Editing Mars Observer (section)

{{short description|Failed NASA orbiter mission to Mars (1992–1993)}}
{{Use mdy dates|date=August 2018}}
{{italic title}}
{{Infobox spaceflight
| name                  = Mars Observer
| names_list            = Mars Geoscience and Climatology Orbiter
| image                 = Mars Observer.jpg
| image_size            = 300px
| image_caption         = Artist rendering of ''Mars Observer'' in orbit around Mars

| mission_type          = [[Mars]] orbiter
| operator              = [[NASA]] / [[JPL]]
| website               = [https://science.nasa.gov/mission/mars-observer/ science.nasa.gov]
| COSPAR_ID             = 1992-063A
| SATCAT                = 22136
| mission_duration      = {{time interval|25 Sept 1992|21 Aug 1993|show=dhm}}<br/><small>Mission failure</small>

| spacecraft_type       =
| spacecraft_bus        = Mars Observer bus (AS-4000-TIROS/DMSP hybrid)
| manufacturer          = [[General Electric]]<br>Astro Space
| dry_mass              = 
| launch_mass           = {{cvt|1018|kg|lb}}
| power                 = 1,147&nbsp;watts

| launch_date           = {{start date text|September 25, 1992, 17:05:01|timezone=yes}}&nbsp;UTC
| launch_rocket         = {{nowrap|[[Commercial Titan III]]/[[Transfer Orbit Stage|TOS]]}}
| launch_site           = [[Cape Canaveral Space Force Station|Cape Canaveral]] [[Cape Canaveral Air Force Station Space Launch Complex 40|LC-40]]
| launch_contractor     = [[Martin Marietta]]

| last_contact          = {{end date text|August 21, 1993, 01:00|timezone=yes}}&nbsp;UTC

| orbit_epoch           = December 6, 1993<br><small>Planned</small>
| orbit_reference       = [[Areocentric orbit|Areocentric]]
| orbit_inclination     = 92.869°
| orbit_semimajor       = {{cvt|3766.159|km|mi}}
| orbit_eccentricity    = 0.004049
| apsis                 = areion

|interplanetary         = 
 {{Infobox spaceflight/IP
   |type                = flyby
   |note                = failed insertion
   |object              = [[Mars]]
   |arrival_date        = August 24, 1993
 }}

| programme             = '''[[Planetary Observer program]]'''
}}
The '''''Mars Observer''''' spacecraft, also known as the '''''Mars Geoscience/Climatology Orbiter''''', was a [[Robotic spacecraft|robotic]] [[space probe]] launched by [[NASA]] on September 25, 1992, to study the Martian surface, atmosphere, climate and magnetic field.  On August 21, 1993, during the interplanetary cruise phase, communication with the spacecraft was lost, three days prior to the probe's [[orbital insertion]].  Attempts to re-establish communications with the spacecraft were unsuccessful.