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Upper Martian atmosphere UV emission spectrum observation noting carbon dioxide photoionization, ion fluorescent scattering and photon/electron dissociative excitation
Mariner 6 and 7 UV spectrometers, describing technical details, operating characteristics and calibration of planetary coronagraph and Ebert- Fastie monochromator used for Martian atmosphere analysis
In-flight UV spectrometric measurements of simulated Jupiter atmosphere, using sunlit gas mixture released from Mariner spacecraft in interplanetary space
Mariner 1969 flyby Mars UV spectrum observations, interpreting data in terms of atmospheric, topographic and polar cap adsorptive characteristics
Atomic hydrogen dayglow Lyman alpha structure of Mars exosphere from Mariner 6 and 7 UV spectrometric observations
The Mariner 6 and 7 UV spectrometer experiments observed intense emissions from CO, O, and CO2(+) in the Martian airglow. Analysis shows that they are excited predominantly by the absorption of solar EUV photons by CO2 and constitute a major energy-loss mechanism for the thermosphere. Models of the thermospheric temperature profile and the airglow layer that demonstrate the effects of neutral chemistry and ionospheric composition are developed. With their aid, the observed CO Cameron-band emission scale height of 19 (plus or minus 4.5) km is shown to suggest an exospheric temperature of 315 (plus or minus 75) K. Consideration of other data suggests a 'best' value of about 350 K. Within the uncertainties in the excitation efficiencies and in the thermospheric cooling mechanisms, the observations are consistent with the measured electron density. There is no indication in the data that the ionosphere is modified by the solar wind below 200 km.
The UV airglow spectrum of Mars has been measured from an orbiting spacecraft during a 30-day period in November and December 1971. Significant variations in the scale height of the CO Cameron band airglow have been observed during a period of variable solar activity. The atomic oxygen and hydrogen airglow lines are present during all the observations. Measurements of the reflectance of the lower atmosphere of Mars show the spectral characteristics of particle scattering and a magnitude that is about 50% of that measured during the Mariner 6 and 7 experiments in 1969.
Photoelectric spectra have been obtained for a number of early-type stars in the 1100- to 2000-A region with the Mariner 9 UV spectrometer. The resonance lines of H I, Si IV, and C IV are easily identified, as are features due to C II, C III, Si III, Fe II N IV. The absolute energy distribution derived from the data lie about 20% below those of OAO-2 in the 1200- to 2000-A region.
Analysis of the O I 1304- and 1356-A data from Mariner 6 and 7, and estimation of the atomic oxygen concentration of the Martian atmosphere. Derived values of the parameters describing the sources of excitation differ considerably from previous estimates. A detailed statistical treatment is used in the analysis. At an exospheric temperature of 350 K the atomic oxygen concentration at 135 km is estimated to be between 0.5 and 1%. The likely source of the 1304-A intensity is resonance scattering of solar 1304-A photons. For the 1356-A emission, the likely source is photodissociation of CO2. There is an indication of a diurnal variation of the Martian upper atmosphere.
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The test plan defines the tests to be conducted, identifies and describes all test items, and states the objectives of all tests required to verify that the performance and design goals of the Contract End Item Specification, 7232-0009, have been met and that flight hardware is acceptable. Additionally, environmental conditions, testing time or cycles, allowable maintenance, logging requirements, manner of analysis and utilization of test results, disposition of test specimens, retest requirements, location of tests, facilities and support requirements, and the time phasing of the tests are presented.
The stress analysis report verifies the structural integrity of the Apollo S-169 UV-spectrometer experiment. The methods by which the various members were analyzed are described. A detailed summary of results for the individual structural elements appears in the form of a table of minimum margins of safety. No negative margins of safety were experienced. It is concluded that the component structure is more than adequate to withstand the environmental load conditions given in the design criteria.
The qualification methods used to verify that the UVS hardware meets the technical requirements of the contract are defined. Included in this plan are test location, the qualification UVS to be tested, test objectives, and all tests required to verify that the UVS meets all performance and environmental requirements of the CEI specification. Additionally, environmental test conditions, testing time or cycles, allowable maintenance, logging requirements, manner of analysis, and utilization of test results, disposition of test specimens, failure criteria, retest requirements, facilities and support requirements, and the time phasing of the tests are presented.
Early design studies showed that the UV spectrometer thermal design margins were very small so that an experimental confirmation of the analytical model would be desirable. At that time the prototype unit was scheduled too far downstream to be of value, so a separate thermal model was built for use in verifying the analytical model.
The quality progress plan establishes the requirements for a system of controls to assure compliance with the quality assurance requirements as set forth in NASA quality program provisions for aeronautical and space system contractors.
Selected results are presented for a considerable quantity of Mariner 9 1304-A data for the first 100 revolutions from both the bright limb and disk of Mars. The limb data suggest that the exospheric temperature is less than it was in 1969 when Mariners 6 and 7 encountered the planet. Similar (O) concentrations (0.5 to 1%) are derived for a temperature of about 300 K. Structure in the limb profiles below 200 km suggests the possibility that about 0.2 kR of the observed approximately 0.8 kR near 150 km is due to dissociative excitation of CO2. Significant differences in selected limb profiles suggest that local as well as random variations in (O) occur.