Completed · full success Orbiter 1996

Mars Global Surveyor (MGS)

Mars Global Surveyor (MGS), launched by NASA in November 1996, was a pioneering orbital mission that revolutionized our understanding of Mars. After a long aerobraking phase, it globally mapped the surface, studied mineralogy, analyzed the remnant magnetic field, and demonstrated the past presence of abundant liquid water.

Agency NASA
Launch SOL 34 OF BOREO OF YEAR 23 · 14:12 MTC
Arrival at Mars SOL 37 OF JUVENO OF YEAR 23 · 16:29 MTC
Operations Start SOL 8 OF GANGIO OF YEAR 24 · 02:34 MTC
Mission End SOL 17 OF HESPERO OF YEAR 28 · 07:47 MTC
of travel 308 days · ~299 sols
of operations 2,720 sols · 2,795 days
Cruise to Mars308 days
Arrival & commissioning543 days
Operations2,795 days

Trajectory to Mars

Calculated in your browser with the real positions of Earth and Mars on those dates (Lambert transfer). Move the slider to fly with the probe.

Open the orbital map →

Technical Analysis of the Mars Global Surveyor (MGS) Mission

  • Mission Designation: Mars Global Surveyor (MGS)
  • COSPAR Designation: 1996-060A
  • Operating Agency: NASA (Jet Propulsion Laboratory / JPL)
  • Launch Date: November 7, 1996, 17:00 UTC
  • Launch Vehicle: Delta II Rocket (model 7925, D239)
  • Launch Site: Cape Canaveral Air Force Station, Launch Complex 17A (LC-17A), USA
  • Orbital Insertion Date: September 12, 1997, 01:17 UTC
  • Mission Status: Mission Complete

1. Historical Context and Detailed Objectives

The scientific void that the Mars Global Surveyor mission aimed to fill encompassed the global and systematic understanding of the red planet following the losses suffered by previous missions. Primary objectives focused on:

Scientific:

  • Globally examine the surface, atmosphere, ionosphere, and interior of Mars.
  • Map global topography using high-resolution laser altimetry (MOLA).
  • Study the mineralogical and thermal composition of the surface and investigate geological morphology and water history.
  • Analyze the remnant magnetic field and the structure of the atmosphere and gravity.

Engineering:

  • Act as a communications relay satellite (Mars Relay Antenna) for future surface missions.
  • Validate complex aerobraking techniques for efficient orbital adjustment with low propellant consumption.

2. Vehicle Architecture and Main Subsystems

The dry mass of the spacecraft was 1,030.5 kg, with a total launch mass of 1,050.3 kg (including 311.5 kg of hydrazine propellant). Its dimensions in the main rectangular body configuration spanned approximately 1.17 m x 1.17 m x 1.7 m. The power system consisted of deployable solar arrays providing a nominal power of 980 W and powering two 20 Ah nickel-hydrogen (NiH2) batteries. Communications were carried out via high and low gain antennas linked to the Deep Space Network (DSN), incorporating a specific relay antenna. Mobility was governed by hydrazine propulsion for attitude control and maneuvers in a sun-synchronous areocentric orbit.

3. Payload and Scientific Instrumentation

  • MOC (Mars Orbiter Camera): Camera to capture detailed high-resolution surface images and global panoramas of climate and clouds.
  • MOLA (Mars Orbiter Laser Altimeter): Laser altimeter tasked with measuring altitude to map the three-dimensional global topography of Mars.
  • TES (Thermal Emission Spectrometer): Thermal emission spectrometer to determine the mineralogical composition of the surface and study the atmosphere.
  • MAG/ER (Magnetometer / Electron Reflectometer): Magnetometer and electron reflectometer to investigate the crustal remnant magnetic field and space environment.
  • RS / USO (Radio Science / Ultrastable Oscillator): Radio science experiment to analyze gravitational fields and atmospheric refractive profiles.

4. Chronology and Mission Phases

Following the launch in November 1996 and orbital insertion in September 1997, the spacecraft executed a long aerobraking phase until February 1999 to adjust its orbit. Systematic scientific mapping began on March 9, 1999. The primary mission concluded in January 2001, giving way to successive extended mission phases. Final contact with the orbiter was recorded on November 2, 2006, following a computer anomaly during a solar array reorientation.

5. Results and Discoveries

MGS revolutionized planetary knowledge by demonstrating that Mars harbored abundant water in the past through the identification of river valleys, ancient sedimentary deposits, and clay minerals. It discovered recent morphological indications of seasonal liquid water flows in crater gullies and revealed the absence of an active global dipole magnetic field, detecting intense remnant magnetic anomalies in the ancient crust.

6. Legacy and Importance

The mission laid the foundations for modern Mars cartography and served as a vital communications node for subsequent rovers. With a cost of approximately 247 million dollars, it completed over nine years of continuous operational service, vastly exceeding its initial expectations.

Related

Marspedia terms