Editing Phobos 2

{{short description|Soviet Mars moon probe (1988–1989)}}
{{Use dmy dates|date=May 2020}}
{{italic title}}
{{Infobox spaceflight
| name                  = ''Phobos 2''
| image                 = [[Image:Phobos Marte.jpg|300px]]
| image_caption         = Illustration of the Phobos spacecraft
| image_alt             = <!--image alt text-->
<!--Basic details-->
| mission_type          = Orbiter
| operator              =[[Soviet Union]]
| COSPAR_ID             = 1988-059A
| SATCAT                = 19287
| website               = {{URL|http://www.iki.rssi.ru/IPL/phobos.html}}
| mission_duration      = 8 months, 15 days (launch until comm failure)
| distance_travelled    = <!--How far the spacecraft travelled (if known)-->
| orbits_completed      = <!--number of times the spacecraft orbited the Earth - see below for spacecraft beyond Earth orbit-->
| suborbital_range      = <!--downrange distance reached if spacecraft did not enter orbit-->
| suborbital_apogee     = <!--altitude reached if spacecraft did not enter orbit-->

<!--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           = 6,220 kg (with orbital insertion hardware)<ref>[http://nssdc.gsfc.nasa.gov/planetary/phobos.html nasa.gov: Phobos Project Information]</ref><ref>{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/beyond-earth-tagged.pdf |title=Fobos 2 |publisher=NASA |access-date=December 1, 2022}}</ref>
| BOL_mass              = <!--spacecraft mass in orbit at beginning of operational life, after LEOP phase-->
| 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|1988|07|12|17|01|43|7=Z|df=y}}
| launch_rocket         = [[Proton rocket|Proton-K rocket]]
| 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-->
| deactivated           = <!--when craft was decommissioned-->
| destroyed             = <!--when craft was destroyed (if other than by re-entry)-->
| last_contact          = 27 March 1989 (spacecraft signal failed to be reacquired).<!--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) 
-->

<!--orbit parameters-->
<!--as science-related articles, SI units should be the principal units of measurement, however we usually use {{convert}} to display imperial units in parentheses after the initial values-->
| orbit_reference       = [[Areocentric orbit|Areocentric]]
| orbit_regime          = <!--high, low, medium, molniya, GSO - please link (e.g. [[Low Earth orbit|Low Earth]] - please don't use acronyms-->
| orbit_longitude       = <!--geosynchronous satellites only-->
| orbit_slot            = <!--Designation of orbital position or slot, if not longitude (e.g plane and position of a GPS satellite)-->
| orbit_semimajor       = <!--semimajor axis-->
| orbit_eccentricity    = <!--orbital eccentricity-->
| orbit_periapsis       = <!--periapsis altitude--> 
| orbit_apoapsis        = <!--apoapsis altitude--> 
| orbit_inclination     = <!--orbital inclination--> 
| orbit_period          = <!--time taken to complete an orbit-->
| orbit_RAAN            = <!--right ascension of the ascending node-->
| orbit_arg_periapsis   = <!--argument of perigee/periapsis-->
| orbit_mean_anomaly    = <!--mean anomaly at epoch, only use in conjunction with an epoch value-->
| orbit_mean_motion     = <!--mean motion of the satellite, usually measured in orbits per day-->
| orbit_repeat          = <!--repeat interval/revisit time-->
| orbit_velocity        = <!--speed at which the spacecraft was travelling at epoch - only use for spacecraft with low orbital eccentricity-->
| orbit_epoch           = <!--the date at which the orbit parameters were correct-->
| orbit_rev_number      = <!--revolution number-->
| apsis                 = areion

|interplanetary         = <!--Infobox spaceflight/IP can be called multiple times for missions with multiple targets or combined orbiter/lander missions, etc-->
 {{Infobox spaceflight/IP
   |type                = orbiter
   |object              = [[Mars]]
   |orbits              = <!--number of orbits completed at target body (if applicable and known)-->
   |component           = <!--part of the spacecraft involved, if spacecraft split into multiple components-->
   |arrival_date        = 29 January 1989
   |departure_date      = <!--Date of leaving orbit for orbiters, date of launch for landers which took off again-->
   |location            = <!--landing/impact site, including EOM impacts for atmospheric probes and lunar/asteroid orbiters-->
   |distance            = <!--closest approach distance for flybys, distance travelled on surface for rovers, omit for others-->
   |sample_mass         = <!--mass of samples returned (sample return missions only)-->
   |surface_EVAs        = <!--number of EVAs on the surface-->
   |surface_EVA_time    = <!--time spent on surface EVAs-->
   
   <!--Orbit parameters, ONLY USE IF THE ABOVE ORBIT PARAMETERS SECTION DOESN'T APPLY TO THE TARGET-->
   |periapsis           = <!--periapsis altitude-->
   |apoapsis            = <!--apoapsis altitude--> 
   |inclination         = <!--inclination to the object's equator-->
   |apsis               = areion
 }}

<!--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             = [[Phobos program]]
| previous_mission      = ''[[Phobos 1]]''
| 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-->
}}

'''''Phobos 2''''' was the last space probe designed by the [[Soviet Union]]. It was designed to explore the [[moons of Mars]], [[Phobos (moon)|Phobos]] and [[Deimos (moon)|Deimos]]. It was launched on 12 July 1988, and entered orbit on 29 January 1989.

''Phobos 2'' operated nominally throughout its cruise and Mars orbital insertion phase on 29 January 1989, gathering data on the Sun, interplanetary medium, Mars, and Phobos. ''Phobos 2'' investigated the Mars surface and atmosphere and returned 37 images of Phobos<ref name=ScienceMag>[http://www.nature.com/nature/journal/v341/n6243/abs/341585a0.html Nature Publishing Group, Television observations of Phobos]</ref> with a resolution of up to 40 meters.

Shortly before the final phase of the mission, during which the spacecraft was to approach within {{val|50|u=m}} of Phobos' surface and release two landers (one, a mobile {{em|hopper}}, the other, a stationary platform) contact with ''Phobos 2'' was lost. The mission ended when the spacecraft signal failed to be reacquired on 27 March 1989. The cause of the failure was determined to be a malfunction of the on-board [[computer]].<ref name=ScienceMag/>

==Background==
The mission to Phobos was announced on 14 November 1984.<ref name=Harvey246 /> Phobos was chosen as the target in order to avoid direct competition with previous American missions.<ref name=Harvey246 /> The original 1986 launch plan was later moved to 1988.<ref name=Harvey246>{{cite book |last=Harvey |first=Brian |date=2007 |title=Russian Planetary Exploration History, Development, Legacy and Prospects  |publisher=Springer-Praxis |page=246 |isbn=9780387463438}}</ref>

==Mission profile==
Phobos 2 started to develop problems during the interplanetary flight phase of the mission.<ref name=Harvey253 /> By the time the probe reached Mars orbit, two of its three computers were malfunctioning.<ref name=Harvey253 /> One computer was completely dead, and a second was starting to fail.<ref name=Harvey253 /> Since the probe depended on two computers to agree on any decision, the one healthy computer would not be able to control the craft because it could not outvote two bad computers.<ref name=Harvey253 /> The craft's high speed transmitter had also developed issues.<ref name=Harvey253>{{cite book |last=Harvey |first=Brian |date=2007 |title=Russian Planetary Exploration History, Development, Legacy and Prospects  |publisher=Springer-Praxis |pages=253–254 |isbn=9780387463438}}</ref>

Phobos 2 successfully carried out three preliminary encounters with Phobos by using its Videospectrometric Camera, the Combined Radiometer and Photometer for Mars and the Imaging Spectrometer for Mars.<ref name=Murchiea>{{cite journal |last1=Murchiea |first1=Scott  |last2=Erardb |first2= Stephane |date=September 1996 |title=Spectral Properties and Heterogeneity of Phobos from Measurements by Phobos 2 |journal=Icarus |volume=123 |issue=1 |pages=63–86 |doi=10.1006/icar.1996.0142 |bibcode=1996Icar..123...63M |doi-access=free }}</ref>

==Spacecraft design==
===Instruments===

The ''Phobos 2'' [[Thermal infrared spectroscopy|infrared spectrometer]] (ISM) obtained 45000 spectra in the near infrared (from {{val|0.75|to|3.2|u=um}}) in the equatorial areas of Mars, with a spatial resolution ranging from {{val|7|to|25|u=km}}, and 400 spectra of Phobos at 700 m resolution. These observations made it possible to generate the first mineralogical maps of the planet and its satellite, and to study the atmosphere of Mars. ISM was developed at [[Institut aéronautique et spatial|IAS]] and [[DESPA]] ([[Paris Observatory]]) with support from [[CNES]].

List of instruments:
* "VSK" TV imaging system
* PROP-F "hopping" lander.
**ARS-FP automatic X-ray fluorescence spectrometer
**ferroprobe [[magnetometer]]
**Kappameter magnetic permeability / susceptibility sensor
**gravimeter
**temperature sensors
**BISIN conductometer / tiltmeter
**mechanical sensors (penetrometer, UIU accelerometer, sensors on hopping mechanism)
*"DAS" (long-lived autonomous station) lander
**TV camera
**ALPHA-X Alpha-Proton-X-Ray Spectrometer
**LIBRATION [[Sun sensor]] (also known as STENOPEE)
**Seismometer
**RAZREZ anchor penetrometer
**Celestial mechanics experiment
* "ISM" thermal infrared spectrometer/radiometer - {{val|1|2|u=km}} resolution
* near-infrared imaging spectrometer
* thermal imaging camera; magnetometers
* gamma-ray spectrometers
* X-ray telescope
* radiation detectors
* radar and laser altimeters
* Lima-D laser experiment - designed to vaporize material from the Phobos surface for chemical analysis by a mass spectrometer
* Automatic Space Plasma Experiment with Rotating Analyzer (ASPERA), an electron spectrometer and ion mass analyzer from the [[Swedish Institute of Space Physics]].

==Results==
The craft took 37 photos of Phobos imaging the majority (80%) of the moon.<ref name=Harvey264 /> The infrared spectrometer found no sign of water.<ref name=Harvey264>{{cite book |last=Harvey |first=Brian |date=2007 |title=Russian Planetary Exploration History, Development, Legacy and Prospects  |publisher=Springer-Praxis |page=264|isbn=9780387463438}}</ref>

==Legacy==
The Phobos design was used again for the long delayed ''[[Mars 96]]'' mission which ended in failure when the launch vehicle's fourth stage misfired. In addition, the ''[[Fobos-Grunt]]'' mission, also designed to explore Phobos, failed in 2011. There has yet to be a completely successful probe to Phobos.

==References==
{{reflist}}

==External links==
* [https://web.archive.org/web/20150717180620/http://www.strykfoto.org/phobos2.htm High quality processed images from the ''Phobos 2'' mission]
* [http://www.iki.rssi.ru/IPL/phobos.html Phobos mission images from the Space Research Institute (IKI)]
* [http://www.ias.u-psud.fr/ism/ Raw image data from the ''Phobos 2'' ISM infrared instrument]
* [http://www.federalspace.ru/Doc1Show.asp?DocID=16 What we are searching for on Phobos] {{Webarchive|url=https://web.archive.org/web/20090720230440/http://www.federalspace.ru/Doc1Show.asp?DocID=16 |date=20 July 2009 }} - an article on the Phobos program at the Web site of the [[Russian Space Agency]] {{in lang|ru}}
* [https://web.archive.org/web/20060316104137/http://www.astrosurf.com/nunes/explor/explor_ph2.htm Another site with processed images from the Soviet ''Phobos 2'' mission]
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{{Use American English|date=January 2014}}

{{DEFAULTSORT:Phobos Program}}
[[Category:Missions to Mars]]
[[Category:1988 in the Soviet Union]]
[[Category:Soviet Mars missions]]
[[Category:Derelict space probes]]
[[Category:Phobos (moon)]]
[[Category:Derelict satellites orbiting Mars]]
[[Category:Non Earth orbiting satellites of the Soviet Union]]
[[Category:Spacecraft launched in 1988]]