SAWE Technical Papers

@inproceedings{3737,

title = {3737. Use of Mass Growth Allowance to Dynamically Manage Mass Risk},

author = {Zaid Karajeh},

url = {https://www.sawe.org/product/paper-3737},

year  = {2020},

date = {2020-07-01},

booktitle = {2020 SAWE Tech Fair},

pages = {6},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Virtual Conference},

abstract = {Management of mass budgets and the associated risks in the aerospace industry has positive impacts that affect delivery and launch of spacecraft. This paper presents a novel feedback control method to manage mass risk over the course of spacecraft design and production. The control method uses a dynamic upper and lower boundary formed as a function of heritage spacecraft mass risk. Spacecraft that deviate above the upper bound fall out of compliance and should trigger action. By observing how the risk mass varies over time with respect to the boundaries, scheduling risks could be identified preserving launch date and potentially acting as a cost saving effort for the spacecraft manufacturer.},

keywords = {19. Weight Engineering - Spacecraft Estimation, 26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3697,

title = {3697. The Case for In-Service Mass Properties of Missiles and Space Vehicles},

author = {Robert L. Zimmerman},

url = {https://www.sawe.org/product/paper-3697},

year  = {2018},

date = {2018-05-01},

booktitle = {77th Annual Conference, Irving, Texas},

pages = {14},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Irving, Texas},

abstract = {With many misconceptions regarding the invariability of missiles and space systems vehicles during their in-service life, this paper presents the case that these mass properties are not only variable, but highly contingent on time-phased operations of the vehicles. Various space vehicles are described depicting how the type of vehicle and its components greatly affect the mass properties of the vehicle during its service life. An example mission with a high-level description of the changes that affect mass properties is used to illustrate just how much the mass properties can change throughout a mission. Finally, a brief discussion of current requirements documents is presented to show that these misconceptions are accounted for by the industry.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3701,

title = {3701. Mass Properties in Support of Class Analysis (a.k.a. MP End of Days)},

author = {Ricardo Roy},

url = {https://www.sawe.org/product/paper-3701},

year  = {2018},

date = {2018-05-01},

booktitle = {77th Annual Conference, Irving, Texas},

pages = {18},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Irving, Texas},

abstract = {You receive the following Program Office Request: In lieu of mission specific analysis, it is dictated to you that Class Analysis be instituted to lower overall program cost. There may be other methods to address this request but this paper addresses one process that provided mass properties in support of program 'Class Analysis'. To get started, a definition of Class Analysis is prudent. Class Analysis is any single study that incorporates all conceived configurations of a vehicle from mass properties (MP) perspective and the MP uncertainties associated with them.The main purpose is to provide a range of mass properties with a high likelihood that the current and future fleet elements will not exceed them.This process is based on simulated aerospace hardware data and does not reflect any specific line of vehicles. Additionally, the same process may be applied to non-aerospace production programs. All that is required is a good history of launch vehicle segments along with mass properties and uncertainties for each segment. Ten (10) years of history is ideal, but a smaller term is acceptable knowing that risk may be incurred. A segment is defined as any portion of the launch vehicle that may get jettisoned during the launch cycle. A robust verification process to validate that the assumed variables are still compliant is also a must.This analysis will not only be performed by the mass properties group but also by all the downstream users (Guidance, Flight Mechanics, Separation, Structures, Ground Ops ...etc.). Mass Properties is the initial cog in a long string of analysis that will be scrutinized. This being said, the mass properties group must not operate in a vacuum, but coordinate with these downstream users to access the effects of your assumptions. All data units herein will be presented as: Mass (M) = pounds-mass (lbm); Center of Mass (CM) = inches (in) or stations; and Moment and Product of Inertias (MOI and POI) = slug-foot2 (sl-ft2). Inertias will be in respect to the CM. A positive integral definition will be used for POI.},

keywords = {15. Weight Engineering - Missile Estimation, 19. Weight Engineering - Spacecraft Estimation, 21. Weight Engineering - Statistical Studies},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3593,

title = {3593. Trade Study of System Level Ranked Radiation Protection Concepts for Deep Space Exploration},

author = {Jeffrey Cerro},

url = {https://www.sawe.org/product/paper-3593},

year  = {2013},

date = {2013-05-01},

booktitle = {72nd Annual Conference, St. Louis, Missouri},

pages = {18},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Saint Louis, Missouri},

abstract = {A strategic focus area for NASA is to pursue the development of technologies which support exploration in space beyond the current inhabited region of low earth orbit. An unresolved issue for crewed deep space exploration involves limiting crew radiation exposure to below acceptable levels, considering both solar particle events and galactic cosmic ray contributions to dosage. Galactic cosmic ray mitigation is not addressed in this paper, but by addressing credible, easily implemented, and mass efficient solutions for the possibility of solar particle events, additional margin is provided that can be used for cosmic ray dose accumulation. As a result, NASA's Advanced Engineering Systems project office initiated this Radiation Storm Shelter design activity. This paper reports on the first year results of an expected 3 year Storm Shelter study effort which will mature concepts and operational scenarios that protect exploration astronauts from solar particle radiation events. Large trade space definition, candidate concept ranking, and a planned demonstration comprised the majority of FY12 activities. A system key performance parameter is minimization of the required increase in mass needed to provide a safe environment. Total system mass along with operational assessments and other defined protection system metrics provide the guiding metrics to proceed with concept developments. After a downselect to four primary methods, the concepts were analyzed for dosage severity and the amount of shielding mass necessary to bring dosage to acceptable values. Besides analytical assessments, subscale models of several concepts and one full scale concept demonstrator were created. FY12 work terminated with a plan to demonstrate test articles of two selected approaches. The process of arriving at these selections and their current envisioned implementation are presented in this paper.},

keywords = {18. Weight Engineering - Spacecraft Design, 19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3497,

title = {3497. New Mass Properties Engineers' Aerospace Ballasting Challenge Facilitated by the SAWE Community},

author = {Amanda Cutright and Brendan Shaughnessy},

url = {https://www.sawe.org/product/paper-3497},

year  = {2010},

date = {2010-05-01},

booktitle = {69th Annual Conference, Virginia Beach, Virginia},

pages = {27},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Virginia Beach, Virginia},

abstract = {The discipline of Mass Properties Engineering tends to find the engineers; not typically vice 

versa. In this case, two engineers quickly found their new responsibilities deep in many aspects 

of mass properties engineering and required to meet technical challenges in a fast paced 

environment. As part of NASA's Constellation Program, a series of flight tests will be conducted 

to evaluate components of the new spacecraft launch vehicles. One of these tests is the Pad Abort 

1 (PA-1) flight test which will test the Launch Abort System (LAS), a system designed to provide 

escape for astronauts in the event of an emergency. The Flight Test Articles (FTA) used in this 

flight test are required to match mass properties corresponding to the operational vehicle, which 

has a continually evolving design. Additionally, since the structure and subsystems for the Orion 

Crew Module (CM) FTA are simplified versions of the final product, thousands of pounds of 

ballast are necessary to achieve the desired mass properties. These new mass properties 

engineers are responsible for many mass properties aspects in support of the flight test, including 

meeting the ballasting challenge for the CM Boilerplate FTA. SAWE expert and experienced 

mass properties engineers, both those that are directly on the team and many that supported via a 

variety of Society venues, significantly contributed to facilitating the success of addressing this 

particular mass properties ballasting challenge, in addition to many other challenges along the 

way. This paper discusses the details regarding the technical aspects of this particular mass 

properties challenge, as well as identifies recommendations for new mass properties engineers 

that were learned from the SAWE community along the way.},

keywords = {17. Weight Engineering - Procedures, 19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3355,

title = {3355. Reference Models For Structural Technology Assessment and Weight Estimation},

author = {Jeffrey Cerro and Martinovic and Eldred},

url = {https://www.sawe.org/product/paper-3355},

year  = {2005},

date = {2005-05-01},

booktitle = {64th Annual Conference, Annapolis, Maryland},

pages = {21},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Annapolis, Maryland},

abstract = {Previously the Exploration Concepts Branch of NASA Langley Research Center has developed techniques for automating the preliminary design level of launch vehicle airframe structural analysis for purposes of enhancing historical regression based mass estimating relationships. This past work was useful and greatly reduced design time, however its application area was very narrow in terms of being able to handle a large variety in structural and vehicle general arrangement alternatives. Features of that work such as the utilization of Object Oriented JAVA Programming and the incorporation of flexible commercial FEA and commercial structural design software are retained in this continuing work, but a new emphasis has been placed on making the integrating JAVA modules much more generic. The goal has been to develop a library of JAVA modules which when placed in the desired sequence facilitate the automated structural sizing of a greater variety of component and vehicle systems. The finite element procedures wrapped by JAVA routines now trend towards being more generic in the sense that the routine inputs are not as much design and FEA program specific as they are design and FEA process specific. A later goal in this analysis system development would be to arrive at a working group defined set of JAVA Interface Classes that describe input and output required for particular stages of analysis of automated structural design. Along with standardized input/output parameters there would also be a set of standard data processing functions, which are then useful to the structural designer in providing the flexibility required for designing numerous parts, sub-assemblies, and full vehicle configurations. In JAVA programming terminology these Class definitions become generic Interfaces which are then implementable at any corporate or academic organization utilizing internal and possibly proprietary procedures. Model data may be exchanged between these organizations and will be processable by any of the organizations which have implemented the defined standard Interface. Similar work is ongoing in the area of Simulation Based Acquisition (SBA) via the Simulation Interoperability Standards Organization (SISO) and particularly in the area of integrating distributed simulations by the High Level Architecture - Commercial off the shelf Simulation Package Interoperation Forum (HLA~CSPIF). For those more interested in preliminary design in a collaborative environment the NAVY NAVSEA division has pursued similar themes of modularity and multi-disciplinary interoperability by utilizing a CORBA and IDL (Interface Definition Language) based approach to Simulation Based Design (SBD). A quote from Optimization in the Simulations Based Design Environment by W. A. Kusmik shows the great utility of implementing a formal Simulation Based Design approach. 

'High Potential was evidenced by the ability to integrate high-fidelity modeling and simulation tools to provide insight into overarching system-level performance attributes and the ability of the integration process itself to promote informal collaboration between various domain experts.' 

These too are the features being encouraged and developed within the Exploration Concepts Branch to enable functionally and organizationally collaborative multidisciplinary design for the purposes of defining and building vehicle elements which best help us achieve the nation's vision for manned space exploration.},

keywords = {12. Weight Engineering - Computer Applications, 19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3357,

title = {3357. A Manned Mission to Mars: Mass Properties Implications},

author = {Ian O. MacConochie},

url = {https://www.sawe.org/product/paper-3357},

year  = {2005},

date = {2005-05-01},

booktitle = {64th Annual Conference, Annapolis, Maryland},

pages = {14},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Annapolis, Maryland},

abstract = {A cursory assessment of the mass properties associated with a manned mission to Mars suggests that a flotilla of boosters with their payloads should be considered for the mission. Using the flotilla concept, during transit to Mars, it is envisioned that multiple spacecraft would be launched simultaneously from an Earth orbiting platform. The spacecraft would fly in formation and astronauts would visit other spacecraft when needed for supplies during the 7 to 9 month trip. Many other supporting systems for a Martian camp, such as power and communications modules, would have been delivered earlier on much smaller boosters than the manned flotilla types. Robots would work the Martian campsite, setting up the support modules in anticipation of the arrival of the astronauts. Two to four astronauts would be planned for the mission.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3329,

title = {3329. WAMI - a Menu-Driven Computer Program for the Estimation of Weight and Moment of Inertia of Earth-to-Orbit Transports},

author = {Ian O. MacConochie and White and Mills},

url = {https://www.sawe.org/product/paper-3329},

year  = {2004},

date = {2004-05-01},

booktitle = {63rd Annual Conference, Newport, California},

pages = {17},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Newport, California},

abstract = {A program, entitled Weights, Areas, and Mass Properties (or WAMI) is centered around an array of menus that contain constants that can be used in various mass estimating relationships for the ultimate purpose of obtaining the mass properties of Earth-to-Orbit Transports. The current Shuttle mass property data was relied upon heavily for baseline equation constant values from which other options were derived. 

Characterization of the mass properties of any Earth-to-Orbit transport is complicated by the enormous amount of detail that is needed to support the end result ? the end result principally being weights and centers of gravity for the various stages of any one mission. In the WAMI program, menus are provided containing a number of options for constants for each subsystem. Usually, one of the menu options is based on the current Shuttle. Additional values are based on various technological and configurational assumptions. 

The menu system to obtain mass properties facilitates both the work of the user and the ability of the recipient in understanding the results. In using Shuttle data for the calculation of the basic constants, the fidelity of the mass estimating equations is enhanced. It is not practical, at least at the conceptual level, to identify all of the non-optimum weights that should be assigned to a given subsystem. For example, analytic solutions for structure are still needed to identify innovative configurations and to demonstrate the utility of new materials. However, the so-called ?stress? wing is typically only about one half the weight of the ?real? wing. By utilizing Shuttle mass properties as a base, data for realistic values for non-optimums and the all-up structure are obtained.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3024,

title = {3024. An Unmanned Spacecraft Subsystem Cost Model for Advance Mission Planning},

author = {George Madrid},

url = {https://www.sawe.org/product/paper-3024},

year  = {2000},

date = {2000-06-01},

booktitle = {59th Annual Conference, St. Louis, Missouri, June 5-7},

pages = {18},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {St. Louis, Missouri},

abstract = {This paper reports on the development of a parametric cost model that is being built at JPL to estimate costs of future, deep space, robotic science missions. Because of the changes in the mission implementation process and technology changes, the model is being built in a dramatically different manner than past models which have had access to a data base that drew heavily on the correlation between mass and actual costs. Instead, the data base is based on the results of an interdisciplinary team of technical experts that make up the core team that assesses new proposals as they are being planned under the new business process being instituted at JPL. The model is then validated against actual mission costs as the projects are implemented. The discussion will provide a summary of this new process as it relates to the development of the model, some of the details of the model itself, and the status of its validation and plans for the future.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2409,

title = {2409. Addressing Uncertainty in Weight Estimates},

author = {R W Monroe and R A Lepsch and R Unal},

url = {https://www.sawe.org/product/paper-2409},

year  = {1998},

date = {1998-05-01},

booktitle = {57th Annual Conference, Wichita, Kansas, May 18-20},

pages = {11},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Wichita, Kansas},

abstract = {At the conceptual design stage, parameters used for weight estimating are subject to significant uncertainty. One can choose to ignore uncertainty or attempt to address uncertainty in some fashion. This paper describes a methodology to explicitly address uncertainty related to a weight estimation task. The methodology utilizes expert judgment to quantify uncertainty associated with weight estimation parameters. A risk analysis is then possible utilizing the data generated by the methodology. An example case for a launch vehicle design is evaluated. Results from the risk analysis are expressed as a range of estimates or a cumulative probability distribution for the estimated value. Results in this form that may be useful for other downstream users such as cost estimating. The primary elements of the methodology were validated by a group of weight estimating/conceptual design engineers. The methodology proved to be a practical and useful technique for addressing uncertainty. Other issues related to the practicality of the methodology and the usefulness of the methodology are discussed in the paper.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2323,

title = {2323. Risk Analysis of Weight Estimates for a Launch Vehicle},

author = {R W Monroe and R A Lepsch and R Unal},

url = {https://www.sawe.org/product/paper-2323},

year  = {1996},

date = {1996-06-01},

booktitle = {55th Annual Conference, Atlanta, Georgia, June 3-5},

pages = {12},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Atlanta, Georgia},

abstract = {The interrelationship between cost and weight has long been recognized by the aircraft, aerospace and the shipbuilding industries. Since weight is an important input to cost estimating, the accuracy of weight estimates is critical for developing accurate cost estimates. In these industries, lack of data often hampers the conceptual design engineer when preparing a weight estimate. In the aerospace industry, the launch vehicle conceptual design engineer must develop a variety of estimates based on new technologies with little or no historical data to rely upon. One such estimating task is weight estimation using weight estimating relationships (WER's) encompassing various design parameters. This paper will describe a methodology used to elicit the weight expert's knowledge in usable form and will address the difficulties encountered along the way. The methodology results in a data set that includes the expert's judgment of uncertainty for the design parameters. The data set permits the execution of a risk analysis for a launch vehicle weight estimate. the risk analysis simulation results can then be used as an input for cost estimating.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1941,

title = {1941. Weight Estimating Methodology: NASP vs Other Programs},

author = {G Bonardi},

url = {https://www.sawe.org/product/paper-1941},

year  = {1990},

date = {1990-05-01},

booktitle = {49th Annual Conference, Chandler, Arizona, May 14-16},

pages = {16},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Chandler, Arizona},

abstract = {The intent of this paper is to explain the difference between the preliminary design weight estimation methodologies used on the National Aerospace Plane (NASP) and previous programs. Discussions focus upon issues inherent to NASP, special requirements, and other factors which drive the need for credible and accurate preliminary design weight estimates. Issues such as weight growth factors, non-optimum factors, airframe/engine vehicle integration constraints, manufacturing constraints, and incorporation of the ''illities'': Reliability, Maintainability, Supportability, and Safety (RMSS) are discussed. The design process is described, outlining die integrated approach used. This takes into account all disciplines and their individual and integrated effects upon the vehicle. The methodologies concepts are discussed as they are used on NASP with major differences between NASP and previous programs being outlined. Several charts comparing mass fractions for structures, landing gear, propulsion, and subsystems of NASP to those of previous programs are shown. These charts show where NASP is in relationship to history.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1943,

title = {1943. Weight Parametrization of the Hermes Space Vehicle},

author = {G Guirado and C Michelon-Edery and D Cavalli},

url = {https://www.sawe.org/product/paper-1943},

year  = {1990},

date = {1990-05-01},

booktitle = {49th Annual Conference, Chandler, Arizona, May 14-16},

pages = {24},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Chandler, Arizona},

abstract = {The Hermes space vehicle configuration studies conducted in the last two years were mainly driven by the mass constraints imposed by its launching with the Ariane V rocket and its reentry from orbit. Other drivers were also: 1) main mission (orbital station servicing) requirements, 2) crew safety (crew escape module), 3) in orbit life and operations, and 4) ground operations. Using the launcher adapter as an integrated part of the space vehicle, the current Hermes configuration displays two separable parts: 1) the Hermes spaceplane (HSP), which is designed for earth return, and 2) the expandable Hermes Resources Module (HRM). The Hermes spaceplane houses the ejectable cockpit (crew escape module), the crew living quarters, a pressurized payload zone, and unpressurized equipment compartments. The Hermes Resources Module includes the space station servicing elements (i.e., payload zone, airlock, docking interface, and telemanipulator arm) and the space vehicle elements (i.e., propulsion system for orbital maneuvers, thermal control radiators, and ECLS). The paper describes one configuration (called the 5M2 configuration), and the parametrization application.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1887,

title = {1887. In Flight Demonstration of Mass Properties Identification and Jet Plume Interaction on the Aero Assist Flight Experiment},

author = {E V Bergman and R C Blanchard},

url = {https://www.sawe.org/product/paper-1887},

year  = {1989},

date = {1989-05-01},

booktitle = {48th Annual Conference, Alexandria, Virginia, May 22-24},

pages = {23},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Alexandria, Virginia},

abstract = {Algorithms for in-flight demonstration of spacecraft mass, center of mass, and inertia matrix have been developed. These algorithms are intended to provide the capability to autonomously measure mass properties as they change in-flight due to consumable expenditure, payload deployment and retrieval, and docking. Prior to serious consideration of these algorithms for actual spacecraft applications, it is highly desirable to test their performance in an actual flight environment. The mass properties estimator is a second order, nonlinear filter which resembles an extended Kalman filter. It contains a model for the dynamics of a rigid spacecraft with the mass properties as parameters. When jets are fired, that model is used with the current estimate of mass properties to predict the output of rate gyros and accelerometers on the spacecraft, and that prediction is compared to actual measured values. The filter operates on this comparison to revise its estimate of spacecraft mass properties. Simulation results indicate that the vehicle inertia matrix, center of mass, and mass can be determined by a sequence of eleven individual jet firings. Starting with arbitrary numerical values for each parameter, the mass properties can be determined to better than 1%.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1673,

title = {1673. Space Station Design to Cost: A Massive Engineering Challenge},

author = {M C Simon},

url = {https://www.sawe.org/product/paper-1673},

year  = {1985},

date = {1985-05-01},

booktitle = {44th Annual Conference, Arlington, Texas, May 20-22},

pages = {11},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Arlington, Texas},

abstract = {To meet Space Station Program objectives within established cost constraints, NASA and its contractors must adhere to a rigorous design-to-cost approach to Space Station design, development, and production. This will require a fundamental change in attitude regarding the role of cost analysis in the engineering process. Cost estimating and evaluation must be regarded as an integral part of the design task, rather than an external support function. Through trade studies and sensitivity analyses, cost analysis must in fact play a leading role in the definition of Space Station capabilities and elements. While certain Space Station requirements have been described by NASA as mandatory, the ultimate size, shape, and function of the Space Station will be determined by cost more than by any other single evaluation criterion. Both engineering and program management must rise to the task of design-to-cost by striving to increase awareness of cost-related issues at all levels and by making every reasonable effort to incorporate cost analysis into the research and development process.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1559,

title = {1559. Orbiter Spacecraft Weight and Center of Gravity Determination},

author = {J G Fraley},

url = {https://www.sawe.org/product/paper-1559},

year  = {1983},

date = {1983-05-01},

booktitle = {42nd Annual Conference, Anaheim, California, May 23-25},

pages = {23},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Anaheim, California},

abstract = {This paper describes the procedure for determination of the weight and the location of the center 

of gravity (c.g.) of a Space Shuttle Orbiter Spacecraft, at the Kennedy Space Center (KSC), Florida. 

This task is performed at the completion of the horizontal processing of each Orbiter (Orb) in 

conjunction with jack down and preparation for vertical mating to the Shuttle launch vehicle. 

The operation is performed in the Orbiter Processing Facility (OPF). It is conducted by NASA and 

Rockwell International Corporation personnel of KSC along with Mass Properties Engineers fron the 

Orbiter design centers of the Johnson Space Center (JSC), Houston, Texas, and Rockwell International 

Space Division, Downey, California. 

The following sections will briefly describe the general characteristics and physical dimensions of 

the Orbiter spacecraft, the program requirements and test procedure for weight and c.g. determination, 

data evaluation and a summary. In addition, a glossary appears on page 13.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1458,

title = {1458. An Interactive Weight Estimating Program for Maneuverable Reentry Vehicles},

author = {D Stachowitz and T F Reed and J W Pieper},

url = {https://www.sawe.org/product/paper-1458},

year  = {1982},

date = {1982-05-01},

booktitle = {41st Annual Conference, San Jose, California, May 17-19},

pages = {10},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {San Jose, California},

abstract = {During the development of next-generation aerospace vehicles, predicting the weight and size of these vehicles can be very challenging to the weight engineer. A computer program was constructed using mass estimating relationships (IMERS), generated under various NASA and Air Force contracts, to predict the weight of these vehicles using existing design technologies. A NASA study was used to aid in predicting the vehicle weight and size based on projected technology advancements.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1435,

title = {1435. Weight Considerations for On-Orbit Maintenance Satellites},

author = {G S Mathews},

url = {https://www.sawe.org/product/paper-1435},

year  = {1981},

date = {1981-05-01},

booktitle = {40th Annual Conference, Dayton, Ohio, May 4-7},

pages = {28},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Dayton, Ohio},

abstract = {With the advent of the shuttle orbiter, it is cost effective to extend the on-orbit life, or change 

some mission aspects of a satellite by on-orbit maintenance and reboost by the shuttle/orbiter. The 

Space Telescope (ST) is the first of the long life satellites. Its mission requires maintenance and 

reboost at the end of two and one half years and at the end of five years return to earth for refurbishment. 

The cycle is repeated over the expected fifteen year life of the vehicle. 

The intent of the author is to alert the mass properties engineer to new sources of weight inherent in the 

requirements for on-orbit maintenance. Concepts and data presented are based on design activity of the Support 

Systems Module of the ST, NASA Contract NA.58-32697, for Marshall Space Flight Center. 

The ST is 42.3 ft. long, and varies from 10 ft. to 14 ft. in diameter. The launch weight of the ST is approximately 

24,000 lb., of which 10,300 lb. is attributable to the SSM. Figure 1-1 depicts the size of the ST and establishes 

perspective in relation to the requirements. 

Specific areas discussed or presented include general requirements for crew safety, crew aids and crew member 

imposed loads, orbital replacement units, doors and wiring, and equipment required for Remote Manipulator System 

(RMS) deployment/retrieval/berthing.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1382,

title = {1382. Automating the Process of Estimating Spacecraft Mass},

author = {D L Skinner},

url = {https://www.sawe.org/product/paper-1382},

year  = {1980},

date = {1980-05-01},

booktitle = {39th Annual Conference, St. Louis, Missouri, May 12-14},

pages = {39},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {St. Louis, Missouri},

abstract = {In addition to cost, a major design constraint on planetary exploration spacecraft designed at the Jet Propulsion Laboratory has been mass, because of limited launch vehicle capability and the desire to maximize science return. Difficulties in accurately estimating the mass and performance of spacecraft based on their capabilities in the early phases of the design process have contributed to the need for costly mass reduction late in the design process. To help prevent such problems in the future, the process of estimating spacecraft mass has been analyzed and identified in algorithmic form, and software is currently being written to allow trained users to interface with these algorithms in an automated fashion. Such software will potentially lower the cost of preliminary spacecraft design, and the cost-effective ease with which alternative designs can be evaluated should produce better overall mission designs. 

As an integral part of this effort, a data base of the appropriate parameters from historical spacecraft is being developed. The software will use the historical data to extrapolate future values of a given time dependent parameter. To obtain the mass moments of inertia and other mass properties, plans call for the current technique of using static graphics to create and modify the initial spacecraft configuration to be replaced by an interactive dynamic graphics configuration builder. The algorithms are to be tested for accuracy by being used to design specific historical spacecraft with the associated data for the spacecraft in question temporarily removed from the data base. The predicted results will then be compared to the actual results. The algorithms developed for mass estimation were found to be part of an algorithmic approach to spacecraft design synthesis that could also provide improved estimates of cost and various other parameters. Future expansions of this work promise to automate the entire conceptual mission design process. Also, the rigorous definition of the spacecraft design process will provide a much needed basis for training and research in the technical discipline of spacecraft systems.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{1315,

title = {1315. Mass Estimating Techniques for Earth-to-Orbit Transports With Various Configuration Factors and Technologies Applied},

author = {P J Klich and Ian O. MacConochie},

url = {https://www.sawe.org/product/paper-1315},

year  = {1979},

date = {1979-05-01},

booktitle = {38th Annual Conference, New York, New York, May 7-9},

pages = {27},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {New York, New York},

abstract = {An array of advanced Earth-to-orbit space transportation systems have been studied with a focus on mass properties and technology requirements. Methods needed for estimation of weights on these vehicles differ from mass 2stimating methods used for commercial and military aircraft. The new techniques are described with primary emphasis on winged horizontal and vertical take-off advanced transportation system. The space shuttle subsystem m as properties are utilized as a database for the weight estimating equations. From the space shuttle database, plus information obtained from basic and applied research; normal growth and accelerated technology factors are applied for the advanced systems. 

'The weight equations for advanced transportation vehicles require information on the mission profile, the vehicle structural materials, the thermal protection system (TPS) and the ascent propulsion system. The weight equations allow a 'shopping list'' of constants for the type of construction, (hot or cold, aluminum or composite) and for various propellant tank shapes both integral and non-integral. With the basic knowledge of a vehicle, one can apply these estimating techniques and constants to calculate the overall systems weights. The weight equations have been incorporated into the Systems Engineering Mass Properties (SEMP) Computer program. These techniques for estimating weights of Earth-to-orbit transportation systems have proven to be reasonable.},

keywords = {19. Weight Engineering - Spacecraft Estimation},

pubstate = {published},

tppubtype = {inproceedings}

}