SEARCH · Engineering Papers

Results for “TRANSFER VEHICLE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17

All sources NASA NTRS DOE OSTI

NASA NTRS1983

Space station needs, attributes and architectural options: Architectural options and selection

The approach, study results, and recommendations for defining and selecting space station architectural options are described. Space station system architecture is defined as the arrangement of elements (manned and unmanned on-orbit facilities, shuttle vehicles, orbital transfer vehicles, etc.), the number of these elements, their location (orbital inclination and altitude, and their functional performance capability, power, volume, crew, etc.). Architectural options are evaluated based on the degree of mission capture versus cost and required funding rate. Mission capture refers to the number of missions accommodated by the particular architecture.

Nelson, W. G.↗

NASA NTRS1986

Space Station communications system design and analysis

Attention is given to the methodologies currently being used as the framework within which the NASA Space Station's communications system is to be designed and analyzed. A key aspect of the CAD/analysis system being employed is its potential growth in size and capabilities, since Space Station design requirements will continue to be defined and modified. The Space Station is expected to furnish communications between itself and astronauts on EVA, Orbital Maneuvering Vehicles, Orbital Transfer Vehicles, Space Shuttle orbiters, free-flying spacecraft, coorbiting platforms, and the Space Shuttle's own Mobile Service Center.

Ratliff, J. E.↗

NASA NTRS1987

Advanced propulsion activities in the USA

An evaluation is made of technology development prospects for launch vehicle, orbit transfer vehicle, satellite, and planetary exploration spacecraft propulsion systems being contemplated by NASA and its research contractors. Attention is given to such electric propulsion systems as arcjet, pulsed plasma, ion, and resistojet thrusters, as well as to solar thermal heat exchanger powerplants, beamed energy propulsion systems, and ultra-advanced nuclear fission and fusion propulsion concepts.

Garrison, P. W.↗

NASA NTRS1988

Real-time space system control with expert systems

Many aspects of space system operations involve continuous control of real time processes. These processes include electrical power system monitoring, prelaunch and ongoing propulsion system health and maintenance, environmental and life support systems, space suit checkout, onboard manufacturing, and vehicle servicing including satellites, shuttles, orbital maneuvering vehicles, orbital transfer vehicles and remote teleoperators. Traditionally, monitoring of these critical real time processes has been done by trained human experts monitoring telemetry data. However, the long duration of future space missions and the high cost of crew time in space creates a powerful economic incentive for the development of highly autonomous knowledge based expert control procedures for these space systems.

Leinweber, David↗

NASA NTRS1990

Technologies for aerobraking

Aerobraking is one of the largest contributors to making both lunar and Mars missions affordable. The use of aerobraking/aeroassist over all-propulsive approaches saves as much as 60 percent of the initial mass required in LEO, thus reducing the number and size of earth-to-orbit launch vehicles. Lunar transfer vehicles, which will be used to transport personnel and materials from LEO to lunar outposts, will aerobrake into earth's atmosphere at aproximately 11 km/sec on return from the lunar surface. Current plans for both manned and robotic missions to Mars use aerocapture during arrival at Mars and at earth return. At Mars, the entry velocities will range from about 6 to 9.5 km/sec, and at earth the return velocity will be about 12.5 to 14 km/sec. In order to successfully design aerobrakes to withstand the aerodynamic forces and heating associated with these entry velocities, as well as to make them efficient, several critical technologies must be developed. These are vehicle concepts and configurations, aerothermodynamics, thermal protection system materials, and guidance, navigation, and control systems. This paper describes the status of each of these technologies and outlines what must be accomplished in each area to meet the requirements of the Space Exploration Initiative.

Cooper, David M.↗

NASA NTRS1990

A Personnel Launch System for safe and efficient manned operations

Several Conceptual designs for a simple, rugged Personnel Launch System (PLS) are presented. This system could transport people to and from Low Earth Orbit (LEO) starting in the late 1990's using a new modular Advanced Launch System (ALS) developed for the Space Exploration Initiative (SEI). The PLS is designed to be one element of a new space transportation architecture including heavy-lift cargo vehicles, lunar transfer vehicles, and multiple-role spcecraft such as the current Space Shuttle. The primary role of the PLS would be to deliver crews embarking on lunar or planetary missions to the Space Station, but it would also be used for earth-orbit sortie missions, space rescue missions, and some satellite servicing missions. The PLS design takes advantage of emerging electronic and structures technologies to offer a robust vehicle with autonomous operating and quick turnaround capabilities. Key features include an intact abort capability anywhere in the operating envelope, and elimination of all toxic propellants to streamline ground operations.

Petro, Andrew J.↗

NASA NTRS1991

Human exploration of space and power development

Reasons for mounting the Space Exploration Initiative, the variables facing U.S. planners, and the developmental technologies that will be needed to support this initiative are discussed. The three more advanced technological approaches in the field of power generation described include a lunar-based solar power system, a geosynchronous-based earth orbit solar power satellite system, and the utilization of helium-3/deuterium fusion reaction to create a nuclear fuel cycle. It is noted that the major elements of the SEI will include a heavy-lift launch vehicle, a transfer vehicle and a descent/ascent vehicle for use on lunar missions and adaptable to Mars exploration.

Cohen, Aaron↗

NASA NTRS1992

A cislunar guidance methodology and model for low thrust trajectory generation

A guidance methodology for generating low-thrust cislunar trajectories was developed and incorporated in a computer model. The guidance methodology divides the cislunar transfer into three phases. Each phase is discussed in turn. To establish the effectiveness of the methodology and algorithms the computer model generated three example cases for the cislunar transfer of a low-thrust electric orbital transfer vehicle (EOTV). Transfers from both earth orbit to lunar orbit and from lunar orbit back to earth orbit are considered. The model allows the determination of the low-thrust EOTV's time-of-flight, propellant mass, payload mass, and thrusting history.

Korsmeyer, David J.↗

NASA NTRS1984

The next generation of reentry vehicles: NASA's view

The term reentry vehicle is used in the broad sense. The vehicles addressed include not only those that return from orbit to the Earth's surface, but also aeroassisted orbit transfer vehicles that use aerodynamic forces generated during atmospheric passes to achieve orbital changes with a smaller expenditure of energy than is required for an all-propulsion vehicle. Advanced reusable launch vehicles with special emphasis on system concepts and the influence of advanced technology on entry vehicle configuration are considered. Three categories of orbital transfer vehicles discussed: synergetic plane-change vehicles, planetary aerocapture vehicles, and LEO to GEO orbital transfer vehicles. While the orbital transfer and planetary vehicles are quite different from conventional winged Earth entry vehicles, synergetic plane change and high cross-range Earth entry vehicles have many similarities. Finally, a possible scenario for the development of the next generation of reentry vehicles is presented.

Walberg, G. D.↗

NASA NTRS1980

Technology requirements for future Earth-to-geosynchronous orbit transportation systems. Volume 2: Technical results

Technologies either critical to performance of offering cost advantages compared to the investment required to bring them to usable confidence levels are identified. A total transportation system is used as an evaluation yardstick. Vehicles included in the system are a single stage to orbit launch vehicle used in a priority cargo role, a matching orbit transfer vehicle, a heavy lift launch vehicle with a low Earth orbit delivery capability of 226, 575 kg, and a matching solar electric cargo orbit transfer vehicle. The system and its reference technology level are consistent with an initial operational capability in 1990. The 15 year mission scenario is based on early space industrialization leading to the deployment of large systems such as power satellites. Life cycle cost benefits in discounted and undiscounted dollars for each vehicle, technology advancement, and the integrated transportation system are calculated. A preliminary functional analysis was made of the operational support requirements for ground based and space based chemical propulsion orbit transfer vehicles.

Caluori, V. A.↗

NASA NTRS1991

Lunar mission aerobrake performance study

Nine lunar mission scenarios were developed to show the transfer vehicle performance benefits of aerobraking into low Earth orbit (LEO) upon Earth return as opposed to an all-propulsive maneuver. The initial mass in LEO (IMLEO) of the lunar transfer vehicle is considered the measure of vehicle performance. Four types of mission profiles in conjunction with two vehicle concepts were used to construct the scenarios. These nine scenarios were designed to represent a broad range of possible lunar missions so that a general knowledge base of aerobraking and lunar transfer vehicle performance levels could be obtained. Also discussed are the mass sensitivities of each transfer vehicle to changes in the selected design parameters: Isp, crew module mass, payload to surface, and aerobrake mass fraction. A parametric study was performed on two of the mission scenarios to help quantify the performance benefits by adding a set of drop tanks to the vehicle. The parametric study also provides partial derivatives which show the sensitivities of IMLEO to the four design parameters listed. A ranking is given based on vehicle performance.

Mulqueen, J.↗

NASA NTRS1980

Satellite Power Systems (SPS) concept definition study. Volume 4: Transportation analysis

Transportation system elements were synthesized and evaluated on the basis of their potential to satisfy overall satellite (SPS) transportation requirements and of their sensitivities, interfaces, and impact on the SPS. Additional analyses and investigations were conducted to further define transportation system concepts that will be needed for the developmental and operational phases of an SPS program. To accomplish these objectives, transportation systems such as shuttle and its derivatives have been identified; new heavy lift launch vehicle concepts, cargo and personnel orbital transfer vehicles and intra-orbit transfer vehicle concepts have been evaluated. To a limited degree, the program implications of their operations and costs were assessed. The results of these analyses have been integrated into other elements of the overall SPS concept definition studies.

Hanley, G. M.↗

NASA NTRS1999

Communications and Tracking of Visiting Vehicles near ISS: The Design of the Reusable Launch Vehicle Communications

The International Space Station (ISS) will provide for the visitation of various vehicles such as the Shuttle, Automated Transfer Vehicle (ATV), H-II Transfer Vehicle (HTV), Crew Return Vehicle (CRV), Reusable Launch Vehicle (RLV) and Soyuz. These vehicles will provide for crew replacement, consumables resupply, and equipment delivery. In order for these vehicles to approach and eventually dock with the ISS, there must be near continuous communications coverage between the visiting vehicle and the ISS, as well as communications between the vehicle and a Mission Control Center (MCC). Since the ISS communications systems are already designed and scheduled for ISS activation, the vehicles must either utilize these communications systems or provide their own. There are two means of two-way communications with the ISS. These are (1) S-Band communications using TDRSS, and (2) UHF communications using some form of the Space to Space Station Radio (SSSR) link. The RLV utilizes ISS compatible communications systems to communicate with both the ISS and a Mission Control Center. Since all vehicles must adhere to the Visiting Vehicle Interface requirements given in reference 1, the RLV communications system design must meet these requirements during entry into the ISS Approach Ellipsoid (AE) and during Proximity Operations. Included in this paper are descriptions of these communications approaches as well as their potential utilization in the ISS communications system.

Stillwagen, Frederic H.↗

NASA NTRS2003

An Updated Zero Boil-Off Cryogenic Propellant Storage Analysis Applied to Upper Stages or Depots in a LEO Environment

Previous efforts have shown the analytical benefits of zero boil-off (ZBO) cryogenic propellant storage in launch vehicle upper stages of Mars transfer vehicles for conceptual Mars Missions. However, recent NASA mission investigations have looked at a different and broad array of missions, including a variety of orbit transfer vehicle (OTV) propulsion concepts, some requiring cryogenic storage. For many of the missions, this vehicle will remain for long periods (greater than one week) in low earth orbit (LEO), a relatively warm thermal environment. Under this environment, and with an array of tank sizes and propellants, the performance of a ZBO cryogenic storage system is predicted and compared with a traditional, passive-only storage concept. The results show mass savings over traditional, passive-only cryogenic storage when mission durations are less than one week in LEO for oxygen, two weeks for methane, and roughly 2 months for LH2. Cryogenic xenon saves mass over passive storage almost immediately.

Plachta, David↗

NASA NTRS1987

The Space Station and recommendations of the National Commission on Space

The planned NASA Space Station, and its associated orbit transfer vehicle, are only the first of a series of Space Stations and transfer vehicles that the United States will need to pioneer the space frontier in the 21st century. The initial station and transfer vehicle will develop some of the technology and systems needed for follow-on stations, vehicles, and bases on the moon and Mars.

Tilton, E. Lee↗

NASA NTRS1993

Nonequilibrium effects on the aerothermodynamics of transatmospheric and aerobraking vehicles

A 3D CFD algorithm is used to study the effect of thermal and chemical nonequilibrium on slender and blunt body aerothermodynamics. Both perfect gas and reacting gas air models are used to compute the flow over a generic transatmospheric vehicle and a proposed lunar transfer vehicle. The reacting air is characterized by a translational-rotational temperature and a vibrational-electron-electronic temperature and includes eight chemical species. The effects of chemical reaction, vibrational excitation, and ionization on lift-to-drag ratio and trim angle are investigated. Results for the NASA Ames All-body Configuration show a significant difference in center of gravity location for a reacting gas flight case when compared to a perfect gas wind tunnel case at the same Mach number, Reynolds number, and angle of attack. For the same center of gravity location, the wind tunnel model trims at lower angle of attack than the full-scale flight case. Nonionized and ionized results for a proposed lunar transfer vehicle compare well to computational results obtained from a previously validated reacting gas algorithm. Under the conditions investigated, effects of weak ionization on the heat transfer and aerodynamic coefficients were minimal.

Hassan, Basil↗

NASA NTRS1980

Electric propulsion for SPS

The design and characteristics of the solar power satellite electric propulsion system are described. Both the payload powered orbital transfer vehicle and the independent powered transfer vehicle configuations are discussed. Mass estimates for the system, the average cost per system unit, and the cost per flight estimates are also given.

Crum, E. M.↗

NASA NTRS1980

Geostationary platform systems concepts definition study. Volume 2: Technical, book 2

A selected concept for a geostationary platform is defined in sufficient detail to identify requirements for supporting research and technology, space demonstrations, GFE interfaces, costs, and schedules. This system consists of six platforms in geostationary orbit (GEO) over the Western Hemisphere and six over the Atlantic, to satisfy the total payload set associated with the nominal traffic model. Each platform is delivered to low Earth orbit (LEO) in a single shuttle flight, already mated to its LEO to GEO transfer vehicle and ready for deployment and transfer to GEO. An alternative concept is looked at briefly for comparison of configuration and technology requirements. This alternative consists of two large platforms, one over the Western Hemisphere consisting of three docked modules, and one over the Atlantic (two docked modules), to satisfy a high traffic model. The modules are full length orbiter cargo bay payloads, mated at LEO to orbital transfer vehicles (OTVs) delivered in other shuttle flights, for transfer to GEO, rendezvous, and docking. A preliminary feasibility study of an experimental platform is also performed to demonstrate communications and platform technologies required for the operational platforms of the 1990s.

Source record↗