View source for Chemistry:Venus In Situ Atmospheric and Geochemical Explorer

{{Infobox spaceflight
| name                  =  <!--defaults to page title-->
| names_list            = VISAGE <!--list of previous names if the spacecraft has been renamed. 
Include the dates applicable if possible, and separate each name with a linebreak. 
Omit if the spacecraft has only ever been known by one name. 
Do not include Harvard, COSPAR/NSSDC or SATCAT/NORAD/NASA designations as alternative names-->

<!--image of the spacecraft/mission-->
| image                 = <!--omit the "file" prefix-->
| image_caption         = <!--image caption-->
| image_alt             = <!--image alt text-->
| image_size            = <!--include px/em; defaults to 220px-->

<!--Basic details-->
| mission_type          = Reconnaissance <!--eg. Technology, Reconnaissance, ISS assembly, etc-->
| operator              = NASA <!--organisation(s) that operate(d) the spacecraft-->
| COSPAR_ID             = <!--spacecraft launched since 1963 only (aka NSSDC ID; eg. 1998-067A)-->
| SATCAT                = <!--satellite catalogue number, omit leading zeroes (e.g. 25544)-->
| website               = <!--Homepage of the craft/mission, OFFICIAL PAGES ONLY-->
| mission_duration      = cruise: 12 months <br>lander: 4.5 hours <!--How long the mission lasted-->
| distance_travelled    = <!--How far the spacecraft travelled (if known)-->

<!--Spacecraft properties-->
| spacecraft            = <!--Spacecraft name/serial number (eg. Space Shuttle ''Discovery'', Apollo CM-118), etc-->
| spacecraft_type       = <!--eg. GPS Block II, Kobalt-M, US-K, etc-->
| spacecraft_bus        = <!--eg. A2100M, Star-2, etc-->
| manufacturer          = <!--company or companies who built the satellite-->
| launch_mass           = <!--fuelled mass at launch, not including rocket or upper stage-->
| BOL_mass              = <!--spacecraft mass in orbit at beginning of operational life, after LEOP phase-->
| landing_mass          = <!--Mass after landing (recovered spacecraft only)-->
| dry_mass              = <!--spacecraft mass in orbit without fuel-->
| payload_mass          = <!--Mass of cargo carried by spacecraft (eg. for Space Shuttle), or total mass of instrumentation/equipment/experiments for mission-->
| dimensions            = <!--body dimensions and solar array span-->
| power                 = <!--end-of-life power, in watts-->

<!--Launch details-->
| launch_date           = <!--{{start date|YYYY|MM|DD|hh|mm|ss|TZ=Z}}-->
| launch_rocket         = <!--Rocket that launched the satellite, include upper stage if distinct from rocket* and if possible flight/tail/serial number-->
| launch_site           = <!--Where the rocket launched from, including complex and pad; do not include the full address or country-->
| launch_contractor     = <!--organisation(s) that conducted the launch (eg. United Launch Alliance, Arianespace, etc)-->
| deployment_from       = <!--place where deployed from-->
| deployment_date       = <!--date deployed-->
| entered_service       = <!--date on which the spacecraft entered service, if it did not do so immediately after launch-->
<!-- * - e.g. Proton-M/Briz-M not Proton-M, but Titan IV(401)A not Titan IV(401)A-Centaur-->

<!--end of mission-->
| disposal_type         = <!--Whether the spacecraft was deorbited, decommissioned, placed in a graveyard orbit, etc-->
| declared              = <!--when the operator/agency officially ended the mission-->
| deactivated           = <!--when craft was decommissioned-->
| destroyed             = <!--when craft was destroyed (if other than by re-entry)-->
| last_contact          = <!--when last signal received if not decommissioned-->
| recovery_by           = <!--recovered by-->
| recovery_date         = <!--recovery date-->
| decay_date            = <!--when craft re-entered the atmosphere, not needed if it landed-->
| landing_date          = <!--when the spacecraft made a controlled landing, not needed if it did not return intact-->
| landing_site          = <!--where the craft landed; site/runway or coordinates-->
<!--
    The following template should be used for ONE of the three above fields "end_of_mission", "decay" or "landing" if the spacecraft is no longer operational.
    If it landed intact, use it for the landing time, otherwise for the date it ceased operations, or the decay date if it was still operational when it re-entered.
    {{end date|YYYY|MM|DD|hh|mm|ss|TZ=Z}} (for Zulu/UTC) or {{end date|YYYY|MM|DD}} (if time unknown) 
-->

|interplanetary         = <!--Infobox spaceflight/IP can be called multiple times for missions with multiple targets or combined orbiter/lander missions, etc-->
 {{Infobox spaceflight/IP
   |type                = lander <!--delete as appropriate, MUST BE ONE OF THESE OPTIONS: flyby/orbiter/impactor/atmospheric/lander/rover -->
   |object              = [[Astronomy:Venus|Venus]] <!--body visited - e.g. Jupiter, Venus, etc-->
    |component           = <!--part of the spacecraft involved, if spacecraft split into multiple components-->
   |arrival_date        = <!--Flybys: date/time of closest approach; Orbiters; orbital insertion date; Impactors/Landers/Rovers: impact/landing date/time; Atmospheric probes: atmospheric entry time-->
   |distance            = <!--closest approach distance for flybys, distance travelled on surface for rovers, omit for others-->
 }}

<!--transponder parameters-->
| trans_band            = <!--Transponder frequency bands-->
| trans_frequency       = <!--specific frequencies-->
| trans_bandwidth       = <!--bandwidth-->
| trans_capacity        = <!--capacity of the transponders-->
| trans_coverage        = <!--area covered-->
| trans_TWTA            = <!--TWTA output power-->
| trans_EIRP            = <!--equivalent isotropic power-->
| trans_HPBW            = <!--half-power beam width-->

<!--Only use where a spacecraft/mission is part of a clear programme of sequential missions. 
If in doubt, leave it out-->
| programme             = [[Astronomy:New Frontiers program|New Frontiers program]]
| previous_mission      = [[Astronomy:OSIRIS-REx|OSIRIS-REx]]
| next_mission          =

<!--mission insignia or patch-->
| insignia              = <!--omit the "file" prefix-->
| insignia_caption      = <!--image caption-->
| insignia_alt          = <!--image alt text-->
| insignia_size         = <!--include px/em; defaults to 180px-->
}}

'''Venus In Situ Atmospheric and Geochemical Explorer''' ('''VISAGE''') is a proposed [[Astronomy:Venus|Venus]] lander mission that would perform atmospheric and surface science investigations.

The mission was proposed in 2017 to NASA's [[Astronomy:New Frontiers program|New Frontiers program]] to compete for funding and development,<ref name='VISAGE EPSC2017'>[http://meetingorganizer.copernicus.org/EPSC2017/EPSC2017-275-1.pdf The New Frontiers Venus In Situ Atmospheric and Geochemical Explorer (VISAGE) Mission Proposal]. (PDF) L.W. Esposito, D.H. Atkinson, K.H. Baines, A. Allwood, F. Altieri, S. Atreya, M. Bullock, A. Colaprete, M. Darrach, J. Day, M. Dyar, B. Ehlmann, K. Farley, J. Filiberto, D. Grinspoon, J. Head, J. Helbert, S. Madzunkov, G. Piccioni, W. Possel, M. Ravine, A. Treiman, Y. Yung, K. Zahnle. EPSC Abstracts. Vol. 11, EPSC2017-275-1, 2017. European Planetary Science Congress 2017.</ref> but it was not selected.<ref name=ibtimes>[http://www.ibtimes.com/nasas-new-frontier-mission-will-search-alien-life-or-reveal-solar-systems-history-2631073 NASA's New Frontier Mission Will Search For Alien Life Or Reveal The Solar System's History]. Elana Glowatz, ''IB Times''. 20 December 2017.</ref>

== Overview==
[[File:PIA00103 Venus - 3-D Perspective View of Lavinia Planitia.jpg|alt=The plains of Venus are outlined in red and gold, with impact craters leaving golden rings across the surface|thumb|[[Astronomy:Impact crater|Impact crater]]s on the surface of Venus (image reconstructed from radar data)]]
If selected for development, VISAGE would have launched in December 2024 with a targeted flyby of Venus in May 2025, and Venus arrival in December 2025.<ref name='VISAGE EPSC2017'/>  A carrier spacecraft would deploy the lander five days before it flew by Venus. The atmosphere of Venus at the surface has an average temperature of 450&nbsp;°C and is highly acidic and corrosive, which severely limits the time a lander can function. The VISAGE lander would function autonomously while descending (1 hour) and would operate on the surface for additional 3.5 hours, and it would transmit its acquired data to the nearby carrier module for relay to Earth.<ref name='VISAGE 2017'>[https://www.hou.usra.edu/meetings/lpsc2017/pdf/2444.pdf Venus In Situ Atmospheric and Geochemical Explorer (VISAGE): A Proposed New Frontiers Mission]. (PDF) Esposito, L. W. ''Lunar and Planetary Science'' XLVIII (2017)</ref><ref name='VISAGE EPSC2017'/>

==Science investigations==

During its parachute descent, the VISAGE lander would analyse atmospheric [[Chemistry:Noble gas|noble gas]]es and light stable isotopes inventory, as well as reactive and trace gases, and measure the atmospheric structure profile. It would also image the surface starting from an altitude of {{convert|15|km|mi|abbr=on}} and acquire panoramic images of the landing site.

The VISAGE lander would drill on the shallow subsurface and samples would be brought on board to measure the mineralogy and elemental composition.<ref name='VISAGE 2017'/>

===Goals===

The proposed mission goals are:<ref name='VISAGE EPSC2017'/>
* to measure noble gases to test models of the origin and evolution of Venus, and measure sulfur compounds and trace gas profiles to constrain atmospheric cycles, surface-atmosphere interactions, and climate models.
* to understand whether Venus was ever like Earth: VISAGE would measure surface and subsurface composition, determine surface rock type, mineralogy, and texture to understand geochemical processes, weathering, and [[Earth:Aeolian processes|aeolian processes]].
* to understand clues about exoplanets.

==Payload==

The proposed lander payload comprises five instruments:<ref name='VISAGE EPSC2017'/> the Atmospheric Structure Investigation including Doppler Wind measurements, a Neutral Mass Spectrometer, an Imaging System, an X-ray Fluorescence experiment, and a Visible Near-Infrared
Spectrometer.  The total surface science data return is expected to be ~1.4 GBits.<ref name='VISAGE EPSC2017'/>

==See also==

* [[Astronomy:Venus In situ Composition Investigations|Venus In situ Composition Investigations]] (VICI), a competing atmospheric probe and lander
* [[Astronomy:Venus Origins Explorer|Venus Origins Explorer]] (VOX), a competing atmospheric probe and orbiter

==References==
{{reflist}}

{{Venus}}
{{Venus spacecraft}}
{{Planetary Missions Program Office|New Frontiers=y}}

[[Category:Missions to Venus]]
[[Category:Extraterrestrial atmosphere entry]]
[[Category:Proposed NASA space probes]]

{{Sourceattribution|Venus In Situ Atmospheric and Geochemical Explorer|1}}