Ames has developed a set of engineering-based analysis and design tools for conceptual-level exploration vehicle definition studies and initial technology assessment and evaluation. These tools are integrated into an interactive and collaborative design environment for quick turn-around vehicle trade studies and technology impact assessment.

Benefit
NASA Ames has several technologies and techniques that provide space transportation system architecture design and technology assessment.

Research Overview
Ames expertise has produced several engineering analysis capabilities. These include discipline analysis tools, data visualization techniques and integration schemes.

Extensive Information Technology (IT) skills were utilized to develop these capabilities using modern programming and integration technologies.

Right: Vehicle trade studies designs.

The geometry tool ComGeom performs initial launch vehicle layout and automated Outer Mode Line (OML) surface grid definition. Major internal components such as propellant tanks are defined by the tool. The resulting surface grids are used in turn by CBAERO, CART3D and OVERFLOW as well as TPSSZR resulting in consistent analysis on a common geometry.

The CBAERO aerothermodynamics tool computes performance based on the specific configuration surface model. Pressure distributions are computed using linearized panel methods for subsonic flight, while independent panel methods are applied for super/hypersonic Mach numbers. Reference enthalpy methods are used to compute skin friction and heat transfer coefficients, coupled with newtonian velocity streamline distributions.

Mission is a 3 degree of freedom, XML-based trajectory tool. It is applicable for both powered and un-powered ascent and descent trajectories, as well as constrained trajectory optimization.

TPSZZR computes TPS material distribution and insulation thickness distributions using one-dimensional transient heat transfer analysis. TPSSZR operates on the same OML grid as the CBAERO tool using trajectory-specific environment data from Mission .

The XML Weights Analysis Tool ( XWAT) solves an arbitrary set of Mass Estimation Relationships (MERs) in an arbitrary hardware structure. This allows modification to both hardware elements and their associated MERs without any modifications to compiled code.

SAFE is a vehicle safety and reliability tool that utilizes a historical failure database to compute total vehicle and crew loss probabilities.

Together with tools from other NASA centers, these codes enable conceptual and preliminary level technology assessment and vehicle sizing capabilities. These discipline tools are integrated in an analysis framework that links their respective inputs and outputs in an automated fashion, greatly reducing multi-disciplinary analysis time.

Ames’ tools and capabilities are developed using the latest software technologies. Extensive in-house experience with web portal, object-oriented programming, database design and XML technologies ensure that products are stable, robust and scalable.

Background
A fundamental task of the Office of Exploration Systems Human and Robotic Technology (H&RT) project will be to identify and mature high pay-off technologies related to the Vision for Space Exploration. Ames has a long history of experience supporting industry and government technology identification and architecture assessment activities.

Right: Common Data Language system architecture.

Over the past several years, Ames has supported technology assessment for the National Aerospace Plane (NASP), X-33, Space Launch Initiative (SLI) and Next Generation Launch Technology (NGLT) programs. Candidate technologies and technology suites were evaluated and characterized by these programs using tools and processes partially developed by Ames research staff.

Ames also has extensive experience and involvement in industry led launch vehicle design studies, including NRA 8-27 and NRA 8-30. Ames was responsible for the preliminary thermal protection system design and analysis of the aerospace prime TSTO launch vehicle. This activity included the development of an aerothermal design environment that coupled engineering-based tools with high-fidelity computational fluid dynamics codes such as OVERFLOW.

As part of the NASA Advanced Engineering Environment (AEE), Ames was the lead for the development and integration of engineering tools. These included aerothermodynamic environments, Thermal Protection System (TPS) material selection and sizing, vehicle subsystem weights and sizing, geometry modeling and system risk assessment.