Analysis of the advanced Nimbus power systems
Solar-conversion power-supply subsystem for Nimbus B, using pulse width modulated voltage regulator
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Solar-conversion power-supply subsystem for Nimbus B, using pulse width modulated voltage regulator
The design of the X-ray Large Array (XLA) which is to be assembled and operated in space is discussed. The XLA is a 100 sq m array of 64 detector modules with a total of 512 detectors, each similar to the ones flown on the HEAO-1 spacecraft, packaged in groups of eight to form a module. The XLA will be able to deal with many extremely fast processes which occur in compact X-ray sources and will be used to study black hole candidates; its fine time resolution will make it possible to resolve the spatial structure of celestial X-ray sources using lunar occulatation, the angular structure of quasars, and active galactic nuclei. Details of the XLA configuration, and the assembly and packaging options are described together with systems requirements. Multiple configuration diagrams are included.
High capacity communications from Martian distances, required for the envisioned human exploration and desirable for data-intensive science missions, is challenging. NASA s Deep Space Network currently requires large antennas to close RF telemetry links operating at kilobit-per-second data rates. To accommodate higher rate communications, NASA is considering means to achieve greater effective aperture at its ground stations. This report, focusing on the return link from Mars to Earth, demonstrates that without excessive research and development expenditure, operational Mars-to-Earth RF communications systems can achieve data rates up to 1 Gbps by 2020 using technology that today is at technology readiness level (TRL) 4-5. Advanced technology to achieve the needed increase in spacecraft power and transmit aperture is feasible at an only moderate increase in spacecraft mass and technology risk. In addition, both power-efficient, near-capacity coding and modulation and greater aperture from the DSN array will be required. In accord with these results and conclusions, investment in the following technologies is recommended:(1) lightweight (1 kg/sq m density) spacecraft antenna systems; (2) a Ka-band receive ground array consisting of relatively small (10-15 m) antennas; (3) coding and modulation technology that reduces spacecraft power by at least 3 dB; and (4) efficient generation of kilowatt-level spacecraft RF power.
Cassini is an international cooperative effort between NASA, which is producing the orbiter spacecraft, the European Space Agency, which is providing the Huygens Probe, and the Italian Space Agency, which is responsible for the spacecraft radio antenna and portions of three scientific experiments. In the U.S., the mission is managed by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. Lockheed-Martin successfully bid on the contract to build the PMS (Propulsion Module Subsystem) for this project. The Cassini spacecraft will be launched on an expedition to Saturn in October, 1997. Its mission is to enter orbit around Saturn in July, 2004, and to explore its moons, rings, and magnetic environment for four years. Cassini will carry the Huygens probe, an instrument package equipped with a parachute, which is designed to study the atmosphere and surface of Saturn's largest moon, Titan.
The 1971 Apollo 14 Mission to Fra Mauro, a lunar highland area, is highlighted in this video. The mission's primary goal was the collection of lunar rocks and soil samples and lunar exploration. The soil and rock sampling was for the geochronological determination of the Moon's evolution and its comparison with that of Earth. A remote data collection station was assembled on the Moon and left for continuous data collection and surface monitoring experiments. The Apollo 14 astronauts were Alan B. Shepard, Edgar D. Mitchell, and Stuart A. Rossa. Astronauts Shepard and Mitchell landed on the Moon (February 5, 1971) and performed the sampling, the EVA, and deployment of the lunar experiments. There is film-footage of the lunar surface, of the command module's approach to both the Moon and the Earth, Moon and Earth spacecraft launching and landing, in-orbit command- and lunar-module docking, and of Mission Control.
Apollo/lem mission - requirements of orbital rendezvous, in-transit rendezvous, & planetary rendezvous
Conceptual design study of advanced Mariner space probe - development plan and cost estimate for flyby bus/lander on Mars mission
Lunar surface mobility systems comparison and evolution - resource planning for mobility systems derived from lunar module, command module, and multimission module
Orbital motion of lunar module/Apollo telescope mount tethered to S-IVB orbital workshop
LEM optical astronomy package /OAP/ containing astronomical telescope, spectrophotometer, data processing subsystem and other devices, for unmanned landing and life support
Wire-connected electronic packaging module system providing change capability, design flexibility, arrangement freedom and volumetric efficiency
All nuclear space acceleration system and basic spacecraft consisting of biconic earth entry module, mission module, vehicle control, experiment laboratories, and excursion module
The Infrared Scanning Radiometer (ISR) was designed to map the thermal emission of the lunar surface from the service module of the orbiting Apollo 17 spacecraft. Lunar surface nighttime temperatures, which are extremely difficult to map from earth based telescopes were measured. The ISR transmitted approximately 90 hours of lunar data spread over 5 days in lunar orbit. Approximately 10 to the 8th power independent lunar temperature measurements were made with an absolute accuracy of 2K. Spatial resolution at nadir was approximately 2.2 km (depending on orbital altitude), exceeding that of earth based measurements by at least an order of magnitude. Preliminary studies of the data reveal the highest population of thermal anomalies (or hot spots) in Oceanus Procellarum. Very few anomalies exist on the far side of the moon as was predicted from the association of anomalies with mare on the near side. A number of negative anomalies (or cold spots) have also been found.
Beginning with the challenges presented by Sputnik 1 in 1957, and the formation of NASA, the apollo lunar exploration program is reviewed through Apollo Flight 11. The focal points are the spacecraft including the command and service modules, and the lunar module.
Phytoplankton biomass and diversity among various algal species are important for marine productivity assessments. The spatial heterogeneity of phytoplankton in coastal and estuarine environments complicates estimates of total biomass using conventional surface sampling techniques. Since synoptic or near-synoptic data can be quite useful in these studies, this area is a natural focal point for development of remote sensors. However, it is very difficult to sense phytoplankton density and diversity with spacecraft-borne passive sensors primarily because modulation in the signal due to phytoplankton is of the same order as that of atmospheric effects. The same sensors mounted on aircraft may be able to detect and quantify high concentrations of phytoplankton (blooms), but the current lack of knowledge about the spectral reflectance signatures of the major phytoplankton color groups rules out any diversity measurements by this type of sensor. An active fluorosensor mounted on a low-flying aircraft or helicopter is not limited by any of these constraints. A brief survey of the four currently active systems is presented.
The Apollo II Second Generation Lunar Exploration System includes the direct landing spacecraft which consists of cargo command module, service module, and landing module. The landing module is also capable of being used as the Lunar Landing Vehicle (LLV) for landing unmanned cargos consisting of shelter modules such as the Lunar Occupancy Payload and other cargo in support of lunar surface operations. High energy cryogenic propellants are utilized to permit direct landing, manned, or logistic missions with use of a single Saturn V class booster. In last year's studies, the LLV was configured for maximum payload and with consideration for the direct three-man landing and return mission. Light weight and low vehicle height above the lunar surface at touchdown were major objectives. Logistic cargos of more than 27,000 pounds landed on the Moon were achieved within the single Saturn V boost capability. For the manned mission, the lunar take-off weight was determined to be 28,000 pounds ready for the return-to-Earth portion of the mission. The command module utilized was an advanced light-weight design weighing 10,000 pounds including supporting subsystems. Cryogenic oxygen/hydrogen propulsion was again used for maximum propulsion efficiency. Study of the Lunar Occupancy Payload was also accomplished last year. This module was configured to serve as an early lunar shelter or outpost station or as a basic module of an integrated base module complex. Single and dual compartment versions, as well as special mission versions, were studied.
The temporal changes in the differential intensity and energy spectra of anomalous oxygen, and in the O/C ratios of the anomalous cosmic ray component during the 1974-79 time period were examined using data from the IMP-8 and ISEE-3 spacecrafts. In addition to the solar modulation of the intensity of anomalous oxygen, the strength of the source of this component varies, and in 1978 the anomalous component disappeared almost completely. The results disagree with the existence of a purely galactic source but are consistent with expectations based on an heliospheric origin hypothesis as formulated by Fisk et al., (1974).