Search NASA⌕ Search

SEARCH · Search NASA

Results for “Shuttle Payload Loads”

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 109 records · Page 6

Expendable solid rocket motor upper stages for the Space Shuttle

A family of expendable solid rocket motor upper stages has been conceptually defined to provide the payloads for the Space Shuttle with performance capability beyond the low earth operational range of the Shuttle Orbiter. In this concept-feasibility assessment, three new solid rocket motors of fixed impulse are defined for use with payloads requiring levels of higher energy. The conceptual design of these motors is constrained to limit thrusting loads into the payloads and to conserve payload bay length. These motors are combined in various vehicle configurations with stage components derived from other programs for the performance of a broad range of upper-stage missions from spin-stabilized, single-stage transfers to three-axis stabilized, multistage insertions. Estimated payload delivery performance and combined payload mission loading configurations are provided for the upper-stage configurations.

Davis, H. P.↗

Centerline latch tool for contingency orbiter door closure

The centerline latch tool was designed and developed as an EVA manual backup device for latching the Space Shuttle Orbiter's payload bay doors for reentry in case of a failure of the existing centerline latches to operate properly. The tool was designed to satisfy a wide variety of structural, mechanical, and EVA requirements. It provides a load path for forces on the payload bay doors during reentry. Since the tool would be used by an EVA crewmember, control, handgrips, operating forces, and procedures must be within the capabilities of a partially restrained, suited crewmember in a zero-gravity environment. The centerline latch tool described was designed, developed, and tested to meet these requirements.

Trevino, R. C.↗

Static stability of a three-dimensional space truss

Space station requirements for power have resulted in a need for photovoltaic solar arrays possessing large blanket surface area. However, due to the limited shuttle payload volume solar array designers have been driven to a deployable concept that by nature is extremely flexible. The principal support for this array system is the Folding Articulating Square Truss Mast (FASTMast). In order to accomodate service loads the FASTMast is expected to exhibit nonlinear behavior which could possibly result in structural instability. Presented herein are the results of the Lewis Research Center test and analysis efforts performed in an effort to characterize the FASTMast structural behavior in terms of stability. Results include those obtained from recent nonlinear testing and analysis involving a 1/10 segment of the FASTMast flight article. Implications of these results as they relate to expected behavior of the flight unit will also be discussed.

Shaker, John F.↗

Static Stability of a Three-Dimensional Space Truss

Space Station requirements for power have resulted in a need for photovoltaic solar arrays possessing large blanket surface area. However, due to the limited Shuttle payload volume solar array designers have been driven to a deployable concept that by nature is extremely flexible. The principal support for this array system is the Folding Articulating Square Truss Mast (FASTMast). In order to accommodate service loads the FASTMast is expected to exhibit nonlinear behavior which could possibly result in structural instability. Presented herein are the results of the Lewis Research Center test and analysis efforts performed in an effort to characterize the FASTMast structural behavior in terms of stability. Results include those obtained from recent nonlinear testing and analysis involving a 1/10 segment of the FASTMast flight article. Implications of these results as they relate to expected behavior of the flight unit will also be discussed.

Shaker, John F.↗

STS payload retention system concept

A payload retention concept that may be utilized on Space Shuttle missions is investigated. This concept appears to embody all the desirable features for the very demanding requirements for space flight. Desirable features include light weight, low cost, high reliability, excellent load distribution, versatility, and insensitivity to critical alignment.

Clark, K. H.↗

Solar dynamic power systems for space station

The Parabolic Offset Linearly Actuated Reflector (POLAR) solar dynamic module was selected as the baseline design for a solar dynamic power system aboard the space station. The POLAR concept was chosen over other candidate designs after extensive trade studies. The primary advantages of the POLAR concept are the low mass moment of inertia of the module about the transverse boom and the compactness of the stowed module which enables packaging of two complete modules in the Shuttle orbiter payload bay. The fine pointing control system required for the solar dynamic module has been studied and initial results indicate that if disturbances from the station are allowed to back drive the rotary alpha joint, pointing errors caused by transient loads on the space station can be minimized. This would allow pointing controls to operate in bandwidths near system structural frequencies. The incorporation of the fine pointing control system into the solar dynamic module is fairly straightforward for the three strut concentrator support structure. However, results of structural analyses indicate that this three strut support is not optimum. Incorporation of a vernier pointing system into the proposed six strut support structure is being studied.

Irvine, Thomas B.↗

Space processing applications payload equipment study. Volume 2B: Payload interface analysis (power/thermal/electromagnetic compatibility)

As a part of the task of performing preliminary engineering analysis of modular payload subelement/host vehicle interfaces, a subsystem interface analysis was performed to establish the integrity of the modular approach to the equipment design and integration. Salient areas that were selected for analysis were power and power conditioning, heat rejection and electromagnetic capability (EMC). The equipment and load profiles for twelve representative experiments were identified. Two of the twelve experiments were chosen as being representative of the group and have been described in greater detail to illustrate the evaluations used in the analysis. The shuttle orbiter will provide electrical power from its three fuel cells in support of the orbiter and the Spacelab operations. One of the three shuttle orbiter fuel cells will be dedicated to the Spacelab electrical power requirements during normal shuttle operation. This power supplies the Spacelab subsystems and the excess will be available to the payload. The current Spacelab sybsystem requirements result in a payload allocation of 4.0 to 4.8 kW average (24 hour/day) and 9.0 kW peak for 15 minutes.

Hammel, R. L.↗

Study of power management technology for orbital multi-100KWe applications. Volume 2: Study results

The preliminary requirements and technology advances required for cost effective space power management systems for multi-100 kilowatt requirements were identified. System requirements were defined by establishing a baseline space platform in the 250 KE KWe range and examining typical user loads and interfaces. The most critical design parameters identified for detailed analysis include: increased distribution voltages and space plasma losses, the choice between ac and dc distribution systems, shuttle servicing effects on reliability, life cycle costs, and frequency impacts to power management system and payload systems for AC transmission. The first choice for a power management system for this kind of application and size range is a hybrid ac/dc combination with the following major features: modular design and construction-sized minimum weight/life cycle cost; high voltage transmission (100 Vac RMS); medium voltage array or = 440 Vdc); resonant inversion; transformer rotary joint; high frequency power transmission line or = 20 KHz); energy storage on array side or rotary joint; fully redundant; and 10 year life with minimal replacement and repair.

Mildice, J. W.↗

STS-41 Ulysses Breakfast, Suit-up, C-7 Exit, Launch and ISOS Cam Views

Live footage shows the crewmembers of STS-41, Commander Richard N. Richards, Pilot Robert D. Cabana, Mission Specialists William M. Shepherd, Bruce E. Melnick, and Thomas D. Akers, participating in the traditional activities the day of their flight. The crew are seen eating breakfast, suiting-up, walking out to the Astronaut-Van, putting on life vests in the 'White Room' area, and entering the crew module of the Discovery Orbiter. Footage also includes preparation of the Ulysses Payload. Engineers are seen loading Ulysses to the upper stage, transferring Discovery to an upright position, bolting Discovery to the external tank, rolling Discovery out to the launch pad, and finally installing the Ulysses Payload inside Discovery. Also shown are both night and morning panoramic shots of the shuttle on the pad, main engine start, ignition, liftoff, booster separation, and various camera views of the launch.

Source record↗

M.E.366-J embodiment design project: Portable foot restraint

During space shuttle operations, astronauts require support to carry out tasks in the weightless environment. In the past, portable foot restraints (PFR) with orientations adjustable in pitch, roll, and yaw provided this support for payload bay operations. These foot restraints, however, were designed for specific tasks with a load limit of 111.2 Newtons. Since the original design, new applications for foot restraints have been identified. New designs for the foot restraints have been created to boost the operational work load to 444.8 Newtons and decrease setup times. What remains to be designed is an interface between the restraint system and the extravehicular mobility unit (EMU) boots. NASA provided a proposed locking device involving a spring-loaded mechanism. This locking mechanism must withstand loads of 1334.4 Newtons in any direction and weigh less than 222.4 Newtons. This paper develops an embodiment design for the interface between the PFR and the EMU boots. This involves design of the locking mechanism and a removable cleat that allows the boot to interface with this mechanism. The design team used the Paul Beitz engineering methodology to present the systematic development, structural analysis, and production considerations of the embodiment design. This methodology provides a basis for understanding the justification behind the decisions made in the design.

Heaton, Randall↗

A cost-effective component modes analysis for Shuttle payloads using a combination of frequency domain and time domain approaches

A combination of the time and frequency domains which employs the latter only where the former is inefficient or uncertain is used in Space Shuttle payloads' component mode analyses. Attention is given to the time histories at the launch vehicle/spacecraft interface. The frequency domain allows interface acceleration to be determined without recourse to a new, merged system eigenvalue solution and subsequent 'system modal' responses. The approach has been employed in Galileo spacecraft loads analyses.

Trubert, M.↗

Mass-additive modal test method for verification of constrained structural models

A method for deriving constrained or fixed-base modes and frequencies from free-free modes of a structure with mass-loaded boundaries is developed. Problems associated with design and development of test fixtures can be avoided with such an approach. The analytical methodology presented is used to assess applicability of the mass-additive method for three types of structures and to determine the accuracy of derived constrained modes and frequencies. Results show that mass loading of the boundaries enables local interface modes to be measured within a desired frequency bandwidth, thus allowing constrained modes to be derived with considerably fewer free-free modes than for unloaded boundaries. Good convergence was obtained for a simple beam and a truss-like Shuttle payload, both of which had well-spaced modes and stiff interface support structures. Slow convergence was obtained for a space station module prototype, a shell-like structure having high modal density.

Admire, John R.↗

NASGRO 3.0: A Software for Analyzing Aging Aircraft

Structural integrity analysis of aging aircraft is a critical necessity in view of the increasing numbers of such aircraft in general aviation, the airlines and the military. Efforts are in progress by NASA, the FAA and the DoD to focus attention on aging aircraft safety. The present paper describes the NASGRO software which is well-suited for effectively analyzing the behavior of defects that may be found in aging aircraft. The newly revised Version 3.0 has many features specifically implemented to suit the needs of the aircraft community. The fatigue crack growth computer program NASA/FLAGRO 2.0 was originally developed to analyze space hardware such as the Space Shuttle, the International Space Station and the associated payloads. Due to popular demand, the software was enhanced to suit the needs of the aircraft industry. Major improvements in Version 3.0 are the incorporation of the ability to read aircraft spectra of unlimited size, generation of common aircraft fatigue load blocks, and the incorporation of crack-growth models which include load-interaction effects such as retardation due to overloads and acceleration due to underloads. Five new crack-growth models, viz., generalized Willenborg, modified generalized Willenborg, constant closure model, Walker-Chang model and the deKoning-Newman strip-yield model, have been implemented. To facilitate easier input of geometry, material properties and load spectra, a Windows-style graphical user interface has been developed. Features to quickly change the input and rerun the problem as well as examine the output are incorporated. NASGRO has been organized into three modules, the crack-growth module being the primary one. The other two modules are the boundary element module and the material properties module. The boundary-element module provides the ability to model and analyze complex two-dimensional problems to obtain stresses and stress-intensity factors. The material properties module allows users to store and curve-fit fatigue-crack growth data. On-line help and documentation are provided for each of the modules. In addition to the popular PC windows version, a unix-based X-windows version of NASGRO is also available. A portable C++ class library called WxWindows was used to facilitate cross-platform availability of the software.

Mettu, S. R.↗

Space Shuttle Atmospheric ascent flight dynamics

The atmospheric ascent flight phase of the mated composite booster and orbiter is discussed. The composite recoverable space shuttle booster and orbiter exhibits unique flight control characteristics. This uniqueness results from large lifting surfaces and aerodynamic and structural assymetrics. An effective load relief technique reduces aerodynamic loads on both the booster and the orbiter. Reducing aerodynamic loads permits decreasing the structural weight of the lifting and stabilizing surfaces. An orbiter payload penalty is caused by trajectory deviations resulting from load relief. However, the net effect of an effective load relief technique is an increase in payload capability. Atmospheric launch dynamics investigations have been carried out for different configuration types, which include expendable, straight wing, delta wing, and ballistic recoverable boosters.

Patha, J. T.↗

Comparison of damping measurement for a trunnion supported Shuttle payload

The damping of a trunnion-supported Space Shuttle payload, the Centaur G Prime upper stage launch vehicle, is measured using three different methods. The structural system behaves nonlinearly, and the damping values are found to be dependent on the response amplitude. The results of the damping measurements are compared, and their validities with respect to the coupled loads analysis are examined.

Chen, J.-C.↗

One Idea for a Next Generation Shuttle

In this configuration, the current Shuttle External Tank serves as core structure for a fully reusable second stage. This stage is equipped with wings, vertical fin, landing gear, and thermal protection. The stage is geometrically identical to (but smaller than) a single stage that has been tested hyper-sonically, super-sonically, and sub-sonically in the NASA Langley Research Center wind tunnels. The three LOX/LH engines that currently serve as main propulsion for the Shuttle Orbiter, serve as main propulsion on the new stage. The new stage is unmanned but is equipped with the avionics needed for automatic maneuvering on orbit and for landing on a runway. Three rails are installed along the top surface of the vehicle for attachment of various payloads. Pay- loads might include third stages with satellites attached, personnel pods, propellants, or other items.

MacConochie, Ian O.↗

Space Shuttle Program Update News Conference with Wayne Hale

Jessica Rye from NASA Public Affairs introduces: Wayne Hale, Space Shuttle Deputy Program Manager; Mike Leinbach, NASA Launch Director; and Tim Wilson, from the NASA Engineering and Safety Center. Hale begins the discussion with a video showing the following processes: 1) Changing of gap fillers at Orbiter Processing Facility; 2) The Orbiter Boom Sensor System (OBSS) being loaded into Discovery payload bay; 3) Engine installation; 4) Spacecrew at Michoud Assembly observing the area where the PAL ramps were removed; 5) Test being performed to mitigate liquid air forming underneath foam; and 6) Roll out of ET119 from New Orleans. Hale also presents a slide of the ET debris Mitigation Activities and ET Ice/Frost Ramps. Mike Leinbach says that Kennedy Space Center is ready to receive the tank and that he is ready to get on with the mission. Tim Wilson heads the team to resolve foam loss issues which is his primary goal before this flight. A question and answer period follows.

Source record↗

A study to define an in-flight dynamics measurement and data applications program for space shuttle payloads

Data measurement and interpretation techniques were defined for application to the first few space shuttle flights, so that the dynamic environment could be sufficiently well established to be used to reduce the cost of future payloads through more efficient design and environmental test techniques. It was concluded that: (1) initial payloads must be given comprehensive instrumentation coverage to obtain detailed definition of acoustics, vibration, and interface loads, (2) analytical models of selected initial payloads must be developed and verified by modal surveys and flight measurements, (3) acoustic tests should be performed on initial payloads to establish realistic test criteria for components and experiments in order to minimize unrealistic failures and retest requirements, (4) permanent data banks should be set up to establish statistical confidence in the data to be used, (5) a more unified design/test specification philosophy is needed, (6) additional work is needed to establish a practical testing technique for simulation of vehicle transients.

Rader, W. P.↗