Lyles, G. M. | Engineering Papers

NASA NTRS2000

We Must Take the Next Steps Towards Safe, Routine Space Travel

This paper presents, in viewgraph form, six in a half generations of airplanes in a century. Some of the topics include: 1) Enterprise goals; 2) Generations of Reusable Launch Vehicles; 3) Space Transportation Across NASA; 4) Three Tiered Implementation Approach for Future Space Transportation Technology; 5) Develop a Comprehensive, Agency Level Space Transportation Plan That Will Enable NASA's Strategic Plan; 6) Timeline for Addressing NASA's Needs; 7) Significant 2nd Generation Technology Drivers; 8) Example Large Scale Ground Demonstrations; and 9) Example Pathfinder Demonstrations. The paper also includes various aircraft designs and propulsion system technology.

Lyles, G. M.↗

NASA NTRS1991

Space transportation main engine cycle assessment process

The Advanced Launch System (ALS) program selection process for a space transportation main engine (STME) power cycle is described in terms of the methodology employed. Low cost, robustness, and high reliability are the primary parameters for engine choice, suggesting simplicity of design and efficient fabrication methods as the crucial characteristics. An evaluation methodology is developed based on the Pugh (1981) process and the King (1989) matrices. The cycle configurations considered are the gas generator (GG), the closed expander, and the open expander. The cycle assessment team determined that the GG cycle is favored by most cycle discriminators, based on an assessment of the characteristics in terms of ALS goals. The lower development risk of the GG-cycle STME is consistent with the goals of the ALS program in terms of reliability and cost efficiency.

Mcconnaughey, H. V.↗