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Updated 2/21/2017


Mission LaunchDate Landing Date Termination Date Result


Pressure  Data?
Soviet Sputnik 24 4 Nov 1962   19 Jan 1963 Failure.   No
Soviet Mars 3 28 May 1971 2 Dec 1971 2 Dec 1971 Failure.  Landed, but transmission ceased within 15 seconds No
Soviet Mars 6 5 Aug 1973 12 Mar 1974 12 Mar 1974 Failure.  Data during descent, not after landing. No
Soviet Mars 7 9 Aug 1973 9 Mar 1974 9 Mar 1974 Failure.    No
U.S. Viking 1 20 Aug 1975 20 Jul 1976 13 Nov 1982 Success Yes
U.S. Viking 2 9 Sep 1975 3 Sep 1976  11 Apr 1980 Success Yes
Soviet Phobos 1 7 Jul 1988   2 Sep 1988 Failure.   No
Soviet Phobos 2 12 Jul 1988   29 Jul 1989 Failure.   No
U.S. Mars Pathfinder 4 Dec 1996 4 Jul 1997 27 Sep 1997 Success Yes
U.S Mars Polar Lander 3 Jan 1999 3 Dec 1999 3 Dec 1999 Failure.    No
U.S Deep Space 2 3 Jan 1999 3 Dec 1999 3 Dec 1999 Failure.   


British Beagle 2 2 Jun 2003   6 Feb 2004


Finally found after 11 years.


U.S. MER A – Spirit 10 Jun 2003 4 Jan 2004 Still operational. Success


U.S. MER B - Opportunity 7 Jul 2003 25 Jan 2004 Still operational. Success No
U.S. Phoenix 4 Aug 2007 25 May 2008 10 Nov 2008 Success Yes
 U.S. Mars Science Lab
 26 Nov 2011  6 Aug 2007  Still operational.  Success  Yes
ExoMars 2016 Schiaparelli Lander 14 March 2016 19 October 2016 19 October 2016 Failure

 * Source:
   For Mars Pathfinder, pressure was measured by a Tavis magnetic reluctance diaphragm sensor similar to that used by Viking, both during descent and after landing. 

     The Phoenix lander in 2008 also carried a meteorological station.  However, it carried a 26-gram instrument developed by the Finish Meteorological Institute.  The device is based on the Vaisala Oy sensor technology and components for the instrument which was delivered by the Micro Analog Systems Oy and Selmic Oy. 

The Vikings were designed to only measure pressure up about 13.79 mbar.  The Pathfinder was designed to only measure pressure up to 12 mbar.  The Phoenix was limited to 5 to 12 mbar.  None of these landers had equipment that could function right on Earth below an altitude of at least 68,000 feet - and that's figuring that the Tavis sensor would work past its designed 13.79 mbar level right up to 36 mbar.  If they would not work right past 13.79 mbar, then the figure would be 81,000 feet above the Earth.  The Tavis magnetic reluctance transducer works on the basis of converting pressure to voltage, with 0 volts at 0 mbar, 5 volts at 0.2 psia (about 13.79 mbar), which was its rating, and 15 volts maximum possible voltage allowed.  After that its a real question of what would happen.  The instrument was apparently designed to work well only with temperatures above -50 degrees Celsius, but it was regularly exposed to -78 C. Pathfinder was also exposed to -170 degrees Celsius at 80 km on its entry.



MARTIAN LANDING COORDINATES:  To find specific sites on Mars, you can now use Google Mars.  The landing sites for Mars landers are given below, however the topography (MOLA) map included further below appears to use a different coordinate system for denoting longitudes.  On Earth longitude coordinates are given from the Prime Meridian (0O) to 180O East or West.  Phoenix was plotted by this writer, but for Viking 1, Viking 2, and PathFinder (MPF) there are West longitudes in excess of 180O.  In the case of Viking 1 it looks like the 49.97O West correlates with the plotted longtitude of about 310 (360-49.97O West).     
     For MPF, the table given longitude of 33.22O West correlates well with  the plotted value of about 327 (360-33.22O West).  The Google map shows Isidis, which is where the British Beagle was supposed to land, but that probe failed.  So the map must have been produced before that failure and the landing of Phoenix that I had to add.  This leaves us with one problem, Viking 2.  It is plotted at about 135 (East), but the chart lists it as landing at 225.74 O West. However, these longitude positions are basically equal. There are two systems in use for longitudes on Mars:

Planetographic latitude with west longitude. This is the coordinate system originally used in the Gazetteer of Planetary Nomenclature, and the system used for maps produced before approximately 2002. An ellipsoidal equatorial radius of 3396.0 km and polar radius of 3376.8 km are assumed. 

Planetocentric latitude with east longitude. This is the coordinate system used for maps produced after approximately 2002, although the planetographic latitudes and west longitudes are also shown on printed maps for reference, and the radii on which these are based are different (3396.19 and 3376.20 km).







JULY 20, 1976

22.48 N (Smith et al.states

22.2692 N)

49.97 W (Smith et al.states

311.8113 E)


SEP 3, 1976

47.97 N (Smith et al.states

47.6680 N)

225.74 W (Smith et al.states

134.0430 E)


JULY 4, 1997

19.13 N (Smith et al.states

19.0949 N)

33.22 W (Smith et al.states

326.5092 E)

SPIRIT at Gusev Crater

JAN 4, 2004

14.5718 S

175.4785 W

(Mars globe shows 184.5W, 14.7 S)  


JAN 25, 2004

1.95 S

354.47 E


MAY 25, 2008

68 N

234 E

 AUG 6, 2012  4.59 S

  137.44 E



Smith figures from Smith, D. E., et al. (2001), Mars Orbiter Laser Altimeter: Experiment summary after the first year of global mapping of Mars, J. Geophys. Res., 106, 23,689–23,722, doi:10.1029/2000JE001364.


On Earth there is a loss of about 1 inch of mercury (about 33.86 mbar) for each thousand feet ascended.  Lander altitude and latitude can have an impact on pressure readings, and must be compensated for when comparing mission pressure readings. The source for the information below is a draft copy of a paper by Peter A. Taylor, et. al. (October 20, 2009) entitled On Pressure Measurement and Seasonal Pressure Variations during the Phoenix Mission.  Because Pathfinder is at a higher altitude, its minimum pressure was adjusted from 670 Pa (6.7 mbar) to 698 Pa.  They state that Viking 1 amplitudes are increased by a factor of 1.0455 to compare them with the Phoenix values (Viking 1 was higher, so it feels less air pressure than Phoenix) while Viking 2 values should be reduced by a factor of 0.967 to compare with Phoenix (Viking 2 was lower than Phoenix, so it should feel more pressure than Phoenix).  The paper listed the mean (adjusted) pressure at sites as follows: Viking 1 year A = 7.936 mbar, Viking 1 Year B = 7.942 mbar and Phoenix 8.326 mbar.  Again, the above Pathfinder pressure was listed not as a mean, but rather as a minimum.  






















Landing sites

Figure 1 below: MOLA map of Mars with major topographic features, landing sites, and locations of methane plumes identified by Krasnopolsky et al. (2004).