDD does not address operational procedures or off-nominal situations, nor does it dictate implementation or design features behind the mating interface. It is the responsibility of the spacecraft developer to perform all hardware verification and validation, and to perform final docking analyses to ensure the needed docking performance and to develop the final certification loads for their application. While there are many other critical requirements needed in the development of a docking system such as fault tolerance, reliability, and environments (e.g. vibration, etc.), it is not the intent of the IDSS IDD to mandate all of these requirements; these requirements must be addressed as part of the specific developer's unique program, spacecraft and mission needs. This approach allows designers the flexibility to design and build docking mechanisms to their unique program needs and requirements. The purpose of the IDSS IDD is to provide basic common design parameters to allow developers to independently design compatible docking systems. The IDSS is intended for uses ranging from crewed to autonomous space vehicles, and from Low Earth Orbit (LEO) to deep-space exploration missions.The purpose of the IDSS IDD is to provide basic common design parameters to allow developers to independently design compatible docking systems. The IDSS is intended for uses ranging from crewed to autonomous space vehicles, and from Low Earth Orbit (LEO) to deep-space exploration missions. The purpose of the IDSS IDD is to provide basic common design parameters to allow developers to independently design compatible docking systems. The IDSS is intended for uses ranging from crewed to autonomous space vehicles, and from Low Earth Orbit (LEO) to deep-space exploration missions.

docking↗