Georgi Petrov

Optimization of Inflatable Spacecraft Interior Volume Using Constraints Driven Design

Over the past two decades, the emergence of mature associative geometry modeling tools and the related sophistication in associated manufacturing processes has enabled the design and realization of complex, nonlinear structures. To demonstrate the use of intelligent associative models, the design team developed an iterative method for refining the shell and interior design of surface endoskeletal inflatable modules (SEIM). The salient features of the design method are: the use of a custom shape-finding mathematical model written in the Processing integrated development environment (IDE) to determine the correct inflated shape of the shell; a 3D parametric model of the interior, built using the Grasshopper plugin for Rhinoceros 3D by Robert McNeel & Associates; and a semi-automated two-way transfer of data between the design and analysis tools. This paper presents preliminary results of the design method’s application to the optimization of the habitat version of SEIM. Here the independent variable is the inflatable shell geometry, which is controlled by the length of the structural strands in the two principle directions. The dependant variable is the ratio of floor area with a minimum clear height of 2.15 meters to the total available floor area. Fixed parameters are the geometry of the rigid frame and the stowed volume inside the launch platform. The parametric model allows rapid evaluation of the quality of the habitable spaces for a number of shell geometries.

The Surface Endoskeletal Inflatable Module (SEIM)

With the development of the TransHab hybrid inflatable habitat, a team at NASA’s Johnson Space Center broke with historical paradigms by developing the first endoskeletal space module. The value of this design was cost-effectiveness, efficiency, and the possibility for new forms to support human-rated vehicles and modules for exploration missions. The “TransHab Paradigm” is a complex, semi-inflatable vehicle whose two basic configurations - launch and deployed - are each optimized for their respective environments while retaining fundamental system integration for autonomy and efficient deployment. In this study, the architecture team has undertaken to adapt the paradigm in two ways: first, by designing a module with similar operations concept, but operating in a different environment - that of a planetary surface; and second, by streamlining the relationship between the hard and membranous structures that make up this type of module’s principal components.

Spaceport Master Planning: Principles and Precedents

INTRODUCTION While the past two years have witnessed marvelous breakthroughs in private space initiatives and in commercial support for spaceflight, the specific issues inherent in the design of spaceports require special examination. The airport paradigm has evolved over the course of the twentieth century from its basic functionality of airfield or runway strip and hangar to a complex transportation nexus of rail, air, road and sea transit, supported by various hospitality and training functions and other logistical functions. To date, spaceflight has been restricted to government programs which can accommodate internal planning and the ability to leverage other facilities, both military and civilian, to meet its needs. The advent of commercial spaceflight will effect a radical change in the operational requirements for launch facilities, and along with these operational shifts come associated technical complexity that cannot always be met by leveraging publicly owned resources. In addition, there is every reason to expect that the facilities supporting commercial space access will follow a similar pattern of formal transformation to that which traces the history of air access, as technologies emerge and mature and as the market grows from the initial handful of wealthy suborbital tourists to a mass market we can now only imagine.

The Mars Homestead: a Mars Base Constructed from Local Materials

A preliminary design, the “Hillside Base”, has been completed. We assume that 12 people will deploy, bootstrap, and maintain small, semi-automated refining and manufacturing facilities. Using locally produced fiberglass, metal, ceramics, and simple plastics, they then construct permanent quarters for themselves. This Hillside Base includes living quarters, workshops, greenhouses, maintenance facilities, waste processing, refining, manufacturing, and other areas needed to live and work. After they move into their completed quarters, they continue construction for an additional dozen people, mostly scientists, who arrive about every two and a half years. The base grows into a permanent manufacturing settlement, producing equipment for additional scientific outposts and other permanent settlements.

Effects of Perimeter to Core Connectivity on Tall Building Behavior

The Pertamina Energy Tower (PET) and Manhattan West North Tower (MWNT) are two supertall towers recently designed and engineered by Skidmore, Owings & Merrill (SOM). The structural system for both buildings consists of an interior reinforced concrete core and a perimeter moment frame system, which is primarily structural steel. As is typical for tall towers with both concrete and steel elements, staged construction analysis was performed in order to account for the long term effects of creep and shrinkage, which result in differential shortening between the interior concrete core and steel perimeter frame. The particular design of each tower represents two extremes of behavior; PET has a robust connection between the perimeter and core in the form of three sets of outriggers, while the perimeter columns of MWNT do not reach the ground, but are transferred to the core above the base. This paper will present a comparison of the techniques used during the analysis and construction stages of the design process with the goal of understanding the differences in structural behavior of these two building systems in response to the long term effects of creep and shrinkage. This paper will also discuss the design and construction techniques implemented in order to minimize the differential shortening between the interior and exterior over the lifespan of these towers.

Geometric Optimization of Kuwait University Stadium and Tennis Centre

Kuwait University is developing a brand new campus on a 5.2 square kilometer tract of land. The project calls for athletic facilities including a sports complex consisting of a 15,000 seat track-and-field and football Grand Stadium and a 2,000 seat indoor Tennis Centre. The Tennis Centre is covered by a thin shell concrete roof. The geometry in the form of a catenary dome was developed by the design team to optimize the use of material and span the entire arena. The dome is further reinforced with a series of reinforced concrete ribs that frame the openings and allow for higher point loads at desired locations. The structure for the Grand Stadium roof consists of a primary triangular steel arched truss spanning 200 meters and supporting the roofing system. Planar transverse steel trusses span between front and the back truss. The shape of this arched truss was optimized into a catenary with varying tributary load from the tapering fabric roof system.

King Abdullah Financial District Conference Center

King Abdullah Financial District Conference Center, with a total gross area of approximately 125,000m, consists of auditorium, conference and banquet facilities, a monorail station, and parking. These functions are housed within four substructure and three superstructure levels and enclosed in a multifaceted roof with a unique shape and geometry. The primary feature of the building is this multifaceted, monolithic, independent Mega-Roof structure that covers all the program spaces housed within the building. The architectural, structural and environmental engineering teams collaborated closely to devise a parametric design and analysis methodology to integrate the multiple parameters controlling the design of the roof. Further, the extremely aggressive design and construction schedule was achieved by assimilating the work of the design, fabrication and construction teams into a seamless process incorporating digital exchange of information.

LUNAR REGOLITH PARTICLES IN OUTPOSTS

The US, India, China, Japan, and Europe plan for future crewed lunar missions. While mission architecture may be superficially similar to the American Apollo program of the 1960s and 1970s, future missions will vary considerably from that precedent in duration and complexity. Long-duration lunar stays with tens of extravehicular activities per mission will expose crews and equipment to lunar regolith dust for increased periods. Lunar regolith soil (fragments under 1 cm in diameter) is primarily constituted of poorly sorted, highly irregular agglutinated silicates, the result of the fragmentation of the young lunar crust by meteoroid impacts, followed by the mixing of the lunar surface by meteoroid and micrometeoroid impacts and radiation for over 4.5 billion years. Regolith contains particulate matter (PM) recently conclusively shown to include the fine and ultrafine regimes (diameters <2.5 µm and <0.1 µm, respectively). The correlation between elevated cardiovascular risks to human health and ultrafine particles is well-established in the scientific literature. The success of future long-duration lunar missions will hinge on the development of effective lunar suits, vehicles, and habitats. Understanding the mechanisms of lunar regolith PM exposure, deposition, resuspension, and tracking will be key to developing such equipment. This paper reviews the literature of lunar PM petrography, lunar mission histories, aerosol science, and medicine, with the intent of aiding designers of lunar mission human factors equipment. A model is proposed for determining lunar regolith PM migration into a hypothetical crew compartment from a given airlock volume. The authors further propose a novel inflatable airlock configuration to mitigate such PM migration.

Optimized Architecture for Passenger Spacecraft

An iterative, integrated systems process for spacecraft architecture has been shown to reduce risk while improving efficiency and performance. Such a process is particularly important for the successful development of human-rated vehicles due to the lower margins and higher emphasis on mission safety and success. The Crew Return Vehicle (CRV) was one of several historically proposed lifeboats for the International Space Station (ISS). It was developed by NASA in the late 1990s until the program’s cancellation due to budgetary pressures in 2002. This paper summarizes the lessons learned from the development process of the CRV in cabin architecture and how they can be applied to the design process and implementation of future passenger spacecraft for Low Earth Orbit (LEO) access, lunar missions and beyond.