280 research outputs found
Pioneer 10 Jupiter atmospheric definition results: A summary
The various entry probes for measuring outer planetary atmospheric compositions are discussed. Considered are chemical components and physical accumulation processes observable by spectroscopic studies, as well as pressure gauges, temperature gauges, accelerometers, nephelometers, and visible and infrared sensors for determining abundances
Ka-band (32 GHz) benefits to planned missions
The benefits of using 32 GHz downlinks for a set of deep space missions, as well as the implications to radio science and the Deep Space Network (DSN) are documented. The basic comparison is between the use of the current X-band (8.4 GHz) and a 32 GHZ (Ka-band) downlink. There was shown to be approximately an 8 dB (about 600%) link advantage for 32 GHz. This 8 dB advantage would be able to either reduce mission cost or improve mission science return. Included here are studies on how the 8 dB advantage would be used for the Cassini and Mars Sample Return missions. While the work is preliminary, it shows that the 8 dB advantage can be exploited to provide large benefits to future deep space missions. There can be significant mass and/or power savings to the spacecraft, which can translate into cost savings. Alternatively, the increased downlink telecommunications performance can provide a greater science return
Ionosphere of Callisto from Galileo radio occultation observations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95670/1/jgra16576.pd
The ionosphere of Saturn as observed by the Cassini Radio Science System
Fifty‐nine ionsopheric radio occultation observations of the vertical electron density profile in the Saturn ionosphere have been made since the Cassini spacecraft was inserted in orbit around Saturn in 2004. Significant orbit to orbit variations were observed, but the general trend noted in earlier orbits, namely, increasing electron densities with increasing latitude was reconfirmed and bolstered with this extended data base. This trend is likely to be due to some combination of increasing ionization rates and decreasing water influx with latitude. Key Points Density properties of the ionosphere diminish with decreasing latitude This diminution starts over the main rings and is maximum inside the D ring This confirms transport of water from the tingsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108640/1/grl52007.pd
Unusual electron density profiles observed by Cassini radio occultations in Titan's ionosphere: Effects of enhanced magnetospheric electron precipitation?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95188/1/jgra21399.pd
Preliminary results of the Mariner IV radio occultation measurements of the upper atmosphere of Mars
Mariner IV radio occultation measurements of Mars upper atmospher
Preliminary results of the Mariner IV OCCULATION measurement of the atmosphere of Mars
Mariner IV radio occultation measurement of Mars atmospher
Mesospheric vertical thermal structure and winds on Venus from HHSMT CO spectral-line observations
We report vertical thermal structure and wind velocities in the Venusian
mesosphere retrieved from carbon monoxide (12CO J=2-1 and 13CO J=2-1) spectral
line observations obtained with the Heinrich Hertz Submillimeter Telescope
(HHSMT). We observed the mesosphere of Venus from two days after the second
Messenger flyby of Venus (on June 5 2007 at 23:10 UTC) during five days.
Day-to-day and day-to-night temperature variations and short-term fluctuations
of the mesospheric zonal flow were evident in our data. The extensive layer of
warm air detected recently by SPICAV at 90 - to 100 km altitude is also
detected in the temperature profiles reported here. These data were part of a
coordinated ground-based Venus observational campaign in support of the ESA
Venus Express mission. Furthermore, this study attempts to cross-calibrate
space- and ground-based observations, to constrain radiative transfer and
retrieval algorithms for planetary atmospheres, and to contribute to a more
thorough understanding of the global patterns of circulation of the Venusian
atmosphere.Comment: 35 pages, 18 figures. Shortcut URL to this page:
http://www.sciencedirect.com/science/journal/0032063
Hot oxygen corona at Europa
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95283/1/grl11783.pd
First results from the ionospheric radio occultations of Saturn by the Cassini spacecraft
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94835/1/jgra18257.pd
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