MCO

Mars Climate Orbiter
(MCO) satellite


This page contains philatelic information on the Mars Climate Orbiter (MCO) satellite. Catalog numbers, years of issue, and notes on the satellites featured are given when available. If readers know of additional information or images, please contact the authors using the e-mail addresses at the bottom of this page.

Launch information
(found elsewhere)
Launch covers
(including anniversary-of-launch covers, and launch-related event covers)
(farther below)
Other postal items
(stamps, souvenir sheets, aerogrammes, postal cards, etc.)
(immediately below)
Mars Surveyor 1998 Orbiter2 [canceled] Mars Surveyor 1998 Orbiter2
(MCO forerunner)
MCO MCO MCO


Below is a list of Mars Climate Orbiter satellite postal items (stamps, souvenir sheets, aerogrammes, postal cards, etc.).

CountryCatalog NumberType of ItemYear of IssueNotes on Content
Mars Surveyor 1998 Orbiter2 (MCO Forerunner)
Palau412 (BL47)SS11996The "Surveyor spacecraft" (full name Mars Surveyor 1998 Orbiter, which became the MCO) was part of the Mars Surveyor 1998 program2, along with the Mars Surveyor 1998 Lander, which became the MPL
Palau412 fdcSS1 on FDC
Mars Climate Orbiter (MCO)
Comoro Islands1009d (Mi1949)One of MS6 (1009 (a-f)) (Mi1946-1951)2008"Mars Climate" Orbiter
DjiboutiMi8678One of MS4 (Mi8675-8678)2024"Mars Climate Orbiter"
Ivory CoastUnknown a (Mi none)One of MS4 (a-d) [known illegal issue]2012"Mars Climate Orbiter"
LiberiaUnknown b (Mi?)One of MS4 (a-d)2023Mars Surveyor 1998 program mission patch1 (includes depictions of MCO and MPL)
LiberiaUnknown ss (BL?)In (lower-left) margin of SS1
Maldive IslandsMi8593One of MS4 (Mi8590-8593)2019Mars Surveyor 1998 program mission patch2 (includes depictions of MCO and MPL)
Nevis1215 (BL187)SS12000"Mars Climate Orbiter"
Niger1076c (Mi1910A)
i1076c (Mi1910B)
One of MS9 (1076 (a-i)) (Mi1908A-1916A)
One of imperforate MS9 (i1076 (a-i))
2001"Mars Climate Orbiter"
Palau501b (Mi1457)One stamp and in (upper-right) margin of MS6 (501 (a-f)) (Mi1456-1461)1999"Mars Climate Orbiter" (but Mars Odyssey depicted)1 (stamp 'b'); Mars Surveyor 1998 program mission patch2 (includes depictions of MCO and MPL) (in upper-right margin)
Palau503 (BL84)SS1"Mars Climate Orbiter"
St. Kitts870c (Mi1370)From MS4 (870 (a-d)) (Mi1368-1371)2014"Mars [Climate] Orbiter" (but Mars Odyssey depicted)1
St. Kitts870d (Mi1371)"Mars Climate" Orbiter
Sierra Leone5367a (Mi11169)One of MS4 (5367 (a-d)) (Mi11169-11172)2019Mars Surveyor 1998 program mission patch2 (includes depictions of MCO and MPL)
Sierra LeoneUnknown a (Mi18550)One of MS5 (a-e + label) (Ni18550-18554)2024Mars Surveyor 1998 program mission patch2 (includes depictions of MCO and MPL)
Togo2035e (Mi3320)
i2035e
One of MS6 (2035 (a-f)) (Mi3316-3321)
One of imperforate MS6 (i2035 (a-f))
2006MCO (but "Odyssey" in text)1
TogoUnknown ss (BL?)In (upper-right) margin of SS12023Mars Surveyor 1998 program mission patch2 (includes depictions of MCO and MPL)
United States3242 fdc (Mi? fdc)(Mystic Stamp Company) back of FDC, also front1998MCO (launched Dec 1998) and MPL (launched Jan 1999) studied "weather changes on Mars, especially in the south polar region"

1Mars Climate Orbiter appears quite similar to Mars Odyssey but without an instrumented boom attached to the spacecraft body.
2Mars Surveyor 1998 program: see https://nasa.fandom.com/wiki/Mars_Surveyor_%2798_program.


Below is a list of Mars Climate Orbiter (MCO) satellite launch covers (including anniversary-of-launch covers, and launch-related event covers).

CountryCancel DateCancel LocationType of ItemNotes on Content
1998-12-11: Mars Climate Orbiter (MCO)
United States1998-12-10Titusville FL, Astronaut Trail Station(DTR) cachet on coverMCO launch
United States1998-12-11Kennedy Space Center FL(DTR) cachet on coverMCO launch
United States1998-12-11Kennedy Space Center FL(FM?) cachet on coverMCO launch
United States1998-12-11Pasadena CA(Mission Operations Station) cancel and (JPL Stamp Club) cachet on coverMCO launch (the "Mars Surveyor 98" program included both the "Mars 98 Climate Observer" (an early name for the MCO) and the MPL; the cachet, which reproduces the mission patch of that program, depicts both); Mars Odyssey (not "Mars Climate Orbiter") in the cancel)
MCO (post-launch events)
United States1999-09-23Pasadena CA(JPL Stamp Club) cachet on coverattempted Mars orbit insertion and loss1 ("Mars [98] Climate Observer" in text)
United States1999-09-23Pasadena CA(Black and purple rubber-stamp) cachet on cover"Spaceraft [sic] lost during MOI" (Mars Orbital Insertion)1 ("Mars Surveyor 98 - Mars Climate Orbiter" in text)

1The Mars Climate Orbiter (MCO) was lost as it was occulted by Mars (went behind Mars as viewed from Earth). The root cause of the loss was found to be the use of English units for thruster performance data generated by a ground based computer program. This data was used in the construction of trajectory models for the spacecraft, and the modelers assumed the data was in metric units as per the specifications.


Back to Planetary-exploration spacecraft.
Back to Un-manned Satellite (or Spacecraft) Philately.



Copyright © 2014-2026, Colorado State University. All rights reserved.
This Website created and maintained by Don Hillger and Garry Toth.
Updated: 2026-03-02