NASAThe National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for...
's
Mars Reconnaissance Orbiter (
MRO) is a multipurpose
spacecraftA spacecraft is a craft or machine designed for spaceflight. On a sub-orbital spaceflight, a spacecraft enters space then returns to the Earth. For an orbital spaceflight, a spacecraft enters a closed orbit around the planetary body. Spacecraft used for human spaceflight carry people on board as...
designed to conduct
reconnaissanceReconnaissance is a military and medical term denoting exploration conducted to gain information. Militarily, its shorthand Canadian and British form is recce , its American usage form is recon...
and exploration of
MarsMars is the fourth planet from the Sun in the Solar System. The planet is named after Mars, the Roman god of war. It is also referred to as the "Red Planet" because of its reddish appearance, due to iron oxide prevalent on its surface....
from orbit.
When MRO entered orbit there were five other spacecraft in orbit of or on Mars:
Mars Global SurveyorThe Mars Global Surveyor was a US spacecraft developed by NASA's Jet Propulsion Laboratory and launched November 1996. It began the United States's return to Mars after a 10-year absence. It completed its primary mission in January 2001 and was in its third extended mission phase when, on , the...
,
Mars Express,
Mars Odyssey, and two
Mars Exploration RoverNASA's Mars Exploration Rover Mission is an ongoing robotic mission of exploring Mars, that began in 2003 with the sending of two rovers — MER-A Spirit and MER-B Opportunity — to explore the Martian surface and geology....
s; a then record for most spacecraft operational in Mars vicinity. The $720 million
USDThe United States dollar is the unit of currency of the United States. The U.S. dollar is normally abbreviated as the dollar sign, $, or as USD or US$ to distinguish it from other dollar-denominated currencies and from others that use the $ symbol. It is divided into 100 cents .The U.S...
spacecraft was built by
Lockheed MartinLockheed Martin is a multinational aerospace manufacturer, global security and advanced technology company formed in 1995 by the merger of Lockheed with Martin Marietta. It is headquartered in Bethesda, Maryland, in the Washington Metropolitan Area. Lockheed Martin employs 146,000 people...
under the supervision of the
Jet Propulsion LaboratoryJet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is situated in the northern portion of Pasadena...
. It was launched August 12, 2005, and attained Martian orbit on March 10, 2006. In November 2006, after five months of
aerobrakingAerobraking is a spaceflight maneuver that reduces the high point of an elliptical orbit by flying the vehicle through the atmosphere at the low point of the orbit . The resulting drag slows the spacecraft...
, it entered its final science orbit and began its primary science phase.
MRO contains a host of scientific instruments such as
camerathumb |right|Cameras from Large to Small, Film to Digital A camera is a device that records images, either as a still photograph or as moving images known as videos or movies...
s,
spectrometerA spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization...
s, and
radarRadar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for RAdio Detection And...
, which are used to analyze the
landformIn the earth sciences and geology sub-fields, a landform or physical feature comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography...
s,
stratigraphyStratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
,
mineralA mineral is a naturally occurring solid formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties. A rock, by comparison, is an aggregate of minerals and/or mineraloids, and need not have a specific...
s, and
iceIce is a solid phase, usually crystalline, of a non-metallic substance that is liquid or gas at room temperature, such as carbon dioxide ice , ammonia ice, or methane ice. However, the predominant use of the term ice is for water ice, technically restricted to one of the 15 known crystalline phases...
of Mars. It paves the way for future spacecraft by monitoring daily weather and surface conditions, studying potential landing sites, and hosting a new telecommunications system.
MROs telecommunications system will transfer more dataData transmission, digital transmission or digital communications is the physical transfer of data over a point-to-point or point-to-multipoint transmission medium. Examples of such media are copper wires, optical fibers, wireless communication media, and storage media...
back to Earth than all previous interplanetary missions combined, and MRO will serve as a highly capable relay satellite for future missions.
The mission is managed by the
Jet Propulsion LaboratoryJet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is situated in the northern portion of Pasadena...
, a division of the
California Institute of TechnologyThe California Institute of Technology is a private research university located in Pasadena, California, United States. The Institute maintains a strong emphasis on the natural sciences and engineering, and operates and manages NASA's neighboring Jet Propulsion Laboratory...
, Pasadena, Calif., for
NASAThe National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for...
's Science Mission Directorate, Washington, D.C.
Prior to launch
It was one of two missions being considered for the 2003 Mars
launch windowLaunch window is a term used in spaceflight to describe a time period in which a particular rocket must be launched. If the rocket does not launch within the "window", it has to wait for the next window....
; however, during the proposal process the orbiter lost against what became known as the Mars Exploration Rovers. The orbiter mission was rescheduled for launch in 2005, and
NASAThe National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for...
announced its final name, Mars Reconnaissance Orbiter
, on October 26, 2000.
MRO
is modeled after NASA's highly successful Mars Global SurveyorThe Mars Global Surveyor was a US spacecraft developed by NASA's Jet Propulsion Laboratory and launched November 1996. It began the United States's return to Mars after a 10-year absence. It completed its primary mission in January 2001 and was in its third extended mission phase when, on , the...
to conduct surveillance of Mars from orbit. Early specifications of the satellite included a large camera to take high resolution pictures of Mars. In this regard, Jim Garvin, the Mars exploration program scientist for NASA, proclaimed that MRO
would be a "microscope in orbit". The satellite was also to include a visible-near-infrared spectrograph.
On October 3, 2001, NASA chose Lockheed MartinLockheed Martin is a multinational aerospace manufacturer, global security and advanced technology company formed in 1995 by the merger of Lockheed with Martin Marietta. It is headquartered in Bethesda, Maryland, in the Washington Metropolitan Area. Lockheed Martin employs 146,000 people...
as the primary contractor for the spacecraft's fabrication. By the end of 2001 all of the mission's instruments were selected. There were no major setbacks during MROs construction, and the spacecraft was moved to John F. Kennedy Space Center on May 1, 2005 to prepare it for launch.
Mission objectives
MRO science operations will last two Earth years, from November 2006 to November 2008. One of the mission's main goals is to map the Martian landscape with its high-resolution cameras in order to choose landing sites for future surface missions. The
MRO played an important role in choosing the landing site of the
Phoenix LanderPhoenix was a robotic spacecraft on a space exploration mission on Mars under the Mars Scout Program. The Phoenix lander descended on Mars on May 25, 2008...
, which explored the Martian Arctic in
Green ValleyGreen Valley is a region on Mars within Vastitas Borealis that was chosen as the landing site of NASA's Phoenix lander. It is located at 68.35 degrees north, 233 degrees east. The valley is about 50 kilometers wide but only about 250 meters deep; either it was filled in or was never any deeper than...
. The initial site chosen by scientists was imaged with the HiRISE camera and found to be littered with boulders. After analysis with HiRISE and the Mars Odyssey's THEMIS a new site was chosen.
Mars Science LaboratoryThe Mars Science Laboratory , known as Curiosity, is a NASA rover scheduled to be launched between October and December 2011 and perform the first-ever precision landing on Mars. The MSL rover will be over five times as heavy and carry over ten times the weight in scientific instruments as one of...
, a highly maneuverable rover, will also have its landing site inspected. The
MRO will also provide critical navigation data during their landings and act as a telecommunications relay.
MRO is using its on-board scientific equipment to study the Martian
climateClimate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and numerous other meteorological elements in a given region over long periods of time...
,
weatherWeather is a set of all the phenomena occurring in a given atmosphere at a given time. Weather phenomena lie in the troposphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate is the term for the average atmospheric conditions over longer periods...
,
atmosphereAn atmosphere is a layer of gases that may surround a material body of sufficient mass, by the gravity of the body, and are retained for a longer duration if gravity is high and the atmosphere's temperature is low...
, and
geologyGeology is the science and study of the solid and liquid matter that constitutes the Earth. The field of geology encompasses the study of the composition, structure, physical properties, dynamics, and history of Earth materials, and the processes by which they are formed, moved, and changed...
, and to search for signs of water in the polar caps and underground. In addition,
MRO is looking for the remains of the previously lost
Mars Polar LanderMars Polar Lander is one of two exploration vehicles of the NASA Mars Surveyor '98 program. Launched on 3 January 1999, 23 days after its partner, the Mars Climate Orbiter, the mission ended in failure with the loss of both craft in separate incidents...
and
Beagle 2Beagle 2 was an unsuccessful British landing spacecraft that formed part of the European Space Agency's 2003 Mars Express mission. It is not known for certain whether the lander reached the Martian surface; all contact with it was lost upon its separation from the Mars Express six days before its...
spacecraft, and serves as the first step in setting up an
internet protocolThe Internet Protocol is a protocol used for communicating data across a packet-switched internetwork using the Internet Protocol Suite, also referred to as TCP/IP....
network for the planets in our solar system. After its main science operations are completed, the probe's extended mission is to be the communication and navigation system for landers and rover probes.
Launch and orbital insertion
On August 12, 2005,
MRO was launched aboard an
Atlas VAtlas V is an active expendable launch system in the Atlas rocket family. Atlas V was formerly operated by Lockheed Martin, and is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance...
-401 rocket from Space Launch Complex 41 at
Cape Canaveral Air Force StationThe Cape Canaveral Air Force Station is an installation of the Air Force Space Command's 45th Space Wing , headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the State of Florida, CCAFS is the primary Launch Head of the Eastern Range...
. The
Centaur upper stageCentaur is a rocket stage designed for use as the upper stage of space launch vehicles. Centaur boosts its satellite payload to its final orbit or, in the case of an interplanetary space probe, to escape velocity...
of the rocket completed its burns over a fifty-six minute period and placed
MRO in
interplanetary transfer orbitIn orbital mechanics, the Hohmann transfer orbit is an orbital maneuver using two engine impulses which, under standard assumptions, move a spacecraft between two coplanar circular orbits. This maneuver was named after Walter Hohmann, the German scientist who published a description of it in 1925...
towards Mars.
MRO cruised through interplanetary space for seven and a half months before reaching Mars. While en route most of the scientific instruments and experiments were tested and calibrated. To ensure proper orbital insertion upon reaching Mars, four
trajectoryA trajectory is the path a moving object follows through space. The object might be a projectile or a satellite, for example. It thus includes the meaning of orbit - the path of a planet, an asteroid or a comet as it travels around a central mass...
correction maneuvers were planned and a fifth emergency maneuver was discussed. However, only three trajectory correction maneuvers were necessary, saving fuel for
MROs extended mission.
MRO
began orbital insertion by approaching Mars on March 10, 2006, and passing above its southern hemisphere at an altitude of 370–400 km (190 mi). All six of MROs main engines burned for 27 minutes to slow the probe from ~2,900 m/s to ~1,900 m/s (6,500 mph to 4,250 mph). The helium pressurization tank was colder than expected, which reduced the pressure in the fuel tank by about 21
kPaKPA may refer to:* Kenya Ports Authority* Kilopascal , a unit of pressure* Known-plaintext attack, a method of cryptanalysis* Korean People's Army* The Kosovo Property Agency* Also refers to the Montagnard name meaning "straight"....
(3 psi). The reduced pressure caused the engine thrust to be diminished by 2%, but
MRO automatically compensated by extending the burn time by 33 seconds.
Completion of the orbital insertion placed the orbiter in a highly
ellipticalIn astrodynamics or celestial mechanics an elliptic orbit is a Kepler orbit with the eccentricity greater than 0 and less than 1. In a gravitational two-body problem with the eccentricity in this range both bodies follow similar elliptic orbits with the same orbital period around their common...
polar orbit with a period of approximately 35.5 hours. Shortly after insertion, the periapsis – the point in the orbit closest to Mars – was 3,806 km from the planet's center (426 km from its surface). The apoapsis – the point in the orbit farthest from Mars – was 47,972 km from the planet's center (44,500 km from its surface).
On March 30, 2006,
MRO began the process of
aerobrakingAerobraking is a spaceflight maneuver that reduces the high point of an elliptical orbit by flying the vehicle through the atmosphere at the low point of the orbit . The resulting drag slows the spacecraft...
, a three-step procedure that cuts in half the fuel needed to achieve a lower, more circular orbit with a shorter period. First, during its first five orbits of the planet (one Earth week),
MRO used its thrusters to drop the periapsis of its orbit into aerobraking altitude. This altitude depends on the thickness of the
atmosphereMars, the fourth planet from the Sun, has a very different atmosphere than that of the Earth. There has been much interest in studying its composition since the recent detection of a small amount of methane, which may signal life on Mars; it could also be a geochemical process or the result of...
because Martian atmospheric density changes with its seasons. Second, while using its thrusters to make minor corrections to its periapsis altitude,
MRO maintained aerobraking altitude for 445 planetary orbits (about 5 Earth months) to reduce the apoapsis of the orbit to 450 km (280 mi). This was done in such a way so as to not heat the spacecraft too much, but also dip enough into the atmosphere to slow the spacecraft down. After the process was complete,
MRO used its thrusters to move its periapsis out of the edge of the Martian atmosphere, August 30, 2006.
In September 2006
MRO fired its thrusters twice more to fine-tune its final, nearly circular orbit approximately 250 to 316 km (155 to 196 mi) above the Martian surface. The SHARAD dipole antennas were deployed on September 16. All of the scientific instruments were tested and most were turned off prior to the
solar conjunctionSolar conjunction occurs when a planet or other solar system object is on the opposite side of the sun from the Earth. From an Earth reference, the object will pass behind the sun. Communication with any spacecraft in solar conjunction will be severely limited due to the sun's blocking radio...
which occurred from October 7, 2006 to November 6, 2006. After the conjunction ended the "primary science phase" began.
On November 17, 2006 NASA announced the successful test of the MRO as an orbital communications relay. Using the NASA rover "
SpiritSpirit, mission designation MER-A , is the first of the two rovers of NASA's Mars Exploration Rover Mission. It landed successfully on Mars on 04:35 Ground UTC on January 4, 2004, three weeks before its twin Opportunity landed on the other side of the planet...
" as the point of origin for the transmission, the MRO acted as a relay for transmitting data back to Earth.
Events and discoveries
On September 29, 2006, MRO took its first high resolution image from its science orbit. This image is said to resolve items as small as 90 cm (3 feet) in diameter.
On October 6, 2006,
NASAThe National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for...
released detailed pictures from the MRO of Victoria crater along with the
Opportunity roverOpportunity, mission designation MER-B , is the second of the two rovers of NASA's Mars Exploration Rover Mission. It landed successfully at Meridiani Planum on Mars on January 25, 2004 05:05 Ground UTC , three weeks after its twin Spirit had landed on the other side of the planet...
on the rim above it.
In November 2006, problems began to surface in the operation of two MRO spacecraft instruments. A stepping mechanism in the
Mars Climate SounderThe Mars climate sounder is a major instrument on the Mars Reconnaissance Orbiter. The Mars Climate Sounder will look both down and horizontally through the atmosphere in order to quantify the global atmosphere’s vertical variations of water vapor, dust and temperature...
(MCS) skipped on multiple occasions resulting in a field of view that is slightly out of position. By December normal operations of the instrument was suspended, although a mitigation strategy allows the instrument to continue making most of its intended observations. Also, an increase in noise and resulting bad pixels has been observed in several
CCDA charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
s of the High Resolution Imaging Science Experiment (HiRISE). Operation of this camera with a longer warm-up time has alleviated the issue. However, the cause is still unknown and may return.
HiRISE continues to return images which have enabled discoveries regarding the geology of Mars. Foremost among these is the announcement of banded terrain observations indicating the presence and action of liquid carbon dioxide or water on the surface of Mars in its recent geological past. HiRISE was able to photograph the
PhoenixPhoenix was a robotic spacecraft on a space exploration mission on Mars under the Mars Scout Program. The Phoenix lander descended on Mars on May 25, 2008...
lander during its parachuted descent to
Vastitas BorealisVastitas Borealis is the largest lowland region of Mars. It is in the northerly latitudes of the planet and encircles the northern polar region. Vastitas Borealis is often simply referred to as the Northern plains or Northern lowlands of Mars. The plains lie 4–5 km below the mean radius of...
on May 25, 2008.
Instruments
Three cameras, two spectrometers and a radar are included on the orbiter along with two "science-facility instruments", which use data from engineering subsystems to collect science data. Three technology experiments will test and demonstrate new equipment for future missions. It is expected
MRO will obtain about 5,000 images a year.
HiRISE (camera)
The High Resolution Imaging Science Experiment camera is a 0.5 m
reflecting telescopeA reflecting telescope is an optical telescope which uses a single or combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century as an alternative to the refracting telescope which, at that time, was a design that suffered from...
, the largest ever carried on a
deep spaceDeep Space may refer to:In Star Trek:* Battle of Deep Space Nine, the first major battle of the Dominion War* Deep Space Nine, space station in the fictional Star Trek universe* Deep Space Nine relaunch, number of novels released since 2000...
mission, and has a
resolutionAngular resolution or 'spatial resolution' describes the resolving power of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye.- Definition of terms :...
of 1 microradian (μrad), or 0.3 m from an altitude of 300 km. In comparison,
satellite images of EarthSatellite imagery consists of photographs of Earth or other planets made by means of artificial satellites.- History : First satellite photographs of Earth were made August 14, 1959 by the US satellite Explorer 6. The first satellite photographs of the Moon might have been made on October 6, 1959...
are generally available with a resolution of 0.5 m, and satellite images on
Google MapsGoogle Maps is a web mapping service application and technology provided by Google, free , that powers many map-based services, including the Google Maps website, Google Ride Finder, Google Transit, and maps embedded on third-party websites via the Google Maps API...
are available to 1 m. HiRISE collects images in three color bands, 400 to 600 nm (
blueBlue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal...
-
greenGreen is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...
or B-G), 550 to 850 nm (
redRed is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked human eye...
) and 800 to 1,000 nm (near infrared or NIR).
Red color images are 20,264
pixelIn digital imaging, a pixel is the smallest item of information in an image. Pixels are normally arranged in a 2-dimensional grid, and are often represented using dots or squares. Each pixel is a sample of an original image, where more samples typically provide more-accurate representations of the...
s across (6 km wide), and B-G and NIR are 4,048 pixels across (1.2 km wide). HiRISE's on-board computer reads these lines in time with the orbiter's
ground speedGround speed is the speed of an aircraft relative to the ground. It is the sum of the aircraft's true airspeed and the current wind and weather conditions; a headwind subtracts from the ground speed, while a tailwind adds to it...
, and images are potentially unlimited in length. Practically however, their length is limited by the computer's 28
GigabitGigabit is a unit of digital information storage, with the symbol Gbit .1 gigabit = 109 = 1,000,000,000 bits...
(Gb) memory capacity, and the nominal maximum size is 20,000 × 40,000 pixels (800 megapixels) and 4,000 × 40,000 pixels (160 megapixels) for B-G and NIR images. Each 16.4 Gb image is compressed to 5 Gb before transmission and release to the general public on the HiRISE website in
JPEG 2000JPEG 2000 is a wavelet-based image compression standard. It was created by the Joint Photographic Experts Group committee in the year 2000 with the intention of superseding their original discrete cosine transform-based JPEG standard...
format. To facilitate the mapping of potential landing sites, HiRISE can produce
stereo pairsPhotogrammetry is the first remote sensing technology ever developed in which geometric properties about objects are determined from photographic images...
of images from which topography can be calculated to an accuracy of 0.25 m.
HiRISE was built by Ball Aerospace & Technologies Corp.
CTX (camera)
The Context Imager (CTX) provides
grayscaleIn photography and computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample, that is, it carries only intensity information...
images (500 to 800 nm) with a
pixelIn digital imaging, a pixel is the smallest item of information in an image. Pixels are normally arranged in a 2-dimensional grid, and are often represented using dots or squares. Each pixel is a sample of an original image, where more samples typically provide more-accurate representations of the...
resolution of 6 m. The CTX is designed to provide context maps for the targeted observations of HiRISE and CRISM. The optics of CTX consist of a 350 mm
focal lengthThe focal length of an optical system is a measure of how strongly it converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus...
Maksutov
CassegrainThe Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas.In a symmetrical Cassegrain...
telescope with a 5,064 pixel wide line array
CCDA charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
similar to the HiRISE instrument. The instrument takes pictures 30 km (19 mi) wide and has enough internal memory to store an image 160 km long before loading it into the main computer.
MARCI (camera)
The Mars Color Imager (MARCI) is a wide-angle, low-resolution camera that views the surface of Mars in five visible and two
ultravioletUltraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
bands. Each day, MARCI collects about 84 images and produces a global map with pixel resolutions of 1 to 10 km. This map provides a daily weather report for Mars, helps to characterize its seasonal and annual variations, and maps the presence of water vapor and ozone in its atmosphere.
CRISM (spectrometer)
The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument is a
visibleVisible is billed as a not-for-profit, free, quarterly magazine dedicated to the history of the lesbian, gay, bisexual, and transgender community. See also LGBT history....
and near infrared (
VNIRVNIR is an initialism for visible and near-infrared, a portion of the electromagnetic spectrum having wavelengths between approximately 400 and 1400 nanometers ...
)
spectrometerA spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization...
that is used to produce detailed maps of the surface
mineralogyMineralogy is an Earth Science focused around the chemistry, crystal structure, and physical properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their...
of Mars. It operates from 370 to 3920 nm, measures the spectrum in 544
channelsColor digital images are made of pixels, and pixels are made of combinations of primary colors. A channel in this context is the grayscale image of the same size as a color image, made of just one of these primary colors. For instance, an image from a standard digital camera will have a red, green...
(each 6.55 nm wide), and has a
resolutionAngular resolution or 'spatial resolution' describes the resolving power of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye.- Definition of terms :...
of at an altitude of . CRISM is being used to identify minerals and chemicals indicative of the past or present existence of water on the surface of Mars. These materials include
ironIron is a metallic chemical element with the symbol Fe and atomic number 26. Iron is a group 8 and period 4 element and is therefore classified as a transition metal. Iron and iron alloys are by far the most common metals and the most common ferromagnetic materials in everyday use...
, oxides, phyllosilicates, and carbonates, which have characteristic patterns in their visible-infrared energy.
MCS (spectrometer)
The
Mars Climate SounderThe Mars climate sounder is a major instrument on the Mars Reconnaissance Orbiter. The Mars Climate Sounder will look both down and horizontally through the atmosphere in order to quantify the global atmosphere’s vertical variations of water vapor, dust and temperature...
(MCS) is a spectrometer with one visible/near infrared channel (0.3 to 3.0 μm) and eight far infrared (12 to 50 μm) channels. These channels were selected to measure temperature, pressure, water vapor and dust levels. MCS observes the atmosphere on the horizon of Mars (as viewed from
MRO) by breaking it up into vertical slices and taking measurements within each slice in 5 km (3 mi) increments. These measurements are assembled into daily global weather maps to show the basic variables of Martian weather: temperature, pressure, humidity and dust density.
SHARAD (radar)
MRO's Shallow Subsurface Radar (SHARAD) experiment is designed to probe the internal structure of the Martian polar
ice capAn ice cap is an ice mass that covers less than 50 000 km² of land area . Masses of ice covering more than 50 000 km² are termed an ice sheet....
s. It also gathers planet-wide information about underground layers of
iceIce is a solid phase, usually crystalline, of a non-metallic substance that is liquid or gas at room temperature, such as carbon dioxide ice , ammonia ice, or methane ice. However, the predominant use of the term ice is for water ice, technically restricted to one of the 15 known crystalline phases...
,
rockIn geology, rock is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
and possibly liquid water that might be accessible from the surface. SHARAD uses
HFHigh frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...
radio waves between 15 and 25 MHz, a range that allows it to resolve layers as thin as to a maximum depth of . It has a horizontal resolution of . SHARAD is designed to operate in conjunction with
Mars ExpressMars Express is a space exploration mission being conducted by the European Space Agency . The Mars Express mission is exploring the planet Mars, and is the first planetary mission attempted by the agency. "Express" originally referred to the speed and efficiency with which the spacecraft was...
's MARSISMARSIS is a low frequency, pulse-limited radar sounder and altimeter used on the ESA Mars Express mission. It features ground-penetrating radar capabilities, which uses synthetic aperture techniques and a secondary receiving antenna to isolate subsurface reflections....
, which has lower resolution but penetrates to a much greater depth. Both SHARAD and MARSIS were made by the
Italian Space AgencyThe Italian Space Agency was founded in 1988 to promote, coordinate, and conduct space activities in Italy. Operating under the Ministry of the Universities and Scientific and Technological Research, the Agency cooperates with numerous international and Italian entities, who are active in space...
.
Engineering instruments
In addition to its imaging equipment,
MRO carries a variety of engineering instruments. The Gravity Field Investigation Package measures variations in the Martian gravitational field through variations in the spacecraft's velocity. Velocity changes are detected by measuring doppler shifts in
MRO's radio signals received on Earth. The package also includes sensitive on-board accelerometers used to deduce the
in situ atmospheric density of Mars during aerobraking.
The Electra is a
UHFUltra high frequency designates a range of electromagnetic waves with frequencies between 300 MHz and 3 GHz . Also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...
software defined radio designed to communicate with other spacecraft as they approach, land, and operate on Mars. In addition to protocol controlled inter-spacecraft data links of 1 kbit/s to 2 Mbit/s, Electra also provides Doppler data collection, open loop recording and a highly accurate timing service based on a 5e-13 USO. Doppler information for approaching vehicles can be used for final descent targeting or descent and landing trajectory recreation. Doppler information on landed vehicles will also enable scientists to accurately determine the surface location of Mars landers and rovers. The two
MERNASA's Mars Exploration Rover Mission is an ongoing robotic mission of exploring Mars, that began in 2003 with the sending of two rovers — MER-A Spirit and MER-B Opportunity — to explore the Martian surface and geology....
spacecraft currently on Mars utilize an earlier generation UHF relay radio providing similar functions through the Mars Odyssey orbiter. The Electra radio has used the MER spacecraft to prove its functionality but it is not scheduled to provide formal relay services until the 2008 arrival of the
Phoenix Mars landerPhoenix was a robotic spacecraft on a space exploration mission on Mars under the Mars Scout Program. The Phoenix lander descended on Mars on May 25, 2008...
. Because the Electra radio is software defined down to the modem level, new modulation, coding or protocol functions can be added or updated while the MRO spacecraft is in orbit around Mars.
The Optical Navigation Camera images the Martian moons,
PhobosPhobos is the larger and closer of two small moons of Mars, the other being Deimos. It is named after the Greek god Phobos , a son of Ares...
and
DeimosDeimos , is the smaller and outer of Mars’ two moons . It is named after Deimos, a figure representing dread in Greek Mythology. Its systematic designation is '.-Discovery:...
, against background stars to precisely determine
MRO's orbit. Although moon imaging is not mission critical, it was included as a technology test for future orbiting and landing of spacecraft. The Optical Navigation Camera was tested successfully in February and March 2006.
Engineering data
Structure
Workers at
Lockheed Martin Space SystemsLockheed Martin Space Systems is one of the 4 major business divisions of Lockheed Martin. It is headquartered in Denver, Colorado.From a rich history of major companies Lockheed Martin has brought them together to offer design, integration, and production of:* satellites for commercial and...
in Denver assembled the spacecraft structure and attached the instruments. Instruments were constructed at the Jet Propulsion Laboratory, the
University of ArizonaThe University of Arizona is a land-grant and space-grant public institution of higher education and research located in Tucson, Arizona, United States. The University of Arizona was the first university in the state of Arizona, founded in 1885...
Lunar and Planetary LaboratoryThe Lunar and Planetary Laboratory is a research center for planetary science located in Tucson, Arizona. It is also a graduate school, constituting the Department of Planetary Sciences at the University of Arizona. LPL is one of the world's largest programs dedicated exclusively to planetary...
in
Tucson, ArizonaTucson is a city in and the county seat of Pima County, Arizona, United States, located 118 miles southeast of Phoenix and 60 miles north of the U.S.-Mexico border. As of July 1, 2006, a Census Bureau estimate puts the city's population at 541,811, with a metropolitan area population at...
,
Johns Hopkins UniversityThe Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university located in Baltimore, Maryland, United States. Johns Hopkins also maintains full-time campuses elsewhere in Maryland, Washington, D.C., Italy, China, and Singapore...
Applied Physics LaboratoryThe Johns Hopkins University Applied Physics Laboratory , located in Howard County, Maryland near Laurel and Columbia, is a not-for-profit, university-affiliated research center employing 4,150 people. APL is primarily a defense contractor. It serves as a technical resource for the Department of...
in
Laurel, MarylandLaurel is a city in northern Prince George's County, Maryland, United States, located midway between Washington, D.C. and Baltimore. Incorporated in 1870, the city maintains a historic district including its Main Street...
, the
Italian Space AgencyThe Italian Space Agency was founded in 1988 to promote, coordinate, and conduct space activities in Italy. Operating under the Ministry of the Universities and Scientific and Technological Research, the Agency cooperates with numerous international and Italian entities, who are active in space...
in
RomeRome is the capital of Italy and the country's largest and most populated municipality , with over 2.7 million residents in , while the population of the urban area is estimated by Eurostat to be 3.46 million. The metropolitan area of Rome is estimated by OECD to have a population of 3.7 million...
, and
Malin Space Science SystemsMalin Space Science Systems is a San Diego, California company that designs, develops, and operates instruments to fly on unmanned spacecraft. MSSS is headed by chief scientist and CEO Michael C. Malin....
in
San Diego, CaliforniaSan Diego , named after Saint Didacus , is the second-largest city in California and the ninth largest city in the United States, located along the Pacific Ocean on the west coast of the United States. The US Census Bureau estimates the city's population at 1,279,329 as of 2008...
. The total cost of the spacecraft was $720 million USD.
The structure is made of mostly carbon composites and aluminum-honeycombed plates. The
titaniumTitanium is a chemical element with the symbol Ti and atomic number 22. Sometimes called the “space age metal”, it has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color.Titanium can be alloyed with iron, aluminium, vanadium, molybdenum, among other...
fuel tank takes up most of the volume and mass of the spacecraft and provides most of its
structural integrityStructural engineering is a field of engineering dealing with the analysis and design of structures that support or resist loads. Structural engineering is usually considered a specialty within civil engineering, but it can also be studied in its own right....
. The spacecraft's total
massIn physics, mass commonly refers to any of three properties of matter, which have been shown experimentally to be equivalent: inertial mass, active gravitational mass and passive gravitational mass...
is less than 2,180
kgThe kilogram is the base unit of mass in the International System of Units .[The spelling kilogram is the modern spelling used by the International Bureau of Weights and Measures , the U.S...]
(4,806
lbThe pound or pound-mass is a unit of mass used in the imperial, United States customary and other systems of measurement...
) with an unfueled
dry massIn aerospace engineering, mass ratio is a measure of the efficiency of a rocket. It describes how much more massive the vehicle is with propellant than without; that is, it is the ratio of the rocket's wet mass to its dry mass...
less than 1,031 kg (2,273 lb).
Power systems
MRO gets all of its electrical power from two
solar panelA photovoltaic module or photovoltaic panel is a packaged interconnected assembly of photovoltaic cells, also known as solar cells. The photovoltaic module, known more commonly as the solar panel, is then used as a component in a larger photovoltaic system to offer electricity for commercial and...
s, each of which can move independently around two axes (up-down, or left-right rotation). Each solar panel measures 5.35 × 2.53 m and has 9.5 m
2 (102 ft
2) covered with 3,744 individual photovoltaic cells. Its high-efficiency triple junction solar cells are able to convert more than 26% of the sun's energy directly into electricity and are connected together to produce a total output of 32 volts. At Mars, the two panels produce 1,000
wattThe watt is a derived unit of power in the International System of Units . It measures rate of energy conversion. One watt is equivalent to 1 joule of energy per second....
s of power; in contrast, the panels would generate 3,000 watts in a comparable Earth orbit by being closer to the Sun.
MRO has two nickel metal hydride rechargeable batteries used to power the spacecraft when it is not facing the sun. Each battery has an energy storage capacity of 50
ampere-hourAn ampere-hour or amp-hour is a unit of electric charge, with sub-units milliampere-hour and milliampere second...
s (180
kCThe coulomb is the SI derived unit of electric charge. It is named after Charles-Augustin de Coulomb.- Definition :If 2 like point charges of equal magnitudes are placed in a vacuum at a distance of 1 metre away from each other and if they repel each other with a force of 9*1000000000 Newton, then...
). The full range of the batteries cannot be used due to voltage constraints on the spacecraft, but allows the operators to extend the battery life—a valuable capability, given that battery drain is one of the most common causes of long-term satellite failure. Planners anticipate that only 40% of the batteries' capacities will be required during the lifetime of the spacecraft.
Electronic systems
MRO‘s main computer is a 133 MHz, 10.4 million
transistorA transistor is a semiconductor device commonly used to amplify or switch electronic signals. A transistor is made of a solid piece of a semiconductor material, with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's...
, 32-bit,
RAD750The RAD750 is a radiation-hardened single board computer, based on IBM's PowerPC 750. The successor of the RAD6000, the RAD750 is manufactured by BAE Systems. It is intended for use in high radiation environments such as experienced on board satellites and spacecraft...
processor. This processor is a
radiation-hardenedRadiation hardening is a method of designing and testing electronic components and systems to make them resistant to damage or malfunctions caused by high-energy subatomic particles and electromagnetic radiation, such as would be encountered in outer space, high-altitude flight, around nuclear...
version of a
PowerPCPowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM. Originally intended for personal computers, PowerPC CPUs have since become popular embedded and high-performance processors...
750 or
G3The PowerPC 7xx is a family of third generation 32-bit PowerPC microprocessors designed and manufactured by IBM and Motorola . This family is called the PowerPC G3 by its well-known customer Apple Computer...
processor with a specially-built
motherboardA motherboard is the central printed circuit board in many modern computers, and holds many of the crucial components of the system, while providing connectors for other peripherals. The motherboard is sometimes alternatively known as the main board, system board, or, on Apple computers, the logic...
. The RAD750 is a successor to the
RAD6000The RAD6000 radiation-hardened single board computer, based on the IBM RISC Single Chip CPU, was manufactured by IBM Federal Systems. IBM Federal Systems was sold to Loral, and by way of acquisition, ended up with Lockheed Martin and is currently a part of BAE Systems...
. This processor may seem underpowered in comparison to a modern
PCA personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end user, with no intervening computer operator...
processor, but it is extremely reliable, resilient, and can function in
solar flareA solar flare is a large explosion in the Sun's atmosphere that can release as much as 6 × 10
25 joules of energy. The term is also used to refer to similar phenomena in other stars, where the more accurate term stellar flare applies....
-ravaged deep space. The operating system software is
VxWorksVxWorks is a real-time operating system made and sold by Wind River Systems of Alameda, California, USA. Intel acquired Wind River Systems on July 17, 2009.VxWorks is designed for use in embedded systems...
and has extensive fault protection protocols and monitoring.
Data is stored in a 160
GbGigabit is a unit of digital information storage, with the symbol Gbit .1 gigabit = 109 = 1,000,000,000 bits...
(20 GB) flash memory module consisting of over 700 memory chips, each with a 256
MbitA megabit is an SI-multiple of the unit of bit for digital information storage or transmission. The International Electrotechnical Commission's standard IEC 60027 specifies the symbol to be Mbit, but Mb is also in common use....
capacity. This memory capacity is not actually that large considering the amount of data to be acquired; for example, a single image from the HiRISE camera can be as large as 28 Gb.
Attitude determination
In order to determine the spacecraft's orbit and facilitate maneuvers, sixteen sun sensors – eight primaries and eight backups – are placed around the spacecraft to calibrate solar direction relative to the orbiter's frame. Two star trackers,
digital cameraA digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor....
s used to map the position of catalogued
starA star is a massive, luminous ball of plasma that is held together by gravity. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth. Other stars are visible in the night sky, when they are not outshone by the Sun...
s, provide NASA with full, three-axis knowledge of the spacecraft orientation and attitude. A primary and backup
Miniature Inertial Measurement Unit (MIMU)Miniature Inertial Measurement Unit is an Inertial Measurement Unit developed and built by Honeywell International to control and stabilize spacecraft during mission operations. MIMUs can also be configured to perform as an Inertial Reference Unit...
, provided by
HoneywellHoneywell is a major conglomerate company that produces a variety of consumer products, engineering services, and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments....
, measures changes to the spacecraft attitude as well as any non-gravitationally induced changes to its linear velocity. Each MIMU is a combination of three
accelerometerAn accelerometer measures the acceleration it experiences relative to freefall.Single- and multi-axis models are available to detect magnitude and direction of the acceleration as a vector quantity, and can be used to sense orientation, vibration and shock...
s and three ring-laser
gyroscopeA gyroscope is a device for measuring or maintaining orientation, based on the principles of angular momentum. A mechanical gyroscope is essentially a spinning wheel or disk whose axle is free to take any orientation...
s. These systems are all critically important to MRO, as it must be able to point its camera to a very high precision in order to take the high-quality pictures that the mission requires. It has also been specifically designed to minimize any vibrations on the spacecraft, so as to allow its instruments to take images without any distortions caused by vibrations.
Telecommunications system
The Telecom Subsystem on MRO is the best digital communication system sent into deep space so far and for the first time using capacity achieving turbo-codes. It consists of a very large (3 meter) antenna, which is used to transmit data through the
Deep Space NetworkThe Deep Space Network, or DSN, is an international network of large antennas and communication facilities that supports interplanetary spacecraft missions, and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected...
via X-band frequencies at 8 GHz, and it demonstrates the use of the Ka-band at 32 GHz for higher data rates. Maximum transmission speed from Mars is projected to be as high as 6 Mbit/s, a rate ten times higher than previous Mars orbiters. The spacecraft carries two 100-watt X-band
amplifierGenerally, an amplifier or simply amp, is any device that changes, usually increases, the amplitude of a signal. The relationship of the input to the output of an amplifier—usually expressed as a function of the input frequency—is called the transfer function of the amplifier, and the magnitude of...
s (one of which is a backup), one 35-watt Ka-band amplifier, and two
transponderIn telecommunication, the term transponder has the following meanings:...
s.
Two smaller low-gain antennas are also present for lower-rate communication during emergencies and special events, such as launch and Mars Orbit Insertion. These antennas do not have focusing dishes and can transmit and receive from any direction. They are an important backup system to ensure that MRO can always be reached, even if its main antenna is pointed away from the Earth.
The Ka-band subsystem is used for demonstration purposes. Due to lack of spectrum at 8.41 GHz X-band, future high-rate deep space missions will use 32 GHz Ka-band. NASA Deep Space Network (DSN) has implemented Ka-band receiving capabilities at all three of its complexes (Goldstone, Canberra and Madrid) over its 34-m beam-waveguide (BWG) antenna subnet. MRO Ka-band demonstration will demonstrate viability of Ka-band for deep space operations. During the cruise phase, spacecraft Ka-band telemetry was tracked 36 times by these antennas proving DSN Ka-band reception functionality at all the antennas. During the primary science phase, Ka-band demonstration is assigned two passes a week for Ka-band demonstration purposes. The success of Ka-band during cruise also makes it a viable backup for the X-band subsystem on MRO.
Propulsion and attitude control
The spacecraft uses a 1,175
L
(310 US
galA gallon is a measure of volume of approximately four litres. Historically it has had many different definitions, but there are three definitions in current use. These are the U.S. liquid gallon and the lesser used U.S...
) fuel tank filled with 1187 kg (2617 lb) of
hydrazineHydrazine is an inorganic chemical compound with the formula N2H4. It is a colourless liquid with an ammonia-like odor and is derived from the same industrial chemistry processes that manufacture ammonia...
monopropellantMonopropellants are propellants composed of chemicals or mixtures of chemicals which can be stored in a single container with some degree of safety. While stable under defined storage conditions, they react very rapidly under certain other conditions to produce a large volume of energetic gases...
. Fuel pressure is regulated by adding pressurized helium gas from an external tank. Seventy percent of the fuel was used for orbital insertion.
MRO has twenty rocket engine thrusters on board. Six large thrusters each produce 170 N (38
lbfThe pound-force or simply pound is a unit of force.- Definitions :The pound-force is approximately equal to the gravitational force exerted on a mass of one avoirdupois pound on the surface of Earth...
) of thrust for a total of 1,020 N (230 lbf) meant mainly for orbital insertion. These thrusters were originally designed for the
Mars Surveyor 2001 LanderMars Surveyor 2001 Lander was a planned NASA Mars probe which was cancelled in May 2000 in the wake of the failures of the Mars Climate Orbiter and Mars Polar Lander missions in late 1999...
. Six medium thrusters each produce 22 N (5 lbf) of thrust for trajectory correction maneuvers and attitude control during orbit insertion. Finally, eight small thrusters each produce 0.9 N (0.2 lbf) of thrust for attitude control during normal operations.
Four reaction wheels are also used for precise attitude control during activities requiring a highly stable platform, such as high-resolution imaging, in which even small motions can cause blurring of the image. Each wheel is used for one axis of motion. The fourth (skewed) wheel is a backup in case one of the other three wheels fails. Each wheel weighs 10 kg (22 lb) and can be spun as fast as 100 Hz or 6,000
rpmRevolutions per minute is a unit of frequency of rotation: the number of full rotations completed in one minute around a fixed axis...
.
Water Ice in Ice Cap Measured
Results, published in 2009, of radar measurements of the North Polar ice cap determined that the volume of water ice in the cap is 821,000 cubic kilometers (197,000 cubic miles). That's equal to 30% of the Earth's Greenland ice sheet.
Ice Exposed in New Craters
Impressive research, reported in the journal Science in September 2009, has showed that some new craters on Mars show exposed, pure, water ice. After a time, the ice disappears, evaporating into the atomsphere. The ice is only a few feet deep. The ice was confirmed with the Compact Imaging Spectrometer (CRISM)] onboard the Mars Reconnaissance Orbiter (MRO). The ice was found in a total of 5 locations. Three of the locations are in the
Cebrenia quadrangleThe Cebrenia quadrangle covers the area form 180° to 240° west longitude and 30° to 65° north latitude on Mars. Its prominent features are the large craters Mie and Stokes, a volcano, Hecates Tholus, and a group of mountains, Phlegra Montes...
. These locations are 55.57° N, 150.62° E; 43.28° N, 176.9° E; and 45° N, 164.5° E. Two others are in the
Diacria quadrangleThe Diacria quadrangle covers 120° to 180° west longitude and 30° to 65° north latitude on Mars. This area contains some troughs; one of which is Cyane Fossae. Cyane Fossae is a graben, a structure formed by a block moving downward between two faults. HiRISE on Mars...
: 46.7° N, 176.8° E and 46.33° N, 176.9° E.
This discovery proves that future colonists on Mars will be able to obtain water from a wide variety of locations. The ice can be dug up, melted, then taken apart to provide fresh
oxygenOxygen Oxygen Oxygen (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter) is the element with atomic number 8 and represented by the symbol O...
and
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H
2...
for rocket fuel. Hydrogen is the powerful fuel used by the
space shuttleThe Space Shuttle, part of the Space Transportation System , is a spacecraft operated by NASA for orbital human spaceflight missions. It began operations in the 1980s and is scheduled to be retired from service in 2010 after 134 launches...
main engines
Lobate Debris Aprons Are Mostly Water Ice
One of the most important discoveries made by the Mars Reconnaisance Orbiter was that features called
Lobate Debris ApronOf interest from the days of the Viking Orbiters are piles of material surrounding cliffs. These deposits of rock debris are called lobate debris aprons . These features have a convex topography and a gentle slope from cliffs or escarpments; this suggests flow away from the steep source cliff...
s (LDA's) contain large amounts of water ice. Of interest from the days of the
VikingA Viking is one of the Norse explorers, warriors, merchants, and pirates who raided and colonized wide areas of Europe from the late eighth to the early eleventh century. These Norsemen used their famed longships to travel as far east as Constantinople and the Volga River in Russia, and as far...
Orbiters, these LDA's are piles of material surrounding cliffs. They have a convex topography and a gentle slope; this suggests flow away from the steep source cliff. In addition, lobate debris aprons can show surface lineations just as rock glaciers on the Earth. The Shallow Radar on the Mars Reconnaissance Orbiter has provided strong evidence that the LDAs in
Hellas PlanitiaHellas Planitia, also known as the Hellas Impact Basin, is a huge, roughly circular impact basin located in the southern hemisphere of the planet Mars. It is the second or third largest impact crater and the largest visible impact crater known in the Solar System. The basin floor is 3 km deeper...
are
glacierA glacier is a perennial mass of ice which moves over land. A glacier forms in locations where the mass accumulation of snow and ice exceeds ablation over many years...
s that are covered with a thin layer of rocks. Radar from the Mars Reconnaissance Orbiter gave a strong reflection from the top and base of LDAs, meaning that pure water ice made up the balk of the formation (between the two reflections). Based on the experiemnts of the Phoenix lander and the studies of the Mars Odyssey from orbit, frozen water is know to exist a just under the surface of Mars in the far north and south (high latitudes). The discovery of water ice in LDA's demonstrates that water is found at even lower latitudes. Future colonists on Mars will be able to tap into these ice deposits, instead of having to travel to much higher latitudes. Another major advantage of LDA's over other sources of Martian water is that they can easily detected and mapped from orbit. Lobate Debris Aprons are shown below from the Phlegra Montes which are at a latitude of 38.2 degrees north. The Phoenix lander set down at about 68 degrees north latitude, so the discovery of water ice in LDA's greatly expands the range of easily available on Mars. It is far easier to land a spaceship near the equator of Mars, so the closer water is available to the equator the better it will be for future colonists.
Inverted Relief
Some places on Mars show inverted relief. In these locations, a stream bed may be a raised feature, instead of a valley. The inverted former stream channels may be caused by the deposition of large rocks or due to cementation. In either case erosion would erode the surrounding land and leave the old channel as a raised ridge because the ridge will be more resistant to erosion. An image below, taken with HiRISE of Antoniadi Crater shows sinuous ridges that are old channels that have become inverted.
Chloride Deposits
Using data from Mars Global surveyor, Mars Odyssey and the Mars Reconnaissance Orbiter, scientists have found widespread deposits of chloride minerals. A picture below shows some deposits within the Phaethontis quadrangle. Evidence suggests that the deposits were formed from the evaporation of mineral enriched waters. The research suggests that lakes may have been scattered over large areas of the Martian surface. Usually chlorides are the last minerals to come out of solution. Carbonates, sulfates, and silica should precipitate out ahead of them. Sulfates and silica have been found by the Mars Rovers on the surface. Places with chloride minerals may have once held various life forms. Furthermore, such areas should preserve traces of ancient life.
Layers
Columbus Crater contains layers, also called strata. Many places on Mars show rocks arranged in layers. Sometimes the layers are of different colors. Light-toned rocks on Mars have been associated with hydraded minerals like sulfates. The
Mars RoverA Mars rover is a spacecraft which propels itself across the surface of Mars after landing.Rovers have several advantages over stationary landers: they examine more territory, they can be directed to interesting features, they can place themselves in sunny positions to weather winter months and ...
Opportunity examined such layers close-up with several instruments. Some layers are probably made up of fine particles because they seem to break up into fine dust. Other layers break up into large boulders so they are probably much harder. Basalt, a volcanic rock, is thought to in the layers that form boulders. Basalt has been identified on Mars in many places. Instruments on orbiting spacecraft have detected clay (also called phyllosilicates) in some layers. Scientists are excited about finding hydrated minerals such as sulfates and clays on Mars because they are usually formed in the presence of water. Places that contain clays and/or other hydrated minerals would be good places to look for evidence of life.
Rock can form layers in a variety of ways. Volcanoes, wind, or water can produce layers.
See also
- Geography of Mars
- Colonization of Mars
The colonization of Mars by humans is the focus of speculation and serious study, as the surface conditions and availability of water on Mars make it arguably the most hospitable planet in the solar system other than Earth...
- Exploration of Mars
The exploration of Mars has been an important part of the space exploration programs of the Soviet Union , the United States, Europe, and Japan. Dozens of robotic spacecraft, including orbiters, landers, and rovers, have been launched toward Mars since the 1960s...
- Mars Direct
Mars Direct is a proposal for a relatively low-cost manned mission to Mars with current rocket technology. The plan was originally detailed in a research paper by Robert Zubrin and David Baker in 1990. The mission was expanded upon in Zubrin's 1996 book The Case for Mars...
- Planetary science
Planetary science is the scientific study of planets, moons, and planetary systems, in particular those of the Solar System and the processes that form them. It studies objects ranging in size from micrometeoroids to gas giants, aiming to determine their composition, dynamics, formation,...
- Lunar Reconnaissance Orbiter
The Lunar Precursor Robotic Program is a program of robotic spacecraft missions which NASA will use to prepare for future human spaceflight missions to the Moon. Two LPRP missions, the Lunar Reconnaissance Orbiter and the Lunar Crater Observation and Sensing Satellite , were launched in June 2009...
External links