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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.
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Space objects are listed as well as those which decayed during this reporting period. Data provided include international designation and catalog number, nation of source, launch date, inclination, apogee, and perigee. Transmitting frequencies for satellites being monitored by NASA's space flight tracking and data network are given.
This paper describes the process of integrating available environment models into a single package that calculates the radiation environment for any earth orbit quickly and accurately with the only input being initial orbit parameters, launch date and length of mission, and units of output. The radiation dose is calculated for particles penetrating varying aluminum shielding thicknesses and incident upon several materials inside. Included also are modifications that have been made to the codes that account for the decrease of the magnetic field with time, which allows the use of data taken in the past to accurately predict a future environment. The complete package has relatively short run times, 20 minutes per mission on a Micro VAX II, allowing multiple iterations for application to mission design and planning.
Many current manned Mars mission studies are using low lift-to-drag ratio (L/D) vehicles to aerobrake at both Mars and earth. The use of these low L/D vehicles imposes constraints on the allowable velocity at the atmospheric interface. This paper will demonstrate that if these entry velocity constraints are incorporated into the interplanetary analysis, more opportunities can be achieved for a small increase in initial LEO mass. These additional opportunities result from varying the initial launch date, the encounter dates, and possibly using a powered Venus swingby on either the inbound or outbound transfer. This paper presents results for three atmospheric entry velocity ranges at Mars arrival and one velocity limitation upon Earth return. The results indicate that by carefully selecting the interplanetary trajectory, an optimum initial LEO mass mission can be found for even highly restrictive entry velocity missions in practically all of the 15 years studied.
Information on the Space Station Freedom Evolution Symposium is given in viewgraph form. Topics covered include industry development needs and the Office of Commercial Programs strategy, the three-phase program to develop commercial space, Centers for the Commercial Development of Space (CCDS), key provisions of the Joint Endeavor agreement, current commercial flight experiment requirements, the CCDS expendable launch vehicle program, the Commercial Experiment Transporter (COMET) program, commercial launch dates, payload sponsors, the commercial roles of the Space Station Freedom, and a listing of the Office of Commercial Programs Space Station Freedom payloads.
This paper summarizes the findings of a Tri-Agency panel consisting of members from the National Aeronautics and Space Administration (NASA), U.S. Department of Energy (DOE), and U.S. Department of Defense (DOD) that were charged with reviewing the status and availability of facilities to test components and subsystems for megawatt-class nuclear electric propulsion (NEP) systems. The facilities required to support development of NEP are available in NASA centers, DOE laboratories, and industry. However, several key facilities require significant and near-term modification in order to perform the testing required to meet a 2014 launch date. For the higher powered Mars cargo and piloted missions, the priority established for facility preparation is: (1) a thruster developmental testing facility, (2) a thruster lifetime testing facility, (3) a dynamic energy conversion development and demonstration facility, and (4) an advanced reactor testing facility (if required to demonstrate an advanced multiwatt power system). Facilities to support development of the power conditioning and heat rejection subsystems are available in industry, federal laboratories, and universities. In addition to the development facilities, a new preflight qualifications and acceptance testing facility will be required to support the deployment of NEP systems for precursor, cargo, or piloted Mars missions. Because the deployment strategy for NEP involves early demonstration missions, the demonstration of the SP-100 power system is needed by the early 2000's.
An assessment is made of the applicability, benefits, and requirements of nuclear-electric propulsion (NEP) for solar system-exploration missions, within the framework of SP-100 reactor-based power technologies and 30-cm ring-cusp thruster technology. An initial launch date of 2005 is projected from a program-inception date of 2000. The missions in question encompass orbitings and flybys of Pluto, accomplishing in 10-13 years which would ballistically require a transfer time of 40 years; a Neptune orbiting; a Jupiter grand tour which will orbit each of the moons in turn; a Uranus orbiting; and a multiple mainbelt asteroid rendezvous orbiting six selected asteroids.
The Solar Array Module Plasma Interactions Experiment (SAMPIE), an approved Shuttle space flight experiment with a tentative launch date in July 1993, is intended to investigate plasma interactions of high-voltage space power systems. Solar cell modules, representing several technologies, will be biased to high voltages to characterize both arcing (negative potential) and current collection (positive potential). Other solar modules, specially modified in accordance with current theories of arcing and breakdown, will demonstrate the possibility of arc suppression. Finally, several additional test specimens will be included to study the basic nature of these interactions. The authors describe the rationale for the space flight experiment, the measurements to be made, the significance of the expected results, and the current design status of the flight hardware.
This report consists of data computed at the U.S. Space Command, GSFC, or provided by satellite owners. A space objects box score table is presented with data under the following headings: source/organization, objects in orbit, and decayed objects. The objects in orbit and decayed objects headings have payload, debris, and total as subheadings. The bulk of the document is objects-in-orbit tables with data under the following headings: international designation, name, catalog number, source, launch date, period minutes, inclination, apogee (km), perigee (km), and notes.
Space Station Freedom will provide the United States' first permanently manned laboratory in space. It will allow, for the first time, long term systematic life sciences investigations in microgravity. This presentation provides a top-level overview of the planned utilization of Space Station Freedom by NASA's Life Sciences Division. The historical drivers for conducting life sciences research on a permanently manned laboratory in space as well as the advantages that a space station platform provides for life sciences research are discussed. This background information leads into a description of NASA's strategy for having a fully operational International Life Sciences Research Facility by the year 2000. Achieving this capability requires the development of the five discipline focused 'common core' facilities. Once developed, these facilities will be brought to the space station during the Man-Tended Capability phase, checked out and brought into operation. Their delivery must be integrated with the Space Station Freedom manifest. At the beginning of Permanent Manned Capability, the infrastructure is expected to be completed and the Life Sciences Division's SSF Program will become fully operational. A brief facility description, anticipated launch date and a focused objective is provided for each of the life sciences facilities, including the Biomedical Monitoring and Countermeasures (BMAC) Facility, Gravitational Biology Facility (GBF), Gas Grain Simulation Facility (GGSF), Centrifuge Facility (CF), and Controlled Ecological Life Support System (CELSS) Test Facility. In addition, hardware developed by other NASA organizations and the SSF International Partners for an International Life Sciences Research Facility is also discussed.
As a continued element in the Telescience Testbed Program (TTP), the University of Arizona Steward Observatory and the Electrical and Computer Engineering Department (ECE) jointly developed a testbed to evaluate the Operations and Science Instrument System (OASIS) software package for remote control of an instrument for the Space Infrared Telescope Facility (SIRTF). SIRTF is a cryogenically-cooled telescope with three focal plane instruments that will be the infrared element of NASA's Great Observatory series. The anticipated launch date for SIRTF is currently 2001. Because of the complexity of the SIRTF mission, it was not expected that the OASIS package would be suitable for instrument control in the flight situation, however, its possible use as a common interface during the early development and ground test phases of the project was considered. The OASIS package, developed at the University of Colorado for control of the Solar Mesosphere Explorer (SME) satellite, serves as an interface between the operator and the remote instrument which is connected via a network. OASIS provides a rudimentary windowing system as well as support for standard spacecraft communications protocols. The experiment performed all of the functions required of the MIPS simulation program. Remote control of the instrument was demonstrated but found to be inappropriate for SIRTF at this time for the following reasons: (1) programming interface is too difficult; (2) significant computer resources were required to run OASIS; (3) the communications interface is too complicated; (4) response time was slow; and (5) quicklook of image data was not possible.
An approach to multiple asteroid rendezvous missions to the main belt region is proposed. In this approach key information which consists of a launch date and delta V can be generated for all possible pairs of asteroids satisfying specific constraints. This information is made available on a computer file for 1000 numbered asteroids with reasonable assumptions, limitations, and approximations to limit the computer requirements and the size of the data file.
Many current manned Mars mission studies are using low lift-to-drag ratio vehicles to aerobrake at both Mars and Earth. This paper will demonstrate that if entry velocity constraints are incorporated into the interplanetary analysis of aerobraking Mars missions, more opportunities can be achieved for only a small increase in initial mass in low-Earth orbit (IMLEO). These additional opportunities result from varying the initial launch date and the encounter dates and possibly using a powered Venus swingby on either the inbound or outbound transfer. This paper not only presents unconstrained entry velocity missions but also includes results for entry velocities below 12.5 and 14 km/s on Earth return and between 6.0-8.5 km/s at Mars arrival. The results indicate that, regardless of the Mars entry velocity range selected, an Earth entry velocity below 14 km/s is easily attainable for a minimal IMLEO increase. Although there are fewer 12.5 km/s Earth entry velocity missions possible, both Mars entry velocity constraint cases have over 50 percent of their missions requiring a negligible IMLEO increase.
Many current manned Mars mission studies are using low lift-to-drag ratio (L/D) vehicles to aerobrake at both Mars and Earth. The use of these low L/D vehicles could limit the allowable velocity at the atmospheric interface. This paper will demonstrate that if entry velocity constraints are incorporated into the interplanetary analysis of aerobraking Mars missions, many opportunities can be achieved for a small increase in initial mass in low-Earth orbit (IMLEO). These opportunities result from varying the initial launch date and the encounter dates and possibly using a powered Venus swingby on either the inbound or outbound transfer. This paper demonstrates this technique by using three atmospheric entry velocity ranges at Mars arrival (6.0-8.5, 6.4-8.1, and 7.2-7.3 km/s), unconstrained Mars entry velocities, and an Earth return entry velocity below 14 km/s. The results indicate that, by carefully selecting the interplanetary trajectory, an optimum IMLEO mission can be found for even highly restrictive entry velocity missions in practically all of the 15 yr studied.
This report consists of data computed at the U.S. Space Command, GSFC, or provided by satellite owners. A space objects box score table is presented with data under the following headings: source/organization, objects in orbit, and decayed objects. The objects in orbit and decayed objects headings have payload, debris, and total as subheadings. The bulk of the document is objects-in-orbit tables with data under the following headings: international designation, name, catalog number, source, launch date, period minutes, inclination, apogee (km), perigee (km), and notes.
This report consists of data computed at the U.S. Space Command, GSFC, or provided by satellite owners. A space objects box score table is presented with data under the following headings: source/organization, objects in orbit, and decayed objects. The objects in orbit and decayed objects headings have payload, debris, and total as subheadings. The bulk of the document is objects-in-orbit tables with data under the following headings: international designation, name, catalog number, source, launch date, period minutes, inclination, apogee (km), perigee (km), and notes.
This report consists of data computed at the U.S. Space Command, GSFC, or provided by satellite owners. A space objects box score table is presented with data under the following headings: source/organization, objects in orbit, and decayed objects. The objects in orbit and decayed objects headings have payload, debris, and total as subheadings. The bulk of the document is objects-in-orbit tables with data under the following headings: international designation, name, catalog number, source, launch date, period minutes, inclination, apogee (km), perigee (km), and notes.
This report consists of data computed at the U.S. Space Command, GSFC, or provided by satellite owners. A space objects box score table is presented with data under the following headings: source/organization, objects in orbit, and decayed objects. The objects in orbit and decayed objects headings have payload, debris, and total as subheadings. The bulk of the document is objects-in-orbit tables with data under the following headings: international designation, name, catalog number, source, launch date, period minutes, inclination, apogee (km), perigee (km), and notes.
Work on the RADARSAT system is progressing towards the currently scheduled launch date of early 1995. The spacecraft bus and the Synthetic Aperture Radar (SAR) payload are at various stages of development. Requirements for the ground segment have been mostly established. The design of the ground elements such as the mission control facility and the SAR data processor is underway. The SAR applications development work is continuing and the chosen distributor, RADARSAT International Inc. (RSI) is making preparations to market RADARSAT data internationally. A plan for the follow-on to RADARSAT 1 is being finalized to ensure continuity of SAR data under the Radarsat program.