Engineering topics

Harris, Ronald J.

Publications and source records attributed to Harris, Ronald J..

5 records

NASA NTRS1992

Progress on the National Launch System demonstrates national commitment

The paper discusses the process and measures involved in the design and development efforts now underway to achieve the construction of a new NASA/DOD heavy-lift launch system, the National Launch System. Special attention is given to the extensive technology development program initiated with the purpose of achieving robustness, operability, and low cost per flight for the NLS. The design features of the NLS and the constraints utilized are discussed.

Gabris, Edward A.↗

NASA NTRS1990

Heavy-lift launch vehicle options for future space exploration initiatives

A review of present heavy-lift launch vehicles (HLLV) capable of placing heavy payloads in earth orbit is presented and the basis for an emerging consensus that an HLLV will be required in the near future is discussed. Some of the factors for the policies governing the roles and requirements for these vehicles in the future, such as cost, technology development, and lead time to first use are addressed. Potential Space Station Freedom application is discussed as well as application to the proposed initiatives for human exploration of Mars and the moon.

Branscome, Darrell R.↗

NASA NTRS1970

Status Report on Nuclear Stage Definition

This status report on nuclear stage definition should convey the message that a comprehensive analysis is underway, embracing many vehicle concepts and the full range of expected RNS operations. Flexible use in the future space program is one objective; economy and ease of operations are also major goals. Not until details unfold in the several mission areas and in definitions of interrelated systems can the RNS studies be narrowed down to fewer alternatives. Consequently, the current phase of the NSSD study is emphasizing (1) in-space operations, especially as they are affected by aftercooling and the radiation environment of the stage, and (2) RNS concepts in which the unique features of nuclear propulsion are utilized or designed around. Studies to date indicate that significant benefits can be realized through use of an RNS in the missions of the 1980's. Tn the broader context of technology advancement and foundation-building for later decades, the development of a reusable nuclear stage is highly desirable. The next year's efforts will, we trust, bring us much nearer to a full understanding of the RNS and its role in the future space program.

Johnson, Paul G.↗

NASA NTRS1966

A Modular Nuclear Vehicle System with Multi-Mission Capability for Mars Stopover Missions

In depth studies conducted over the past two years have established a modular nuclear stage concept which offers multi-mission capability with a maximum of hardware commonality, i.e., a concept which minimizes total hardware development effort and investment in facilities while providing a logical development evolution from ground test systems to flight test and from initial to more ambitious space applications. Recent results oriented toward the definition and application of such a vehicle concept for the manned Mars landing mission are presented. The basic modular concept employing NERVA nuclear rocket engines is reviewed and the mission peculiar factors affecting the module sizes and number of modules required are discussed. Specific results presented are restricted primarily to the 1982 Mars landing mission via the opposition class mission mode since this is the earliest anticipated date for such a mission. The realistic effects of orbital launch windows are considered and brief discussions of orbital assembly and packaging options with a modular approach are given. Typical ground launch and orbital assembly operations are defined assuming an uprated Saturn V class launch vehicle and the connecting mode of orbital assembly, in which all modules are orbited fully loaded with propellant. The effect of a significant increase in nuclear engine specific impulse is discussed.

Harris, Ronald J.↗

NASA NTRS1961

Calculation of Wind Compensation for Launching of Unguided Rockets

A method for calculating wind compensation for unguided missiles s derived which has a greater degree of flexibility than the previously proposed methods. Utilization of the wind-compensation technique is demonstrated by using the Shotput vehicle as a model. Postflight simulations of four of these missiles with the use of measured winds show that if the winds are known, very good accuracy can be obtained by using the proposed method.

James, Robert L., Jr.↗