MARS GLOBAL SURVEYOR
Launch Date: 07 November 1996 UT 17:00:50
Launch Vehicle: Delta II
On-orbit mass: 1030.5 kg
Power System: 4 Solar Array Panels, 667 W
The Mars Global Surveyor (MGS) mission is designed as a rapid, low-cost recovery of the Mars Observer mission objectives. The science objectives involve high resolution imaging of the surface, studies of the topography and gravity, the role of water and dust on the surface and in the atmosphere of Mars, the weather and climate of Mars, the composition of the surface and atmosphere, and the existence and evolution of the Martian magnetic field.
The spacecraft began its Mars orbit insertion burn at 01:17 UT 12 September 1997 (9:17 p.m. EDT September 11) after a 10 month cruise phase. The time for the radio signal to travel from Mars to Earth is about 14 minutes, so the Earth received time for these events was 14 minutes later, or 9:31 p.m. EDT for the beginning of the orbit insertion burn. At 9:29 p.m. the spacecraft went behind Mars and contact was lost at Earth at 9:43 p.m., closest approach to Mars on this pass was at 9:30 p.m. The burn was completed at 9:39 p.m. and contact was re-established at Earth at 9:57 p.m. Mars Global Surveyor started in an elliptical (54,021 x 258 km altitude) 45 hour orbit.
Over the sixteen months after orbit insertion, aerobraking and thrusters will slowly convert the original elliptical capture orbit into a nearly circular 2 hour polar orbit with an average altitude of 378 km, allowing complete coverage of the planet every 7 days. The primary mapping mission will begin about March, 1999. (Primary mapping was originally scheduled to begin in March, 1998 but a malfunction of one of the solar panel supports delayed the aerobraking schedule for one year.) The spacecraft will be in a "sun-synchronous" orbit so that each image will be taken with the sun at the same mid-afternoon azimuth. Data will be acquired until April 2002. The spacecraft will also be used as a data relay for later U.S. and international missions over the following two years. Mars Global Surveyor is the first spacecraft to be launched in a decade-long exploration of Mars by NASA. Launches will be occurring every 26 months, in 1998, 2001, 2003 and 2005, involving orbiters, landers, rovers, and probes to Mars. Orbiters launched in 1998 and 2003 will contain other instruments to recover the planned Mars Observer objectives. More detailed information on Mars Global Surveyor is available from the NSSDCA Master Catalog.
The Mars Global Surveyor will consist of six primary investigations:
The Mars Orbiter Camera (MOC)
- Michael Malin, Malin Space Science Systems
The Mars Orbiter Camera will take high resolution images, on the order of a meter or so, of surface features. It will also take lower resolution images of the entire planet over time to enable research into the temporal changes in the atmosphere and on the surface.
Thermal Emission Spectrometer (TES) - Phil Christensen, Arizona State University
The Thermal Emission Spectrometer is a Michelson interferometer that will measure the infrared spectrum of energy emitted by a target. This information will be used to study the composition of rock, soil, ice, atmospheric dust, and clouds.
Mars Orbiter Laser Altimeter (MOLA) - David Smith, Goddard Space Flight Center
This instrument will measure the time it takes for a transmitted laser beam to reach the surface, reflect, and return. This time will give the distance, and hence the height of the surface. Combining these measurements will result in a topographic map of Mars.
Radio Science Investigations (RS) - G. Leonard Tyler, Stanford University
Measurements of the Doppler shift of radio signals sent back to Earth will allow precise determination of changes in the orbit, which will allow for a model of the Mars gravity field. As the spacecraft passes over the poles on each orbit, radio signals pass through the Martian atmosphere on their way to Earth. The way in which the atmosphere affects these signals allows determination of its physical properties.
Magnetic Fields Investigation (MAG/ER) - Mario Acuna, Goddard Space Flight Center
A magnetometer will be used to determine whether Mars has a magnetic field, and the strength and orientation of the field if one exists. An electron reflectometer will measure remnant crustal magnetization.
Mars Relay - Jacques Blamont, Centre National d'Etudes Spatiales
The Mars Relay experiment consists of an antenna which will route received signals through the Mars Observer Camera for transmission to Earth. The relay will be used to support surface landers and rovers from other Russian, European, and U.S. missions.
MISSION OVERVIEW:
Mars Global Surveyor was the first spacecraft in NASA's new Mars Surveyor program that was designed to inaugurate a new generation of American space probes to explore Mars every twenty-six months from 1996 to 2005. The Mars Surveyor program (formulated in 1994) was intended to economize costs and maximize returns by involving a single industrial partner with the Jet Propulsion Laboratory to design, build, and deliver a flightworthy vehicle for Mars every two years.
The Mars Global Surveyor spacecraft carried five instruments similar to those carried by the lost Mars Observer probe that fell silent in 1993. After midcourse corrections on 21 November 1996 and 20 March 1997, Mars Global Surveyor entered orbit around Mars on 12 September 1997 after engine ignition at 01:17 UT. Initial orbital parameters were 258 x 54,021 kilometers.
Commencement of its planned two-year mission was delayed because one of its two solar panels (-Y) had not fully deployed soon after launch, prompting mission planners to reconfigure the aerobraking process required to place the vehicle in its intended orbit. The solar panels were designed to act as atmospheric brakes to change orbit. The modified aerobraking maneuver altered the planned orbit from an afternoon pass over the equator to a nighttime pass and also delayed the mission by a year and at the time seem to have shortened its projected lifetime.
The spacecraft's revised aerobraking maneuvers were finally completed on 4 February 1999 with a major burn from its main engine. A subsequent firing on 19 February finally put Mars Global Surveyor into a Sun-synchronous orbit, and on 9 March 1999, its mapping mission formally began.
Despite the early problems, Mars Global Surveyor began to send back impressive data and images of Mars during its movement to its new orbit. The spacecraft tracked the evolution of a dust storm, gathered information on the Martian terrain, found compelling evidence indicating the presence of liquid water at or near the surface (formally announced by NASA on 22 June 2000), and photographed the infamous "face on Mars" that some believed was an artificial formation.
During its mission, the Mars Global Surveyor also produced the first three-dimensional profiles
of Mars's north pole using laser altimeter readings. By mid-2000, the spacecraft had taken tens of thousands of high-resolution photos of the Red Planet.
Operations were expected to end by 31 January 2001, but the good health of onboard systems allowed scientists to continue the mission. Contact was eventually lost with the orbiter on 14 Nov. 2006, nine years and 52 days after it entered orbit
Launch Vehicle: Delta II
On-orbit mass: 1030.5 kg
Power System: 4 Solar Array Panels, 667 W
The Mars Global Surveyor (MGS) mission is designed as a rapid, low-cost recovery of the Mars Observer mission objectives. The science objectives involve high resolution imaging of the surface, studies of the topography and gravity, the role of water and dust on the surface and in the atmosphere of Mars, the weather and climate of Mars, the composition of the surface and atmosphere, and the existence and evolution of the Martian magnetic field.
The spacecraft began its Mars orbit insertion burn at 01:17 UT 12 September 1997 (9:17 p.m. EDT September 11) after a 10 month cruise phase. The time for the radio signal to travel from Mars to Earth is about 14 minutes, so the Earth received time for these events was 14 minutes later, or 9:31 p.m. EDT for the beginning of the orbit insertion burn. At 9:29 p.m. the spacecraft went behind Mars and contact was lost at Earth at 9:43 p.m., closest approach to Mars on this pass was at 9:30 p.m. The burn was completed at 9:39 p.m. and contact was re-established at Earth at 9:57 p.m. Mars Global Surveyor started in an elliptical (54,021 x 258 km altitude) 45 hour orbit.
Over the sixteen months after orbit insertion, aerobraking and thrusters will slowly convert the original elliptical capture orbit into a nearly circular 2 hour polar orbit with an average altitude of 378 km, allowing complete coverage of the planet every 7 days. The primary mapping mission will begin about March, 1999. (Primary mapping was originally scheduled to begin in March, 1998 but a malfunction of one of the solar panel supports delayed the aerobraking schedule for one year.) The spacecraft will be in a "sun-synchronous" orbit so that each image will be taken with the sun at the same mid-afternoon azimuth. Data will be acquired until April 2002. The spacecraft will also be used as a data relay for later U.S. and international missions over the following two years. Mars Global Surveyor is the first spacecraft to be launched in a decade-long exploration of Mars by NASA. Launches will be occurring every 26 months, in 1998, 2001, 2003 and 2005, involving orbiters, landers, rovers, and probes to Mars. Orbiters launched in 1998 and 2003 will contain other instruments to recover the planned Mars Observer objectives. More detailed information on Mars Global Surveyor is available from the NSSDCA Master Catalog.
The Mars Global Surveyor will consist of six primary investigations:
The Mars Orbiter Camera will take high resolution images, on the order of a meter or so, of surface features. It will also take lower resolution images of the entire planet over time to enable research into the temporal changes in the atmosphere and on the surface.
Thermal Emission Spectrometer (TES) - Phil Christensen, Arizona State University
The Thermal Emission Spectrometer is a Michelson interferometer that will measure the infrared spectrum of energy emitted by a target. This information will be used to study the composition of rock, soil, ice, atmospheric dust, and clouds.
Mars Orbiter Laser Altimeter (MOLA) - David Smith, Goddard Space Flight Center
This instrument will measure the time it takes for a transmitted laser beam to reach the surface, reflect, and return. This time will give the distance, and hence the height of the surface. Combining these measurements will result in a topographic map of Mars.
Radio Science Investigations (RS) - G. Leonard Tyler, Stanford University
Measurements of the Doppler shift of radio signals sent back to Earth will allow precise determination of changes in the orbit, which will allow for a model of the Mars gravity field. As the spacecraft passes over the poles on each orbit, radio signals pass through the Martian atmosphere on their way to Earth. The way in which the atmosphere affects these signals allows determination of its physical properties.
Magnetic Fields Investigation (MAG/ER) - Mario Acuna, Goddard Space Flight Center
A magnetometer will be used to determine whether Mars has a magnetic field, and the strength and orientation of the field if one exists. An electron reflectometer will measure remnant crustal magnetization.
Mars Relay - Jacques Blamont, Centre National d'Etudes Spatiales
The Mars Relay experiment consists of an antenna which will route received signals through the Mars Observer Camera for transmission to Earth. The relay will be used to support surface landers and rovers from other Russian, European, and U.S. missions.
MISSION OVERVIEW:
Mars Global Surveyor was the first spacecraft in NASA's new Mars Surveyor program that was designed to inaugurate a new generation of American space probes to explore Mars every twenty-six months from 1996 to 2005. The Mars Surveyor program (formulated in 1994) was intended to economize costs and maximize returns by involving a single industrial partner with the Jet Propulsion Laboratory to design, build, and deliver a flightworthy vehicle for Mars every two years.
The Mars Global Surveyor spacecraft carried five instruments similar to those carried by the lost Mars Observer probe that fell silent in 1993. After midcourse corrections on 21 November 1996 and 20 March 1997, Mars Global Surveyor entered orbit around Mars on 12 September 1997 after engine ignition at 01:17 UT. Initial orbital parameters were 258 x 54,021 kilometers.
Commencement of its planned two-year mission was delayed because one of its two solar panels (-Y) had not fully deployed soon after launch, prompting mission planners to reconfigure the aerobraking process required to place the vehicle in its intended orbit. The solar panels were designed to act as atmospheric brakes to change orbit. The modified aerobraking maneuver altered the planned orbit from an afternoon pass over the equator to a nighttime pass and also delayed the mission by a year and at the time seem to have shortened its projected lifetime.
The spacecraft's revised aerobraking maneuvers were finally completed on 4 February 1999 with a major burn from its main engine. A subsequent firing on 19 February finally put Mars Global Surveyor into a Sun-synchronous orbit, and on 9 March 1999, its mapping mission formally began.
Despite the early problems, Mars Global Surveyor began to send back impressive data and images of Mars during its movement to its new orbit. The spacecraft tracked the evolution of a dust storm, gathered information on the Martian terrain, found compelling evidence indicating the presence of liquid water at or near the surface (formally announced by NASA on 22 June 2000), and photographed the infamous "face on Mars" that some believed was an artificial formation.
During its mission, the Mars Global Surveyor also produced the first three-dimensional profiles
of Mars's north pole using laser altimeter readings. By mid-2000, the spacecraft had taken tens of thousands of high-resolution photos of the Red Planet.
Operations were expected to end by 31 January 2001, but the good health of onboard systems allowed scientists to continue the mission. Contact was eventually lost with the orbiter on 14 Nov. 2006, nine years and 52 days after it entered orbit
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