Scientific Uses of the Space Shuttle (1974) / Chapter Skim
Currently Skimming:
ATMOSPHERIC AND SPACE PHYSICS
ATMOSPHERIC AND SPACE PHYSICS
Pages 14-39
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 14... ...
These fields will be able to make effective use of the Shuttle and Spacelab when they become available. Optical remote sensing of the mesosphere and stratosphere to study chemical composition, structure and dynamics, active plasma experiments, and controlled study of magnetospheric phenomena requires the payload capacity and flexibility offered by the Shuttle system.
|
From page 15... ...
On the other hand, the relationship among the circulation of the thermosphere, the dynamo current system, and the magnetospheric electric field will not have been adequately studied. A follow-on Electrodynamics Explorer mission to investigate the magnetospheric electric field and its relationship to the largescale dynamics of the thermosphere has been suggested but not yet approved; such a mission would contribute substantially to this study.
|
From page 16... ...
OPTICAL RADIATIONS CHEMICAL EFFECTS STRUCTURAL PROPERTIES DYNAMICAL PROPERTIES FIGURE 2 Interactive scheme of the atmosphere below 120 km (excludes particle precipitation, cosmic radiation, and meteor influx)
|
From page 17... ...
For example, many of the reaction rates involved in the ozone chemistry are strongly temperature-dependent, and the pressure systems arising from heating form the driving force for horizontal motions in the atmosphere. There are several energy inputs into the atmospheric region, 30-120 km, that are significant from the thermal viewpoint, including solar ultraviolet and x rays, auroral particles, Joule heating from electric currents, and the breaking of internal gravity waves.
|
From page 18... ...
6. How important is the transport of chemical energy associated with the global wind circulation to the energy budget of the mesosphere?
|
From page 19... ...
For example, the isotopic abundances of nitrogen in nitrous oxide and other nitrogen oxides are different depending on whether the source is the upper atmosphere or the earth's surface, because of isotopic separation by biological processes in the surface source. The possibility of remote sensing of the abundances and isotopic ratios (14N/1SN)
|
From page 20... ...
3. What are the vertical distributions of the minor atmospheric species, what processes control these distributions, and what role do these species play?
|
From page 21... ...
Are long-lived mesospheric constituents observed to move equatorward from the polar regions at this time?
|
From page 22... ...
Within the closely coupled solar wind-magnetosphere system a number of well-defined boundaries exist between different plasma regimes. Two additional key elements are motion of the medium and associated electric fields and the wide variety of plasma instabilities that are involved in major magnetospheric processes.
|
From page 23... ...
Progress should also be made on many other questions concerning the solar-wind input to the magnetosphere, the nature of magnetospheric boundaries, and the location of particle acceleration regions. The energy budget in the magnetosphere and ionosphere and the phenomena that control magnetosphere-ionosphere coupling would be the main target of research with the proposed, but not yet approved, Electrodynamic Explorer missions, to be carried out during the period between the IMS and the time at which high-inclination Shuttle orbits become available.
|
From page 24... ...
Injecting an intense beam of plasma up a field line or releasing, at large distances, ionized gas from a rocket-launched canister to modify the magnetospheric plasma population under controlled conditions; 3. Modifying the ionospheric conductivity by release of chemicals; 4.
|
From page 25... ...
Injection of intense particle beams along magnetic-field lines can provide an answer to this question.
|
From page 26... ...
2. WAVE-PARTICLE INTERACTIONS, PARTICLE ACCELERATION, AND SCATTERING Although resonant interactions between energetic trapped particles and various wave modes are thought to determine the structure and stability of the radiation belts, few of the important proposed wave-particle interactive processes will have been experimentally confirmed and studied in detail when the Shuttle becomes available.
|
From page 27... ...
Electron and ion accelerators can be used to study the reflection of charged particles injected along magnetic field lines, thereby providing nonlocal information on parallel electric fields.
|
From page 28... ...
The sortie laboratory missions can also provide the scientific community with opportunities to carry out short-term experiments involving development and testing of new diagnostic devices and investigations of new techniques for plasma propulsion.
|
From page 29... ...
3. DIAGNOSTIC AND PROPULSION DEVICES STUDIES Long-standing questions involving the operation of various conventional probes can be attacked with the Shuttle sortie laboratory, making use of precisely known plasma conditions.
|
From page 30... ...
CORE INSTRUMENTS Most experiments envisaged would involve remote sensing of the atmosphere below either the Spacelab or a free-flyer to determine the spatial distribution -- vertical and horizontal -- of the constituents of the stratosphere and mesosphere, with sufficient global coverage to enable us to understand the dynamics and chemistry of these regions. The following modes of study are envisaged: (a)
|
From page 31... ...
The subsatellite might be a corner reflector located from 1 to 2 x 103 km away from the Spacelab in order to return light originating from a laser-telescope system on the Spacelab. Absorption in the ultraviolet would yield the concentration of such species as O, H2, and N in the upper atmosphere, while in the infrared the concentration of such species as O3, H2 O, NO, and O2 in the lower atmosphere could be measured.
|
From page 32... ...
A plasma gun capable of producing intense fluxes of electrically neutral plasma is required to provide high local plasma densities for plasma-physics studies and for injecting high-energy density plasmas into the magnetosphere. A suitable device for generating these plasmas could be a magnetic-plasma dynamic arc of
|
From page 33... ...
A wide variety of diagnostic instrumentation is required to provide the measurements of the local environment necessary for properly identifying the basic magnetospheric phenomena of interest. These instruments include magnetometers for magnetic-field measurements, electrostatic charged-particle energy analyzers for energy-spectrum measurements, Langmuir probes for electron-density and temperature measurements, mass spectrometers for local composition measurements, double probes for electric-field measurements, and loop or search-coil antennas for ac magnetic-field measurements.
|
From page 34... ...
During highly active periods at auroral latitudes, low-energy electron beams could be directed along field lines to detect and measure magnetic-field-aligned electric fields, while during quiet times, high-energy electron pulses could be used to study magnetic-field configuration. Wave injection to stimulate emission of whistler-mode waves will be required for a range of frequencies that generally varies in a known way with latitude but that will also depend to some extent on the conditions at large distances from the Shuttle.
|
From page 35... ...
: a single sortie laboratory facility, a single free-flyer, and a single piggyback package. Each sortie laboratory mission carries a maneuverable subsatellite that will generally be deployed and recovered.
|
From page 36... ...
Rockets would be launched from the Space Shuttle "to inject plasma clouds at radial distances 3-15 earth radii with optical observations of the plasma clouds from the Space Shuttle. The total weight is not well defined at present [see comments on man's role in (C)
|
From page 37... ...
All A&SP sortie missions require about 10,000-12,000 Ib of instrumentation placed on three 3-m pallet sections, and inclusion of the pressurized module will not raise the total weight above the allowable Shuttle limits. It is possible to perform all A&SP sortie missions in a pallet-only mode, if an adequate real-time tracking and control network is set up to give continuous coverage for all contemplated orbits, including those of high inclination.
|
From page 38... ...
develop, design, and test high-power electron and ion accelerators and plasma beam devices with appropriate energy, density, and beam optics requirements. It is also important that laboratory studies of reaction rates and theoretical atmospheric modeling studies be continued to allow
|
From page 39... ...
Scientific Uses of the Space Shuttle 39 optimal use to be made of the atmospheric data to be gathered by the Shuttle mission.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.