Space exploration missions are undergoing a significant transformation as are the expectations of their scientific investigators and the public who participate in these great voyages of exploration. The early reconnaissance missions are giving way to a new data-intensive era of long duration observational outposts, landed vehicles, sample returns, and multi-spacecraft fleets and constellations. Mars exploration has already become a special case of the new operational mode; other destinations will follow. These changes will require orders of magnitude increases in data rates, highly automated and standardized data communications between the remote locations and Earth, more transparent and responsive mission operations procedures, and the ability to engage the public by giving them Internet-based visibility into the missions as they unfold. The new area will demand a new paradigm for the Deep Space Network, with increased emphasis on data networking and the data processing applications that allow users to become more intimately engaged with the conduct of the mission. We call this new paradigm the Interplanetary Network. Its vision is seamless connectivity between scientists and their instruments, new data analysis and visualization tools that will greatly enhance and enable new modes of space exploration, and the involvement of the public via web-based “telepresence.”

The current architecture of the Deep Space Network reflects its heritage of supporting past, and ongoing NASA missions. In the future, the size and character of the Agency's deep space mission fleet will significantly change. Consequently, the DSN must evolve to accomodate anticipated needs.

A summary of calculations describing the Martian atmosphere water vapor content based on data from the Mars Atmospheric Water Detectors carried by the Viking landers is presented. The water column has been observed to vary with season, time of day, and locality. Over 5 yr of continuous data collection has permitted modeling of the Martian year into 24 seasonal periods of planetocentric solar longitude, with gaps in the model due to the presence of dust storms. The vapor content is asymmetric pole-to-pole, but symmetric latitudinally with respect to the equator. Low elevation areas display a higher vapor content, especially with rapid height changes in nearby terrain. Dust storms reduced the total atmospheric vapor, with concentration shifts tending toward the north, from where it is expected renewed balances will be reinstated. Consideration is also given to diurnal variations, and variations due to temperature, composition, and wind velocity.

Observations of the global distribution and seasonal variation of the Martian atmospheric water vapor have been made from the Viking orbiters for a continuous period covering a complete Martian year. The seasonal dependence of the latitude distribution of the column abundance of vapor is consistent with a model in which the vapor is in equilibrium with the regolith at polar and mid‐latitudes. The results are consistent with there being a permanent reservoir of water ice buried at a depth of 10 cm to 1 m at all latitudes poleward of 40°. The behavior of the vapor in the summer hemisphere suggests an annual net transport of the vapor phase from the southern to the northern hemisphere, with deposition of ice of thickness of the order of a few milligrams per square centimeter in the northern polar latitudes. The hemispheric asymmetry is the result of the propagation of the global dust storms originating in the south.

In the paper ‘Mars: Water Vapor Observations From the Viking Orbiters’ by C. B. Farmer et al. (Journal of Geophysical Research 82(28), 4225–42481, 1977), the color key for Plate 1 is light yellow,0–2 pr μm (precipitable micrometers); dark yellow, 2–4 pr μm; yellow orange, 4–6 pr μm; orange, 6–8 pr μm; red, 8–10 pr μm; green, 10– 15 pr μm; light blue, 15–20 pr μm; dark blue, 20–30 pr μm; blue purple 30–40 pr μm; purple 40–60 pr μm; and black, >60 pr μm. The color key for Plates 2a–2c is purple, 0–10 pr μm; black, 10–15 pr μm; brown, 15–20 pr μm; brownish yellow, 20–25 pr μm; pink, 25–30 pr μm; red, 30–35 pr μm; yellow, 35–40 pr μm; and green, 40–50 pr μm. The color key for Plate 2d is red, <15%; dark blue, 15–20%; light blue, 20–25%; green, 25–30%; orange, 30–35%; yellow, >35%. The key to Figure 9 is missing.

Journal of Geophysical Research (1896-1977)Volume 82, Issue 28 p. 4225-4248 Mars: Water vapor observations from the Viking orbiters C. B. Farmer, C. B. FarmerSearch for more papers by this authorD. W. Davies, D. W. DaviesSearch for more papers by this authorA. L. Holland, A. L. HollandSearch for more papers by this authorD. D. Laporte, D. D. LaporteSearch for more papers by this authorP. E. Doms, P. E. DomsSearch for more papers by this author C. B. Farmer, C. B. FarmerSearch for more papers by this authorD. W. Davies, D. W. DaviesSearch for more papers by this authorA. L. Holland, A. L. HollandSearch for more papers by this authorD. D. Laporte, D. D. LaporteSearch for more papers by this authorP. E. Doms, P. E. DomsSearch for more papers by this author First published: 30 September 1977 https://doi.org/10.1029/JS082i028p04225Citations: 160AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract The results of observations of the spatial and temporal variation of water vapor during the Viking primary mission are reported. The instrument, the Mars atmospheric water detector (Mawd), is a five-channel grating spectrometer operating in the 1.4-μm water vapor bands. The seasonal period covered here is the northern summer solstice to the following equinox. The global water vapor, mapped at low resolution at approximately 1-month intervals, has been observed to undergo a gradual redistribution, the latitude of maximum column abundance moving from the northern polar area to the equatorial latitudes, and the integrated global atmospheric vapor content remaining constant. The peak abundances (∼100 precipitable microns) occurred over the dark material of the circumpolar region. The summer residual cap is dirty water ice; at the season of maximum vapor the atmosphere above it is saturated and has a stable lapse rate, of temperature. High-resolution maps show local structure controlled by abrupt changes of surface elevation, suggesting that large variations at a given latitude are orographie in nature and only occur in association with features whose horizontal scale is small in comparison to the product of the atmospheric relaxation time and the local mean wind speed. These results are at variance with the low-resolution global maps, however, which seem to show topographic control even at the regional scale. Attempts to isolate the diurnal variation of the vapor have shown a variety of effects at different latitudes and locations; scattering by dust and condensate particles obscures the intrinsic diurnal variation of the vapor phase. The large diurnal variation reported from earth-based measurements may be largely an observational effect. Citing Literature Volume82, Issue2830 September 1977Pages 4225-4248 This article also appears in:Scientific Results of the Viking Project RelatedInformation